Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China

*Ruili Li, Minwei Chai, Xiaoxue Shen, Cong Shi, Guoyu Qiu and Takayoshi Koike*

#### **Abstract**

Based on Chinese ecological policy, we have been studying mangrove ecosystems in southern China, especially from the perspective of pollutants deposition in mangrove wetlands, physiological ecology of mangrove species on the impact of heavy metal pollution and seeking ecosystem restoration. For these, we explored in three aspects: 1) pollutants distribution and ecological risk in main distribution of mangrove, China, 2) eco-statistics and microbial analyses of mangrove ecosystems (including shellfish) in representative locations where mangrove plants are well developed, especially in Shenzhen, a rapid developing economic city in Guangdong Province, 3) ecophysiological experiments on a representative species of mangrove for evaluating combination effects of major nutrient elements and heavy metal pollution on growth and physiological responses of the seedlings. Based on the results, we proposed how to rehabilitate mangrove ecosystem in China under rapidly changing environmental conditions, with a view to our future survival and to provide nature-based solution as well as the public with more ecosystem services.

**Keywords:** ecosystem, wetland, pollution, restoration, subtropical mangroves, nature based solution

#### **1. Introduction**

Well-developed mangrove forest in southern China has increased their values of environment, eco-tourism resources, and conservation of biodiversity, etc. [1–3]. Mangrove ecosystems are also expected to provide many ecological services: (1) provisioning, (2) regulation, (3) culture, and (4) basic service [4, 5]. Basic service, i.e., means primary productivity of plants, soil formation and nutrient cycling, etc. The rest services are depending on basic services. Therefore, ecophysiology of mangrove is the most fundamental and essential information for this chapter.

In terms of ecological functions, mangroves can provide (1) many foods including fish, shellfish via offering their habitats, dye materials, wood and materials for high quality charcoal, etc., (2) maintain marsh ecosystems: soil conservation, reduction of storm disasters, wave attenuation, acceleration of reclamation, contaminant degradation, clean the atmosphere and marine environment, (3) ecotourism, culture, scientific resources, etc., (4) CO2 fixation and O2 evolution, biomass production, nutrient circulation [6]. However, an increase of anthropogenic

activities in coastal areas reduced mangrove cover and functions, with environment deterioration to be important factor, such as pollution caused by heavy metals. Recent degradation of mangrove functions, such as offering habitat for many living organisms is also reduced by persistent organic pollutants (POPs) including microplastics (MPs), etc. [7–9].

In China, large area of mangroves mainly distributed in six provinces (Zhejiang, Taiwan, Fujian, Hainan, Guangxi, and Guangdong), and two special administrative regions (Hong Kong and Macao). There were 37 mangrove species, representing 20 families and 25 genera, with thermophilic eurytopic species being the dominant components [10]. Mangrove could accumulate various pollutants derived from rivers and tidal waters due to its unique properties, such as high productivity, organic-rich matter scrap, fine grains of wetland soil, and anoxic environment [11, 12].

Pollutants like heavy metals and organic contaminants are generally toxic and persistent in mangrove ecosystems. In estuarine mangroves of New Zealand, the soils were characterized with lower Eh and currents upstream trapped more macro-nutrients and heavy metals compared to downstream [13]. In Southeast Sulawesi of Indonesia, mangrove species significantly bioaccumulated heavy metals (such as Cu, Hg, Cd, Zn, and Pb), with different partitioning and uptake capacity of heavy metals to be detected in tissues of mangrove species [14]. Marchand et al. (2011) explored the relationships between heavy metals and organic matter cycling in mangrove sediments of Conception Bay, New Caledonia [15]. Currently, various pollutions caused by anthropogenic activities are well recognized in mangrove in Shenzhen, the most rapidly developed city in China [16, 17]. Especially, Futian mangrove in Shenzhen has been recognized as one of the most typical urban mangroves located in a big city (**Figure 1**), which has been receiving more and more attention. Shenzhen municipal government has decided to keep their environment in order to achieve the sustainable development goals (SDGs) and adopt mangrove as the iconic plant.

**67**

**Figure 2.**

*sD4.46; Wroot = 0.199 sD2.22.*

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

In this chapter, first, we briefly summarized the history of studies in East Asia; then, we take China as an example to explore current progress in mangrove management and research: i.e. heavy metal distribution and ecological risk in mangrove sediment, as well as POPs (such as polybrominated diphenyl ethers). POPs could affect photosynthesis via belowground root vigor and function, and transfer along food chain/web to bio-accumulate [18]. Thirdly, the status of education effect of mangroves in China, especially for Shenzhen was stated. At last, the future perspective of mangrove research in China was provided. These mangrove functions under current and rapid environmental changes in China may provide a hint of conservation and restoration of mangrove ecosystems in the rest

In recent years, intensively research have been conducted on the productivities of mangrove forests in tropical and sub-tropical areas of southeast Asian countries, including Indonesia, Philippines, Thailand, and southern Japan, etc. [19–22]. As a contribution to the IBP (International Biological Program), we globally estimated the biomass productivity of different types of vegetation and ecosystem. This IBP is dedicated to human survival from the perspective of biomass production as well as conservation of biodiversity including local people's lives [23–25]. In this project, general empirical models for estimating above-ground biomass, especially universal

Mangrove plants are characterized by their unique growth characteristics [28]. They can grow and develop along with brackish region of estuaries, wetlands and sea-shores, and are well-known as "marine forest." Furthermore, the growth of mangrove plant would be affected by other climate factors. For example, from dendrometer monitoring of the diameter growth of *Avicennia alba* growing at brackish region, a pioneer species in east Thailand, diameter growth increased with flooding of fresh water during rainy season [26]. In fact, "annual" ring was found in this species even though *A. alba* grows in western Mahachai bay, Thailand (tropical region without any clear dry season) [29] . This species may use intensively fresh

*Universal allometry equation of above- and below-ground biomass of mangrove forests in Asia (Adopted from Komiyama 2017 [26] modified Komiyama et al. [23] and Komiyama et al. [27]. Sampling;* ○*:* Rhizophora *sp. at south Thailand* ● *n of above- and below-ground bioma* △*:*Rhizophora *sp. at east Indonesia,* ▲*: The other species at east Indonesia,* □*:* Rhizophora *sp. at east Thailand,* ■*:* Rhizophora *sp. in east Thailand. Wtop = 0.251* 

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

**2. Brief history of mangrove studies in East Asia**

equation for root biomass was developed (**Figure 2**) [26].

of the world.

**Figure 1.** *Futian mangrove located in the center of Shenzhen, China (http: //mcf.org.cn/mobile/).*

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

In this chapter, first, we briefly summarized the history of studies in East Asia; then, we take China as an example to explore current progress in mangrove management and research: i.e. heavy metal distribution and ecological risk in mangrove sediment, as well as POPs (such as polybrominated diphenyl ethers). POPs could affect photosynthesis via belowground root vigor and function, and transfer along food chain/web to bio-accumulate [18]. Thirdly, the status of education effect of mangroves in China, especially for Shenzhen was stated. At last, the future perspective of mangrove research in China was provided. These mangrove functions under current and rapid environmental changes in China may provide a hint of conservation and restoration of mangrove ecosystems in the rest of the world.

#### **2. Brief history of mangrove studies in East Asia**

In recent years, intensively research have been conducted on the productivities of mangrove forests in tropical and sub-tropical areas of southeast Asian countries, including Indonesia, Philippines, Thailand, and southern Japan, etc. [19–22]. As a contribution to the IBP (International Biological Program), we globally estimated the biomass productivity of different types of vegetation and ecosystem. This IBP is dedicated to human survival from the perspective of biomass production as well as conservation of biodiversity including local people's lives [23–25]. In this project, general empirical models for estimating above-ground biomass, especially universal equation for root biomass was developed (**Figure 2**) [26].

Mangrove plants are characterized by their unique growth characteristics [28]. They can grow and develop along with brackish region of estuaries, wetlands and sea-shores, and are well-known as "marine forest." Furthermore, the growth of mangrove plant would be affected by other climate factors. For example, from dendrometer monitoring of the diameter growth of *Avicennia alba* growing at brackish region, a pioneer species in east Thailand, diameter growth increased with flooding of fresh water during rainy season [26]. In fact, "annual" ring was found in this species even though *A. alba* grows in western Mahachai bay, Thailand (tropical region without any clear dry season) [29] . This species may use intensively fresh

#### **Figure 2.**

*Mangrove Ecosystem Restoration*

plastics (MPs), etc. [7–9].

environment [11, 12].

as the iconic plant.

activities in coastal areas reduced mangrove cover and functions, with environment deterioration to be important factor, such as pollution caused by heavy metals. Recent degradation of mangrove functions, such as offering habitat for many living organisms is also reduced by persistent organic pollutants (POPs) including micro-

In China, large area of mangroves mainly distributed in six provinces (Zhejiang, Taiwan, Fujian, Hainan, Guangxi, and Guangdong), and two special administrative regions (Hong Kong and Macao). There were 37 mangrove species, representing 20 families and 25 genera, with thermophilic eurytopic species being the dominant components [10]. Mangrove could accumulate various pollutants derived from rivers and tidal waters due to its unique properties, such as high productivity, organic-rich matter scrap, fine grains of wetland soil, and anoxic

Pollutants like heavy metals and organic contaminants are generally toxic and persistent in mangrove ecosystems. In estuarine mangroves of New Zealand, the soils were characterized with lower Eh and currents upstream trapped more macro-nutrients and heavy metals compared to downstream [13]. In Southeast Sulawesi of Indonesia, mangrove species significantly bioaccumulated heavy metals (such as Cu, Hg, Cd, Zn, and Pb), with different partitioning and uptake capacity of heavy metals to be detected in tissues of mangrove species [14]. Marchand et al. (2011) explored the relationships between heavy metals and organic matter cycling in mangrove sediments of Conception Bay, New Caledonia [15]. Currently, various pollutions caused by anthropogenic activities are well recognized in mangrove in Shenzhen, the most rapidly developed city in China [16, 17]. Especially, Futian mangrove in Shenzhen has been recognized as one of the most typical urban

mangroves located in a big city (**Figure 1**), which has been receiving more and more attention. Shenzhen municipal government has decided to keep their environment in order to achieve the sustainable development goals (SDGs) and adopt mangrove

*Futian mangrove located in the center of Shenzhen, China (http: //mcf.org.cn/mobile/).*

**66**

**Figure 1.**

*Universal allometry equation of above- and below-ground biomass of mangrove forests in Asia (Adopted from Komiyama 2017 [26] modified Komiyama et al. [23] and Komiyama et al. [27]. Sampling;* ○*:* Rhizophora *sp. at south Thailand* ● *n of above- and below-ground bioma* △*:*Rhizophora *sp. at east Indonesia,* ▲*: The other species at east Indonesia,* □*:* Rhizophora *sp. at east Thailand,* ■*:* Rhizophora *sp. in east Thailand. Wtop = 0.251 sD4.46; Wroot = 0.199 sD2.22.*

#### **Figure 3.**

*The stratification diagram of a mangrove stand at the northern boundary in the Ryukyu islands, south Japan (Adopted from Hagihara [35]).*

water for its growth. These areas are usually zoned by different species of mangrove depending on their adaptive traits in salt tolerance [30–33] and light utilization characteristics of each species [34]. Mangrove species grow in the front of seashore are light demanding type while a component of well-developed stands is low-light utilization type based on chlorophyll fluorescence.

Hagihara (2006) reviewed production ecology and carbon cycling of mangrove stand (*Kandelia obovata*) in the Ryukyu Islands (**Figure 3**): i.e. northern limit for the distribution of mangrove plants in Japan [35]. This species is very popular in China for ecological study [26, 32]. Hoque et al. (2011) found that Top/Root (T/R) ratio of *K. obovata* in Manko wetland, Okinawa, Japan was around 1.87 [36].

Generally, T/R ratio of mangrove stands was around 1.0 [26, 37] whereas it is ranged between 3 ~ 4 for most forests. From the stratification diagram, estimated value of the extinction coefficient (KF) including branches for *K. obovata* stand was 0.50. The KF was 0.56 ~ 0.69 for *Bruguiera gymnorhiza* stands in Ryukyu Islands, 0.54 ~ 0.57 for *Rhizophora apiculate* in Thailand. KF values of deciduous conifer larch (Larix kaempferi), evergreen oak (*Quercus phillyraeoides*) and Hinoki cypress (*Chamaecyparis obtusa*) were 0.31, 0.36, 0.67 and 0.37, respectively. Thus, compared with other plants, *K. obovata* stand can make good use of incident sunlight in their canopy with their photosynthetic capacity [37].

People recently have again recognized that mangroves have played an important role in preventing Tsunami tide wave after earthquakes in Indonesia, which lead to tsunami in Southeast Asia and cause huge losses and casualties to Southeast Asian Countries, particularly Indonesia [38, 39]. In fact, the mangrove stands along with seacoast of Indonesia protected and lessened destructive power of tide wave at the time [4]. In China, though very few typical examples were available for weaken effect of mangrove on tsunami, the storm prevention of mangrove is one important aspect of mangrove ecosystem services, which have been evaluated to be 10473.3 × 104 RMB in terms of energy value [40].

Recently, due to our concern that global warming will cause rapid rise in sea level, new aspects of salt resistance (tolerance and avoidance) of mangrove species has been studied intensively [33, 41–43]. Sea level rise would increase tidal inundation period and make mangrove species beyond the specific thresholds of flooding tolerance [44, 45]. With intense environmental change, the related knowledge about mangroves have also been systematically summarized through publish of

**69**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

education trail will also be briefly discussed in latter part of this review.

Mangrove species in China belong to the Indo-Malaysia Northeast subgroup of East group and covered >50,000 ha in 1950s [47]. Before 1990s, mangroves in China had been degraded and the areas greatly reduced, with only 22,752 ha remained [47]. Furthermore, mangrove ecological exploitation in China existed many problems, including imbalance between protection and utilization, simple ecological development mode, low economic benefit of ecological development, planning management and related policies and insufficient regional cooperation. Since then, increased government investments have greatly improved the research

In 1995, China's Biodiversity Conservation Action Plan included the action plans, which called for "Increasing mangrove conservation areas". As a result, majority of the national mangroves have been protected as a part of the national wide mangrove nature reserves (**Figure 4**). On the announcement of the leader Mr. Xi Jinping, one of the Chinese ecological policies orients us how to conserve mangrove forest as an ecological unit [49]. Based on this statement, conservation of mangrove ecosystem is one of the national key projects, especially at Fujian and Guangdong Province, especially Shenzhen city government, the most rapid

Over the past decades, large number of studies have significantly improved our understanding of structure and function of the mangrove ecosystems, however, there are still many areas needed to be strengthened: (1) The construction of sea walls plus many skyscrapers behind natural mangrove wetlands may prevent migration landward into areas of higher elevations in response to sea level rise; (2) Biological invasions such as those of *Spartina alterniflora* may compromise habitats. Their invasive mechanisms and efficient measures for controlling such invasion is still unclear; (3) There is still a lack of universal standard system for evaluating the efforts and achievements of mangrove afforestation and restoration in China; (4) Cooperation among related mangrove research institutions should be strengthened to ensure

**3. Mangrove management and research in China**

revised editions of botanical books on mangroves as well as ethnobotanical books [31, 32, 46, 47]. On the other hand, researchers recognized the impact of polluted water caused by anthropogenic activities on growth of mangrove plants, without paying much attention to negative impact of heavy metal pollution on mangrove

The exploration on heavy metal pollution in mangrove wetlands would understand the source, history, and status of heavy metals, and obtain the relationship between heavy metals and mangrove ecosystem, which is important for coordination between economic development and environment protection. With positive leadership of Chinese ecological policy [49], we have been studying on heavy metal pollution, such as mercury (Hg), cadmium (Cd), copper (Cu), and its counter effects on physiology and growth of the representative mangrove plants dominated around southern China. A typical example of pollution is an intensive study on mangrove ecosystems in Shenzhen city where is located north of Hong Kong, one of the most dramatically developed cities in China. Shenzhen City has decided to adopt mangrove plants as the symbolic trees and well organized ecological and environmental education by establishing mangrove museums and field education parks [7]. Environmental

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

ecosystems [26, 31, 46, 48].

**3.1 Mangrove management**

on mangroves in China.

developing economical city in China.

successful conservation, restoration of mangroves in China.

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

revised editions of botanical books on mangroves as well as ethnobotanical books [31, 32, 46, 47]. On the other hand, researchers recognized the impact of polluted water caused by anthropogenic activities on growth of mangrove plants, without paying much attention to negative impact of heavy metal pollution on mangrove ecosystems [26, 31, 46, 48].

The exploration on heavy metal pollution in mangrove wetlands would understand the source, history, and status of heavy metals, and obtain the relationship between heavy metals and mangrove ecosystem, which is important for coordination between economic development and environment protection. With positive leadership of Chinese ecological policy [49], we have been studying on heavy metal pollution, such as mercury (Hg), cadmium (Cd), copper (Cu), and its counter effects on physiology and growth of the representative mangrove plants dominated around southern China. A typical example of pollution is an intensive study on mangrove ecosystems in Shenzhen city where is located north of Hong Kong, one of the most dramatically developed cities in China. Shenzhen City has decided to adopt mangrove plants as the symbolic trees and well organized ecological and environmental education by establishing mangrove museums and field education parks [7]. Environmental education trail will also be briefly discussed in latter part of this review.

#### **3. Mangrove management and research in China**

#### **3.1 Mangrove management**

*Mangrove Ecosystem Restoration*

**Figure 3.**

*(Adopted from Hagihara [35]).*

water for its growth. These areas are usually zoned by different species of mangrove depending on their adaptive traits in salt tolerance [30–33] and light utilization characteristics of each species [34]. Mangrove species grow in the front of seashore are light demanding type while a component of well-developed stands is low-light

*The stratification diagram of a mangrove stand at the northern boundary in the Ryukyu islands, south Japan* 

Hagihara (2006) reviewed production ecology and carbon cycling of mangrove stand (*Kandelia obovata*) in the Ryukyu Islands (**Figure 3**): i.e. northern limit for the distribution of mangrove plants in Japan [35]. This species is very popular in China for ecological study [26, 32]. Hoque et al. (2011) found that Top/Root (T/R) ratio of *K. obovata* in Manko wetland, Okinawa, Japan was around 1.87 [36].

Generally, T/R ratio of mangrove stands was around 1.0 [26, 37] whereas it is ranged between 3 ~ 4 for most forests. From the stratification diagram, estimated value of the extinction coefficient (KF) including branches for *K. obovata* stand was 0.50. The KF was 0.56 ~ 0.69 for *Bruguiera gymnorhiza* stands in Ryukyu Islands, 0.54 ~ 0.57 for *Rhizophora apiculate* in Thailand. KF values of deciduous conifer larch (Larix kaempferi), evergreen oak (*Quercus phillyraeoides*) and Hinoki cypress (*Chamaecyparis obtusa*) were 0.31, 0.36, 0.67 and 0.37, respectively. Thus, compared with other plants, *K. obovata* stand can make good use of incident sunlight in their

People recently have again recognized that mangroves have played an important role in preventing Tsunami tide wave after earthquakes in Indonesia, which lead to tsunami in Southeast Asia and cause huge losses and casualties to Southeast Asian Countries, particularly Indonesia [38, 39]. In fact, the mangrove stands along with seacoast of Indonesia protected and lessened destructive power of tide wave at the time [4]. In China, though very few typical examples were available for weaken effect of mangrove on tsunami, the storm prevention of mangrove is one important aspect of mangrove ecosystem services, which have been evaluated to be

Recently, due to our concern that global warming will cause rapid rise in sea level, new aspects of salt resistance (tolerance and avoidance) of mangrove species has been studied intensively [33, 41–43]. Sea level rise would increase tidal inundation period and make mangrove species beyond the specific thresholds of flooding tolerance [44, 45]. With intense environmental change, the related knowledge about mangroves have also been systematically summarized through publish of

utilization type based on chlorophyll fluorescence.

canopy with their photosynthetic capacity [37].

RMB in terms of energy value [40].

**68**

10473.3 × 104

Mangrove species in China belong to the Indo-Malaysia Northeast subgroup of East group and covered >50,000 ha in 1950s [47]. Before 1990s, mangroves in China had been degraded and the areas greatly reduced, with only 22,752 ha remained [47]. Furthermore, mangrove ecological exploitation in China existed many problems, including imbalance between protection and utilization, simple ecological development mode, low economic benefit of ecological development, planning management and related policies and insufficient regional cooperation. Since then, increased government investments have greatly improved the research on mangroves in China.

In 1995, China's Biodiversity Conservation Action Plan included the action plans, which called for "Increasing mangrove conservation areas". As a result, majority of the national mangroves have been protected as a part of the national wide mangrove nature reserves (**Figure 4**). On the announcement of the leader Mr. Xi Jinping, one of the Chinese ecological policies orients us how to conserve mangrove forest as an ecological unit [49]. Based on this statement, conservation of mangrove ecosystem is one of the national key projects, especially at Fujian and Guangdong Province, especially Shenzhen city government, the most rapid developing economical city in China.

Over the past decades, large number of studies have significantly improved our understanding of structure and function of the mangrove ecosystems, however, there are still many areas needed to be strengthened: (1) The construction of sea walls plus many skyscrapers behind natural mangrove wetlands may prevent migration landward into areas of higher elevations in response to sea level rise; (2) Biological invasions such as those of *Spartina alterniflora* may compromise habitats. Their invasive mechanisms and efficient measures for controlling such invasion is still unclear; (3) There is still a lack of universal standard system for evaluating the efforts and achievements of mangrove afforestation and restoration in China; (4) Cooperation among related mangrove research institutions should be strengthened to ensure successful conservation, restoration of mangroves in China.

**Figure 4.**

*A Flame work of conservation strategy of mangrove ecosystem in China proposed by Dr. Hailei Zheng at Ningde, China in 2019 [49].*

#### **3.2 Mangrove researches**

Since 1970s, mangrove researches in China have mainly focused on taxonomy and ethno-botanical view point, medical use and practical use of mangrove plants [6, 50, 51]. According to uncompleted statistic, China researchers have published 24 monographs or proceedings related with mangrove, including comprehensive basic research, ecological restoration, macro-benthos, birds, pest control, and ecological location, remote sensing monitoring and evaluation, resource management, and popular science [52]. The Shenzhen City Office strongly supports researches and education in mangrove ecosystem (see education section).

*Research topics on mangrove forests in Chinese Ecological Society (CES) in 2019 (Adopted from program leaflet of the meeting of CES [49, 53]).*

**71**

**Figure 7.**

**Figure 6.**

*2019) [52–54].*

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

progress in mangrove researches and practical works. For most researchers, they are engaged in the topics such as remote sensing, biodiversity in mangrove ecosystems, physiological ecology, heavy metal pollutions, etc. These topics are relatively regarded as short-term target compared to those topics more professional

developmental goals) was summarized as follows (**Figure 6**) [49].

Chinese mangrove ecologists hold workshop every two years to make further

At the 9th workshop in Ningde 2019 (in Fujian Province) [53], the recent ecological efforts on mangrove conservation in accordance with the SDGs (Sustainable

The contents were: i.e. policy making, scientific review, practical forestry, and frost resistant researches, which were mainly reported by national and regional research institutes. Among them, one unique research is how to increase mangrove's frost tolerance and freezing avoidance research (**Figure 7**) [56, 57]. In 2010, sudden snow-fall caused death of newly planted mangroves because they were originally grown in sub-tropical and tropical, where there would not be a severe

*Rehabilitation strategy of mangrove forests under pollution, (Adopted from the statement by Dr. Hailei Zheng,* 

*Photos of snow on mangrove seedlings planted in Zhejiang Province, China in 2010. Left photo was offered by Dr. Jianbiao Qiu of Zhejiang Mariculture Research Institute. And right photo at nursery was offered by Dr.* 

*QiuXia Chen of Zhejiang Sub-tropical research institute [55].*

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

(**Figure 5**).

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

Chinese mangrove ecologists hold workshop every two years to make further progress in mangrove researches and practical works. For most researchers, they are engaged in the topics such as remote sensing, biodiversity in mangrove ecosystems, physiological ecology, heavy metal pollutions, etc. These topics are relatively regarded as short-term target compared to those topics more professional (**Figure 5**).

At the 9th workshop in Ningde 2019 (in Fujian Province) [53], the recent ecological efforts on mangrove conservation in accordance with the SDGs (Sustainable developmental goals) was summarized as follows (**Figure 6**) [49].

The contents were: i.e. policy making, scientific review, practical forestry, and frost resistant researches, which were mainly reported by national and regional research institutes. Among them, one unique research is how to increase mangrove's frost tolerance and freezing avoidance research (**Figure 7**) [56, 57]. In 2010, sudden snow-fall caused death of newly planted mangroves because they were originally grown in sub-tropical and tropical, where there would not be a severe

#### **Figure 6.**

*Mangrove Ecosystem Restoration*

**3.2 Mangrove researches**

*Ningde, China in 2019 [49].*

**Figure 4.**

Since 1970s, mangrove researches in China have mainly focused on taxonomy and ethno-botanical view point, medical use and practical use of mangrove plants [6, 50, 51]. According to uncompleted statistic, China researchers have published 24 monographs or proceedings related with mangrove, including comprehensive basic research, ecological restoration, macro-benthos, birds, pest control, and ecological location, remote sensing monitoring and evaluation, resource management, and popular science [52]. The Shenzhen City Office strongly supports researches and

*A Flame work of conservation strategy of mangrove ecosystem in China proposed by Dr. Hailei Zheng at* 

*Research topics on mangrove forests in Chinese Ecological Society (CES) in 2019 (Adopted from program leaflet* 

education in mangrove ecosystem (see education section).

**70**

**Figure 5.**

*of the meeting of CES [49, 53]).*

*Rehabilitation strategy of mangrove forests under pollution, (Adopted from the statement by Dr. Hailei Zheng, 2019) [52–54].*

#### **Figure 7.**

*Photos of snow on mangrove seedlings planted in Zhejiang Province, China in 2010. Left photo was offered by Dr. Jianbiao Qiu of Zhejiang Mariculture Research Institute. And right photo at nursery was offered by Dr. QiuXia Chen of Zhejiang Sub-tropical research institute [55].*

low temperature environment. Glycine-Betaine was employed as a target chemical for species selection and breeding, as this compound is also common in relation to increase of desiccation and frozen tolerance [57]. Clearly, more work is needed to perform practical applications in the future.

#### **4. Ecological statistics and diagnoses of heavy metal pollution in China**

The current situation of heavy metal pollution of the southern part of China from ecological statistics was reported by Shi et al. [58]. As the first integrated analysis of heavy metal pollution in mangrove sediments across China, this study covered whole mangroves in China by selecting 6 sites including Hainan Island and near the border of Vietnam. If we focus on common mangrove species of these regions, *Avicennia marina* (characteristics: this species has pneumatophores [looks like young shoot of bamboo] for respiration in few centimeters from muddy soil) [59], the heavy metal pollution of this species shows very strong correlations in polluted condition of tideland soil (**Figure 8**).

From data of heavy metal pollution at the 6 sites, the pollution level in Futian district of Shenzhen city has higher pollution level. We detected representative heavy metal pollutants cause by high concentration of zinc (Zn), chromium (Cr), lead (Pb), nickel (Ni), arsenic (As) and relatively low concentration of molybdenum (Mo), cobalt (Co) and cadmium (Cd). Although proportion of Cd in the total heavy metal concentrations was low (based on evaluation of geo-accumulation index, contamination factor, potential ecological risk coefficient, pollution load index, and potential ecological risk index), Cd is a cause of the "Itai-itai" disease in Japan [60] and was detected as 0.66 ~ 3.30 μg/g at Futian district of Shenzhen city [61].

The factor affecting capture of heavy metal is particle size of soil with different specific surface areas and adsorption capacities [60, 61]. In fact, the heavy metal concentration was lower at Fangchenggang in Guangxi province where sand is dominant, while it was higher at Dong fang, Yunxiao and Futian district of Shenzhen where silt (between sand and clay) is dominant [62, 63]. We regarded mangrove stands, coral-reef and seaweed fauna as three major inshore marine ecosystems [1, 64, 65]. Furthermore, we explored the heavy metal pollution in Futian mangroves of Shenzhen, China. Futian mangrove is a mangrove forest area of 304 ha located in the Guangdong Province, and is the only mangrove forests located in the middle of Shenzhen, China. Futian mangrove was adjacent to the Mai

#### **Figure 8.**

*Ecological statistics of heavy metals pollution in south China (AM, Avicennia marina a kind of mangrove; MF, mudflat) (Adopted from Shi et al. [58]).*

**73**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

**5. Ecophysiology of heavy metal resistance for mangrove plants**


improved bioaccumulation of pectate and protein integrated Cd in cell to reduce

bioaccumulation of Cd on root cell wall, and limited enter of Cd into cell, which were also verified by decreased bioaccumulation of pectate and protein integrated

Cd immobilization in roots of *K. obovata*; the results of subcellular distribution and chemical forms showed that root cell wall combination and integration with pectate and protein acted as the mainly detoxification strategies of *K. obovata*. Plant transpiration transfer coefficient performed well in indicating the water and high

The use of chlorophyll florescence for diagnose of plant health status under stress, especially for mangrove plants is important in the rapid non-destructive

Mangrove plants have specific nutrient balance for growth and survival because they grow in very special environment (i.e. high NaCl, flooding environment, etc.). Therefore, response of mangrove plants to various environmental stresses is a key information of rehabilitation of degraded regions. Cadmium (Cd), a non-essential element, can easily be taken up by plants and cause chlorosis [69], wilting [70] and cell death [71]. Heavy metals and large amounts of nutrients including nitrogen from domestic sewage also accumulate in mangrove sediment, and change its oligotrophic state [72] and pH [73]. We quantified the effects of ammonium nitrogen on the accumulation, subcellular distribution, and chemical forms of cadmium (Cd) in *K. obovata* [68]. The concentration and total amounts of Cd in leaves, stems and


+

+



Po Nature Reserve, Hong Kong, and has suffered serious heavy metal pollution since

In order to systematically explore ecological risk of heavy metal contamination in Futian mangrove forest, being important for designing management and conservation policy, we quantify the concentrations of heavy metals (Cd, Cr, Cu, Pb and Zn) in mangrove sediments, assess the potential ecological risk and sources of heavy metals, and identify the speciation of heavy metals [66]. The results showed that heavy metal concentrations in surface sediments (0–20 cm depth) varied greatly along the coastline, demonstrating the heterogeneity of sediment to some extent. As for different heavy metal species, the concentrations reduced in the order of Zn > Cr > Pb > Cu > Cd [66]. Furthermore, the combination of studied metals had a 21% probability of being toxic, based on analysis of mean probable effects level quotient. Similarly, high heavy metal contamination was also revealed in term of potential ecological risk index and geo-accumulation index. Among all heavy metals, Cd has higher potential for adverse biological effects, being of primary concern. Take into account the sediment characteristics, clay and silt were important in raising deposition/accumulation of Cr, Cu, and Zn. As for different speciation of heavy metals, the percentage of mobile heavy metals was relatively higher than other fractions; while, no considerable ecological risk to the biota was detected in terms of the risk assessment code. The mobile heavy metals referred to the sum of acid-soluble, reducible, and the oxidizable fractions in terms of heavy

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

the early 1990s [62].

metal speciation [67].

roots increased with NH4

+

50 mg/L NH4

+

toxicity caused by Cd. Under 10 mg/L Cd treatment, NH4

Cd in root cell to some extent. Thus, under Cd stress, NH4

temperature stress conditions plants experienced [74].

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

Po Nature Reserve, Hong Kong, and has suffered serious heavy metal pollution since the early 1990s [62].

In order to systematically explore ecological risk of heavy metal contamination in Futian mangrove forest, being important for designing management and conservation policy, we quantify the concentrations of heavy metals (Cd, Cr, Cu, Pb and Zn) in mangrove sediments, assess the potential ecological risk and sources of heavy metals, and identify the speciation of heavy metals [66]. The results showed that heavy metal concentrations in surface sediments (0–20 cm depth) varied greatly along the coastline, demonstrating the heterogeneity of sediment to some extent. As for different heavy metal species, the concentrations reduced in the order of Zn > Cr > Pb > Cu > Cd [66]. Furthermore, the combination of studied metals had a 21% probability of being toxic, based on analysis of mean probable effects level quotient. Similarly, high heavy metal contamination was also revealed in term of potential ecological risk index and geo-accumulation index. Among all heavy metals, Cd has higher potential for adverse biological effects, being of primary concern. Take into account the sediment characteristics, clay and silt were important in raising deposition/accumulation of Cr, Cu, and Zn. As for different speciation of heavy metals, the percentage of mobile heavy metals was relatively higher than other fractions; while, no considerable ecological risk to the biota was detected in terms of the risk assessment code. The mobile heavy metals referred to the sum of acid-soluble, reducible, and the oxidizable fractions in terms of heavy metal speciation [67].

#### **5. Ecophysiology of heavy metal resistance for mangrove plants**

Mangrove plants have specific nutrient balance for growth and survival because they grow in very special environment (i.e. high NaCl, flooding environment, etc.).

Therefore, response of mangrove plants to various environmental stresses is a key information of rehabilitation of degraded regions. Cadmium (Cd), a non-essential element, can easily be taken up by plants and cause chlorosis [69], wilting [70] and cell death [71]. Heavy metals and large amounts of nutrients including nitrogen from domestic sewage also accumulate in mangrove sediment, and change its oligotrophic state [72] and pH [73]. We quantified the effects of ammonium nitrogen on the accumulation, subcellular distribution, and chemical forms of cadmium (Cd) in *K. obovata* [68]. The concentration and total amounts of Cd in leaves, stems and roots increased with NH4 + -N supply (**Figure 9**).

In terms of subcellular distribution, Cd in roots of *K. obovata* was mainly deposited on cell wall, and the largest chemical forms of Cd was pectate and protein integrated form in all treatment. Under Cd treatments of 1 and 5 mg/L, 50 mg/L NH4 + -N enhanced the transfer of root cell wall-combined Cd into cell, improved bioaccumulation of pectate and protein integrated Cd in cell to reduce toxicity caused by Cd. Under 10 mg/L Cd treatment, NH4 + -N addition improved bioaccumulation of Cd on root cell wall, and limited enter of Cd into cell, which were also verified by decreased bioaccumulation of pectate and protein integrated Cd in root cell to some extent. Thus, under Cd stress, NH4 + -N supply improved Cd immobilization in roots of *K. obovata*; the results of subcellular distribution and chemical forms showed that root cell wall combination and integration with pectate and protein acted as the mainly detoxification strategies of *K. obovata*. Plant transpiration transfer coefficient performed well in indicating the water and high temperature stress conditions plants experienced [74].

The use of chlorophyll florescence for diagnose of plant health status under stress, especially for mangrove plants is important in the rapid non-destructive

*Mangrove Ecosystem Restoration*

perform practical applications in the future.

polluted condition of tideland soil (**Figure 8**).

low temperature environment. Glycine-Betaine was employed as a target chemical for species selection and breeding, as this compound is also common in relation to increase of desiccation and frozen tolerance [57]. Clearly, more work is needed to

**4. Ecological statistics and diagnoses of heavy metal pollution in China**

The current situation of heavy metal pollution of the southern part of China from ecological statistics was reported by Shi et al. [58]. As the first integrated analysis of heavy metal pollution in mangrove sediments across China, this study covered whole mangroves in China by selecting 6 sites including Hainan Island and near the border of Vietnam. If we focus on common mangrove species of these regions, *Avicennia marina* (characteristics: this species has pneumatophores [looks like young shoot of bamboo] for respiration in few centimeters from muddy soil) [59], the heavy metal pollution of this species shows very strong correlations in

From data of heavy metal pollution at the 6 sites, the pollution level in Futian district of Shenzhen city has higher pollution level. We detected representative heavy metal pollutants cause by high concentration of zinc (Zn), chromium (Cr), lead (Pb), nickel (Ni), arsenic (As) and relatively low concentration of molybdenum (Mo), cobalt (Co) and cadmium (Cd). Although proportion of Cd in the total heavy metal concentrations was low (based on evaluation of geo-accumulation index, contamination factor, potential ecological risk coefficient, pollution load index, and potential ecological risk index), Cd is a cause of the "Itai-itai" disease in Japan [60] and was detected as 0.66 ~ 3.30 μg/g at Futian district of Shenzhen

The factor affecting capture of heavy metal is particle size of soil with different specific surface areas and adsorption capacities [60, 61]. In fact, the heavy metal concentration was lower at Fangchenggang in Guangxi province where sand is dominant, while it was higher at Dong fang, Yunxiao and Futian district of Shenzhen where silt (between sand and clay) is dominant [62, 63]. We regarded mangrove stands, coral-reef and seaweed fauna as three major inshore marine ecosystems [1, 64, 65]. Furthermore, we explored the heavy metal pollution in Futian mangroves of Shenzhen, China. Futian mangrove is a mangrove forest area of 304 ha located in the Guangdong Province, and is the only mangrove forests located in the middle of Shenzhen, China. Futian mangrove was adjacent to the Mai

*Ecological statistics of heavy metals pollution in south China (AM, Avicennia marina a kind of mangrove;* 

**72**

**Figure 8.**

*MF, mudflat) (Adopted from Shi et al. [58]).*

city [61].

**Figure 9.**

*The distribution of cadmium (Cd) in Kandelia obovata under nitrogen addition (Adopted from Chai et al.) [68].*

assessment [34]. Physiological activity of coastal mangrove species is evaluated based on a three-temperature (3 T) model using high-resolution thermal infrared remote sensing. This evaluation method is based on growth evaluation of the representative mangrove species, *K. obovata* seedlings treated with different concentrations of Cd and nitrogen input as a simulation of environment at estuary of Shenzhen, China [75].

The cultured *K. obovata* seedlings were promoted for their photosynthesis due to the application of nitrogen, which brought a decrease leaf temperature detected by remote thermometer. In contrast, leaf temperature of *K. obovata* seedlings treated Cd increased due to stomatal closure with Cd toxicity [75]. The toxicity of Cd may be moderated by the existence of nitrogen addition, which can be clearly detected by the images from thermometer. The high-resolution thermal infrared remote sensing +3 T model is practicable for diagnosing plant health status. We should always consider synergy and antagonism in each element including heavy metals and nutritional elements [76]. Generally, the information in single metal contamination research does not reflect the biological toxicity when multiple metals are present together, with their combination toxicity having complicated mutual interactions on plants [77].

Furthermore, the interactive effects of multiple heavy metals (Cu, Pb, and Zn) on growth of *K. obovata* were studied, including plant biomass, photosynthetic parameters, lipid peroxidation and compatible osmolytes [78]. The results showed no significant reduction of biomass under heavy metal stresses, except for decreased root biomass under higher Pb + Cu treatment. This evidence indicates that *K. obovata* is highly tolerant to heavy metal stress. With increasing heavy metal stress (except for Pb + Cu and Pb + Zn + Cu), the photosynthetic parameters detected by a potable porometer (LI-6400; NE, USA) (net photosynthetic rate [Pn], transpiration rate [Tr], and stomatal conductance [Gs]) decreased at ambient CO2 concentration (about 400 ppm) [75].

**75**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

Compared to external binary metal treatment, trinary treatments (Pb + Zn + Cu) improved plant biomass and the photosynthetic capacity. As for root of *K. obovata*, binary treatment reduced biomass and soluble sugar content compared with ternary treatment. These results showed that in Pb combined treatments, the combination of Zn and Cu improved alleviating toxicity than each of them alone. Malondialdehyde (MDA) can reflect the degree of cell membrane lipid

In leaves of *K. obovata*, Zn-containing combined treatments significantly reduced MDA, soluble sugar, and proline content under low concentration, demonstrating antagonistic effects; while, Pb + Cu treatments significantly promoted these parameters, indicated synergistic effects. Furthermore, there were negative correlations between leaf MDA and proline content with Zn concentration (P < 0.05). Leaf MDA content was positively correlated with the osmotic parameters, indicating co-existence of osmotic stress and lipid membranes oxidation under multiple heavy metal stresses. Thus, as for *K. obovata*, the toxicity caused by multiple heavy metals could be indicated by responses of leaf biomass, Tr, leaf

**6. Evaluation of mangrove ecosystem: microbes and shellfish**

At the ecosystem level, mangrove plants, microbes in the soil, any other living organisms, and their natural environment cooperated with each other [3, 81, 82]. There are many places in mangrove stands producing sulfate compounds (e.g. hydrogen sulfide, H2S). We can identify the smell of H2S, implying importance of sulfate producing microbe activities. In the field conditions, heavy metal accumulation is important environmental factor regulating bacterial communities [83, 84]. Sulfate-reducing bacteria (SRB) could utilize sulfate as an electron acceptor in the dissimilatory reduction of sulfate [85]. How about the impacts of heavy metals pollutant on SRB? The effects of heavy metal contamination on sulfate-reducing bacteria (SRB) with both field survey and experimental approaches have been revealed [3]. SRB communities were investigated in mangrove sediments (0–30 cm depth) from 3 districts of mangrove wetlands in Shenzhen with different heavy

The results revealed that SRB community abundance was correlated with depth of mangrove sediments, especially significant correlation was found in soil concentration of Cd and Ni concentrations. From 1980 to 1990s, almost no analysis was done from the view point of biodiversity [81]. The α-diversity index of SRB community was significantly correlated with Cd level in mangrove sediments. Dominant 3 SRB groups (Desulfo-bacteraceae, Desulfobulbaceae, Syntrophobacteraceae) were isolated in the mangrove sediments of Shenzhen mangrove, China [3]. Among these families, Syntrophobacter-aceae was most sensitive to heavy metal contamination. The Unifrace clustering analysis revealed that SRB community structure was influenced by heavy metal stress. Moreover, redundancy analysis (RDA) indicated that Cd and total phosphorus were the major element affecting the SRB structure in

Generally, the structure of mangrove sediment bacterial community could be affected by various factors, including plantation species [86], sediment depths [87], physico-chemical properties of sediment [88], and anthropogenic activities [87]. Different mangroves might reveal the specific biogeographic distribution pattern of bacterial community [89]. We explored the biogeographic distribution of sediment

peroxidation and plant response to stress conditions [79, 80].

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

MDA, leaf proline and soluble sugar [75, 78].

**6.1 Microbe in mangrove sediments**

metal contamination levels.

the mangrove sediments [3].

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

Compared to external binary metal treatment, trinary treatments (Pb + Zn + Cu) improved plant biomass and the photosynthetic capacity. As for root of *K. obovata*, binary treatment reduced biomass and soluble sugar content compared with ternary treatment. These results showed that in Pb combined treatments, the combination of Zn and Cu improved alleviating toxicity than each of them alone. Malondialdehyde (MDA) can reflect the degree of cell membrane lipid peroxidation and plant response to stress conditions [79, 80].

In leaves of *K. obovata*, Zn-containing combined treatments significantly reduced MDA, soluble sugar, and proline content under low concentration, demonstrating antagonistic effects; while, Pb + Cu treatments significantly promoted these parameters, indicated synergistic effects. Furthermore, there were negative correlations between leaf MDA and proline content with Zn concentration (P < 0.05). Leaf MDA content was positively correlated with the osmotic parameters, indicating co-existence of osmotic stress and lipid membranes oxidation under multiple heavy metal stresses. Thus, as for *K. obovata*, the toxicity caused by multiple heavy metals could be indicated by responses of leaf biomass, Tr, leaf MDA, leaf proline and soluble sugar [75, 78].

#### **6. Evaluation of mangrove ecosystem: microbes and shellfish**

#### **6.1 Microbe in mangrove sediments**

*Mangrove Ecosystem Restoration*

of Shenzhen, China [75].

**Figure 9.**

*Chai et al.) [68].*

interactions on plants [77].

concentration (about 400 ppm) [75].

assessment [34]. Physiological activity of coastal mangrove species is evaluated based on a three-temperature (3 T) model using high-resolution thermal infrared remote sensing. This evaluation method is based on growth evaluation of the representative mangrove species, *K. obovata* seedlings treated with different concentrations of Cd and nitrogen input as a simulation of environment at estuary

*The distribution of cadmium (Cd) in Kandelia obovata under nitrogen addition (Adopted from* 

The cultured *K. obovata* seedlings were promoted for their photosynthesis due to the application of nitrogen, which brought a decrease leaf temperature detected by remote thermometer. In contrast, leaf temperature of *K. obovata* seedlings treated Cd increased due to stomatal closure with Cd toxicity [75]. The toxicity of Cd may be moderated by the existence of nitrogen addition, which can be clearly detected by the images from thermometer. The high-resolution thermal infrared remote sensing +3 T model is practicable for diagnosing plant health status. We should always consider synergy and antagonism in each element including heavy metals and nutritional elements [76]. Generally, the information in single metal contamination research does not reflect the biological toxicity when multiple metals are present together, with their combination toxicity having complicated mutual

Furthermore, the interactive effects of multiple heavy metals (Cu, Pb, and Zn) on growth of *K. obovata* were studied, including plant biomass, photosynthetic parameters, lipid peroxidation and compatible osmolytes [78]. The results showed no significant reduction of biomass under heavy metal stresses, except for decreased root biomass under higher Pb + Cu treatment. This evidence indicates that *K. obovata* is highly tolerant to heavy metal stress. With increasing heavy metal stress (except for Pb + Cu and Pb + Zn + Cu), the photosynthetic parameters detected by a potable porometer (LI-6400; NE, USA) (net photosynthetic rate [Pn], transpiration rate [Tr], and stomatal conductance [Gs]) decreased at ambient CO2

**74**

At the ecosystem level, mangrove plants, microbes in the soil, any other living organisms, and their natural environment cooperated with each other [3, 81, 82]. There are many places in mangrove stands producing sulfate compounds (e.g. hydrogen sulfide, H2S). We can identify the smell of H2S, implying importance of sulfate producing microbe activities. In the field conditions, heavy metal accumulation is important environmental factor regulating bacterial communities [83, 84]. Sulfate-reducing bacteria (SRB) could utilize sulfate as an electron acceptor in the dissimilatory reduction of sulfate [85]. How about the impacts of heavy metals pollutant on SRB? The effects of heavy metal contamination on sulfate-reducing bacteria (SRB) with both field survey and experimental approaches have been revealed [3]. SRB communities were investigated in mangrove sediments (0–30 cm depth) from 3 districts of mangrove wetlands in Shenzhen with different heavy metal contamination levels.

The results revealed that SRB community abundance was correlated with depth of mangrove sediments, especially significant correlation was found in soil concentration of Cd and Ni concentrations. From 1980 to 1990s, almost no analysis was done from the view point of biodiversity [81]. The α-diversity index of SRB community was significantly correlated with Cd level in mangrove sediments. Dominant 3 SRB groups (Desulfo-bacteraceae, Desulfobulbaceae, Syntrophobacteraceae) were isolated in the mangrove sediments of Shenzhen mangrove, China [3]. Among these families, Syntrophobacter-aceae was most sensitive to heavy metal contamination. The Unifrace clustering analysis revealed that SRB community structure was influenced by heavy metal stress. Moreover, redundancy analysis (RDA) indicated that Cd and total phosphorus were the major element affecting the SRB structure in the mangrove sediments [3].

Generally, the structure of mangrove sediment bacterial community could be affected by various factors, including plantation species [86], sediment depths [87], physico-chemical properties of sediment [88], and anthropogenic activities [87]. Different mangroves might reveal the specific biogeographic distribution pattern of bacterial community [89]. We explored the biogeographic distribution of sediment

bacterial community in six mangroves across China, including two mangroves in Hainan Province, two in Guangdong Province, one in Guangxi Province and one in Fujian Province [90]. Among all six mangroves, the sediment bacterial demonstrated different characteristics in terms of bacterial abundance, bacterial richness and diversity, and bacterial community structure. Compared with intertidal mudflat, *A. marina* planted zone improved sediment bacterial abundance, richness, and diversity. Furthermore, *Proteobacteria* acted as the largest bacterial phylum in sediments in both intertidal mudflat and *A. marina* planted zone. Therefore, the biogeographic distribution of bacterial community across six mangroves in China was driven by variable wetland tropic status and other physicochemical factors (such as salinity) [90].

In mangrove sediment, *Archaea* sp. played important role in biogeochemical processes, such as ammonia oxidation [91] and methanogenesis [79]. Understanding biogeographic distribution pattern can be helpful to increase the knowledge of microbial function and to predict ecosystem responses to environmental variability [89]. We explored the effect of geographic location on mangrove archaeal community in six mangroves of China [92].

In different geographic location, mangrove archaeal have different community characteristics, which might be related to various environmental factors, including pH, carbon, and nitrogen contents in sediment. Furthermore, the main archaeal communities in mangrove sediments were genus *Thaumarchaeota* and *Euryarchaeota*, with their percentages to be 54.7–85.2% and 11.8–43.9%, respectively. This work would be useful for understanding the characteristics of archaeal community in mangrove ecosystem, which may provide new insight for exploring microbial function and ecosystem responses to variable environment.

#### **6.2 Shellfish as food resources**

Shellfish is an important component in mangrove ecosystems similar to wellknown crabs [32]. Recently, people have eaten more shellfishes as healthy food than before; however, the bio-accumulation of heavy metals in the shellfish can endanger the health of consumer [93]. Shenzhen is a fast-developing city in south China, and has been developed from a small fishermen village to a modern metropolis with about 12 million populations since the reform and opening policy in 1978 [94].

A case study on 3 markets of Shenzhen has received increasing attention. Arsenic (As), Cd, Cu, Hg, and Pb in 10 popular shellfish species and associated health risks were analyzed for Shenzhen's consumers by evaluation of estimated weekly intake (EWI), non-carcinogenic and carcinogenic health risks to the 3 stages in a human life-cycle (children, adolescents, adults) [95]. Based on 50 shellfish samples in each site of market there, they found that the levels of inorganic arsenic (iAs) in *Babylonia areolata* exceeded the maximum permissible-limit decided by the food safety guidelines (0.5 mg/kg), while other elements were below the limit of the guidelines as shown in Ministry of Health of the PR. China: GB 2762–2012. EWI values of the 3 stages of human development were lower than provisional tolerable weekly intakes (PTWIs) of all shellfish species. Analysis of the total target hazard quotients (TTHQ ) showed that the consumption of *B. areolata* in all stages of people would cause non-carcinogenic risks; as for children (< 10 years old), the ingested *Argopecten irradians* and *Chlamys farreri* were at non-carcinogenic risks. As for children, adolescents, and adults, the bioaccumulation of Cd caused by shellfish consumption (*A. irradians, B. areolata, C. farreri*, and *Crassostrea ariakensis*) would lead to cancer risk during life-time, with Pb and iAs to be toxicity acceptable or negligible [96].

From the perspective of species, the concentration of Zn and Cu in the *C. ariakensis* was the highest, the concentration of Cd in *C. farreri* was the highest,

**77**

fish and even human.

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

the *C. ariakensis* is less than 1 kg/d can reach the limit value.

and the concentration in the *Sinonovacula constricta* was relatively low. From the regional differences, Cd content in *C. farreri* of Dandong was the highest; the overall concentration of heavy metals in Qingdao was relatively low; Cu and Zn concentration in *C. ariakensis* and Cd concentration in *C. farreri* of Zhoushan were relatively high; Zn and Cu content in *C. ariakensis* of Shenzhen was the highest. The calculated daily intake-limit-results show that the feeding rate in the *C. farreri* only is 0.04 ~ 0.15 kg/d to reach the limit of Cd, and the feeding rate of Zn, Cu and Cd in

The results of the risk assessment showed that the weekly intake of heavy metals by eating shellfish did not exceed the provisional tolerable weekly intake set by Joint Expert Committee on Food Additives (JECFA\*, \*JECFA, 2010. Joint FAO/WHO Expert Committee on Food Additives, Summary and Conclusions by the JECFA.), and there was no non-carcinogenic risk to the human body. However, in terms of the long overdose of all sampling points of the *C. farreri* and *C. ariakensis* in Dandong, the accumulated Cd has a potential carcinogenic risk

**7. Persistent organic pollutants (POPs) in mangroves of China**

Overuse of POPs like plastic bags pollutes mangrove stands and POPs are hardly decomposed in mangrove ecosystems and consequently degrade habitat for most living organisms in a mangrove stand. The value of mangrove environment is getting worse by accumulation of the POPs, therefore, we should know the effect of POPs on mangrove plants as well as ecosystem for improvement of rehabilitation

Microplastics (MPs) researches have been mainly investigating on food-web and bioconcentration in Japan [97]. For example, in Tokyo Bay, the bowel of several kinds of seabird, sardine, etc. contains huge amount of MP. In detail study on a kind of seabird (*Puffinus tenuirostris*), this bird cannot eat foods due to full with MPs in the bowel. Much worse, the accumulated MPs in their stomach gradually release toxic substances [98], such as PCB. Now, if we eat such polluted sardine, our health condition would not be injured. However, we cannot deny the harmful effects of

MPs are now worldwide serious problem [97, 99]. MPs have a long life-span in ecosystem and become smaller in size of less than 5 mm over time, and deposit toward deep sea [9]. The existence form of MPs in south China was classified as fiber, film, and fine particle with several colors of original products [99]. At the 6 mangrove stands located along the coast of Southern China, the top 3 MPs were detected as health safety substance, including polypropylene (PP), polyethylene (PE), and polystyrene (PS). In terms of shape, color and size, MPs were mainly fibrous, white-transparent and 500 μm-5000 μm, respectively. MPs pollution in mangroves was significantly linked to surrounding socio-economic development. The TOC and silt content of mangrove sediments also affect the deposition of MPs [99]. Based on a comprehensive evaluation using the potential ecological risk factor, potential ecological risk, polymer risk index and pollution load index, MPs showed highest ecological risk in Futian mangrove of Shenzhen, China. These fundamental data on MPs occurring in mangroves of Southern China could support further studies of the ecological consequences of MPs on mangrove macro-fauna, shrimp,

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

to the human body.

**7.1 Microplastics**

strategy of degraded mangrove stands.

PCB and related toxic substances in MPs.

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

and the concentration in the *Sinonovacula constricta* was relatively low. From the regional differences, Cd content in *C. farreri* of Dandong was the highest; the overall concentration of heavy metals in Qingdao was relatively low; Cu and Zn concentration in *C. ariakensis* and Cd concentration in *C. farreri* of Zhoushan were relatively high; Zn and Cu content in *C. ariakensis* of Shenzhen was the highest. The calculated daily intake-limit-results show that the feeding rate in the *C. farreri* only is 0.04 ~ 0.15 kg/d to reach the limit of Cd, and the feeding rate of Zn, Cu and Cd in the *C. ariakensis* is less than 1 kg/d can reach the limit value.

The results of the risk assessment showed that the weekly intake of heavy metals by eating shellfish did not exceed the provisional tolerable weekly intake set by Joint Expert Committee on Food Additives (JECFA\*, \*JECFA, 2010. Joint FAO/WHO Expert Committee on Food Additives, Summary and Conclusions by the JECFA.), and there was no non-carcinogenic risk to the human body. However, in terms of the long overdose of all sampling points of the *C. farreri* and *C. ariakensis* in Dandong, the accumulated Cd has a potential carcinogenic risk to the human body.

#### **7. Persistent organic pollutants (POPs) in mangroves of China**

Overuse of POPs like plastic bags pollutes mangrove stands and POPs are hardly decomposed in mangrove ecosystems and consequently degrade habitat for most living organisms in a mangrove stand. The value of mangrove environment is getting worse by accumulation of the POPs, therefore, we should know the effect of POPs on mangrove plants as well as ecosystem for improvement of rehabilitation strategy of degraded mangrove stands.

#### **7.1 Microplastics**

*Mangrove Ecosystem Restoration*

nity in six mangroves of China [92].

**6.2 Shellfish as food resources**

bacterial community in six mangroves across China, including two mangroves in Hainan Province, two in Guangdong Province, one in Guangxi Province and one in Fujian Province [90]. Among all six mangroves, the sediment bacterial demonstrated different characteristics in terms of bacterial abundance, bacterial richness and diversity, and bacterial community structure. Compared with intertidal mudflat, *A. marina* planted zone improved sediment bacterial abundance, richness, and diversity. Furthermore, *Proteobacteria* acted as the largest bacterial phylum in sediments in both intertidal mudflat and *A. marina* planted zone. Therefore, the biogeographic distribution of bacterial community across six mangroves in China was driven by variable wetland tropic status and other physicochemical factors (such as salinity) [90]. In mangrove sediment, *Archaea* sp. played important role in biogeochemical processes, such as ammonia oxidation [91] and methanogenesis [79]. Understanding biogeographic distribution pattern can be helpful to increase the knowledge of microbial function and to predict ecosystem responses to environmental variability [89]. We explored the effect of geographic location on mangrove archaeal commu-

In different geographic location, mangrove archaeal have different community characteristics, which might be related to various environmental factors, including pH, carbon, and nitrogen contents in sediment. Furthermore, the main archaeal communities in mangrove sediments were genus *Thaumarchaeota* and *Euryarchaeota*, with their percentages to be 54.7–85.2% and 11.8–43.9%, respectively. This work would be useful for understanding the characteristics of archaeal community in mangrove ecosystem, which may provide new insight for exploring

Shellfish is an important component in mangrove ecosystems similar to wellknown crabs [32]. Recently, people have eaten more shellfishes as healthy food than before; however, the bio-accumulation of heavy metals in the shellfish can endanger the health of consumer [93]. Shenzhen is a fast-developing city in south China, and has been developed from a small fishermen village to a modern metropolis with about 12 million populations since the reform and opening policy in 1978 [94]. A case study on 3 markets of Shenzhen has received increasing attention. Arsenic (As), Cd, Cu, Hg, and Pb in 10 popular shellfish species and associated health risks were analyzed for Shenzhen's consumers by evaluation of estimated weekly intake (EWI), non-carcinogenic and carcinogenic health risks to the 3 stages in a human life-cycle (children, adolescents, adults) [95]. Based on 50 shellfish samples in each site of market there, they found that the levels of inorganic arsenic (iAs) in *Babylonia areolata* exceeded the maximum permissible-limit decided by the food safety guidelines (0.5 mg/kg), while other elements were below the limit of the guidelines as shown in Ministry of Health of the PR. China: GB 2762–2012. EWI values of the 3 stages of human development were lower than provisional tolerable weekly intakes (PTWIs) of all shellfish species. Analysis of the total target hazard quotients (TTHQ ) showed that the consumption of *B. areolata* in all stages of people would cause non-carcinogenic risks; as for children (< 10 years old), the ingested *Argopecten irradians* and *Chlamys farreri* were at non-carcinogenic risks. As for children, adolescents, and adults, the bioaccumulation of Cd caused by shellfish consumption (*A. irradians, B. areolata, C. farreri*, and *Crassostrea ariakensis*) would lead to cancer risk during life-time, with Pb and iAs to be toxicity acceptable or

From the perspective of species, the concentration of Zn and Cu in the *C. ariakensis* was the highest, the concentration of Cd in *C. farreri* was the highest,

microbial function and ecosystem responses to variable environment.

**76**

negligible [96].

Microplastics (MPs) researches have been mainly investigating on food-web and bioconcentration in Japan [97]. For example, in Tokyo Bay, the bowel of several kinds of seabird, sardine, etc. contains huge amount of MP. In detail study on a kind of seabird (*Puffinus tenuirostris*), this bird cannot eat foods due to full with MPs in the bowel. Much worse, the accumulated MPs in their stomach gradually release toxic substances [98], such as PCB. Now, if we eat such polluted sardine, our health condition would not be injured. However, we cannot deny the harmful effects of PCB and related toxic substances in MPs.

MPs are now worldwide serious problem [97, 99]. MPs have a long life-span in ecosystem and become smaller in size of less than 5 mm over time, and deposit toward deep sea [9]. The existence form of MPs in south China was classified as fiber, film, and fine particle with several colors of original products [99]. At the 6 mangrove stands located along the coast of Southern China, the top 3 MPs were detected as health safety substance, including polypropylene (PP), polyethylene (PE), and polystyrene (PS). In terms of shape, color and size, MPs were mainly fibrous, white-transparent and 500 μm-5000 μm, respectively. MPs pollution in mangroves was significantly linked to surrounding socio-economic development. The TOC and silt content of mangrove sediments also affect the deposition of MPs [99]. Based on a comprehensive evaluation using the potential ecological risk factor, potential ecological risk, polymer risk index and pollution load index, MPs showed highest ecological risk in Futian mangrove of Shenzhen, China. These fundamental data on MPs occurring in mangroves of Southern China could support further studies of the ecological consequences of MPs on mangrove macro-fauna, shrimp, fish and even human.

#### **7.2 Polybrominated diphenyl ethers (PBDEs)**

Unfortunately, polluted condition with MPs of mangrove forest is getting worse in Shenzhen. As harmful MPs, PBDEs (polybrominated diphenyl ethers) have recently been detected. PBDEs are structurally similar to PCBs and other polyhalogenated compounds. Exposure to PBDEs would cause problems in the hormone system, liver and kidney morphology, neuro-behavioral and sexual development [100, 101]. The health risk of PBDEs and PCBs are increasing, and these chemical compounds have been shown to reduce human fertility to some extent [97]. The amount of PBDEs in a mangrove ecosystem increases with increasing amount of organic matters in soil [95, 102]. Concentration [unit: ng/g-dw] of PBDE-209 in mangrove stands of Hong Kong was 0.5 ~ 5.4 except for Mai Po mangrove (47.2– 112.0) opposite to Futian district of Shenzhen [103]. These values were lower than those of Shenzhen (2.1–1987.6) [102].

In Shenzhen mangroves, the levels of PBDE-209 [unit: ng/g-dw] were 2.1 ~ 110.0 in mangrove sediment and 180 ~ 600 in the leaves. The highest value was detected as 3600 in bark of the avenue trees in Beijing [104]. We found that PBDE-209 was the dominant PBDE congener in all six mangroves in China, including Yunxiao, Futian, Zhanjiang, Fangchenggang, Dongzhaigang and Dongfang [5]. Futian mangrove in Shenzhen was seriously polluted by PBDEs (in particular PBDE-209), compared to the other 5 mangrove wetlands. Total organic matter acted as an effective factor in affecting spatial distribution and ecological risk of PBDEs in sediment of mangroves. In 6 mangroves, sediments may pose low/moderate risk of exposure to penta- and deca-BDE congeners for sediment-dwelling organisms, with penta- and deca-BDE congeners to be major drivers of ecological risk. Furthermore, we explored PBDEs contamination in 4 urban mangroves of Shenzhen, including Shajing mangrove (SJM), Xixiang mangrove (SJM), Futian mangrove (FTM) and Baguang mangrove (BGM) [102]. Regarding urban functional zoning, urban mangroves were featured with industry district (SJM and XXM), central business district (CBD) (FTM), and ecological preserve (BGM) [105–107]. Our result showed that the ranking order of PBDEs contamination in urban mangroves was BGM ≈ FTM < XXM < SJM.

Compositions of PBDEs were complex in SJM, XXM, and FTM, with surface runoff to be the main source apportionment of PBDEs. Thus, in urban mangroves with different urban functional zonings, PBDEs accumulation in mangrove sediment and their bioaccumulation in mangrove plants were different. In the future, much work should be done to decrease e the input of PBDEs into the urban mangrove, such as the inspection of the illegal waste recycling sites and promotion of sewage treatment capacity of PBDEs-related enterprises.

#### **7.3 Other POPs**

Levels of polycyclic aromatic hydrocarbons (PAHs: unit: [ng/g-dw]) in mangrove sediments of China ranged from 15 to 11,098 and decreased in the order of Hong Kong (56–11,098) > Fujian (171–1074) > Guangdong (15–726) > Hainan (31–63) > Guangxi (24) [11, 12, 108]. Higher levels of PAH s in Hong Kong mangrove might be attributed to the intense anthropogenic activities. Levels of PAHs in mangrove sediments of China (24–11,098) were far below effects range mean (ERM) (44,792), with levels of PAHs in Hong Kong to be lower than effects range low (ERL) (4022), indicating that PAHs in Hong Kong may pose little risk to biota in mangrove ecosystems [63, 108]. Li et al. (2014) explored PAH pollution in sediments of three mangrove swamps of Shenzhen, China, namely Futian, Baguang

**79**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

and Water-lands, and found that the mean concentrations of PAHs in Futian (4480) was higher than that in Baguang (1262) and Watersheds (2711) [109]. The higher levels of PAHs in Futian mangrove may be related to various anthropogenic activities, such as continuously discharges of domestic sewage from households and Fengtang River, effluents from industrial processes, construction of highways

In China including Hong Kong, Guangdong, Guangxi, Hainan and Fujian, levels of polychlorinated biphenyls (PCBs) in mangrove sediments ranged from 0.1 to 47 ng/g dry weight [110–113]. In general, PCB concentrations in mangrove sediments from Hong Kong, Shenzhen, and Zhuhai were relatively higher, indicating heavily PCBs-polluted mangrove sediments in the Pearl River Estuary to some extent [114]. The higher PCB levels in sediments from Pearl River Estuary could be linked to high density of electronic/electrical industries and electronic waste recycling

Other organic pollutants in mangrove sediment were limited. Total petroleum hydrocarbons (TPHs) in sediments were reported to be 32–579 mg/kg-dw and a higher level was observed in the Pearl River Estuary, China [82, 115], which mainly derived from vehicle exhausts and incomplete combustion [82, 88]. Tam et al. (2008) reported that the levels of dichlorodiphenyltrichloroethanes (DDTs) and hexachlor-

Although Chinese ecological policy was proposed, ecological and environmental education should be made for conservation and increasing ecological services of mangrove forests [31, 98, 117]. In China, the environmental education mainly focused on the popular science and propaganda of mangrove reserve and park [97, 118–120]. Since there are multiple education stations in China, we show an example of Shenzhen because mangrove species are applied as the symbolic woody plants for the city. The City Hall shows SDGs (sustainable developmental goals) to the public with both ordinal (indoor type) museum as well as field museum (outdoor type). The former exhibits basic information of mangrove ecosystem by indoor exhibition. The latter mainly shows 2 parts; one is a practical method of how to rehabilitate mangrove stand at water front and the other is to conduct ecological research, including pollination biology,

Shenzhen shows all aspects of mangrove conservation and the latest advances in natural education at the city museums. The museum is unique in interactive exhibits, such as many educational quizzes about how to develop mangrove forests as well as to conserve the ecosystem. There are two field museums on the coast of Shenzhen: (1) one is a kind of park to walk in mangrove stand along with the interior experience of different species of forest stands, and (2) the other is to show

**Figure 10A** showed the rehabilitation of mangrove stands in Futian mangrove in Shenzhen. In order to improve ecological function of mangroves [121], the rehabilitation of Geiwai pond in mangrove ecosystem was conducted (**Figure 10B**). Among

the ecological rehabilitation of mangrove stands (**Figure 10**).

cyclohexanes (HCHs) were 28 and 0.07 ng/g-dw in Leizhou Peninsula [116].

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

and heavy traffic [48].

activities [110].

**8. Education effort**

**8.1 General effort**

vegetation, etc.

**8.2 Indoor and outdoor exhibition**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

and Water-lands, and found that the mean concentrations of PAHs in Futian (4480) was higher than that in Baguang (1262) and Watersheds (2711) [109]. The higher levels of PAHs in Futian mangrove may be related to various anthropogenic activities, such as continuously discharges of domestic sewage from households and Fengtang River, effluents from industrial processes, construction of highways and heavy traffic [48].

In China including Hong Kong, Guangdong, Guangxi, Hainan and Fujian, levels of polychlorinated biphenyls (PCBs) in mangrove sediments ranged from 0.1 to 47 ng/g dry weight [110–113]. In general, PCB concentrations in mangrove sediments from Hong Kong, Shenzhen, and Zhuhai were relatively higher, indicating heavily PCBs-polluted mangrove sediments in the Pearl River Estuary to some extent [114]. The higher PCB levels in sediments from Pearl River Estuary could be linked to high density of electronic/electrical industries and electronic waste recycling activities [110].

Other organic pollutants in mangrove sediment were limited. Total petroleum hydrocarbons (TPHs) in sediments were reported to be 32–579 mg/kg-dw and a higher level was observed in the Pearl River Estuary, China [82, 115], which mainly derived from vehicle exhausts and incomplete combustion [82, 88]. Tam et al. (2008) reported that the levels of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorcyclohexanes (HCHs) were 28 and 0.07 ng/g-dw in Leizhou Peninsula [116].

#### **8. Education effort**

#### **8.1 General effort**

*Mangrove Ecosystem Restoration*

**7.2 Polybrominated diphenyl ethers (PBDEs)**

those of Shenzhen (2.1–1987.6) [102].

BGM ≈ FTM < XXM < SJM.

**7.3 Other POPs**

Unfortunately, polluted condition with MPs of mangrove forest is getting worse

in Shenzhen. As harmful MPs, PBDEs (polybrominated diphenyl ethers) have recently been detected. PBDEs are structurally similar to PCBs and other polyhalogenated compounds. Exposure to PBDEs would cause problems in the hormone system, liver and kidney morphology, neuro-behavioral and sexual development [100, 101]. The health risk of PBDEs and PCBs are increasing, and these chemical compounds have been shown to reduce human fertility to some extent [97]. The amount of PBDEs in a mangrove ecosystem increases with increasing amount of organic matters in soil [95, 102]. Concentration [unit: ng/g-dw] of PBDE-209 in mangrove stands of Hong Kong was 0.5 ~ 5.4 except for Mai Po mangrove (47.2– 112.0) opposite to Futian district of Shenzhen [103]. These values were lower than

In Shenzhen mangroves, the levels of PBDE-209 [unit: ng/g-dw] were 2.1 ~ 110.0 in mangrove sediment and 180 ~ 600 in the leaves. The highest value was detected as 3600 in bark of the avenue trees in Beijing [104]. We found that PBDE-209 was the dominant PBDE congener in all six mangroves in China, including Yunxiao, Futian, Zhanjiang, Fangchenggang, Dongzhaigang and Dongfang [5]. Futian mangrove in Shenzhen was seriously polluted by PBDEs (in particular PBDE-209), compared to the other 5 mangrove wetlands. Total organic matter acted as an effective factor in affecting spatial distribution and ecological risk of PBDEs in sediment of mangroves. In 6 mangroves, sediments may pose low/moderate risk of exposure to penta- and deca-BDE congeners for sediment-dwelling organisms, with penta- and deca-BDE congeners to be major drivers of ecological risk. Furthermore, we explored PBDEs contamination in 4 urban mangroves of Shenzhen, including Shajing mangrove (SJM), Xixiang mangrove (SJM), Futian mangrove (FTM) and Baguang mangrove (BGM) [102]. Regarding urban functional zoning, urban mangroves were featured with industry district (SJM and XXM), central business district (CBD) (FTM), and ecological preserve (BGM) [105–107]. Our result showed that the ranking order of PBDEs contamination in urban mangroves was

Compositions of PBDEs were complex in SJM, XXM, and FTM, with surface runoff to be the main source apportionment of PBDEs. Thus, in urban mangroves with different urban functional zonings, PBDEs accumulation in mangrove sediment and their bioaccumulation in mangrove plants were different. In the future, much work should be done to decrease e the input of PBDEs into the urban mangrove, such as the inspection of the illegal waste recycling sites and promotion of

Levels of polycyclic aromatic hydrocarbons (PAHs: unit: [ng/g-dw]) in mangrove sediments of China ranged from 15 to 11,098 and decreased in the order of Hong Kong (56–11,098) > Fujian (171–1074) > Guangdong (15–726) > Hainan (31–63) > Guangxi (24) [11, 12, 108]. Higher levels of PAH s in Hong Kong mangrove might be attributed to the intense anthropogenic activities. Levels of PAHs in mangrove sediments of China (24–11,098) were far below effects range mean (ERM) (44,792), with levels of PAHs in Hong Kong to be lower than effects range low (ERL) (4022), indicating that PAHs in Hong Kong may pose little risk to biota in mangrove ecosystems [63, 108]. Li et al. (2014) explored PAH pollution in sediments of three mangrove swamps of Shenzhen, China, namely Futian, Baguang

sewage treatment capacity of PBDEs-related enterprises.

**78**

Although Chinese ecological policy was proposed, ecological and environmental education should be made for conservation and increasing ecological services of mangrove forests [31, 98, 117]. In China, the environmental education mainly focused on the popular science and propaganda of mangrove reserve and park [97, 118–120]. Since there are multiple education stations in China, we show an example of Shenzhen because mangrove species are applied as the symbolic woody plants for the city. The City Hall shows SDGs (sustainable developmental goals) to the public with both ordinal (indoor type) museum as well as field museum (outdoor type). The former exhibits basic information of mangrove ecosystem by indoor exhibition. The latter mainly shows 2 parts; one is a practical method of how to rehabilitate mangrove stand at water front and the other is to conduct ecological research, including pollination biology, vegetation, etc.

#### **8.2 Indoor and outdoor exhibition**

Shenzhen shows all aspects of mangrove conservation and the latest advances in natural education at the city museums. The museum is unique in interactive exhibits, such as many educational quizzes about how to develop mangrove forests as well as to conserve the ecosystem. There are two field museums on the coast of Shenzhen: (1) one is a kind of park to walk in mangrove stand along with the interior experience of different species of forest stands, and (2) the other is to show the ecological rehabilitation of mangrove stands (**Figure 10**).

**Figure 10A** showed the rehabilitation of mangrove stands in Futian mangrove in Shenzhen. In order to improve ecological function of mangroves [121], the rehabilitation of Geiwai pond in mangrove ecosystem was conducted (**Figure 10B**). Among

#### **Figure 10.**

*Example of mangrove ecosystem rehabilitation in south China. (A) Rehabilitation of mangrove stand; (B) Rehabilitation of Geiwai pond of mangrove ecosystem; (C) Typical example of mangrove ecosystem plantations by Prof. Changyi Lu of Xianmen University.*

these trails, a distinguish exhibition for both tourists and education of mangrove park was established and popular trees were provided to the public near Xiamen, Fujian province, southeast China (**Figure 10C**). The star shaped mangrove restoration indicated that suitable mangrove species selection and planting design would create a beautiful landscape. This is a park showing a symbol of restoration success with mangrove.

#### **8.3 Non-Government Organization in education effect of mangrove**

The protection of mangrove in Shenzhen was closely related with large amounts of non-governmental organization (NGO) and volunteer groups. In 2017, the number of professional volunteers registered in Mangrove Conservation Foundation (MCF) exceeded 300, with 198 newly trained volunteer in one year, and 100,000 people participated in relevant activities in three years. In Shenzhen, China, the above-mentioned citizen acted as the volunteer labor group for Futian mangrove ecological park. These volunteers mainly come from enterprise, residence community and school, and took part in various environmental improvement activities,

#### **Figure 11.**

*Activities carried out by nongovernment organizations. (A) Marine protection activity; (B) vein painting of popular science education; (C) display board of natural education. All photos were offered by RL Li and MW Chai.*

**81**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

including cleaning of invasive plants, collection of marine garbage, replantation of

The implication of these activities increased volunteer number of mangrove protection in Shenzhen. Furthermore, there were also a certain number of volunteers in Overseas Chinese Town (OCT) wetland, Shenzhen Green Fund Association, Shenzhen Spring Environmental Protection Volunteer Association. Some activities related with mangrove education was implicated to improve protection awareness

Anthropogenic pollution in mangrove ecosystems has been intensively studied (including heavy metals and POPs, etc.) and consequently we can obtain many phenomena of current situation, such as sea level-rise [27, 122–124]. Based on the data of mangrove ecosystems in China, we should make further progress in increasing ecological services and forest rehabilitation. In the future, we believe that several aspects should be further explored to improve mangrove afforestation and restoration: (1) Ecological adaptation mechanism of mangrove species under various environmental stresses; (2) The development of mangrove plant breeding and colonization techniques; (3) The remediation of degraded mangrove ecosystem; (4) Digital technology research and development in mangrove ecological engineering.

Ecological exploitation of mangrove would create better ecological environment, economic and social benefits, being important for sustainable development of mangrove resource in the future. Several countermeasures are included to engage ecological exploitation of mangroves: coordinating development and alleviating the contradiction between protection and development; promoting diversified ecological development based on local conditions; improving the economic benefits of ecological development by scientific evaluation; improving relevant policies and plans while promoting regional cooperation and scientific research. We hope our data may contribute for improving restoration practices in the rapid economic

This work was supported by the Program of Science and Technology of Shenzhen (JCYJ20160330095549229, JSGG20170413103811649), Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution Control (18K05ESPCP), and Shenzhen Municipal Development and Reform Commission (Discipline construction of watershed ecological engineering). We thank Emeritus Prof. A. Hagihara of The Univ. of Ryukyu for his kind permission to modify his

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

of mangrove protection (**Figure 11**).

**9. Future perspective**

development regions.

**Acknowledgements**

original figures to cite in the text.

plant, and construction of ecological floating island, etc.

#### *Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

including cleaning of invasive plants, collection of marine garbage, replantation of plant, and construction of ecological floating island, etc.

The implication of these activities increased volunteer number of mangrove protection in Shenzhen. Furthermore, there were also a certain number of volunteers in Overseas Chinese Town (OCT) wetland, Shenzhen Green Fund Association, Shenzhen Spring Environmental Protection Volunteer Association. Some activities related with mangrove education was implicated to improve protection awareness of mangrove protection (**Figure 11**).

#### **9. Future perspective**

*Mangrove Ecosystem Restoration*

*plantations by Prof. Changyi Lu of Xianmen University.*

with mangrove.

**Figure 10.**

these trails, a distinguish exhibition for both tourists and education of mangrove park was established and popular trees were provided to the public near Xiamen, Fujian province, southeast China (**Figure 10C**). The star shaped mangrove restoration indicated that suitable mangrove species selection and planting design would create a beautiful landscape. This is a park showing a symbol of restoration success

*Example of mangrove ecosystem rehabilitation in south China. (A) Rehabilitation of mangrove stand; (B) Rehabilitation of Geiwai pond of mangrove ecosystem; (C) Typical example of mangrove ecosystem* 

The protection of mangrove in Shenzhen was closely related with large amounts of non-governmental organization (NGO) and volunteer groups. In 2017, the number of professional volunteers registered in Mangrove Conservation Foundation (MCF) exceeded 300, with 198 newly trained volunteer in one year, and 100,000 people participated in relevant activities in three years. In Shenzhen, China, the above-mentioned citizen acted as the volunteer labor group for Futian mangrove ecological park. These volunteers mainly come from enterprise, residence community and school, and took part in various environmental improvement activities,

*Activities carried out by nongovernment organizations. (A) Marine protection activity; (B) vein painting of popular science education; (C) display board of natural education. All photos were offered by RL Li and MW* 

**8.3 Non-Government Organization in education effect of mangrove**

**80**

*Chai.*

**Figure 11.**

Anthropogenic pollution in mangrove ecosystems has been intensively studied (including heavy metals and POPs, etc.) and consequently we can obtain many phenomena of current situation, such as sea level-rise [27, 122–124]. Based on the data of mangrove ecosystems in China, we should make further progress in increasing ecological services and forest rehabilitation. In the future, we believe that several aspects should be further explored to improve mangrove afforestation and restoration: (1) Ecological adaptation mechanism of mangrove species under various environmental stresses; (2) The development of mangrove plant breeding and colonization techniques; (3) The remediation of degraded mangrove ecosystem; (4) Digital technology research and development in mangrove ecological engineering.

Ecological exploitation of mangrove would create better ecological environment, economic and social benefits, being important for sustainable development of mangrove resource in the future. Several countermeasures are included to engage ecological exploitation of mangroves: coordinating development and alleviating the contradiction between protection and development; promoting diversified ecological development based on local conditions; improving the economic benefits of ecological development by scientific evaluation; improving relevant policies and plans while promoting regional cooperation and scientific research. We hope our data may contribute for improving restoration practices in the rapid economic development regions.

#### **Acknowledgements**

This work was supported by the Program of Science and Technology of Shenzhen (JCYJ20160330095549229, JSGG20170413103811649), Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution Control (18K05ESPCP), and Shenzhen Municipal Development and Reform Commission (Discipline construction of watershed ecological engineering). We thank Emeritus Prof. A. Hagihara of The Univ. of Ryukyu for his kind permission to modify his original figures to cite in the text.

*Mangrove Ecosystem Restoration*

#### **Author details**

Ruili Li1 \*, Minwei Chai1 , Xiaoxue Shen1 , Cong Shi1 , Guoyu Qiu1 and Takayoshi Koike1,2\*

1 School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, China

2 Research Faculty of Agriculture, Hokkaido University, Japan

\*Address all correspondence to: liruili@pkusz.edu.cn and tkoike@for.agr.hokudai.ac.jp

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**83**

abstract).

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

Plastic resin pellets as a transport medium for toxic chemicals in the marine environment. Environmental Science & Technology, 2001; **35**: 318-324.

[9] Takada H. Chemical substances pollution and micro plastic problems from the view point of matter cycling. Environ Information Science, 2019; **46**:

[10] Li MS, Lee SY. Mangroves of China; a brief review. Forest Ecology and Management, 1997; **96**: 241-259.

[12] Zhang ZW, Xu XR, Sun YX, Yu S, Chen YS, Peng JX. Heavy metal and organic contaminants in mangrove ecosystems of China: a review. Environmental Science and Pollution Research, 2014; **21:** 11938-11950.

[13] Bourgeois C, Alfaro AC, Brown AD, Duprey JL, Denudes A, Marchand C. Stocks and soil-plant transfer of macronutrients and trace metals in temperature New Zealand estuarine mangroves. Plant

and Soil, 2019; **436**: 565-586.

2017; **125**: 472-480.

[14] Analuddin K, Sharma S, Jamili, Septiana A, Sahidin I, Rianse U,

[15] Marchand C, Allenbach M, Vergès EL. Relationships between heavy metals distribution and organic matter cycling in mangrove sediments (Conception Bay, New Caledonia). Geoderma, 2011; **160**: 444-456.

Nadaoka K. Heavy metal bioaccumulation in mangrove ecosystem at the coral triangle ecoregion, Southeast Sulawesi, Indonesia. Marine Pollution Bulletin,

12-16. (in Japanese).

**27:** 42-53.

[11] Tam NFY, Fang Z, Yu S. Heavy metals, polycyclic aromatic hydrocarbons and organochlorine pesticides in the surface sediments of mangrove swamps from coastal sites along the Leizhou Pennsula, South China. Acta Oceanologica Sinica, 2008;

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

[1] Rivera-Monroy VH, Lee S-Y, Kristensen E, Twilley RR. Mangrove Ecosystems: A lobal Biogeographic Perspective -Structure, Function, and Services-, 2017; pp.381. Springer

[2] Sharma S. Introductory Chapter: Mangrove Ecosystem Research Trends - Where has the Focus been So Far, *In*: Mangrove Ecosystem Ecology and Function, 2018; **DOI:** 10.5772/

[3] Wu SJ, Li RL, Xie SG, Shi C. Depthrelated change of sulfate-reducing bacteria community in mangrove sediments: The influence of heavy metal contamination. Marine Pollution

Bulletin, 2019; **140**: 443-450.

[4] Faridah-Hanum I, Latiff A, Hakeem KR, Őzturk M. Mangrove Ecosystems of Asia- Status, Challenges and Management Strategies-, 2014;

[5] MA (Millennium ecosystem assessment). Ecosystems and human well-being: Current state and trends: Chapter **22** dryland systems. Island

[6] Wang YN, Fu XM, Shao CL, Wang CY, Li GQ , Liu GX, Sun SC, Zeng XQ , Ye ZJ, Guan HS. Investigation on the status of mangrove resources and medicinal research in China I. Ecological functions and values. Periodical of Ocean University of China, 2009; **39**: 699-704 (in Chinese with English

[7] Koike T. Research activities of mangrove ecosystems in south China with special references to heavy metal pollution. Japanese Journal of International Forest and Forestry, 2019;

**106**:8-13 (in Japanese).

[8] Mato Y, Isobe T, Takada H, Kanehiro H, Ohtake C, Kaminuma T.

Springer-Verlag, pp. 453.

Press, 2005; pp. 623-662.

Verlag.

**References**

intechopen.80962.

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

#### **References**

*Mangrove Ecosystem Restoration*

**82**

**Author details**

Takayoshi Koike1,2\*

Guangdong, China

\*, Minwei Chai1

and tkoike@for.agr.hokudai.ac.jp

provided the original work is properly cited.

, Xiaoxue Shen1

2 Research Faculty of Agriculture, Hokkaido University, Japan

\*Address all correspondence to: liruili@pkusz.edu.cn

, Cong Shi1

1 School of Environment and Energy, Peking University Shenzhen Graduate School,

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

, Guoyu Qiu1

and

Ruili Li1

[1] Rivera-Monroy VH, Lee S-Y, Kristensen E, Twilley RR. Mangrove Ecosystems: A lobal Biogeographic Perspective -Structure, Function, and Services-, 2017; pp.381. Springer Verlag.

[2] Sharma S. Introductory Chapter: Mangrove Ecosystem Research Trends - Where has the Focus been So Far, *In*: Mangrove Ecosystem Ecology and Function, 2018; **DOI:** 10.5772/ intechopen.80962.

[3] Wu SJ, Li RL, Xie SG, Shi C. Depthrelated change of sulfate-reducing bacteria community in mangrove sediments: The influence of heavy metal contamination. Marine Pollution Bulletin, 2019; **140**: 443-450.

[4] Faridah-Hanum I, Latiff A, Hakeem KR, Őzturk M. Mangrove Ecosystems of Asia- Status, Challenges and Management Strategies-, 2014; Springer-Verlag, pp. 453.

[5] MA (Millennium ecosystem assessment). Ecosystems and human well-being: Current state and trends: Chapter **22** dryland systems. Island Press, 2005; pp. 623-662.

[6] Wang YN, Fu XM, Shao CL, Wang CY, Li GQ , Liu GX, Sun SC, Zeng XQ , Ye ZJ, Guan HS. Investigation on the status of mangrove resources and medicinal research in China I. Ecological functions and values. Periodical of Ocean University of China, 2009; **39**: 699-704 (in Chinese with English abstract).

[7] Koike T. Research activities of mangrove ecosystems in south China with special references to heavy metal pollution. Japanese Journal of International Forest and Forestry, 2019; **106**:8-13 (in Japanese).

[8] Mato Y, Isobe T, Takada H, Kanehiro H, Ohtake C, Kaminuma T. Plastic resin pellets as a transport medium for toxic chemicals in the marine environment. Environmental Science & Technology, 2001; **35**: 318-324.

[9] Takada H. Chemical substances pollution and micro plastic problems from the view point of matter cycling. Environ Information Science, 2019; **46**: 12-16. (in Japanese).

[10] Li MS, Lee SY. Mangroves of China; a brief review. Forest Ecology and Management, 1997; **96**: 241-259.

[11] Tam NFY, Fang Z, Yu S. Heavy metals, polycyclic aromatic hydrocarbons and organochlorine pesticides in the surface sediments of mangrove swamps from coastal sites along the Leizhou Pennsula, South China. Acta Oceanologica Sinica, 2008; **27:** 42-53.

[12] Zhang ZW, Xu XR, Sun YX, Yu S, Chen YS, Peng JX. Heavy metal and organic contaminants in mangrove ecosystems of China: a review. Environmental Science and Pollution Research, 2014; **21:** 11938-11950.

[13] Bourgeois C, Alfaro AC, Brown AD, Duprey JL, Denudes A, Marchand C. Stocks and soil-plant transfer of macronutrients and trace metals in temperature New Zealand estuarine mangroves. Plant and Soil, 2019; **436**: 565-586.

[14] Analuddin K, Sharma S, Jamili, Septiana A, Sahidin I, Rianse U, Nadaoka K. Heavy metal bioaccumulation in mangrove ecosystem at the coral triangle ecoregion, Southeast Sulawesi, Indonesia. Marine Pollution Bulletin, 2017; **125**: 472-480.

[15] Marchand C, Allenbach M, Vergès EL. Relationships between heavy metals distribution and organic matter cycling in mangrove sediments (Conception Bay, New Caledonia). Geoderma, 2011; **160**: 444-456.

[16] Chai MW, Li RL, Shi C, Shen XX, Li RY, Zan QJ. Contamination of polybrominated diphenyl ethers (PBDEs) in urban mangroves of Southern China. Science of the Total Environment, 2019a; **646:** 390-399.

[17] Chai MW, Li RL, Ding H, Zan QJ. Occurrence and contamination of heavy metals in urban mangroves: A case study in Shenzhen, China. Chemosphere, 2019b; **219**:165-173.

[18] Ding H, Chai MW, Gong Y, Li RL. Reviews on organic pollution in mangrove wetlands. Marine Environmental Science, 2019; **38**:153-160 (in Chinese with English abstract).

[19] Poungparn S, Komiyama A, Sangteian T, Maknual C, Patanaponpaiboon P, Suchewaboripont V. High primary productivity under submerged soil raises the net ecosystem productivity of a secondary mangrove forest in eastern Thailand. Journal of Tropical Ecology, 2012; **28**: 303-306.

[20] Abino AC, Castillo JAA, Lee YJ. Assessment of species diversity, biomass and carbon sequestration potential of a natural mangrove stand in Samar, the Philippines. Forest Science and Technology, 2014; **10**: 2-8.

[21] Kamruzzaman M, Mouctar K, Sharma S, Osawa A. Comparison of biomass and net primary productivity among three species in a subtropical mangrove forest at Manko Wetland, Okinawa, Japan. Regional Studies in Marine Science, 2019; **25**: 100475.

[22] Nordhaus I, Yoben M, Fauziyah A. Impact of deforestation on mangrove tree diversity, biomass and community dynamics in the Segara Anakan lagoon, Java, Indonesia: A ten-year perspective. Estuarine, Coastal and Shelf Science, 2019; **227:** 106300.

[23] Komiyama A, Ong JE, Pounngparn S. Allometry, biomass, and productivity of Mangrove forest: A review. Aquatic Botany, 2008; **89**: 128-137.

[24] Nakamura T, Nakasuka T. An introduction to Mangrove - Green forest stand in a sea, 1998; pp. 243, Mekon Publisher, Okinawa, (in Japanese).

[25] Ogino K. Biological processes and regulation mechanism of Mangrove ecosystem in Asian Pacific Ocean. 1990; pp. 116, Final report of KAKEN (Scientific aid by JSPS) No. 63041095.

[26] Komiyama A. Mangrove forests: changing forest ecosystem along seacoast, 2017; pp. 273, Kyoto University Publisher, pp. 273. (in Japanese).

[27] Schuerch M, Spencer T, Temmerman S, Kirwan ML, Wolff C, Lincke D, McOwen CJ. Future response of global wetlands to sea-level rise. Nature, 2018; **561**: 231-234.

[28] Wang WQ, Yan ZZ, Zhang YH, Chen LZ, Lin GH. Mangroves: obligate or facultative halophytes? A review. Trees, 2011; **25**: 953-963.

[29] Tikumporn A, Vipak J, Kwanchai D. Some environmental factors relating growth of *Avicennia alba* Bl. and *Avicemmia marina* (Forsk.) Vierh. Proceeding of 48th Kasetsart University Annual Conference: Natural Resources and Environment, 2010; **48**: 132-139.

[30] Toma T. Ecological study on water quality and soil condition with development of rhizosphere of Mangrove ecosystem. PhD dissertation of United Graduate School of Agriculture of Ehime University, 1992; pp.125, (in Japanese with English abstract).

[31] Tomlinson PB. The Botany of Mangroves, 2nd ed. Cambridge University Press, 2016; pp.432.

**85**

**90**: 774-783.

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

[40] Zhao S, Hong HS, Zhang LP, Chen WQ. Emergy value of mangrove ecosystem services in China. Resources Science, 2007; **29**: 147-154 (in Chinese

Guntenspergen GR, Krauss KW,

[41] Lovelock CE, Cahoon DR, Friess DA,

Reef R, Rogers K, Saunders ML, Sidik F, Swales A, Saintilan N, Thuyen LX, Triet T, The vulnerability of Indo-Pacific mangrove forests to sea-level rise. 2015;

[42] Pickering MD, Reef R, Vafeidis AT, Hinkel J, Nicholls RJ, Brown S. Future response of global coastal wetlands to sea-level rise. Nature, 2018; **561**: https:// doi.org/ 10.1038/s41586-018-0476-5

[43] Soper FM, MacKenzie RA, Sharma S, Cole TG, Litton CM, Sparks JP. Non-native mangroves support carbon storage, sediment carbon burial, and accretion of coastal ecosystems, Global Change Biology, 2019; **25**: https://doi.org/10.1111/

[44] Friess DA, Krauss KW, Horstman EM, Balk T, Bouma TJ, Galli D, Webb EL. Are all intertidal wetlands naturally created equal? Bottlenecks, thresholds and knowledge gaps to mangrove and saltmarsh ecosystems. Biological Reviews of the Cambridge Philosophical Society, 2012;

[45] Saintilan N, Khan NS, Ashe E, Kelleway JJ, Rogers K, Woodroffe CD, Horton BP. Thresholds of mangrove survival under rapid sea level rise. Science, 2020; **368**: 1118-1121.

[46] Hogarth PJ. The Biology of

Oxford University Press, 304pp.

Mangroves and Seagrasses, 3rd ed, 2015;

[47] Wang WQ, Wang M. The mangroves of China, 2007; pp.186, Scientific Publisher, Beijing (in Chinese).

with English abstract).

Nature, **526**: 559-563.

gcb.14813.

**87**: 346-366.

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

[32] Wang M, Wang WQ, Lin GS. Sanya Mangrove forest, 2019; pp.202. Scientific Publisher, Beijing (in

[33] Xu L, Wang M, Xin CP, Liu C, Wang WQ. Mangrove distribution in relation to seasonal water salinity and ion compartmentation: a field study along a freshwater dominated river. Hydrobiologia, 2019; https://doi. org/10.1007/s10750-019-04119-7

[34] Kitao M, Utsugia H, Kuramoto S,

photosynthetic characteristics indicated by chlorophyll fluorescence in five mangrove species native to Pohnpei Island, Micronesia. Physiologia Plantarum, 2003; **117**: 376-382.

[35] Hagihara A. Mangrove stands as carbon storage. *In*: The 21st century COE of The Univ of Ryukyu (ed.) Biodiversity of coral reef and island ecosystems of the Ryukyu, 2006; 258-277, Tokai University Press

[36] Hoque ATMR, Sharma S,

Hagihara A. Above and belowground carbon acquisition of mangrove *Kandelia obovata* trees in Manko wetland, Okinawa, Japan. International Journal of Environment, 2011; **1**: 7-13.

[37] Suwa R. The Production Ecology of a subtropical mangrove in Manko Wetland on Okinawa Island, Tropical

[39] Rajendran CP. Historical accounts of sea disturbances from South India and their bearing on the penultimate predecessor of the 2004 Tsunami. Seismological Research Letters, 2019;

Ecology Letters, 2013; **90**: 2-9.

[38] Birkland TA, Herabat P, Little RG, Wallace WA. The impact of the December 2004 Indian Ocean tsunami on tourism in Thailand. Earthquake Spectra, 2006; **22**: 889-900.

Tabuchi T, Fujimoto K, Lihpaid S. Light-dependent

(in Japanese).

Chinese).

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

[32] Wang M, Wang WQ, Lin GS. Sanya Mangrove forest, 2019; pp.202. Scientific Publisher, Beijing (in Chinese).

*Mangrove Ecosystem Restoration*

[16] Chai MW, Li RL, Shi C, Shen XX, Li RY, Zan QJ. Contamination of polybrominated diphenyl ethers (PBDEs) in urban mangroves of Southern China. Science of the Total Environment, 2019a; **646:** 390-399.

[23] Komiyama A, Ong JE,

128-137.

Pounngparn S. Allometry, biomass, and productivity of Mangrove forest: A review. Aquatic Botany, 2008; **89**:

[24] Nakamura T, Nakasuka T. An introduction to Mangrove - Green forest stand in a sea, 1998; pp. 243, Mekon Publisher, Okinawa, (in Japanese).

[25] Ogino K. Biological processes and regulation mechanism of Mangrove ecosystem in Asian Pacific Ocean. 1990; pp. 116, Final report of KAKEN (Scientific aid by JSPS) No. 63041095.

[26] Komiyama A. Mangrove forests: changing forest ecosystem along

Publisher, pp. 273. (in Japanese).

[27] Schuerch M, Spencer T,

Nature, 2018; **561**: 231-234.

Trees, 2011; **25**: 953-963.

seacoast, 2017; pp. 273, Kyoto University

Temmerman S, Kirwan ML, Wolff C, Lincke D, McOwen CJ. Future response of global wetlands to sea-level rise.

[28] Wang WQ, Yan ZZ, Zhang YH, Chen LZ, Lin GH. Mangroves: obligate or facultative halophytes? A review.

[29] Tikumporn A, Vipak J, Kwanchai D. Some environmental factors relating growth of *Avicennia alba* Bl. and *Avicemmia marina* (Forsk.) Vierh. Proceeding of 48th Kasetsart University Annual Conference: Natural Resources and Environment, 2010; **48**: 132-139.

[30] Toma T. Ecological study on water quality and soil condition with development of rhizosphere of Mangrove ecosystem. PhD

[31] Tomlinson PB. The Botany of Mangroves, 2nd ed. Cambridge University Press, 2016; pp.432.

abstract).

dissertation of United Graduate School of Agriculture of Ehime University, 1992; pp.125, (in Japanese with English

[17] Chai MW, Li RL, Ding H, Zan QJ. Occurrence and contamination of heavy metals in urban mangroves: A case study in Shenzhen, China. Chemosphere,

[18] Ding H, Chai MW, Gong Y, Li RL. Reviews on organic pollution in mangrove wetlands. Marine Environmental Science, 2019; **38**:153-160 (in Chinese with English

[19] Poungparn S, Komiyama A, Sangteian T, Maknual C, Patanaponpaiboon P,

Suchewaboripont V. High primary productivity under submerged soil raises the net ecosystem productivity of a secondary mangrove forest in eastern Thailand. Journal of Tropical Ecology,

[20] Abino AC, Castillo JAA, Lee YJ. Assessment of species diversity, biomass and carbon sequestration potential of a natural mangrove stand in Samar, the Philippines. Forest Science and

[21] Kamruzzaman M, Mouctar K, Sharma S, Osawa A. Comparison of biomass and net primary productivity among three species in a subtropical mangrove forest at Manko Wetland, Okinawa, Japan. Regional Studies in Marine Science, 2019; **25**: 100475.

[22] Nordhaus I, Yoben M, Fauziyah A. Impact of deforestation on mangrove tree diversity, biomass and community dynamics in the Segara Anakan lagoon, Java, Indonesia: A ten-year perspective. Estuarine, Coastal and Shelf Science,

Technology, 2014; **10**: 2-8.

2019b; **219**:165-173.

abstract).

2012; **28**: 303-306.

**84**

2019; **227:** 106300.

[33] Xu L, Wang M, Xin CP, Liu C, Wang WQ. Mangrove distribution in relation to seasonal water salinity and ion compartmentation: a field study along a freshwater dominated river. Hydrobiologia, 2019; https://doi. org/10.1007/s10750-019-04119-7

[34] Kitao M, Utsugia H, Kuramoto S, Tabuchi T, Fujimoto K, Lihpaid S. Light-dependent photosynthetic characteristics indicated by chlorophyll fluorescence in five mangrove species native to Pohnpei Island, Micronesia. Physiologia Plantarum, 2003; **117**: 376-382.

[35] Hagihara A. Mangrove stands as carbon storage. *In*: The 21st century COE of The Univ of Ryukyu (ed.) Biodiversity of coral reef and island ecosystems of the Ryukyu, 2006; 258-277, Tokai University Press (in Japanese).

[36] Hoque ATMR, Sharma S, Hagihara A. Above and belowground carbon acquisition of mangrove *Kandelia obovata* trees in Manko wetland, Okinawa, Japan. International Journal of Environment, 2011; **1**: 7-13.

[37] Suwa R. The Production Ecology of a subtropical mangrove in Manko Wetland on Okinawa Island, Tropical Ecology Letters, 2013; **90**: 2-9.

[38] Birkland TA, Herabat P, Little RG, Wallace WA. The impact of the December 2004 Indian Ocean tsunami on tourism in Thailand. Earthquake Spectra, 2006; **22**: 889-900.

[39] Rajendran CP. Historical accounts of sea disturbances from South India and their bearing on the penultimate predecessor of the 2004 Tsunami. Seismological Research Letters, 2019; **90**: 774-783.

[40] Zhao S, Hong HS, Zhang LP, Chen WQ. Emergy value of mangrove ecosystem services in China. Resources Science, 2007; **29**: 147-154 (in Chinese with English abstract).

[41] Lovelock CE, Cahoon DR, Friess DA, Guntenspergen GR, Krauss KW, Reef R, Rogers K, Saunders ML, Sidik F, Swales A, Saintilan N, Thuyen LX, Triet T, The vulnerability of Indo-Pacific mangrove forests to sea-level rise. 2015; Nature, **526**: 559-563.

[42] Pickering MD, Reef R, Vafeidis AT, Hinkel J, Nicholls RJ, Brown S. Future response of global coastal wetlands to sea-level rise. Nature, 2018; **561**: https:// doi.org/ 10.1038/s41586-018-0476-5

[43] Soper FM, MacKenzie RA, Sharma S, Cole TG, Litton CM, Sparks JP. Non-native mangroves support carbon storage, sediment carbon burial, and accretion of coastal ecosystems, Global Change Biology, 2019; **25**: https://doi.org/10.1111/ gcb.14813.

[44] Friess DA, Krauss KW, Horstman EM, Balk T, Bouma TJ, Galli D, Webb EL. Are all intertidal wetlands naturally created equal? Bottlenecks, thresholds and knowledge gaps to mangrove and saltmarsh ecosystems. Biological Reviews of the Cambridge Philosophical Society, 2012; **87**: 346-366.

[45] Saintilan N, Khan NS, Ashe E, Kelleway JJ, Rogers K, Woodroffe CD, Horton BP. Thresholds of mangrove survival under rapid sea level rise. Science, 2020; **368**: 1118-1121.

[46] Hogarth PJ. The Biology of Mangroves and Seagrasses, 3rd ed, 2015; Oxford University Press, 304pp.

[47] Wang WQ, Wang M. The mangroves of China, 2007; pp.186, Scientific Publisher, Beijing (in Chinese).

[48] Li RL, Chai MW, Qiu GY. Distribution, fraction, and ecological assessment of heavy metals in sedimentplant system in mangrove forest, South China Sea. Plos One, 2016; DOI:10.1371/ journal.pone.0147308.

[49] Koike T, Wang YN. A report of the meeting on mangrove ecosystem organized by Ecological Society of China. Japanese Journal of International Forest and Forestry, 2020; **107**: 28-33, (in Japanese).

[50] Fu XM, Wang YN, Shao CL, Wang CY, Li GQ , Liu GX, Sun SC, Zeng XQ , Ye ZJ, Guan HS. Investigation on the status of mangrove resources and medicinal research in China. II. Resources status, protection and management. Periodical of Ocean University of China, 2009; **39**: 705-711.

[51] Shao CL, Fu XM, Wang CY, Han L, Liu X, Fang YC, Li GQ , Liu GX, Guan HS. Investigation on the status of mangrove resources and medicinal research in China. III. Status of folk medicinal usage and medicinal research. Periodical of Ocean University of China, 2009; **39**: 712-718.

[52] Fan HQ, Wang WQ, Some thematic issues for mangrove conservation in China. Journal of Xiamen University (Natural Science), 2017; **56**: 323-330.

[53] Chen LZ, Wang WQ, Zhang YH, Lin GH. Recent progresses in mangrove conservation, restoration and research in China. Journal of Plant Ecology, 2009; **2:** 45-54 (in Chinese with English abstract).

[54] Chinese Ecological Society (Mangrove ecology WG). Program of working meeting of Chinese mangrove research group. Graduate School of Resources and Environment of Xiamen University, 2019; **9:** 1-19, (in Chinese).

[55] Chen QX, Zheng J, Zhou WP, Wang JW, Yang S, Li XW, Lu X, Liu XA. New *Kandelia obovata* Cultivar 'Longgang', Acta Horticulturae Sinica, 2019; **46**: 2927-2928 (in Chinese with English abstract).

[56] Lu X, Liu X, Wang JW, Yang S, Zhang LN, Ji HJ. Study on overwintering methods for introduced *Kandelia obovata* in Jiangsu Province. Forestry Science & Technology 2019; **44**: 15-17. (in Chinese with English abstract).

[57] Hayes MA, Shor AC, Jesse A, Miller C, Kennedy JP, Feller I. The role of glycine betaine in range expansions; protecting mangroves against extreme freeze events. Journal of Ecology, 2019; **108**: Doi.org/10.1111/1365-2745.13243.

[58] Shi C, Ding H, Zan QJ, Li RL. Spatial variation and ecological risk assessment of heavy metals in mangrove sediments across China. Marine Pollution Bulletin, 2019; **143**: 115-124.

[59] Abrahim GMS, Parker RJ, Nichol SL. Distribution and assessment of sediment toxicity in Tamaki Estuary, Auckland, New Zealand. Environmental Geology, 2007; **52**: 1315-1323.

[60] Horiguchi H, Teranishi H, Niiya K, Aoshima K, Katoh T, Sakuragawa N, Kasuya M. Hypoproduction of erythropoietin contributes to anemia in chronic cadmium intoxication: clinical study on Itai-itai disease in Japan. Archives of Toxicology, 1994; **68**: 632-636.

[61] Sundaramanickam A, Shanmugam N, Cholan S, Kumaresan S, Madeswaran P, Balasubramanian T. Spatial variability of heavy metals in estuarine, mangrove and coastal ecosystems along Parangipettai, Southeast coast of India. Environmental Pollution 2016; **218**: 186-195.

**87**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

Journal of Geochemistry Exploration,

[70] Sterckeman T, Goderniaux M, Sirguey C, Cornu JY, Nguyen C. Do roots or shoots control cadmium accumulation in the hyperaccumulator *Noccaea caerulescens*? Plant and Soil,

[71] Hu YN, Cheng HF, Tao S. The challenges and solutions for cadmiumcontaminated rice in China: a critical review. Environment International,

[72] Farooq MA, Ali S, Hameed A,

Ishaque W, Farid M, Mahmood K, Iqbal Z. Cadmium stress in cotton seedlings: physiological, photosynthesis and oxidative damages alleviated by glycinebetaine. South African Journal of Botany, 2016; **104:**

[73] Lovelock CE, Ball MC, Martin KC, Feller IC. Nutrient enrichment increases mortality of mangroves. PLoS One,

accumulation, subcellular distribution and chemical forms of cadmiu*m in Kandelia obovata*? Ecotoxicology and Environmental Safety, 2018; **162:**

[74] Chai MW, Li RY, Shen XX, Tam NFY, Zan QJ, Li RL. Does ammonium nitrogen affect

[75] Qiu GY, Omasa K, Sase S. An infrared-based coefficient to screen plant environmental stress: concept, test and applications. Functional Plant

[76] Shen XX, Li RL, Chai MW, Yu K, Zan QJ, Qiu GY. Assessing the effect of extra nitrogen on *Kandelia obovata* growth under cadmium stress using high-resolution thermal infrared remote sensing and the three-temperature

Biology, 2009; **36**: 990-997.

2012; **119/120**: 32-43.

2015; **392**: 87-99.

2016; **92-93**: 515-513.

61-68.

2012; **4:** 5600.

430-437.

Bharwana SA, Rizwan M,

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

[62] Bernhoft RA. Cadmium Toxicity and Treatment, Hindawi Publishing Corporation. The Scientific World Journal, 2013; Article ID **394652**, https://doi.org/10.1155/2013/394652

[63] Xie HW, Wen B, Guo Y, Shi YZ, Wu YH. Community characteristics and distribution of metal elements in mangroves in Futian of Shenzhen, China. Guihaia, 2010; **30:** 64-69 (in Chinese with English abstract).

[64] Zhang ZH, Hu G, Liang SC. Mangrove resources and conservation in Guangxi. Marine Environmental

Science, 2007; **26:** 275-279.

[65] Long ER, MacDonald DD, Smith SL, Calder FD. Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments. Environmental

Management, 1995; **19**: 81-97.

English abstract).

[67] Li RY, Li RL, Chai MW,

[66] Sugiura K, Muwamura K, Wu DD, Wang J, Wangang D, Konohira Y,

Nakayama Y. Reclamation and subsequent change of land use of mangrove forests in the northern part of Hainan Island, P. R. China. Journal of Forest Planning, 2007; **41**: 271-280. (in Japanese with

Shen XX, Xu HL, Qiu GY. Heavy metal contamination and ecological risk in Futian mangrove forest sediment in Shenzhen Bay, South China. Marine Pollution Bulletin, 2015; **101:** 448-456.

[68] Tam NFY, Li SH, Lan CY, Chen GZ, Li MS, Wong YS. Nutrients and heavy metal contamination of plants and sediments in Futian mangrove forest. Hydrobiologia, 1995; **295:** 149-158.

[69] Guillén MT, Delgado J, Albanese S, Nieto JM, Lima A, Vivo BD. Heavy metals fractionation and multivariate statistical techniques to evaluate the environmental risk soils of Huelva Township (SW Iberian Peninsula).

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

[62] Bernhoft RA. Cadmium Toxicity and Treatment, Hindawi Publishing Corporation. The Scientific World Journal, 2013; Article ID **394652**, https://doi.org/10.1155/2013/394652

*Mangrove Ecosystem Restoration*

[48] Li RL, Chai MW, Qiu GY.

journal.pone.0147308.

(in Japanese).

Distribution, fraction, and ecological assessment of heavy metals in sedimentplant system in mangrove forest, South China Sea. Plos One, 2016; DOI:10.1371/

[55] Chen QX, Zheng J, Zhou WP, Wang JW, Yang S, Li XW, Lu X, Liu XA. New *Kandelia obovata* Cultivar 'Longgang', Acta Horticulturae Sinica, 2019; **46**: 2927-2928 (in Chinese with

[56] Lu X, Liu X, Wang JW, Yang S, Zhang LN, Ji HJ. Study on overwintering methods for introduced *Kandelia obovata* in Jiangsu Province. Forestry Science & Technology 2019; **44**: 15-17. (in Chinese with English

[57] Hayes MA, Shor AC, Jesse A, Miller C, Kennedy JP, Feller I. The role of glycine betaine in range expansions; protecting mangroves against extreme freeze events. Journal of Ecology, 2019; **108**: Doi.org/10.1111/1365-2745.13243.

[58] Shi C, Ding H, Zan QJ, Li RL. Spatial variation and ecological risk assessment of heavy metals in mangrove sediments across China. Marine Pollution Bulletin,

Nichol SL. Distribution and assessment of sediment toxicity in Tamaki Estuary, Auckland, New Zealand. Environmental

English abstract).

abstract).

2019; **143**: 115-124.

[59] Abrahim GMS, Parker RJ,

Geology, 2007; **52**: 1315-1323.

[60] Horiguchi H, Teranishi H, Niiya K, Aoshima K, Katoh T, Sakuragawa N, Kasuya M.

Toxicology, 1994; **68**: 632-636.

[61] Sundaramanickam A,

Pollution 2016; **218**: 186-195.

Hypoproduction of erythropoietin contributes to anemia in chronic cadmium intoxication: clinical study on Itai-itai disease in Japan. Archives of

Shanmugam N, Cholan S, Kumaresan S, Madeswaran P, Balasubramanian T. Spatial variability of heavy metals in estuarine, mangrove and coastal ecosystems along Parangipettai,

Southeast coast of India. Environmental

[49] Koike T, Wang YN. A report of the meeting on mangrove ecosystem organized by Ecological Society of China. Japanese Journal of International Forest and Forestry, 2020; **107**: 28-33,

[50] Fu XM, Wang YN, Shao CL, Wang CY, Li GQ , Liu GX, Sun SC, Zeng XQ , Ye ZJ, Guan HS. Investigation on the status of mangrove resources and medicinal research in China. II. Resources status, protection and management. Periodical of Ocean University of China, 2009; **39**: 705-711.

[51] Shao CL, Fu XM, Wang CY,

2009; **39**: 712-718.

Han L, Liu X, Fang YC, Li GQ , Liu GX, Guan HS. Investigation on the status of mangrove resources and medicinal research in China. III. Status of folk medicinal usage and medicinal research. Periodical of Ocean University of China,

[52] Fan HQ, Wang WQ, Some thematic issues for mangrove conservation in China. Journal of Xiamen University (Natural Science), 2017; **56**: 323-330.

[53] Chen LZ, Wang WQ, Zhang YH, Lin GH. Recent progresses in mangrove conservation, restoration and research in China. Journal of Plant Ecology, 2009; **2:** 45-54 (in Chinese with English

[54] Chinese Ecological Society (Mangrove ecology WG). Program of working meeting of Chinese mangrove research group. Graduate School of Resources and Environment of Xiamen University, 2019; **9:** 1-19,

**86**

abstract).

(in Chinese).

[63] Xie HW, Wen B, Guo Y, Shi YZ, Wu YH. Community characteristics and distribution of metal elements in mangroves in Futian of Shenzhen, China. Guihaia, 2010; **30:** 64-69 (in Chinese with English abstract).

[64] Zhang ZH, Hu G, Liang SC. Mangrove resources and conservation in Guangxi. Marine Environmental Science, 2007; **26:** 275-279.

[65] Long ER, MacDonald DD, Smith SL, Calder FD. Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments. Environmental Management, 1995; **19**: 81-97.

[66] Sugiura K, Muwamura K, Wu DD, Wang J, Wangang D, Konohira Y, Nakayama Y. Reclamation and subsequent change of land use of mangrove forests in the northern part of Hainan Island, P. R. China. Journal of Forest Planning, 2007; **41**: 271-280. (in Japanese with English abstract).

[67] Li RY, Li RL, Chai MW, Shen XX, Xu HL, Qiu GY. Heavy metal contamination and ecological risk in Futian mangrove forest sediment in Shenzhen Bay, South China. Marine Pollution Bulletin, 2015; **101:** 448-456.

[68] Tam NFY, Li SH, Lan CY, Chen GZ, Li MS, Wong YS. Nutrients and heavy metal contamination of plants and sediments in Futian mangrove forest. Hydrobiologia, 1995; **295:** 149-158.

[69] Guillén MT, Delgado J, Albanese S, Nieto JM, Lima A, Vivo BD. Heavy metals fractionation and multivariate statistical techniques to evaluate the environmental risk soils of Huelva Township (SW Iberian Peninsula).

Journal of Geochemistry Exploration, 2012; **119/120**: 32-43.

[70] Sterckeman T, Goderniaux M, Sirguey C, Cornu JY, Nguyen C. Do roots or shoots control cadmium accumulation in the hyperaccumulator *Noccaea caerulescens*? Plant and Soil, 2015; **392**: 87-99.

[71] Hu YN, Cheng HF, Tao S. The challenges and solutions for cadmiumcontaminated rice in China: a critical review. Environment International, 2016; **92-93**: 515-513.

[72] Farooq MA, Ali S, Hameed A, Bharwana SA, Rizwan M, Ishaque W, Farid M, Mahmood K, Iqbal Z. Cadmium stress in cotton seedlings: physiological, photosynthesis and oxidative damages alleviated by glycinebetaine. South African Journal of Botany, 2016; **104:** 61-68.

[73] Lovelock CE, Ball MC, Martin KC, Feller IC. Nutrient enrichment increases mortality of mangroves. PLoS One, 2012; **4:** 5600.

[74] Chai MW, Li RY, Shen XX, Tam NFY, Zan QJ, Li RL. Does ammonium nitrogen affect accumulation, subcellular distribution and chemical forms of cadmiu*m in Kandelia obovata*? Ecotoxicology and Environmental Safety, 2018; **162:** 430-437.

[75] Qiu GY, Omasa K, Sase S. An infrared-based coefficient to screen plant environmental stress: concept, test and applications. Functional Plant Biology, 2009; **36**: 990-997.

[76] Shen XX, Li RL, Chai MW, Yu K, Zan QJ, Qiu GY. Assessing the effect of extra nitrogen on *Kandelia obovata* growth under cadmium stress using high-resolution thermal infrared remote sensing and the three-temperature

model. Functional Plant Biology, 2018; **45**: 1162-1171.

[77] Marchener P. Marschner's Mineral Nutrition of Higher Plants, 3rd ed. 2012; pp. 672, Academic Press, DOI. org/10.1016/C2009-0-63043-9

[78] Wu XY, Cobbina SJ, Mao GH, Xu H, Zhang Z, Yang LQ. A review of toxicity and mechanisms of individual and mixtures of heavy metals in the environment. Environmental Science and Pollution Research, 2016; **23**: 8244-8259.

[79] Shen XX, Li RL, Chai MW, Cheng SS, Niu ZY, Qiu GY. Interactive effects of single, binary and trinary trace metals (lead, zinc and copper) on the physiological responses of *Kandelia obovata* seedlings. Environmental Geochemistry and Health, 2019; **41**: 135-148.

[80] Choudhary M, Jetley UK, Khan MA, Zutshi S, Fatma T. Effect of heavy metal stress on proline, malondialdehyde, and superoxide dismutase activity in the cyanobacterium *Spirulina platensis*-S5. Ecotoxicology and Environmental Safety, 2007; **66:** 204-209.

[81] Lewis M, Pryor R, Wilking L. Fate and effects of anthropogenic chemicals in mangrove ecosystems: a review. Environmental Pollution, 2011; **159**: 2328-2346.

[82] Masuchi Y. Bacterial flora in mangroves and their biological role. Microbes and Environments, 1998; **13**: 203-215. (in Japanese).

[83] Zhu P, Wang YP, Shi TT, Zhang XL, Huang GQ, Gong J. Intertidal zonation affects diversity and functional potentials of bacteria in surface sediments: a case study of the Golden Bay mangrove, China. Applied Soil Ecology, 2018; **130:** 159-168.

[84] Chuang PC, Young MB, Dale AW, Miller LG, Herrera-Silveira JA,

Paytan A. Methane and sulfate dynamics in sediments from mangrovedominated tropical coastal lagoons, Yucatan, Mexico. Biogensciences, 2016; **13**: 2981-3001.

[85] Guo XP, Lu DP, Niu ZS, Feng JN, Chen YR, Tou FY, Liu M, Yang Y. Bacterial community structure in response to environmental impacts in the intertidal sediments along the Yangtze Estuary, China. Marine Pollution Bulletin, 2018; **126**:141-149.

[86] Muyzer G, Stams AJ. The ecology and biotechnology of sulphate-reducing bacteria. Nature Reviews Microbiology, 2008; **6**, 441-454.

[87] Gomes NCM, Clearly DFR, Pires ACC, Almeida A, Mendonca-Hagler LCS, Smalla K. Assessing variation in bacterial, composition between the rhizosphere of two mangrove tree species. Estuarine Coastal and Shelf Science, 2014; **139**: 40-45.

[88] Basak P, Majumder NS, Nag S, Bhattacharyya A, Roy D, Charkraborty A, SenGupta S, Roy A, Mukherjee A, Pattanayak R, Ghosh A, Chattopadhyay D, Bhattcharyya M. Spatial temporal analysis of bacterial diversity in sediments of Sundarbans using parallel 16S rRNA gene tag sequencing. Microbial Ecology, 2015; **69:** 500-511.

[89] Vane CH, Harrison I, Kim AW, Moss-hayes V, Vickers BP, Hong K. Organic and metal contamination in surface mangrove sediments of South China. Marine Pollution Bulletin, 2009; **58**: 134-144.

[90] Ma B, Dai ZM, Wang HZ, Dsouza M, Liu XM, He Y, Wu JJ, Rodrigues JLM, Gilbert JA, Brookes PC, Xu JM. Distinct biogeographic patterns for archaea, bacteria, and fungi along the vegetation gradient at the continental scale in eastern China. Systems 2017; **2**. UNSP e00174-16.

**89**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

[98] Environmental Chemistry Society (ed.). An inconvenience chemical in global environment, Blue-backs of Kodansha-publisher, 2019; Tokyo,

[99] Ohishi Y, Inoue M. Forest Education, Kaisei-sha Press, 2012; pp. 239. Kaisei-sha Publisher, Otsu.

[100] Li RL, Yu LY, Chai MW, Wu HL, Zhu XS. The distribution, characteristics and ecological risks of microplastics in the mangroves of Southern China. Science of the Total Environment, 2020; **708:** 135025.

[101] Cetin B, Yurdakul S,

**646**: 1164-1171.

Odabasi M. Spatio-temporal variations of atmospheric and soil polybrominated diphenyl ethers (PBDEs) in highly industrialized region of Dilovasi. Science of the Total Environment, 2019;

[102] Chao HR, Shy CG, Wang SL, Chih-Cheng Cheng S, Koh TW, Chen FA, Chang-Chien GP, Tsou TC. Impact of non-occupational exposure to polybrominated diphenyl ethers on menstruation characteristics of reproductive-age females. Environment

International, 2010; **36:** 728-735.

[103] Chai MW, Li RL, Shi C, Shen XX, Li RY, Zan QJ. Contamination of polybrominated diphenyl ethers (PBDEs) in urban mangroves of Southern China. Science of the Total Environment, 2019b; **646**: 390-399.

[104] Zhu HW, Wang Y, Wang XW, Luan TG, Tam NFY. Distribution and accumulation of polybrominated diphenyl ethers (PBDEs) in Hong Kong mangrove sediments. Science of the Total Environment, 2014; **468/469:**

[105] Hu JC, Jin J, Wang Y, Ma ZH, Zheng WJ. Levels of polybrominated

130-139.

(in Japanese).

(in Japanese).

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

[91] Tong TL, Li RL, Wu SJ, Xie SG. The distribution of sediment bacterial community in mangrove across China was governed by geographic location and eutrophication. Marine Pollution

Bulletin, 2019; **140:** 198-203.

[92] Marcos MS, Barboza AD, Keijzer RM, Laanbroek HJ. Tide as steering factor in structuring archaeal and bacterial ammonia-oxidizing communities in mangrove forest soils dominated by *Avicennia germinans* and *Rhizophora mangle*. Microbial Ecology,

[93] Li RL, Tong TL, Wu SJ, Chai MW, Xie SG. Multiple factors govern the biogeographic distribution of archaeal community in mangroves across China. Estuarine Coastal and Shelf Science,

[94] Prato E, Biandolino F, Palapiano I, Giandomenico S, Denti G, Calò M, Spada L, Leo AD. Proximate, fatty acids and metals in edible marine bivalves from Italian market: beneficial and risk for consumers health. Science of the Total Environment, 2019; **648**:

[95] Shenzhen Statistics Bureau. Shenzhen Statistical Yearbook. China Statistics Press, Beijing, 2017.

[96] Gong Y, Chai MW, Ding H,

Shi C, Wang Y, Li RL. Bioaccumulation and human health risk of shellfish contamination to heavy metals and As in most rapid urbanized Shenzhen, China. Environmental Science and Pollution Research, 2020; **27**:

[97] Chai MW, Ding H, Shen XX, Li RL. Contamination and ecological risk of polybrominated diphenyl ethers (PBDEs) in surface sediments of

mangrove wetlands: A nationwide study in China. Environmental Pollution,

2018; **75:** 997-1008.

2019; **231**: 106414.

153-163.

(in Chinese).

2096-2106.

2019a; **249**, 992-1001.

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

[91] Tong TL, Li RL, Wu SJ, Xie SG. The distribution of sediment bacterial community in mangrove across China was governed by geographic location and eutrophication. Marine Pollution Bulletin, 2019; **140:** 198-203.

*Mangrove Ecosystem Restoration*

**45**: 1162-1171.

8244-8259.

135-148.

2328-2346.

model. Functional Plant Biology, 2018;

Paytan A. Methane and sulfate

**13**: 2981-3001.

2008; **6**, 441-454.

Science, 2014; **139**: 40-45.

[88] Basak P, Majumder NS, Nag S, Bhattacharyya A, Roy D, Charkraborty A, SenGupta S, Roy A, Mukherjee A, Pattanayak R, Ghosh A, Chattopadhyay D, Bhattcharyya M. Spatial temporal analysis of bacterial diversity in sediments of Sundarbans using

parallel 16S rRNA gene tag sequencing. Microbial Ecology, 2015; **69:** 500-511.

[89] Vane CH, Harrison I, Kim AW, Moss-hayes V, Vickers BP, Hong K. Organic and metal contamination in surface mangrove sediments of South China. Marine Pollution Bulletin, 2009;

[90] Ma B, Dai ZM, Wang HZ, Dsouza M, Liu XM, He Y, Wu JJ,

for archaea, bacteria, and fungi along the vegetation gradient at the continental scale in eastern China. Systems 2017; **2**. UNSP e00174-16.

Rodrigues JLM, Gilbert JA, Brookes PC, Xu JM. Distinct biogeographic patterns

**58**: 134-144.

dynamics in sediments from mangrovedominated tropical coastal lagoons, Yucatan, Mexico. Biogensciences, 2016;

[85] Guo XP, Lu DP, Niu ZS, Feng JN, Chen YR, Tou FY, Liu M, Yang Y. Bacterial community structure in response to environmental impacts in the intertidal sediments along the Yangtze Estuary, China. Marine Pollution Bulletin, 2018; **126**:141-149.

[86] Muyzer G, Stams AJ. The ecology and biotechnology of sulphate-reducing bacteria. Nature Reviews Microbiology,

[87] Gomes NCM, Clearly DFR, Pires ACC, Almeida A, Mendonca-Hagler LCS, Smalla K. Assessing variation in bacterial, composition between the rhizosphere of two mangrove tree species. Estuarine Coastal and Shelf

[77] Marchener P. Marschner's Mineral Nutrition of Higher Plants, 3rd ed. 2012; pp. 672, Academic Press, DOI. org/10.1016/C2009-0-63043-9

[78] Wu XY, Cobbina SJ, Mao GH, Xu H, Zhang Z, Yang LQ. A review of toxicity and mechanisms of individual and mixtures of heavy metals in the environment. Environmental Science and Pollution Research, 2016; **23**:

[79] Shen XX, Li RL, Chai MW, Cheng SS, Niu ZY, Qiu GY. Interactive effects of single, binary and trinary trace metals (lead, zinc and copper) on the physiological responses of *Kandelia obovata* seedlings. Environmental Geochemistry and Health, 2019; **41**:

[80] Choudhary M, Jetley UK, Khan MA, Zutshi S, Fatma T. Effect of heavy metal stress on proline, malondialdehyde, and superoxide dismutase activity in the cyanobacterium *Spirulina platensis*-S5. Ecotoxicology and Environmental

[81] Lewis M, Pryor R, Wilking L. Fate and effects of anthropogenic chemicals in mangrove ecosystems: a review. Environmental Pollution, 2011; **159**:

[82] Masuchi Y. Bacterial flora in mangroves and their biological role. Microbes and Environments, 1998; **13**:

[83] Zhu P, Wang YP, Shi TT, Zhang XL, Huang GQ, Gong J. Intertidal zonation affects diversity and functional potentials of bacteria in surface sediments: a case study of the Golden Bay mangrove, China. Applied Soil Ecology, 2018; **130:** 159-168.

[84] Chuang PC, Young MB, Dale AW, Miller LG, Herrera-Silveira JA,

203-215. (in Japanese).

Safety, 2007; **66:** 204-209.

**88**

[92] Marcos MS, Barboza AD, Keijzer RM, Laanbroek HJ. Tide as steering factor in structuring archaeal and bacterial ammonia-oxidizing communities in mangrove forest soils dominated by *Avicennia germinans* and *Rhizophora mangle*. Microbial Ecology, 2018; **75:** 997-1008.

[93] Li RL, Tong TL, Wu SJ, Chai MW, Xie SG. Multiple factors govern the biogeographic distribution of archaeal community in mangroves across China. Estuarine Coastal and Shelf Science, 2019; **231**: 106414.

[94] Prato E, Biandolino F, Palapiano I, Giandomenico S, Denti G, Calò M, Spada L, Leo AD. Proximate, fatty acids and metals in edible marine bivalves from Italian market: beneficial and risk for consumers health. Science of the Total Environment, 2019; **648**: 153-163.

[95] Shenzhen Statistics Bureau. Shenzhen Statistical Yearbook. China Statistics Press, Beijing, 2017. (in Chinese).

[96] Gong Y, Chai MW, Ding H, Shi C, Wang Y, Li RL. Bioaccumulation and human health risk of shellfish contamination to heavy metals and As in most rapid urbanized Shenzhen, China. Environmental Science and Pollution Research, 2020; **27**: 2096-2106.

[97] Chai MW, Ding H, Shen XX, Li RL. Contamination and ecological risk of polybrominated diphenyl ethers (PBDEs) in surface sediments of mangrove wetlands: A nationwide study in China. Environmental Pollution, 2019a; **249**, 992-1001.

[98] Environmental Chemistry Society (ed.). An inconvenience chemical in global environment, Blue-backs of Kodansha-publisher, 2019; Tokyo, (in Japanese).

[99] Ohishi Y, Inoue M. Forest Education, Kaisei-sha Press, 2012; pp. 239. Kaisei-sha Publisher, Otsu. (in Japanese).

[100] Li RL, Yu LY, Chai MW, Wu HL, Zhu XS. The distribution, characteristics and ecological risks of microplastics in the mangroves of Southern China. Science of the Total Environment, 2020; **708:** 135025.

#### [101] Cetin B, Yurdakul S,

Odabasi M. Spatio-temporal variations of atmospheric and soil polybrominated diphenyl ethers (PBDEs) in highly industrialized region of Dilovasi. Science of the Total Environment, 2019; **646**: 1164-1171.

[102] Chao HR, Shy CG, Wang SL, Chih-Cheng Cheng S, Koh TW, Chen FA, Chang-Chien GP, Tsou TC. Impact of non-occupational exposure to polybrominated diphenyl ethers on menstruation characteristics of reproductive-age females. Environment International, 2010; **36:** 728-735.

[103] Chai MW, Li RL, Shi C, Shen XX, Li RY, Zan QJ. Contamination of polybrominated diphenyl ethers (PBDEs) in urban mangroves of Southern China. Science of the Total Environment, 2019b; **646**: 390-399.

[104] Zhu HW, Wang Y, Wang XW, Luan TG, Tam NFY. Distribution and accumulation of polybrominated diphenyl ethers (PBDEs) in Hong Kong mangrove sediments. Science of the Total Environment, 2014; **468/469:** 130-139.

[105] Hu JC, Jin J, Wang Y, Ma ZH, Zheng WJ. Levels of polybrominated diphenyl ethers and hexabromocyclododecane in the atmosphere and tree bark from Beijing, China. Chemosphere, 2011; **84:** 355-360.

[106] Sanders RA. Urban vegetation impacts on the hydrology of Dayton, Ohio. Urban Ecology, 1986; **9:** 361-376.

[107] Tu W, Hu ZW, Li LF, Cao JZ, Jiang JC, Li QP, Li QQ. Portraying urban functional zones by coupling remote sensing imagery and human sensing data. Remote Sensing, 2018; **10:** 141. DOI:10.3390/rs10010141

[108] Yang XP, Fang ZX, Yin L, Li JY, Zhou Y, Lu SW. Understanding the spatial structure of urban commuting using mobile phone location data: a case study of Shenzhen, China. Sustainability, 2018; **19**: 1435. URL: https://www.mdpi. com/2071-1050/10/5/1435/

[109] Tam NFY, Ke L, Wang XH, Wong YS. Contamination of polycyclic aromatic hydrocarbons in surface sediments of mangrove swamps. Environmental Pollution, 2001; **114:** 255-263.

[110] Li FL, Zeng XK, Yang JD, Zhou K, Zan QJ, Lei AP, Tam NFY. Contamination of polycyclic aromatic hydrocarbons (PAHs) in surface sediments and plants of mangrove swamps in Shenzhen, China. Marine Pollution Bulletin, 2014; **85:** 590-596.

[111] Zheng GJ, Lam MHW, Lam PKS, Richardson BJ, Man BKW, Li AMY. Concentrations of persistent organic pollutants in surface sediments of the mudflat and mangroves at Mai Po Marshes Nature Reserve, Hong Kong. Marine Pollution Bulletin, 2000; **40**: 1210-1214.

[112] Tam NFY, Yao MWY. Concentrations of PCBs in coastal mangrove sediments of Hong Kong. Marine Pollution Bulletin, 2002; **44**: 642-651.

[113] Vane CH, Harrison I, Kim AW, Moss-Hayes V, Vickers BP, Hong K. Organic and metal contamination in surface mangrove sediments of South China. Marine Pollution Bulletin, 2009; **58**: 134-144.

[114] Zhao B, Zhou YW, Chen GZ. The effect of mangrove reforestation on the accumulation of PCBs in sediment from different habitats in Guangdong, China. Marine Pollution Bulletin, 2012; **64**: 1614-1619.

[115] Zhang ZW, Li JL, Sui T, Cheng MM, Sun KF. Organic contamination in mangrove ecosystems of China. Ecological Science, 2017; **36:** 232-240 (in Chinese with English abstract).

[116] Tam NFY, Wong TWY, Wong YS. A case study on fuel oil contamination in a mangrove swamp in Hong Kong. Marine Pollution Bulletin, 2005; **51:** 1092-1100.

[117] Tang Y, Fang Z, Yu S, 2008. Heavy metals, polycyclic aromatic hydrocarbons and organochlorine pesticides in the surface sediments of mangrove swamps from coastal sites along the Leizhou Peninsula, South China. Acta Oceanologica Sinica, 2008, **27**: 42-53 (in Chinese with English abstract).

[118] Sharma S, MacKenzie RA, Tieng T, Soben K, Tulyasuwan N, Resanond A, Blate C, Litton GM. The impacts of degradation, deforestation and restoration on mangrove ecosystem carbon stocks across Cambodia. Science of the Total Environment, 2019; **706**: https://doi.org/10.1016/j. scitotenv.2019.135416

[119] Hwang GJ, Hung PH, Chen NS, Liu GZ. Mindtool-assisted in field learning (MAIL): an advanced ubiquitous learning project in Taiwan. Journal of Educational Technology & Society, 2014; **17**: 4-16.

[120] Li Y, Ru ZZ, Cheng HR, Wang ZL, Zan X. Study on management modes

**91**

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China*

*DOI: http://dx.doi.org/10.5772/intechopen.95339*

of mangrove wetlands in Shenzhen, China. Guangdong Forestry Science and Technology, 2013; **29**: 31-37 (in Chinese

[121] Qin WH, Qiu QW, Zhang Y, Shen XX. Experiences of management and conservation in Hong Kong's Maipo Nature Reserve. Wetland Science & Management, 2010; **6:** 34-37 (in Chinese with English abstract).

[122] Sun YX, Luo XJ, Mo L, Zhang Q , Wu JP, Chen SJ, Zou FS, Mai BX. Brominated flame retardants in three terrestrial passerine birds from South China: geographic pattern and implication for potential sources. Environmental Pollution, 2012; **162**:

[123] Komiyama A, Pounngparn S, Kato T. Common allometric equations for estimating the tree weight of

mangroves. Journal of Tropical Ecology,

[124] Fu HF, Tao YJ, Wang WQ. Some issues about the impacts of sea level rise on mangroves in China. Chinese Journal

of Ecology, 2014; **33**: 2842-2848 (in Chinese with English abstract).

with English abstract).

381-388.

2005; **21**: 471-477.

*Environmental and Education Trials for Mangrove Ecosystem Rehabilitation in China DOI: http://dx.doi.org/10.5772/intechopen.95339*

of mangrove wetlands in Shenzhen, China. Guangdong Forestry Science and Technology, 2013; **29**: 31-37 (in Chinese with English abstract).

*Mangrove Ecosystem Restoration*

diphenyl ethers and hexabromocyclododecane in the atmosphere and tree bark from Beijing, China. Chemosphere, 2011; **84:** 355-360.

[113] Vane CH, Harrison I, Kim AW, Moss-Hayes V, Vickers BP, Hong K. Organic and metal contamination in surface mangrove sediments of South China. Marine Pollution Bulletin, 2009;

[114] Zhao B, Zhou YW, Chen GZ. The effect of mangrove reforestation on the accumulation of PCBs in sediment from different habitats in Guangdong, China. Marine Pollution Bulletin, 2012; **64**:

[115] Zhang ZW, Li JL, Sui T, Cheng MM, Sun KF. Organic contamination in mangrove ecosystems of China. Ecological Science, 2017; **36:** 232-240 (in Chinese with English abstract).

[116] Tam NFY, Wong TWY, Wong YS. A case study on fuel oil contamination in a mangrove swamp in Hong Kong. Marine Pollution Bulletin, 2005; **51:** 1092-1100.

[118] Sharma S, MacKenzie RA, Tieng T, Soben K, Tulyasuwan N, Resanond A, Blate C, Litton GM. The impacts of degradation, deforestation and restoration on mangrove ecosystem carbon stocks across Cambodia. Science of the Total Environment, 2019; **706**: https://doi.org/10.1016/j.

[119] Hwang GJ, Hung PH, Chen NS, Liu GZ. Mindtool-assisted in field learning (MAIL): an advanced

ubiquitous learning project in Taiwan. Journal of Educational Technology &

[120] Li Y, Ru ZZ, Cheng HR, Wang ZL, Zan X. Study on management modes

[117] Tang Y, Fang Z, Yu S, 2008. Heavy metals, polycyclic aromatic hydrocarbons and organochlorine pesticides in the surface sediments of mangrove swamps from coastal sites along the Leizhou Peninsula, South China. Acta Oceanologica Sinica, 2008, **27**: 42-53 (in Chinese with English

**58**: 134-144.

1614-1619.

abstract).

scitotenv.2019.135416

Society, 2014; **17**: 4-16.

[106] Sanders RA. Urban vegetation impacts on the hydrology of Dayton, Ohio. Urban Ecology, 1986; **9:** 361-376.

[107] Tu W, Hu ZW, Li LF, Cao JZ, Jiang JC, Li QP, Li QQ. Portraying urban functional zones by coupling remote sensing imagery and human sensing data. Remote Sensing, 2018; **10:** 141.

[108] Yang XP, Fang ZX, Yin L, Li JY, Zhou Y, Lu SW. Understanding the spatial structure of urban commuting using mobile phone location data: a case study of Shenzhen, China. Sustainability, 2018; **19**: 1435. URL: https://www.mdpi.

DOI:10.3390/rs10010141

com/2071-1050/10/5/1435/

255-263.

[109] Tam NFY, Ke L, Wang XH, Wong YS. Contamination of polycyclic aromatic hydrocarbons in surface sediments of mangrove swamps. Environmental Pollution, 2001; **114:**

[110] Li FL, Zeng XK, Yang JD, Zhou K, Zan QJ, Lei AP, Tam NFY. Contamination of polycyclic aromatic hydrocarbons (PAHs) in surface sediments and plants of mangrove swamps in Shenzhen, China. Marine Pollution Bulletin, 2014; **85:** 590-596.

[111] Zheng GJ, Lam MHW, Lam PKS, Richardson BJ, Man BKW, Li AMY. Concentrations of persistent organic pollutants in surface sediments of the mudflat and mangroves at Mai Po Marshes Nature Reserve, Hong Kong. Marine Pollution Bulletin, 2000; **40**:

**90**

1210-1214.

642-651.

[112] Tam NFY, Yao MWY.

Concentrations of PCBs in coastal mangrove sediments of Hong Kong. Marine Pollution Bulletin, 2002; **44**: [121] Qin WH, Qiu QW, Zhang Y, Shen XX. Experiences of management and conservation in Hong Kong's Maipo Nature Reserve. Wetland Science & Management, 2010; **6:** 34-37 (in Chinese with English abstract).

[122] Sun YX, Luo XJ, Mo L, Zhang Q , Wu JP, Chen SJ, Zou FS, Mai BX. Brominated flame retardants in three terrestrial passerine birds from South China: geographic pattern and implication for potential sources. Environmental Pollution, 2012; **162**: 381-388.

[123] Komiyama A, Pounngparn S, Kato T. Common allometric equations for estimating the tree weight of mangroves. Journal of Tropical Ecology, 2005; **21**: 471-477.

[124] Fu HF, Tao YJ, Wang WQ. Some issues about the impacts of sea level rise on mangroves in China. Chinese Journal of Ecology, 2014; **33**: 2842-2848 (in Chinese with English abstract).

**93**

**1. Introduction**

**Chapter 5**

*and Ali Djunaedi*

**Abstract**

The Commercial Value of

Mangrove-Based Pigments as

Natural Dye for Batik Textiles

*Delianis Pringgenies, Ali Ridlo, Lutfianna Fatma Dewi* 

mangrove waste is a quite promising product and increases people's income.

One of the most valuable and potential natural resources in coastal areas of Indonesia is the mangrove forest. With a coastal line exceeding 80,000 km,

**Keywords:** batik, mangrove, natural dye, *Rhizopora mucronata*, waste

Mangrove, or bakau as it is known in Indonesia, is one of the vegetations commonly found along the shallow coasts, estuaries, deltas and protected coastal areas and are still influenced by rising tides. After the Aceh tsunami disaster, mangrove restoration was intensively conducted in coastal areas all over Indonesia and was made into a special conservation program by the government. Mangrove is distinguishable by its big, wooden stilt roots, sharpening tip in the form of supporting leaves. The roots of the mangrove tree are morphologically distinguishable into heart root which grows into the ground and the stilt root which appear to grabs onto the surface of the ground. Mangrove forests serve several important ecological roles: they act as filters which turns saline water into fresh water, buffer from seawater intrusion, prevent erosion and abrasion, hold sediments to form new habitats, feeding ground, nursery ground, and spawning ground for a number of aquatic wildlife. Mangrove forest also possess economical functions such as as source of income, industrial ingredients for the locals and as source of new mangrove seedlings. Mangunhardjo Village, Urban Community of Mangunhardjo, Mangkang Area, Kecamatan of Tugu, Semarang City, Indonesia was an area dotted with brackish water pond. However, the area had been suffering from the effects of climate change, being inundated by overflow of river and seawater intrusion (rob). These disasters caused decline in the productivity of the ponds in the area. In an effort to combat the adverse effect of environmental change in the area, the locals of Mangunhardjo village decided to shift their livelihood by restoring the surrounding mangrove forest. Mangrove conservation at Mangunhardjo Village was conducted through activities of the program such as mangrove planting, mangrove-based food production, and mangrove waste management by applications of bioactivator bacteria for mangrove composting and production of mangrove-based natural dye for batik fabric. Mangrove-based natural dye for batik fabric from *Rhizopora mucronata*

#### **Chapter 5**
