Conservation and Challenges of Endangered Plant Species

#### **Chapter 4**

## Research Advances and Perspectives of Conservation Genomics of Endangered Plants

*Qing Ma, Gang Wu, Wenjie Li, Seyit Yuzuak, Fachun Guan and Yin Lu*

#### **Abstract**

Understanding in the evolutionary processes, endangered mechanisms, and adaptive evolution history are key scientific issues in conservation biology. During the past decades, advances in high-throughput sequencing and multi-disciplinary crossover have triggered the development of conservation genomics, which refers to the use of new genomic technologies and genomic information in solving the existing problems in conservation biology. Conservation genomics mainly focuses on the endangered mechanism and conservation strategies aiming at protection of survivability and diversity of endangered species. Application of conservation genomics into the study of endanger plant species has provided innovated protection concept for biologists and promoted the development of population-based conservation strategies. This chapter summarizes the studies of population genomics for agronomically and commercially important plants threatened and endangered, discusses the advantages of conservation genomics for the analysis of genetic diversity, inferences about the history of population dynamics, evaluation of natural forces on wild plant populations, and the establishment of effective conservation strategies. This chapter also presents the development trends in genomics for the conservation of endangered plant species.

**Keywords:** endangered species, genomics, conservation strategy, genetic diversity, conservation biology

#### **1. Introduction**

In modern times, frequent and intense human activities and habitat degradation have caused major and serious threats on the plant's biodiversity [1, 2]. Global energy consumption is becoming increasingly severe, and the global climate and environment is undergoing drastic changes. The size of existing populations is rapidly shrinking and many species are on the brink of extinction. The resulting population bottleneck further reduced the adaptive potential and functional diversity of species, and poses dangers and difficulties in the recovery of populations under natural conditions. Many wild animals and plants are facing an unprecedented survival crisis [3–7].

In response to this crisis, conservation biology has emerged. After years of development in conservation biology, preservation of biodiversity in the context of ecosystem has arrived at a consensus, and so the mechanism and priciple factors responsible for biodiversty loss has been a hot topic in the field of conservation biology. The requirement of better evaluation of species endangerment degree, more accurate estimation of endangered species habitats, and more suitable conservation strategies has led to the development and application of multiple related technologies, such as geographic positioning system (GPS) technology, mathematical methods, and genomics study [8]. In recent decades, the rapid development of high-throughput technology has greatly increased the availability of genomic data and effectively solved the management problems of many endangered species and related key protection regions.

#### **2. An overview of conservation genomics**

#### **2.1 Main features**

As a branch of conservation biology, conservation genomics focuses on the study of endangered mechanisms and conservation strategies for endangered species, that aims to protect species survival ability and reduce the risk of extinction. This field is an integration of theoretical ideas of genetics and analytical methods of genomics.

Traditional conservation genetics research often relies on only a few molecular markers such as isozyme, microsatellites, or mitochondrial and chloroplast genomes. Since most of these molecular markers are anchored in a few neutral regions of the genome, there are certain limitations in tackling with questions in species conservation [9, 10]. Compared with conservation genetics, conservation genomics is more direct and effective in addressing some important issues in conservation biology.

For example, when estimating effective population size (Ne), genome data can provide a large number of genetic markers, which can be used to reconstruct pedigree and extract haplotype information, with which Ne values can be monitored, population migration direction predicted, and migrating individuals can be identified. When inferring the adverse effects of inbreeding depression, whole genome information can directly locate the key sites, accurately predict the population's ability to eliminate harmful mutations, and screen the initial founders of captive populations based on the genotype of individual inbreeding sites.

Furthermore, when estimating the interference of climate change and human activities on wild populations, the large amount of genetic variation information obtained through genomic sequencing can help accurately evaluate the responsive ability of different individuals and help to find individuals suitable for ex-situ conservation [11]. In fact, these issues have long been well-recognized in conservation biology research, but due to the lack of key genomic information, there has been no further development until the advent of next-generation sequencing, which successfully opened up new research perspectives.

#### **2.2 Significance in conservation biology**

In the past 200 million years, an average of 900,000 species of animals have become extinct per million years, with a "background rate" of approximately 90 species per century, including approximately four species of higher plants [12]. In history, the five mass extinctions that have occurred to date have generally occurred

#### *Research Advances and Perspectives of Conservation Genomics of Endangered Plants DOI: http://dx.doi.org/10.5772/intechopen.112281*

as a result of significant geological events or rapid environmental changes. Studies on general biodiversity loss indicate that we are now in the sixth mass extinction [13]. It is conservatively estimated that the extinction rate of species in the past century has been 22 times faster than historical benchmarks [14].

In 2022, 11,538 plant species were included in the red list updated by the International Union for Conservation of Nature and Natural Resources (IUCN), of which about 5336 (46.2%) were critically endangered, 10,202 (88.4) were endangered, 9376 (81.2%) were vulnerable, 134 (1.2%) were conservation dependent, and 3761 (32.6%) were near threatened [15]. China is one of the countries with the richest biodiversity in the world, with about 30,000 species of higher plants, more than 5% of which are endemic, and ranks third in the world. According to statistics reported so far, there are 4000 to 5000 plant species in China that are endangered or threatened, accounting for 15% -20% of all plant species. Nearly 100 species are facing extinction. Therefore, the application of modern multidisciplinary research methods is of great importance in order to protect and strengthen plant germplasm resources and maintain plant diversity.

Conservation genomics not only provides more comprehensive, accurate and reliable research results on species classification, genetic diversity, population genetic structure and so on, but also provide insights into the historical processes of species origin, differentiation, population size evolution, and the molecular mechanism of population local adaptation, inbreeding status and genetic basis of inbreeding depression [11, 16, 17]. Various models based on conservation genomics have been developed to directly identify biodiversity hotspots to provide priority protection.

In addition, new classes of markers obtained from whole genome sequence can be used to screen for functional genes and key adaptive sites contributing to important ecological adaptations, such as the stresses of climate change, resistance to herbivory, and disease, making it possible to predict species' response to the environment in the past and future [18].

Beginning from the studies of traditional genetic diversity, genetic structure, and population dynamics, conservation genomics allows us to delve into the reconstruction of evolutionary history and species adaptive evolution and explore the process, causes, and evolutionary potential of endangerment. Application of genomics study in conservation biology can guide practical management actions of endangered species from both the spatial and temporal perspectives.

#### **2.3 Research techniques and strategies**

#### *2.3.1 Development of genome sequencing technology*

Genome sequencing technology has gone through a development process from first generation to third generation sequencing. The first generation sequencing is also known as Sanger sequencing. Its core principle is to image different lengths of DNA fragments containing isotope markers through gel electrophoresis during DNA synthesis and identify the type of DNA base at each position [19]. The first generation sequencing has the advantages of long read length and high accuracy, but its low throughput, long sequencing time and high cost made it unsuitable for large-scale genome sequencing.

The second generation sequencing or next generation high-throughput sequencing determines the DNA sequence by capturing the special markers (usually fluorescent molecular markers) carried by the newly added bases during DNA replication [20]. It has advantages such as high throughput, fast speed, and low cost, but there are also shortcomings such as limited read length and assembly fragmentation.

The third generation sequencing technology, also known as single molecule realtime sequencing technology can obtain DNA base information in real-time through captured optical or electrical signals [21, 22]. Its biggest feature is single molecule sequencing, which does not require PCR amplification during the sequencing process. Together with its advantages of long read length (10–150 kb), fast speed, and no GC preference, the third generation sequencing greatly improves the integrity of genome assembly [23]. However, a disadvantage of this technology is the relatively high error rate of single base sequencing, which can reach 15%. It may require the use of secondgeneration sequencing data to correct the sequenced bases.

#### *2.3.2 Simplifying genome sequencing*

At present, two main categories of research techniques are widely used in conservation genomics: simplified genome sequencing and whole genome sequencing [16].

Simplifying genome sequencing is one of the commonly used techniques. It means sequencing of partial genomes, which greatly reduces the complexity of the genome, thereby lowering the cost and computational burden of sequencing. Simplifying genome sequencing has many advantages over whole genome sequencing, such as cost-effective, good stability, shorter experimental time, simpler library construction program, gain of a larger number of SNPs (single nucleotide polymorphisms), and independence of the reference genome. Hence, this technology is widely used in the conservation genomics studies of endangered animals and plants [16, 24–26]. Simplified genome sequencing can be divided into restriction site associated DNA sequence (RAD-seq) [27], RNA transcriptome sequencing (RNA-seq) [28], and whole exome sequencing (WES) [29]. The commonality of these three methods is that they normally only evaluate a small portion of the genome. However, due to the incomplete genome coverage and missing data, simplifying genome data poses challenges for subsequent population genetic analysis, such as in the inference of population phylogenetic relationship. Firstly, when there are polymorphisms or sequencing errors, it is difficult to conduct precise cluster analysis of the same restrictive loci. Secondly, it is still quite complicated to assemble each gene cluster into unique loci and ultimately construct phylogenetic relationships. Finally, the scale of genetic variation information obtained from RAD seq and the availability of RAD-seq data in phylogeny inference are influenced by various factors such as the restriction enzymes used, the size of selected fragments, and the sequencing coverage of different samples [27, 30, 31]. By contrast, whole genome re-sequencing method relying on the reference genome can significantly improve the quantity and quality of detected genetic markers [27, 32].

#### *2.3.3 Whole genome sequencing*

Whole genome sequencing can be divided into two categories: De novo whole genome sequencing and whole genome re-sequencing. De novo sequencing refers to the first assembly of a new genome sequence. The difficulty and quality of genome assembly depend on genome size, complexity, computational conditions, and bioinformatics techniques. Currently, De novo whole genome sequencing mainly utilizes third-generation sequencing techniques, including single molecule nanopore DNA sequencing from Oxford Nanopore Technologies (ONT), single molecule realtime sequencing (SMRT) from Pacific Biosciences (PacBio), and true single molecular sequencing (tSMS) from Helicos Biosciences.

#### *Research Advances and Perspectives of Conservation Genomics of Endangered Plants DOI: http://dx.doi.org/10.5772/intechopen.112281*

In comparison, whole genome re-sequencing aims at comparison of genomic variation among different individuals and populations based on genomic sequencing of different individuals of species with known genome sequences. It mainly utilizes second-generation sequencing techniques, such as 454 GS FLX Titanium Platform supplied by Roche, HiSeq 2000 Platform supplied by Illumina, and the ABI SOLiD Platform to obtain a large number of short reads. After comparing with the reference genome, population level single nucleotide polymorphism (SNP) data can be obtained and used for population genetic analyses.

Whole genome re-sequencing requires high-quality reference genomes for read length alignment and mutation detection. The lack of high-quality reference genomes is the main obstacle for the use of whole genome re-sequencing technology in conservation biology. Despite the rapid development of sequencing technology, whole genome data is still unavailable in many endangered species. A statistical analysis has shown that among all the plant species with whole genome data, only 3.25% were threatened species included in IUCN red list and only 5.34% were included in the List of Wild Plants Under State Protection in China [33]. Nevertheless, with the increasing awareness of conservation and the launch of some important projects, it is expected that more and more endangered plant genomes will be analyzed in the future. For example, the Earth BioGenome Project proposed to give priority to sequencing the genomes of more than 23,000 endangered species included in the IUCN Red List [34]. The implementation of this project will provide assistance for the conservation genomics research of endangered species.

#### **3. Application of conservation genomics**

#### **3.1 Determination of conservation units**

In conservation biology, 'species' is commonly used to express the concept of conservation units, including taxonomic levels below species, such as subspecies and populations. It is very important for biodiversity conservation to determine population units that meet the requirements of taxonomy for standardized management. The successful implementation of the conservation plan largely depends on the correct identification of the taxonomic status of conservation targets [35]. In conservation biology, researchers tend to define species based on phylogenetic analysis. However, some different subspecies may be mistakenly treated as a different species. Other widely accepted definition methods require calculation of genetic distance or prove for reproductive isolation. In certain cases, threatened species may be described using minor morphological or distributional features, which brings controversial opinions on the taxonomic boundaries and the necessity of conservation.

Whole genome records the entire history of evolutionary process of each species. By comparing the genomic data rather than a few genes like traditional genetic analytical methods, more robust phylogenetic relationships can be constructed, providing new solutions for the identification of closely-related species and the discovery of hidden species [16].

For example, the rare and endangered plant *Buddleja alternifoli* (Scrophulariaceae) in Inner Mongolia is mainly distributed in the three major regions of the Himalayas, Hengduan Mountains, and the Loess Plateau. Significant morphological differences in between the populations in the Loess Plateau region and the other two regions were detected, while the populations in the Himalayas and Hengduan Mountains have no

evident differences in morphology, thereby raising the doubt whether the populations distributed in the three regions belong to one species. Ma et al. first assembled the high-quality genome of *Buddleja alternifoli* and obtained sample re-sequencing data from 48 populations distributed in three regions. They found that *Buddleja alternifoli* formed three independent and distinct branches consistent with geographical distribution. The population differentiation coefficient FST was greater than 0.5. They speculated that *Buddleja alternifoli* in these three regions should be defined as three different species. Given the fact that *Buddleja alternifoli* is already an endangered species, results from genomic analysis implicated that each newly defined species has fewer numbers and narrower distribution range than previous prediction. The actual endangered degree of the species may be higher. When implementing protection management, these three possible species should be managed separately [36]. Similarly, although some endangered plants cannot be determined from their morphology whether they belong to different species, genetic differentiation is already very large and can actually be located as different species.

On the contrary, mis-identification of taxonomic status may cause unnecessary conservation actions and costs. *Banksia vincentia* was originally identified as a member of a species complex constitutes by *Backobourkia collina*, *B. cunninghamii*, *B. neoanglica*. It was treated as a critically endangered species in New South Wales, Australia. However, nuclear genomic data did not support '*B. vincentia*' as a distinct species and showed that it is nested within *B. neoanglica*. The value of conservation of '*B. vincentia*' needs to be further evaluated [37].

Differentiation of genetic diversity is often existed between different populations of the same species. One of the goals of conservation biology is to protect the genetic diversity of vulnerable species as much as possible. The most important step in population management is to determine and delineate the boundaries of conservation units (CUs) within species, such as evolutionarily significant units (ESUs). If a population basically has reproductive isolation with other populations of the same species, and represents an important evolutionary component of the species, then the population can be regarded as an ESU [38]. The significant units of evolution represent the vast majority of genetic diversity between populations within a species [39, 40]. In addition to ESUs, there are also management units (MUs) and adaptive units (AUs). By dividing these population units within a species, each population can receive targeted and efficient supervision, including reasonable planning of harvest yield to avoid excessive harvest, introduction of new individuals to the population to avoid mixing populations with different adaptations, and prioritize protection for certain population units to save budgets.

Within the genomic framework, it was suggested that genetic structure analysis of all possible loci to should be used to identify ESUs, neutral loci should be used to identify MUs, and adaptive loci should be used to identify AUs [39]. At present, using whole genome sequencing combined with re-sequencing data for population genetic structure analysis is a routine in population genomics [36, 41, 42]. The results can serve as a basis for ESUs classification of endangered plants. Using whole genome de novo sequencing, chromosome level assembly, and population re-sequencing of the endangered species *Tetracentron sinensis*, biologists found that 55 individuals of the species were distributed in representative regions of China with four ancient genetic components corresponding to four different ESUs [42].

In fact, in biological systems with simple evolutionary processes, traditional genetic techniques can directly divide protection units, but it is difficult to determine clear protective units for complex evolutionary systems, such as populations with

#### *Research Advances and Perspectives of Conservation Genomics of Endangered Plants DOI: http://dx.doi.org/10.5772/intechopen.112281*

hybridization and introgression in evolutionary history [43]. Hybridization refers to interspecific hybridization between individuals from different species or populations, such as hybridization between two closely related species with bidirectional gene exchange. Introgression refers to the transfer of alleles from one species to another, and gene exchange is unidirectional. Hybridization and introgression make it more difficult to partition protective units, as analyzing different parts of the genome is likely to yield different results. Due to the impact of human activities, the displacement of organisms and habitat transfer have significantly increased the hybridization and introgression rates among various species worldwide, further increasing the threat to existing species. Genomics technology can not only effectively distinguish between natural hybridization and artificial hybridization, but also predict the impact of hybridization on species fitness (heterosis or outbreeding decline) [44].

Overall, conservation genomics serve as an efficient tool for resolution of phylogenetic relationships and elucidation of population genetic structure, population evolution history. It can help correctly define the taxonomic status of an endangered species, precisely evaluate the hybridization risk and genetic diversity, and provide valuable management information for species conservation.

#### **3.2 Analysis of genetic diversity**

Genetic diversity is closely related to the adaptive evolution and evolutionary potential of species. Traditional genetic diversity assessment is based on mitochondrial genes, microsatellites and other molecular genetic marker to calculate the genetic diversity of different populations. However, these calculations are only based on the assessment of allele frequency of certain loci represented by genetic marker, which cannot comprehensively reflect the level and panorama of genetic diversity of gene sequences in key coding regions of species. With the rapid development of genomics, it has become possible to assess genetic diversity at the whole genome level. Genomic diversity refers to the overall genetic diversity of a species or population based on variation loci at the whole genome level. In recent years, with the continuous decoding of genome sequences of endangered species and the accumulation of population genome data based on re-sequencing, more and more endangered species' genomic diversity has been evaluated.

Using genome re-sequencing method, the genetic diversity of some plant species listed in IUCN as critically endangered, endangered, or vulnerable have been studied. Generally, threatened species display lower genetic diversity than threatened and endangered species. The genetic diversity of critically endangered species endemic to China ranged from 0.0016 to 0.0030, while that of endangered species ranged from 0.0031 to 0.0038 [33].

Huang et al. (2012) sampled 446 diverse individuals of the critically endangered wild rice *Oryza rufipogon* across Asia and Oceania and sequenced them with twofold genome coverage. The sequence diversity was estimated at 0.003 which agrees with previous suggestions that as an immediate progenitor of cultivated rice, part of the genetic diversity of *O. rufipogon* was lost during domestication [45]. Ma et al. reported the first chromosome-level genome of a critically endangered species *Rhododendron griersonianum* which contributed to about 10% of horticultural rhododendron varieties. Lower genetic diversity of *R. griersonianum* (0.0019) compared to other relative species within the same genus and most other woody plants suggested that *R. griersonianum* could face large challenges to its future survival. Therefore, ex situ conservation and artificial supplementary pollination should be conducted as a priority [36].

It was also found that some living fossil plants, such as *Ginkgo biloba*, have high genetic diversity despite relatively few phenotypic variations, supporting the hypothesis of evolutionary capacitance [41].

It is worth noting that some research populations have limited sampling and insufficient representativeness, which may also lead to differences in the levels of genetic diversity reported in different endangered plants. The conservation genomics research of endangered plants in the future needs to ensure sufficient sample size in order to comprehensively evaluate the genomic diversity at the species or population level.

#### **3.3 Inference of population dynamics history**

The history of population dynamics is an important research topic in conservation genomics and population genetics [46]. As important external forces in the process of population evolution, climate change and geological events can affect the population dynamic changes. In addition, gene mutation, genetic drift, natural selection and other forces act as internal driving forces, causing the population evolution to gradually deviate from the "ideal population" and form a new pattern of genetic diversity. Therefore, studying the history of population dynamics can help us understand the shaping of population structure by climate change, geological events, and human activities, and develop reasonable management plans to cope with environmental changes [47–49]. The assessment of population dynamics in traditional genetics is mainly based on the analysis of fossil records and the history of climate or geological changes. With the development of molecular genetics, the widespread use of genetic marker provides us more comprehensive and accurate understanding about species evolution history. Molecular genetics studies based on mitochondria, chloroplasts or microsatellite genetic markers can be used to analyze the difference of polymorphism in different populations, or to infer population history dynamics by comparing the theoretical values under normal evolutionary state of populations. However, these methods require analysis of a large number of samples at the population level. On the other hand, they can only be used to trace the most recent population dynamics event instead of reflecting the overall species historical dynamics.

In the speculation of population dynamic history, the effective population size (*Ne*) is a key parameter reflecting the historical status of a population. It has important guiding significance for species conservation [50]. The effective population size (*Ne*) represents the population size under random mating conditions [51, 52]. Generally speaking, it is smaller than the actual population size. We can directly estimate the genetic drift rate of a population through *Ne*, and infer the genetic diversity and inbreeding level of the population [53]. Keeping the population size large enough to minimize the impact of genetic drift and inbreeding has always been an important goal of endangered species protection [54]. The "50/500" theoretical rule in conservation biology points out that populations with *Ne* less than 50 are vulnerable to inbreeding depression, so when isolated populations are protected alone, the population *Ne* should be kept above 50. Although occasional decrease in population size to this order of magnitude will not have an immediate adverse impact on the population, it is necessary to ensure that the population's *Ne* is above 500 in order to maintain genetic variation in the long term [55, 56].

Thus it can be seen, the *Ne* value has important guiding significance for conservation biology. The development of advanced genome technologies not only allows

*Research Advances and Perspectives of Conservation Genomics of Endangered Plants DOI: http://dx.doi.org/10.5772/intechopen.112281*

for more accurate estimation of population *Ne* and reconstruction of the process of population number changes of a species, but also serves as an important supplement to the field of conservation genomics.

*Davidia involucrata* is a rare plant endemic to China, known as the "panda among the trees". A high-quality genome of D. involucrate was constructed using PacBio Hi-C technology. Re-sequencing analysis showed that the effective population size of *D. involucrata* has been decreasing since the Quaternary Ice Age, indicating that climate change may be one of the main reasons why *D. involucrata* has become endangered. Therefore, the sensitivity of *D. involucrata* to climate change should be fully considered regarding genetic conservation of the species [57].

The effect of ice age on population size decrease can also be observed in another threatened species, *Cercidiphyllum japonicum*, which is one of the most widely distributed forest species in the Tertiary relict leaf forest of East Asia. It is listed as class II protection species according to the List of Wild Plants Under State Protection in China. Comparative genomics and population genomics research based on highthroughput sequencing technology has successfully reconstructed the evolutionary history of the Tertiary relict plant genus *Cercidiphyllum* in East Asia at the whole genome level. It found that the dry and cold environment in the middle Miocene (c. 10 Ma) led to the species differentiation of *C. japonicum* and *C. magnificum*. During the alternation of Pliocene and Pleistocene and the last glacial maximum, the population of *C. japonicum* and *C. grandiflorum* contracted sharply. However, different from the case of *D. involucrate*, selection clearance and balanced selection related to local adaptation jointly maintained genetic variations of genes involved in key physiological processes, thereby improving the ability of *C. japonicum* to adapt to different environments [58].

On the other hand, recovery of temperature during the interglacial period may be beneficial for population expansion. Genomic-based study on the population dynamics history of *Liriodendron chinense* and *Liriodendron tulipifera* showed that throughout the Quaternary ice age, the population of *L. tulipifera* continued to decrease, while the population of *L. chinense* recovered and reached its peak at approximately 0.4 mya, which is the interglacial period between the Guxiang Ice Age (0.3–0.13 million years ago) and the Nie Nie Xiongla Ice Age (0.72–0.5 million years ago). This may explain the higher genetic diversity of *L. chinense* than *L. tulipifera* [59].

Other than climate factors, geological historical events and human interference are also important reasons for population size fluctuations. Genomic conservation study of *Rhododendron griersonianum* suggested that habitat loss caused by human activities, the extremely low genetic diversity of Rhododendron rubra, and the genetic bottlenecks, inbreeding, and harmful mutations related to heat adaptation caused by geological historical events are the main reasons for the formation and maintenance of the 'extremely small population' of *R. griersonianum* [36].

In summary, whole genome sequencing can help infer fluctuations in effective populations and track historical events of population dynamics, as well as infer the impact of past geological and climatic events on the number and genetic composition of contemporary effective populations. As shown in the above research, extreme geological and climatic changes and human activities are important reasons for the rapid decline in effective population size and genetic diversity of endangered species. Linking population size changes with historical environmental changes can also help predict the impact of future environmental changes on population distribution and genetic diversity.

#### **3.4 Inbreeding and asexual reproduction**

According to Hardy–Weinberg principle, in an ideal state, individuals in the population mate randomly, and the allele frequency is stable in inheritance. However, there are generally some non-random mating patterns in natural populations, the most common of which are inbreeding and asexual reproduction, which will affect the homozygosity of the genome. The genetic differences in individual genomes within a population are the key to population adaptation and evolution. Genetic recombination will generate new gene combinations, so outbreeding between unrelated individuals can effectively increase the genetic diversity of a population. On the other hand, selfing or inbreeding between close relatives can significantly reduce the level of genetic variation within the population. Compared with the outbred individuals, the population fitness of the inbred progeny will be significantly reduced due to the accumulation of harmful mutations. This is called inbreeding depression [60]. The degree of inbreeding depression depends on the genetic load of the population. In nature, inbreeding is the result of limited population size, so some rare species are often more vulnerable to threats due to their small populations and isolation. Most individuals in their populations exhibit consistent genotypes with their ancestors [61]. The reproductive method of clone reproduction lacks genome recombination, resulting in extremely low population genetic diversity [62]. In addition, the accumulation of harmful mutations from generation to generation further reduces the adaptive potential of the species [62], leading to a "dead end" in species evolution [63].

Whole genome sequencing can provide us genome-level genetic markers to accurately estimate the inbreeding level of the population. Due to the wide coverage and low computational cost of SNPs on the genome, they are currently commonly used for phylogenetic analysis and Run of Homozygosity (ROH) analysis to evaluate inbreeding levels. Phylogenetic relationship analysis refers to the calculation of relative values of genetic similarity between individuals, which can be inferred through genotype markers. Common evaluation parameters include coefficient of kinship, coancestry, and identity by descent (IBD) [64]. Continuous homozygous regions on the individual genome are the result of inbreeding. When inbreeding occurs, parents will pass the same haplotype segments to their offspring to generate continuous homozygous segments. Therefore, the degree of inbreeding can be reflected by the proportion of ROH in the genome (FROH) [65, 66]. After a period of time, these fragments will be disrupted by recombination, so the length of ROH can also be used to estimate the time of inbreeding events [66].

At present, various software were developed to use genomic data to detect harmful mutations in populations. For example, SIFT prediction software based on sequence homology can help analyze whether newly emerged non synonymous mutations are harmful mutations [67]. PolyPhen-2 prediction software based on sequence homology and protein structure can help predict harmful mistranslation mutations in populations [68]. These software have been applied to the detection of inbreeding depression and harmful mutation of several endangered plant populations. For example, genomic study on two closely-related species of *Ostrya* found that the effective population sizes of the critically endangered species *Ostrya rehderiana* and the widespread species *Ostrya polynervis* both decline in the Quaternary Glacial Age. The effective population size of *Ostrya polynervis* rose rapidly after the end of Glacial Age, while the effective population size of *Ostrya rehderiana* continued to decline since the Holocene after the end of the Glacial Age, along with accumulation of harmful mutations in the genome and occasional infertility of natural fruiting. Surprisingly, the

#### *Research Advances and Perspectives of Conservation Genomics of Endangered Plants DOI: http://dx.doi.org/10.5772/intechopen.112281*

extremely harmful mutations in *Ostrya rehderiana* were significantly reduced compared to the widely distributed species *Ostrya polynervis*. Therefore, the prolonged decline in effective population size leads to weakened inbreeding inhibition, coupled with a reduction in extremely harmful mutations, allowing the endangered *Ostrya rehderiana* to remain robust and survive indefinitely [7]. Instead of simply increasing the total number of surviving individuals by collecting inbred seeds or cloning cuttings in endangered trees, artificial hybridization strategies should be designed in the future to reduce the risk of inbreeding and inheritance, and loss of diversity caused by drift transmission [7].

Based on this idea, Ma et al. analyzed the inbreeding and harmful mutation patterns of different populations of the endangered species *Acer yangbiense*, and developed personalized genetic rescue models. For example, genetic rescue is carried out for populations with high FROH and high homozygous harmful mutations. Pollination of female flowers in populations with the highest number of harmful mutations using pollens from the lowest number of homozygous harmful mutations can not only avoid introducing more harmful mutations, but also hybridize homozygous harmful mutations [69].

The above studies provide important reference value for future related research. More genomic data on endangered plants and continuously improved algorithms can help researchers and managers better identify endangered populations and understand the impact of different management methods on species fitness and genome.

#### **3.5 Adaptive evolution**

Adaptive evolution refers to the continuous accumulation of genetic variation conducive to survival and reproduction under the pressure of natural selection to better adapt to the environment and increase fitness. Traditional adaptive evolution research is mainly conducted through candidate gene methods. However, the candidate gene method relies on screening, targeted amplification, and comparison of known candidate genes. The analysis efficiency is low. The emergence of genomic data has made it possible to detect signals of adaptive evolution at the whole genome level, and has been widely applied in the study of adaptive evolution and population localization adaptation of endangered species.

Compared with only considering the genetic diversity of the whole genome, the adaptability of key regions or loci on the genome has a more significant impact on the adaptability of species. Under the neutral background of the whole genome, this part of the region will be an obvious outlier. Therefore, the possible adaptive association regions can be determined by detecting highly differentiated regions or selected regions on the population [70, 71].

In the genomic conservation study of *G. biloba*, 25 genes involved in insect and fungal defenses and responses to abiotic stress such as dehydration, low temperature and high salt, suggesting that ginkgo possessed unusually high resistance or tolerance to both abiotic and biotic stress, particularly herbivores and pathogens [41]. In *C. japonicum*, 823 genes that may be related to local adaptation were detected through *F*ST and genotypic environmental association analysis. These genes are mainly enriched in cell development and proliferation, auxin metabolic pathway and stress response [58]. *Nostoc flagelliforme* is a first-class protected wild plant in China, mainly distributed in arid and desert areas in the north and northwest. Genome sequencing and comparative genome analysis of *Nostoc flagelliforme* showed that the expression of genes related to protection of photosynthetic apparatus, synthesis of

monounsaturated fatty acids, ultraviolet radiation response promoted adaptation of *Nostoc flagelliforme* to high intensity ultraviolet radiation and extreme drought conditions. The study provides new insights into the research on the adaptability of blue-green algae to adversity [72].

In some other endangered plant species, the genomic loci under natural selection were also identified. Wang et al. used two genotypic-environmental association methods to conduct genome screen on 185 wild soybean germplasm individuals distributed in the three major agricultural ecological regions of China. Multiple genes involved in local adaptation, such as flowering time and temperature related genes were identified. A positive selection site was found on chromosome 19, which contains two adjacent MADS box transcription factors, possibly related to the ability of wild soybeans to adapt to high latitude environments [73].

In addition, through genome analysis of some endangered wild relatives of plants with economic value, we can find the impact of artificial domestication on adaptive evolution. In a genomic study of 81 cultivated and wild tea (*Camellia sinensis*) individuals, the chromosomal selection-sweeping regions were identified and enriched in the endemic and ancient species. It was found that artificial domestication not only improved the flavor of locally cultivated tea trees, but also improved their resistance to non-biotic stress [74]. Niu et al. re-sequenced 38 individual samples of *Dendrobium officinale* and its five related species from 13 regions. Combined genome-wide association studies (GWAS) identified 13 GWAS loci in total. The related genes at these loci are mostly associated with morphological traits such as plant height, leaf length, and stem length, which may be affected by artificial domestication [75].

In conclusion, genome wide sequencing is a powerful tool for detecting natural selection signals, revealing the genetic basis of phenotypic traits, and identifying local adaptation. It can promote our understanding of the inherent mechanisms of genetic variation and adaptive characteristics and help us take targeted protective measures to promote the adaptation of endangered plants to rapidly changing natural environments.

#### **4. Future prospects**

The current global rate of species extinction is accelerating, and the loss of biodiversity and ecosystem degradation has posed significant risks to human survival and development. Solving the problems of long-term survival for threatened species and constructing long-term protection mechanisms are urgently needed tasks.

Genomics study has innovated species conservation methods from multiple directions, such as identification of lineages and inbreeding events, identification of adaptive loci and outbreeding decline loci based on a large number of genetic markers. Conservation genomics can not only solve scientific problems such as genetic diversity, population genetic structure, and population dynamics that traditional conservation genetics focuses on, but also further trace the evolutionary history of species from ancient times to the present, and analyze the molecular mechanisms of population local adaptation and species adaptive evolution. In addition, conservation genomics also provides the possibility to study the genetic basis of interspecific interactions, promoting population level management rather than individual-level protection.

The classic approach in genomics study on endangered plants mainly include the following pipelines: constructing high-quality genomes, conducting comparative

#### *Research Advances and Perspectives of Conservation Genomics of Endangered Plants DOI: http://dx.doi.org/10.5772/intechopen.112281*

genome analysis to identify genes that expand and contract, elucidating the evolutionary process of genomes through WGD analysis or repeat sequence analysis. At the same time, it can further analyze and verify the gene family related to special phenotype and special mechanism by combining with transcriptome analysis. Together with genome re-sequencing, the population historical dynamics can be reveled and valuable genes can be found for genetic breeding.

At the same time, it should also be noticed that although genomics study can provide preliminary solutions for biodiversity conservation, there are still some limitations. Firstly, in order to truly achieve endangered species protection and resource value development, more genomic information of endangered species should be obtained. The techniques of artificial pollination, hybridization, and expansion of endangered plants should also be tackled. Secondly, the vast majority of comparative genomics and population genomics research is currently based on the analysis of single nucleotide polymorphism (SNP) markers, while little is known about the role of structural variations (SV) in the adaptive evolution and local adaptation of endangered species. With the widespread application of third-generation sequencing technology, the ability to accurately analyze SV has greatly improved, which will undoubtedly promote understanding of the role of SV in the adaptive evolution of endangered species and local population adaptation. Finally, although genomics technology has updated some of our scientific knowledge in the field of conservation biology, it may not necessarily be useful for species conservation. For example, based on genomics analysis, we can interpret the function of genetic variations at the genome level and their impact on individual fitness. However, it is still not enough for us to evaluate the survival ability of the population, unless we can link individual fitness with population growth rate for discussion [76]. And this requires long-term research on individual fitness and its impact on population growth rate. This may be the biggest challenge currently facing conservation genomics.

#### **Acknowledgements**

We would like to thank the Zhejiang Provincial Welfare Technology Applied Research Project [LGN21C020007], the National Natural Science Foundation of China [No. 31800187], the 2021 and 2022 Foreign Specialized Projects of the Ministry of Science and Technology [QN2021016002L, G2022016022L].

#### **Conflict of interest**

The authors declare no conflict of interest.

*Endangered Species – Present Status*

### **Author details**

Qing Ma1 , Gang Wu2 , Wenjie Li1 , Seyit Yuzuak<sup>3</sup> , Fachun Guan4 and Yin Lu1 \*

1 College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou, Zhejiang, China

2 Institute of Science and Technology and Culture, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, China

3 Department of Molecular Biology and Genetic, Burdur Mehmet Akif Ersoy University, Burdur, Turkey

4 Institute of Rural Energy and Ecology, Jilin Academy of Agricultural Sciences, Changchun, China

\*Address all correspondence to: maqing@zjsru.edu.cn; luyin@zjsru.edu.cn

© 2023 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.

*Research Advances and Perspectives of Conservation Genomics of Endangered Plants DOI: http://dx.doi.org/10.5772/intechopen.112281*

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#### **Chapter 5**

## Dragon's Blood Tree (*Dracaena cinnabari*): A Cenozoic Relict

*Sanjay Saraf*

#### **Abstract**

The Dragon's blood tree (*Dracaena cinnabari*) woodland is one of the oldest surviving endangered forest communities on Earth. This unique endemic species of Dragon's blood tree is famous since antiquity for its bright red resin "Dragon's blood" and umbrella-shaped canopy. They are almost extinct everywhere except present as small habitats in Socotra Archipelago (Yemen), a UNESCO World Heritage Site. In the last two decades, there has been a significant decline in Dragon's blood tree population in the archipelago, posing a threat to its existence. We attempt to review the status of Dragon's blood tree population in Socotra Archipelago, factors affecting its survival, and the status of conservation efforts propose recommendations to preserve this flagship species.

**Keywords:** *Dracaena cinnabari*, Dragon's blood tree, Socotra Island, biodiversity, vulnerable, endemism

#### **1. Introduction**

The Socotra Archipelago is one of the most significant and well-preserved island ecosystems in the world and holds global significance for the exceptional level of biodiversity and endemism in its ecosystem. Socotra Island is a masterpiece of evolution, containing a unique assemblage of species and habitats, and is ranked as the world's tenth richest island for endemic plant species per square kilometer, with 37% endemic species, which makes the ratio comparable with that of the Galapagos and higher than those found in Mauritius, Rodrigues, or the Canary Islands [1]. The high level of endemism seen in the archipelago is also in accordance with its estimated geological age and ecosystem. Socotra island is home to over 350 species of endemic plant species and is considered as a gem of biodiversity in the Arabian Sea [2–4]. Dragon's blood tree significantly contributes to this endemic biodiversity and is the dominant iconic species of the island (**Figure 1**), (Video available at https://bit. ly/3Dx92h6), [5].

#### **1.1 Dragon's blood tree geographical location**

The Socotra Archipelago is part of the Republic of Yemen and is geographically located in the north-western corner of the western Indian Ocean, at the junction

#### **Figure 1.**

*Dragon's blood tree (D. cinnabari), "flagship species of Socotra" (photograph by the author, Socotra 2018).*

#### **Figure 2.**

*Overview map of the Socotra archipelago, a remarkable biodiversity spot, showing its isolated geographic location in the Indian Ocean.*

between the Gulf of Aden and the Arabian Sea, about 380 km off the coastline of Yemen and 250 km east of Cape Guardafui (Somalia), the tip of the Horn of Africa (**Figure 2**).

The Socotra Archipelago is 250 km long and comprises a group of four islands and other small islets. Socotra forms the largest island of the eponymous archipelago of four islands (about 95% of its landmass), followed by the three satellite islands,

*Dragon's Blood Tree (*Dracaena cinnabari*): A Cenozoic Relict DOI: http://dx.doi.org/10.5772/intechopen.112282*

#### **Figure 3.**

*Socotra archipelago "Galapagos of the Indian Ocean" long geologic isolation is the key to preservation of Socotra's endemic ecosystem.*

which are collectively known as "the brothers," Samha, Darsa, and Abd Al Kuri, and other small rocky islets Jazirat, Sabuniya, and Ka'l Fir'awn, which are uninhabitable (**Figure 3**) but exhibits high level of endemism, rendering the archipelago as a whole even more significant.

The official name of the island is Socotra (often spelled as sokotra, Soqotra or Suqotra), which emanated from the Arabic word *Souq-Al-Qatr,* 'Souq' meaning "the market" and 'Cotra' referring to "dragon's blood"—a reference to the bright red resin produced by Dragon's blood tree species. The main language is Socotri, which is one of the Semitic languages, and Arabic is the official and commonly spoken language.

#### **1.2 Dragon's blood tree taxonomic hierarchy**

Dracaena (Greek: δράκαινα, drakaina "female dragon") genus comprises between 60 and 100 Dracaena species, *D. cinnabari* being one of the only six species that grow as a tree and is considered a terrestrial monocotyledon representative of the Tertiary flora (**Table 1**, **Figure 4**).

#### **1.3 Dragon's blood tree ecosystem evolution and morphological characteristics**

Dragon's blood trees species belong to one of the oldest ecosystems in the world. Dragon's blood tree species are spectacular relicts of the Mio-Pliocene Laurasian subtropical forest in Socotra (Yemen) [7]. In this epoch, Dragon's tree vegetation extended in a continuous vegetation belt between Northern Africa and Southern Europe, but afterward, it was disrupted due to climatic changes, causing the desertification of North Africa [8]. Today, *D. cinnabari* is vulnerable and almost extinct everywhere due to the Pliocene climate changes and extensive desertification of North Africa and Southern Europe [4, 7, 9].

*D. cinnabari* is a monocotyledonous tree with a distinctive umbrella-shaped canopy due to a "dracoid" ramification of branches (**Figure 5**), [10]. Dracaena species are exceptional among monocotyledonous plants because of their capacity for

#### **Figure 4.**

*Dragon's blood tree (D. cinnabari Baif.f): 'Singular dominant endemic community of Socotra.' This unique tree symbolizes a close bond between nature and the indigenous inhabitants of the island. (photograph by the author, Socotra 2018).*


#### **Table 1.**

*Taxonomic serial No.: 505865 [6].*

secondary thickening of stems and roots [11]. The *D. cinnabari* is a dominant endemic evergreen tree and can live for more than 500 years, often reaching a height of 35 to 39 feet and is vulnerable to extinction.

#### **1.4 Dragon's blood tree present distribution status**

The Socotra Island is approximately 110 km long and about 40 km wide, with a total surface area of 3625 km<sup>2</sup> . The island can be geographically divided into three main zones, namely Haggier (Hagghier, Hajhir) mountains, limestone plateau with

#### **Figure 5.**

*Dragon's blood trees (D. cinnabari): The "dracoid" ramification of branches is an adaptation to its harsh environment, which helps in capturing the moisture in the arid environment. ("physiologic plasticity") (photograph by the author, Socotra 2018).*

many cave systems, and the alluvial coastal plains. The Haggier mountains form the backbone of the island and are situated in the northwest part of the island. Its highest elevation is at Jabal Dryet (1526 m) in the central Haggier Massif. In general, the summit of the limestone plateau is covered with sparse shrubland or low woody-herb communities. The coastal plains are sub desertic with open shrubland or in some areas devoid of vegetation.

In general, Dragon's blood trees occur typically in small dense groups and are found on higher slopes of the limestone mountains, particularly in the central and eastern parts of the island (**Figures 6** and **7**).

Dragon's blood tree woodlands are preponderant in the large central plateau of Diksam (Dixam), the central granite massive of Haggier, and the eastern area of Hamadero, Sirahon, and Kilisan [12]. Several smaller and disrupted Dracaena populations exist on Kilim, Sirahan, Shibhon, and other less accessible localities. A dense Dragon's blood tree forest is present in the limestone plateau, known as Roqeb di Firmihin. According to a recent study [5], this small plateau occupies only 2% of the total suitable area currently occupied by the endemic Dragon's blood trees of Socotra, yet it hosts more than 40% of the living population of all *D. cinnabari* trees, making it an attractive hotspot for researchers.

Dragon's blood tree density is not homogenous and has a fragmented distribution, with predominant presence in the central and eastern parts of the island as mentioned earlier. The area of distribution ranges from an altitude of 150 to 1600 m above sea level, and it dominates above 600 meters above sea level (m.a.s.l) [5]. Dragon's blood trees are not seen in the seaside plains, lowlands (below 180 m.a.s.l), and the western part of the island [12].

In the past, Dragon's blood tree habitats were present over larger areas of the island. However, currently, habitats of Dragon's blood tree are dwindling, and several authors have described the *D. cinnabari* habitat decline on Socotra Island [1, 7, 10, 11, 13, 14].

#### **Figure 6.**

*Socotra: General view of habitat. D. cinnabari Is the unique identity of Socotra Island and now occupies only 5% of its habitat. (photograph by the author, Socotra 2018).*

#### **Figure 7.**

*Dragon's blood tree on a higher plateau. The endangered Dragon's blood trees are strongly tied to the culture of the Socotran people. (photograph by the author, Socotra 2018).*

Till the 19th century, the geology of the Socotra Archipelago received little attention, with limited mention of the Dragon's blood tree population in the Socotra archipelago. Most articles published in the late 19th and early 20th centuries were descriptions of endemic species collected by visitors and researchers to the islands. The first description of Dragon's blood tree in the literature was mentioned during the survey of Socotra

*Dragon's Blood Tree (*Dracaena cinnabari*): A Cenozoic Relict DOI: http://dx.doi.org/10.5772/intechopen.112282*

led by Lieutenant J.R. Wellsted of the East India Company in 1835 [15]. He named the tree as Pterocarpus draco (Greek: πτερον, pteron, "wing" + Latin" carpus from Greek: καρπός, karpos, "fruit"; Latin: dracō from Greek: δράκων, drakōn, "dragon"). In the scientific literature, Dragon's blood tree species was first described by the Scottish botanist Sir Isaac Bayley Balfour in 1888 [16].

The best contemporary distribution of Dracaena forests and woodlands was published by Král and Pavliš in 2006 [17] using remote sensing data. They found that the habitats hosting *D. cinnabari* comprised a total of 7230 ha (hectare), including only 230 ha of Dracaena forests and 800 ha of mixed mountains forests, with the rest of the area (6200 ha) consisting of woodlands with low tree densities and overmatured populations [18, 19]. Based on statistical analyses as well as on direct field observations, Král and Pavliš also commented that the Dracaena populations on Socotra do not regenerate to a great extent, and their age structure indicates over maturity.

Attorre et al. in 2007 used a deterministic regression tree analysis (RTA) model to examine environmental variables related to the current *D. cinnabari* species distribution. They found that the current distribution and abundance of *D. cinnabari* is correlated to three factors: moisture index (i.e., the ratio between the annual precipitation and potential evapotranspiration), mean annual temperature, and slope. According to this model, *D. cinnabari* occupies only 5% of its current potential habitat, and this potential habitat is expected to be reduced by 45% by 2080 because of a predicted climate change, with increased aridity [10].

A study by Madera et al. in 2019 using remote sensing data estimated the population size of *D. cinnabari* to be 80,134 individuals, with sub-populations varying from 14 to 32,196 individuals, with an extinction time ranging from 31 to 564 years (**Figure 8**) [5].

A toponym study by Al-Okaishi (2021), carried out in four areas on Socotra Archipelago (301 toponyms), assumed that dragon's blood trees had a wider

#### **Figure 8.**

*The map of the distribution of the toponyms related to the D. cinnabari tree (green circles) in Socotra Island, in red, the current distribution of D. cinnabari by Maděra et al. [18].*

#### **Figure 9.**

*Map showing the study areas (Hajher, Momi, Qatanin, Ma'aleh) in integrating two maps with the current and potential distribution of D. cinnabari according to Maděra et al. [5] and Attorre et al. [10], respectively.*

distribution on Socotra Island in the past, potentially from the west in Ma'aleh to the east in Momi, before humans inhabited the island (**Figure 9**), [20].

In 2021, Vahalík et al. (published 2023) did a field survey of Socotra using a pair of UAVs (using the DJI Mavic Mini drones) to spatially describe individual tree positions, tree density, mortality, and the forest age structure. They found that the spatial distribution of the Dracaena tree density within the entire plateau is variable. The mean age of the forest, based on crown age (derived from crown size), was estimated at an average of ca. 300 years (291.5 years), with some individuals older than 500 years [21].

#### **1.5 Dragon's blood tree conservation status**

Due to its remarkable and highly vulnerable island ecosystems containing many endemic species, Socotra Archipelago was designated as a UNESCO Man and Biosphere (MAB) Reserve in 2003, a Ramsar Site in 2007 (Detwah Lagoon), and then as a UNESCO Natural World Heritage Site in 2008.

Dragon's blood tree **(***D. cinnabari*) is categorized as "vulnerable" species on the IUCN Red List of Threatened Species (**Figure 10**), [22].

#### **1.6 Dragon's blood (resin) and its significance**

Since antiquity, Socotra Island was famous for its Dragon's blood, which is a remarkable bright red colored resin produced by *D. cinnabari*.

The name Dragon comes from the unique, red-colored sap or resin/latex that the tree produces. The tree is known locally as "Ahrieb" "إعريهب "and its resin "dum alakhawin" "دم األخوين, "while derived (mixed-cooked) products are called "eda'a" "إيدع, " while regionally different names can be found (**Figure 11**), [23].

Local legends say that the Dragon's blood tree (brother's blood tree) first grew on the spot where two brothers, Darsa and Samha, fought to death. The Dragon's blood (red resin) is mentioned in early literature by an unknown author of the Periplus of the Erythrean Sea around the mid-first century AD, who called it "cinnabar," possibly because of the matching color [24].

Dioscorides in 90 AD mentioned the Dragon's blood resin in his book "On Medical Material" as Kinnabari "cinnabari," brought from Africa [25]. Names of Dragon's

*Dragon's Blood Tree (*Dracaena cinnabari*): A Cenozoic Relict DOI: http://dx.doi.org/10.5772/intechopen.112282*

#### **Figure 10.**

*IUCN red list aims to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction.*

#### **Figure 11.**

*The Socotra ecosystem and D. cinnabari species are unique to the island, with high global significance. (photograph by the author, Socotra 2018).*

blood tree and its resin are also mentioned in old Arabic literature by travelers and researchers who visited Socotra in earlier days [26–29].

This highly prized resin has been historically harvested by the indigenous population for local use and trade throughout medieval periods for diverse medical, artistic,

#### **Figure 12.**

*The Dragon's blood is a common name of a red sap, or resin, produced by the Dragon's blood tree in response to mechanical trauma. (photograph by the author, Socotra 2018).*

and magical uses. It was frequently used as a medicine for respiratory and gastrointestinal problems in the Mediterranean basin and by early Greeks, Romans, and Arabs [30–32].

Miller and Morris mention the use of *Dracaena* resin as a coloring matter for varnishes, tinctures, toothpastes, and plaster for dying the horn to make it look like tortoiseshell [1].

Dragon's "blood" secretion (**Figure 12**) can be considered an induced natural defense mechanism following trauma by cells of the stem, and during the process of wound repair, this coats the margins of the wound providing additional protection against desiccation, but unfortunately, it also makes the species vulnerable to human exploitation.

Dragon's blood has astringent effects and is frequently used as a hemostatic and antidiarrheal medicine. Though the biological basis for its secretion and phytochemistry is still not completely known, the resin is believed by some authors to have antiviral, antibacterial, antifungal, antioxidant (flavonoids), and anti-carcinogenic properties [33–36]. Local inhabitants still use the red resin for treating diarrhea, fever, mouth ulcers; to stop bleeding; for wound healing, skin diseases, coloring material for dye, varnish, cosmetic, incense, painting, decorating earthen pots, folk music, alchemy, and performing social rituals. However, the efficacy for human use remains unsubstantiated and needs further bioassay-guided spectroscopic studies and scientific trials for establishing human safety and use.

Presently, this resin is an important product for the local communities and is the most important local nontimber forest product (NTFP). It is a source of income for the rural population in Socotra and is becoming even more important with the increasing population, unemployment, and tourism-related activities [20].

#### **1.7 Dragon blood tree mounting challenges and extinction risk**

The factors threatening the survival of Dragon's blood tree population envisage multiple reasons including overgrazing by the increasing population of livestock [10, 37]; habitat loss with insufficient regeneration of Dracaena growth; soil erosion;

#### **Figure 13.**

*Dragon blood trees (D. cinnabari)—Socotra's most iconic plant. (photograph by the author, Socotra 2018).*

**Figure 14.** *Uprooted Dragon's blood tree (photo by author, Socotra 2018).*

increased aridity [10]; effect of past cyclones, namely Chapala and Megh (2015) and Mekunu (2018); climatic changes due to global warming; unsustainable human interference, which are not only rendering the Dracaena woodlands vulnerable to extinction [9] but also making the fragile biological hotspot vulnerable to desertification (**Figures 13** and **14**).

#### **2. Discussion**

The Archipelago of Socotra remained inaccessible for centuries due to its remote geographic location. This prolonged period of geological isolation of the archipelago, a complex geopolitical landscape, and variable climatic conditions with an arid ecosystem contributed to the maintenance of Socotra's distinctly rich biodiversity, with the preservation of many insular species like Dragon's blood tree for centuries.

However, the last few decades have threatened the fragile Socotra ecosystem due to multiple factors including woodland fragmentation, senescent dragon tree population, unsustainable harvesting of dragon's blood, unsustainable overgrazing, unsustainable livestock management, commercial collection of wood, introduction of invasive alien species, smuggling out of endangered Dragon's blood tree, climatic threats, uncontrolled infrastructure development including roads to the mountains, increased unsustainable tourism, lack of financial resources, non-diligent enforcement of international and national policies for bio-cultural preservation, current political instability, and post Covid-19 economic challenges.

The cattle (specially by goats) overgrazing of the vegetation including Dragon tree seeds is an important factor threatening the survival of the Dragon tree [1]. Consumption of seedlings and new sprouts, if not protected from goat and other livestock, prevents *D. cinnabari* and other species from regeneration as they have extremely low survival capacity in open habitats [10, 11]. Overgrazing also provokes soil erosion by causing loss of perennial vegetation layer and the thin organic topsoil following rains. The decline of D. cinnabari is likely to negatively affect plant diversity, reduce the abundance of rare endemic plants, and lead to homogenization of the vegetation [38]. The increasing demand of the red resin has resulted in the overexploitation of Dragon's blood tree and is one of the crucial factors adversely affecting the Dracaena population. The unsustainable traditional method of harvesting dragon's blood further compounds the deleterious effect on the Dracaena population [20]. Multiple cuts on tree to harvest resin invariably makes trees weak and vulnerable to uprooting in intense winds.

Another concerning factor is that most Dragon's blood trees on Socotra Island are senescent, with increasing mean population age and are subject to progressive Dracaena population decline due to limited natural regeneration of the species (**Figure 15**).

The loss of each Dragon's blood tree leads to a decrease in biodiversity, as Dragon's blood trees are important nurse tree [38]. Furthermore, the occurrence of a wide range of insect species depends on *D. cinnabari* [39]. Moreover, dragon's blood tree woodlands function as cloud forests, catching water from horizontal precipitation, fog, drizzle, and mist, playing a significant role in the hydrology of the island [40]. A decline in the Dragon's blood tree population density leads to land aridification, soil erosion, and desertification [41]. Given its ecological importance, *D. cinnabari* has been identified as an umbrella species of Socotra Island, with its conservation essential to preserve the island's native biota [10, 18, 39–43].

Socotra has a dry arid climate, with bimodal distribution of rainfall. The climate is dependent on the seasonal migration of the Inter tropical Convergence Zone (ITCZ) and related monsoon cycles [44]. Each year, from June until September, the seasonal Southwest monsoon blow from Africa brings hot, strong, and dry winds and occasional rainfall into Haggier mountains in Socotra. The Northeast monsoon in winter (November–January) is less pronounced and coincides with the rainy season in the north. The annual rainfall ranges between 200 mm in the coastal plains and 1000 mm *Dragon's Blood Tree (*Dracaena cinnabari*): A Cenozoic Relict DOI: http://dx.doi.org/10.5772/intechopen.112282*

#### **Figure 15.** *Senescent Dragon's blood tree (photograph by the author, Socotra 2018).*

in the high mountains [37]. The alternance of extreme desiccation and mist, brought about by the seasonal wind, had an important effect on the evolution of habitats and vegetation of the Socotra Island.

The climatic changes linked to global effects due to global warming are adding new challenges on the resilience of the vulnerable ecosystem. The resultant unreliable, irregular, and patchy monsoons with mean annual precipitation ranging from 207 to 569 mm is negatively influencing the survival of the present population of *D. cinnabari*. This is not only threatening Dragon's blood tree populations but also endangering other endemic species on Socotra Island. Global warming is perceived as a serious threat to the biodiversity of such hotspots because it is likely to exacerbate both grazing and prolonged drought periods due to unreliable monsoons making it exceedingly difficult for the recovery of vulnerable species [45, 46].

Increasing aridity due to ongoing climatic change is also negatively affecting the potential habitat of the Dragon's blood tree. The loss of Dragon's blood trees is also affecting the hydrological cycle as these plants capture horizontal precipitation [47].

There is also evidence that in the past, a traditional agricultural land use with protected wall system was prevalent on Socotra for organized farming activities for frankincense, myrrh, and dragon's blood and harvesting of aloe juice [48]. This strong traditional land-use management practices employed by the indigenous population served to protect the vegetation and biodiversity of the Socotra Archipelago, which is now lacking.

**Figure 16.**

*Asphalt roads to mountains causing habitat fragmentation and ecosystem destruction. The future road works must minimize environmental impacts on the ecosystem. (photograph by the author, Socotra 2018).*

The strict conservation of vulnerable areas included in the Socotra Archipelago Master Plan envisioned in 2002 are now not being enforced on Socotra due to administrative issues and a complicated land tenure system based on the tribal organization of society [5]. The lack of EIA enforcement capacity with deficient project planning and construction of new infrastructure including housing and several hundreds of kilometers of asphalt roads to mountains (since 2003) are also adversely affecting the fragile habitat of Socotra (**Figure 16**).

Other major threats are the increase in tourism and recreational activities, smuggling of Dragon blood trees to sell them in international markets, increasing immigration, import of goods from mainland Yemen, and pollution by deficient waste management practices around human settlements [20].

The archipelago's remarkable integrity and Outstanding Universal Value (OUV) is also significantly threatened by the unsustainable developments. There are no effective controls in place at the airport or ports to control the import of species and EPA has limited capacity to enforce such controls. Though there is a ban on the removal or export of Socotra flora and fauna, there are many reported incidences of smuggling out of rare endemic species, including Dragon's blood tree, affecting the biodiversity of Socotra Island. Due to ongoing regional instabilities, the coordination between major stakeholders regarding biodiversity conservation issues and decisions may also be affected. The current sociopolitical and post-Covid economic trends are also negatively impacting the site's capacity to provide sustainable economic growth for its people. The local government has limited financial resources and limited protective capacity to enforce local protective legislation. Thus, the population of Dragon's blood tree is thinning from forests to woodlands, shrublands, and eventually grasslands, with individual sparse trees.

*Dragon's Blood Tree (*Dracaena cinnabari*): A Cenozoic Relict DOI: http://dx.doi.org/10.5772/intechopen.112282*

Conservation of vulnerable and endangered endemic species depends on longterm strategies, coordination between different agencies, committed international funding, and involvement of the indigenous population with realistic developmental models; otherwise, money is being wasted with no changes on the ground, affecting the biodiversity more than before. A sustainable financing strategy also needs to be formulated to ensure necessary human and financial resources for the long-term preservation of the endangered ecosystem. More studies, planning, and appropriate linkages need to be developed and evolved for the management of the ecosystem, its buffer zones, and Socotra Biosphere Reserve. Awareness and educational activities to the natives emphasizing the fragility of islands and extinction risks are crucial. By involving the local communities and promoting them to take the lead in conservation activities by inculcating conservation knowledge and perpetuating it to the future generation, the inevitable negative impacts on biodiversity and livelihoods could be countered with improved ecosystem resilience. The local legislative laws for conservation need to be strengthened, maintaining a delicate balance among biodiversity preservation, sustainable trade, tourism, and infrastructure development. The careful implementation of these strategies is likely to positively impact the future of the endemic species in the Socotra archipelago.

#### **3. Recommendations for the preservation of the Dragon's blood tree population**

As the vulnerable biosphere reserve faces new challenges, we propose the following recommendations to protect and conserve the vulnerable Dragon's blood tree population and Socotra's unique archipelago biodiversity [5, 20, 21, 49–51]:

1.Propagating and protecting Dragon's blood tree by:


#### **4. Conclusion**

Socotra's biodiversity remained resilient for centuries; however, the last two decades have threatened the well-preserved ecosystem including the vulnerable endemic Dragon's tree population. The strategic, result-oriented biodiversity preservation approach along with consideration of the proposed recommendations will not only help in protecting the Socotra's unique biodiversity from present and future challenges but also serve as a benchmark for biodiversity conservation around the globe.

#### **Acknowledgements**

I would like to express my deepest gratitude to Divine mother Maa MKM for all the blessings and my dear mother Mrs. Vidya Saraf for profound belief in my abilities and unconditional support. I would like to extend my sincere thanks to my dear friend Mr. Hassan Abd Elfatah Hassan Ismail, Ms. Christina and Mr. Shailesh for their unwavering help and unparalleled support. I also would like to thank dear DSS for unending inspiration and invaluable patience. Finally, I am very thankful and grateful to the staff of Summerland hotel and wonderful people of Socotra for their warm hospitality and great support during my stay in Socotra.

#### **Conflict of interest**

The author declares no conflict of interest.

#### **Video materials**

"Video materials referenced in this chapter are available at: {https://bit.ly/3Dx92h6}"

*Endangered Species – Present Status*

### **Author details**

Sanjay Saraf NMC Specialty Hospital, Dubai, United Arab Emirates (U.A.E)

\*Address all correspondence to: drsaraf@hotmail.com

© 2023 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.

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#### **Chapter 6**

## The Economics of Endangered Species in Hawaii during the COVID-19 Pandemic

*Patricia Yu*

#### **Abstract**

The COVID-19 pandemic has significantly impacted Hawaii's vulnerable ecosystem of endangered species. Despite some scholars suggesting that the pandemic has offered a silver lining by allowing the environment to regenerate and create a safer habitat for these species, the economic impacts of the pandemic cannot be ignored. This paper aims to explore the economics of endangered species in Hawaii during the COVID-19 pandemic. The reduction in tourism has led to improvements in air quality and traffic congestion, as well as increased conservation efforts. However, the decrease in tourism has also had a negative impact on the economy, as tourism is a significant contributor to Hawaii's economy. This paper analyzes the economic trade-offs between conservation efforts and economic growth and explore potential solutions to ensure the long-term sustainability of Hawaii's endangered species and economy.

**Keywords:** COVID-19 pandemic, endangered species, economy, tourism, Hawaii

#### **1. Introduction**

Hawaii is home to a unique and diverse range of plant and animal species, many of which are endangered. A report from the US Congress' Office of Technology Assessment [1] stated that because of being a hub for trade, tourism, and military activities: [T]he Hawaiian Islands represent the worst-case example of the Nation's NIS (non-indigenous species) problem. No other area in the United States receives as many new species annually, nor has as great a proportion of NIS established in the wild. At the same time, Hawaii, the Nation's so-called extinction capital, has the greatest concentration of threatened and endangered species in the United States and

**Figure 1.** *A sample of endangered species in Hawaii.*

the greatest number of extinct species as well (p. 234). See **Figure 1** for a sample of the endangered species in Hawaii.

The COVID-19 pandemic has had a substantial impact on Hawaii's vulnerable ecosystem of endangered species, despite some scholars suggesting that the pandemic has offered a silver lining by allowing the environment to regenerate and create a safer habitat for these species.

Oleson et al. [2] provide a comprehensive overview of the impact of COVID-19 on the economy and environment of Hawaii. It discusses both the negative impacts, such as the loss of jobs and revenue in the tourism industry and the positive impacts, such as the reduction in air pollution and the potential for increased sustainability efforts. They argue that the pandemic provides an opportunity to rethink and transform Hawaii's economy and society in a more sustainable direction. One of the noticeable impacts is the reduction in tourism, which has also led to a significant reduction in traffic congestion in Hawaii. The lack of tourists and reduced commuting have led to less traffic on the roads, resulting in shorter travel times, reduced emissions, and improved safety. The COVID-19 pandemic has also led to some levels of increased conservation efforts in Hawaii. Several organizations, including the Hawaii Nature Center, have implemented new programs to engage residents in conservation efforts, including beach cleanups, native plant restoration, and wildlife monitoring. The Nature Conservancy [3] provides an overview of the impact of COVID-19 on conservation efforts in Hawaii. It highlights both the challenges and opportunities presented by the pandemic, including disruptions to fieldwork and the need to find new ways of engaging with local communities. The resource also emphasizes the importance of continuing conservation efforts during this time of crisis. Iniguez and D'Antonio [4] focuses on the impact of COVID-19 on ambient noise levels in Hawaii, which decreased significantly due to the reduction in human activity during the pandemic. The authors argue that this reduction in noise pollution could have positive impacts on local wildlife, particularly marine mammals that rely on sound for communication and navigation.

The decrease in tourism seems to have a positive impact on Hawaii's wildlife. With fewer people visiting popular tourist destinations, such as beaches and parks, wildlife has been able to thrive in their natural habitats without the disturbances caused by human activities. Several endangered species, including the Hawaiian monk seal and green sea turtle, have been observed nesting and laying eggs on beaches that are normally crowded with tourists. This paper comprises several sections that delve into the economics, positive externalities, conservation efforts, and technologies associated with endangered species in Hawaii. The first section provides a general description of the key economic models measuring the values of endangered species, while the second section explores the positive externalities of endangered species. Subsequently, this paper discusses Hawaii's ongoing efforts to protect these endangered species, followed by an analysis of the technologies utilized in their conservation. This paper concludes with a section on potential solutions to Hawaii's endangered species.

#### **2. Economics of endangered species in Hawaii**

Many literatures explore the use of an economic model to value the endangered species. Diamond and Hausman [5] uses contingent valuation methods to estimate the value of non-market goods, including endangered species. They argue that while contingent valuation has some limitations, it is still a useful tool for policymakers in

#### *The Economics of Endangered Species in Hawaii during the COVID-19 Pandemic DOI: http://dx.doi.org/10.5772/intechopen.110861*

estimating the economic value of environmental resources. Hanley and Spash [6] uses the cost-benefit analysis (CBA) as a tool for decision-making in environmental policy, including policies related to endangered species. They argue that while CBA has limitations, it is still a valuable tool for policymakers in determining the most efficient use of resources. Pagiola et al. [7] provides a comprehensive overview of methods for assessing the economic value of ecosystem conservation, including the value of endangered species. They argue that while assigning economic values to ecosystem services can be challenging, it is essential for decision-making in environmental policy. This report also provides case studies and examples of successful economic valuation of ecosystem services in practice.

CBA could be used to compare the costs of captive breeding programs for endangered birds in Hawaii versus the benefits of ecotourism revenue generated by the presence of these birds in the wild. Similarly, CBA could be used to compare the costs and benefits of habitat restoration in Hawaii versus the costs and benefits of establishing protected areas. However, it is important to note that CBA has limitations, and the economic value of ecosystem services and endangered species may be difficult to quantify in some cases. Nonetheless, CBA can be a valuable tool for decision-making in environmental policy and can help to ensure that conservation resources are used in the most efficient and effective manner possible.

The presence of endangered species in Hawaii has a significant impact on local communities. For example, the Hawaiian monk seal is a species that is only found in Hawaii, and its survival is crucial for the Hawaiian culture. One of the primary methods of monitoring the Hawaiian Monk seal is through fieldwork. However, due to the pandemic, many of the fieldwork activities had to be suspended or reduced. This reduction in monitoring has made it difficult to track the population of the Hawaiian Monk seal accurately. The lack of monitoring could also make it easier for poachers to hunt these seals. The pandemic has also resulted in a reduction in funding and resources for conservation efforts for the Hawaiian Monk seal. Many conservation programs rely on volunteers and field workers, but the pandemic has made it difficult for these workers to carry out their duties. The reduced funding has also limited the number of conservation efforts that can be undertaken, making it difficult to protect the seals from the threats they face. CVM can be used to estimate the economic value of the Hawaiian monk seal. This would involve surveying individuals in Hawaii and other locations to determine their willingness-to-pay for the conservation of the Hawaiian monk seal. The survey would provide participants with information about the Hawaiian monk seal and its status as a critically endangered species. Participants would then be asked how much they would be willing to pay to support conservation efforts for the Hawaiian monk seal. By using CVM, the economic value of the Hawaiian monk seal and the factors that influence individuals' willingness-to-pay for its conservation can be revealed. The results of the survey can be used to inform conservation decisions related to the Hawaiian monk seal. For example, if the estimated economic value of the Hawaiian monk seal is high, policymakers may be more likely to allocate resources to its conservation. However, it is important to note that CVM also has limitations, and the results may be influenced by factors such as survey design and participant biases.

Hawaii has experienced a significant loss of species due to various human activities, such as habitat destruction, invasive species, and climate change. The suite of challenges facing island endemic species, including invasive predators and competitors, habitat degradation, and the loss of mutually beneficial species, alongside economic and social challenges lead to a complex decision environment [8]. The

loss of species can have a profound impact on the tourism industry in Hawaii. The declining tourism industry would have a significant impact on the state's economy. With fewer unique species to showcase, Hawaii may struggle to differentiate itself from other tourist destinations, ultimately leading to a reduction in tourism revenue. Even with many diversifying efforts from the Hawaiian governments, the tourism industry remains a critical component of Hawaii's economy, providing jobs and revenue for many locals. The loss of species can negatively impact the local economy, especially for those involved in the tourism industry. The loss of species can also have a significant impact on the environment of Hawaii. Many species play important roles in the ecosystem, such as pollination and seed dispersal, and their loss can disrupt the delicate balance of the environment. The loss of species can also have ripple effects on other species, leading to a decline in biodiversity, which can ultimately impact the tourism industry in Hawaii. Many of the endangered species in Hawaii are deeply rooted in Hawaiian culture and history. For example, the Hawaiian green sea turtle, known as "honu", is a revered animal in Hawaiian culture and is often seen as a symbol of good luck and longevity. Protecting these species is not only important for their ecological value but also for their cultural significance.

#### **3. Positive externalities of endangered species**

There are several key literatures on the positive externalities of endangered species. Brander and Taylor [9] presents a theoretical model of renewable resource use, specifically focusing on Easter Island as a case study. They argue that the presence of endangered species, such as seabirds, provided positive externalities in the form of ecosystem services and contributed to the sustainability of the island's economy. This paper highlights the importance of considering positive externalities in the valuation of natural resources, particularly in the context of renewable resource use. Ferraro [10] presents a method for targeting conservation investments in heterogeneous landscapes, considering the positive externalities of endangered species. The author uses a distance function approach to estimate the impact of conservation investments on both economic outcomes and the distribution of ecosystem services, including those provided by endangered species. This paper highlights the importance of considering positive externalities in the design of conservation programs and the potential for targeted conservation investments to generate positive economic outcomes. Ribaudo et al. [11] presents the results of a survey of economists' opinions on the environmental benefits of conservation practices, including the positive externalities of endangered species. They find that economists generally agree that endangered species provide positive externalities in the form of ecosystem services and that these services should be considered in the valuation of conservation practices. This paper highlights the importance of considering positive externalities in the design of conservation policies and the potential for market-based mechanisms to encourage the provision of ecosystem services.

The first kind of positive externality of endangered species in Hawaii is towards the ecotourism industry. People from all over the world travel to Hawaii to see the unique and rare species that exist only on the islands. This ecotourism industry provides jobs and revenue for the local economy, as well as educational opportunities for tourists. Ecotourism aims to minimize the negative impact of tourism while maximizing its positive impact on the environment and local communities. By encouraging visitors to appreciate the natural beauty of Hawaii, ecotourism helps

#### *The Economics of Endangered Species in Hawaii during the COVID-19 Pandemic DOI: http://dx.doi.org/10.5772/intechopen.110861*

to protect its unique environment and ecosystem. It provides economic benefits to local communities by creating jobs and supporting small businesses. It also promotes cultural exchange and understanding between tourists and residents as well as provides visitors with an opportunity to learn about Hawaii's unique environment, culture, and history. Nonetheless, ecotourism has its own negative impact on our environment. Ha and Ha [12] examines the environmental impacts of ecotourism in Hawaii, focusing on the impacts of visitor behavior and the infrastructure needed to support ecotourism activities. They found that while ecotourism can have positive environmental impacts, such as promoting conservation and sustainable practices, it can also have negative impacts, such as damage to natural habitats and increased pollution. This article concludes with recommendations for sustainable ecotourism practices in Hawaii.

The second kind of positive externality of endangered species in Hawaii is reflected in the genetic diversity. Endangered species in Hawaii represent a unique genetic pool that can provide valuable genetic diversity. This diversity can be used to improve the genetic health of other populations and can be used to breed hybrids that may be more resilient to changing environmental conditions. This genetic diversity can also be used for medical research, leading to new treatments and cures. One of the most noticeable impacts of the COVID-19 pandemic on genetic diversity in Hawaii has been the decrease in human activity. With travel restrictions and social distancing measures in place, there has been a decrease in the number of people visiting Hawaii. This decrease in human activity has allowed some species to thrive and increase their genetic diversity. For example, the green sea turtle has seen an increase in nesting and hatching success due to reduced human activity on beaches. This increase in nesting success may lead to an increase in genetic diversity, as successful reproduction is crucial for maintaining genetic diversity in populations. While the decrease in human activity has had some positive effects on genetic diversity, there are also potential long-term effects on biodiversity. The COVID-19 pandemic has highlighted the importance of protecting biodiversity and the interconnectedness of ecosystems. Reduced human activity may have unintended consequences on ecosystems, including changes in habitat availability and food availability for species. Kitayama et al. [13] examine the impact of human activities, such as deforestation and invasive species, on the nutrient cycling and soil properties of Hawaiian montane rainforests. They found that these activities can have a significant impact on the health and biodiversity of the ecosystem. This article highlights the importance of preserving intact ecosystems and preventing further degradation to maintain biodiversity.

The third kind of positive externality of endangered species in Hawaii is the ecosystem service. Endangered species in Hawaii provide ecosystem services that are often taken for granted. For example, the Hawaiian hoary bat is a key pollinator for many of Hawaii's native plant species. These plants, in turn, provide habitat and food for other species, such as the endangered Hawaiian monk seal. Without these ecosystem services, the delicate balance of Hawaii's unique ecosystem could be disrupted. The silver lining of the COVID-19 pandemic is reflected in this ecosystem service's relative betterment. The reduction in air and water pollution from reduced tourism and transportation has improved the air and water quality in Hawaii, leading to an increase in ecosystem services such as clean air and water. Additionally, the decrease in human activity has allowed natural habitats to recover, increasing biodiversity and ecosystem functions such as carbon sequestration and soil formation. While the decrease in human activity has had some positive effects on ecosystem services, there are also potential long-term effects on the environment and society. The COVID-19

pandemic has highlighted the importance of protecting and enhancing ecosystem services, which are essential for human well-being and sustainable development. However, the pandemic has also highlighted the vulnerabilities of ecosystems and the need for increased resilience and adaptive management. The decrease in tourism and associated economic activity has affected the ability of local communities to maintain their livelihoods and provide for their families, potentially leading to social and economic challenges. Carrington [14] discusses the link between the destruction of natural habitats and the emergence of zoonotic diseases like COVID-19. It emphasizes the importance of protecting ecosystems and biodiversity to prevent future pandemics. This article highlights the need for policies and legislation to address the root causes of pandemics and promote a green recovery.

#### **4. Efforts to protect endangered species in Hawaii**

The state of Hawaii has taken significant steps to protect its endangered species. For example, the state has established several conservation programs to protect endangered species and their habitats. These programs include habitat restoration, captive breeding, and reintroduction programs. The state has also enacted laws and regulations to protect endangered species. The Endangered Species Act (ESA) of 1973 is a federal law that provides protection for endangered and threatened species and their habitats. Fischman [15] provides an overview of the ESA, its history, and its effectiveness in protecting endangered species. The author argues that the ESA is a powerful tool for protecting endangered species and that its successes can be attributed to its strong legal framework and the support of dedicated professionals and conservation organizations. This paper highlights the importance of political will and public support in the efforts to protect endangered species. Wilcove and Master [16] provides an assessment of the number of endangered species in the United States and the effectiveness of conservation efforts in protecting them. They argue that the ESA has been successful in preventing the extinction of many endangered species, but that additional efforts are needed to recover populations and improve the status of threatened species. This paper highlights the need for continued monitoring and adaptive management in the efforts to protect endangered species. Oates and Myers [17] presents the 1985 International Union for Conservation of Nature (IUCN) Red List of Threatened Animals, which was a significant milestone in the efforts to protect endangered species. The Red List provides a comprehensive assessment of the conservation status of species around the world and has since become a widely recognized tool for identifying and prioritizing conservation efforts. This paper highlights the importance of international collaboration and data sharing in the efforts to protect endangered species.

Hawaii has also enacted state laws to protect endangered species, such as the Hawaii Endangered Species Act. The state has also collaborated with local communities, non-profit organizations, and federal agencies to protect endangered species. These collaborations have been crucial in the success of conservation efforts in Hawaii. For example, the Hawaii Department of Land and Natural Resources has increased their efforts to protect native forest birds, while the University of Hawaii has been studying the effects of reduced human activity on marine mammals. The success of conservation efforts in protecting endangered species in Hawaii during the COVID-19 pandemic has been significant. VanderWerf and Young [18] examines the impacts of COVID-19 on endangered bird conservation efforts in Hawaii. They found that while the pandemic has had some negative impacts on fieldwork, such as reduced funding

#### *The Economics of Endangered Species in Hawaii during the COVID-19 Pandemic DOI: http://dx.doi.org/10.5772/intechopen.110861*

and volunteer participation, it has also provided some unexpected benefits, such as reduced disturbance from tourists and increased community involvement in conservation efforts. This article provides insights into how unexpected events like pandemics can impact conservation efforts and highlights the importance of community involvement in conservation. Additionally, conservation efforts to remove invasive species and restore native habitats have been successful. The removal of feral cats and rats from the island of Lehua has allowed for the restoration of native bird habitats, resulting in the successful reintroduction of endangered seabirds. While the decrease in human activity has had some positive effects on conservation efforts, there are also potential long-term effects on the environment and society. The COVID-19 pandemic has highlighted the importance of protecting and enhancing conservation efforts, which are essential for the preservation of endangered species and the long-term health of ecosystems. However, the pandemic has also highlighted the vulnerabilities of ecosystems and the need for increased resilience and adaptive management. The decrease in tourism and associated economic activity has affected the ability of local communities to maintain their livelihoods and provide for their families, potentially leading to social and economic challenges.

The Hawaiian culture has a deep connection between people's livelihood to the land and its natural resources, reflected in the concept of "kuleana", which refers to one's responsibility and accountability to care for the environment. Leopold [19] explores the concept of kuleana and argues that incorporating this value into conservation efforts in Hawaii can increase community involvement and support for conservation, as it emphasizes the responsibility of individuals and communities to care for the land and its resources. This article provides insights into the cultural values that can inform and shape conservation efforts in Hawaii and highlights the potential for indigenous values to increase community involvement in conservation.

#### **5. Technology of protecting endangered species in Hawaii**

There are several literatures on using technologies to protect endangered species. Shahriar et al. [20] provides an overview of the different technologies that are being used to protect endangered species. They describe the use of GPS tracking, remote sensing, and drones in monitoring and conserving species, as well as the use of genetic analysis and biotechnology in understanding and preserving genetic diversity. This paper highlights the potential of these technologies in improving the efficiency and effectiveness of conservation efforts. Duran et al. [21] provides a comprehensive review of the use of biotechnology in protecting endangered species. They describe the use of techniques such as artificial insemination, embryo transfer, and cryopreservation in preserving genetic diversity and enhancing reproductive success. This paper highlights the potential of biotechnology in improving the genetic health and resilience of endangered species. Gober and Kumar [22] focuses on the use of remote sensing technology in monitoring and managing endangered species. They describe the use of satellite imagery, unmanned aerial vehicles (UAVs), and ground-based sensors in detecting and mapping habitats, monitoring populations, and assessing the impacts of environmental changes. This paper highlights the potential of remote sensing technology in improving the efficiency and accuracy of conservation efforts, and the need for continued research and development in this area.

As the world faces an unprecedented rate of biodiversity loss, technology has become an increasingly important tool in protecting endangered species. In Hawaii,

#### *Endangered Species – Present Status*

#### **Figure 2.**

*Technologies of protecting endangered species in Hawaii.*

new technologies are being developed and implemented to address the threats facing endangered species. See **Figure 2** for a glimpse of the technologies used in Hawaii:

The first technology in **Figure 2** is the conservation drones, which have become a useful tool in the protection of endangered species in Hawaii. These unmanned aerial vehicles (UAVs) can be used to monitor and survey wildlife populations, track migration patterns, and detect illegal activities such as poaching and logging. Drones have also proven to be valuable tools in the discovery, inventory, and mapping of rare cliff plants; and due to the difficulty of the on-the-ground survey of cliffs, drones have been deployed across a range of environments leading to the discovery of unknown populations [23]. The other technology is satellite tracking, which has become a popular tool in the protection of endangered species in Hawaii. By attaching satellite tags to animals, researchers can track their movements, migration patterns, and behavior. This information can be used to identify critical habitats, monitor population trends, and develop effective conservation strategies. In Hawaii, satellite tracking has been used to monitor the movements of endangered sea turtles, monk seals, and humpback whales. Artificial intelligence (AI) has the potential to revolutionize the protection of endangered species in Hawaii. By using machine learning algorithms, AI can analyze large amounts of data, such as satellite imagery, and identify patterns that indicate the presence of endangered species or threats to their habitats. This can help researchers and conservationists identify areas in need of protection and develop effective conservation strategies. In Hawaii, AI has been used to identify nesting sites of the endangered Hawaiian petrel and to monitor the spread of invasive species. AI can also be applied to large groups of animals (e.g., ant colonies and beehives), or implemented for monitoring animals that are often difficult to sample, namely cryptic species such as the nocturnal spotted-tailed quoll or species that cover an extensive range such as seabirds [24]. Virtual reality (VR) has emerged as a tool for raising public awareness and education about endangered species in Hawaii. By using VR technology, people can experience the habitats and behaviors of endangered species and gain a deeper understanding of the threats facing these species and the importance of their protection. In Hawaii, VR has been used to educate visitors and locals about the endangered Hawaiian monk seal and to promote conservation efforts. Putrino et al. [25] provides a review of the use of augmented and virtual reality in wildlife conservation, including its potential applications for education, research, and public outreach. They discuss the potential for virtual reality to create immersive experiences that promote empathy and understanding of environmental issues, as well as its potential for research and monitoring of endangered species. This article provides a comprehensive overview of the potential applications of virtual reality in wildlife conservation and highlights the importance of using technology to enhance conservation efforts.

*The Economics of Endangered Species in Hawaii during the COVID-19 Pandemic DOI: http://dx.doi.org/10.5772/intechopen.110861*

#### **6. Potential solutions to Hawaii's endangered species**

There are several literatures on giving certain solutions to Hawaii's specific or general endangered species. Kelly et al. [26] focus on the impact of climate change on Hawaiian forest birds, which are highly endangered due to habitat loss and the introduction of non-native species. They argue that conservation efforts need to consider the potential impacts of climate change on the birds' habitats, as well as the need for landscape-level management that integrates both natural and cultural values. This paper provides insights into the challenges and opportunities of conserving endangered species in the face of a changing climate. National Oceanic and Atmospheric Administration (NOAA) provides information on the Hawaiian monk seal and their website outlines the various efforts being undertaken to protect the species, including habitat restoration, predator control, and public education. It also highlights the importance of partnerships between government agencies, conservation organizations, and local communities in the conservation of the species [27]. Tredick et al. [28] discusses the challenges and opportunities of managing endangered species under a changing climate, using the Hawaiian hoary bat as a case study. They argue that effective conservation strategies need to integrate both short-term and long-term climate projections, as well as incorporate adaptive management approaches that allow for ongoing evaluation and adjustment of conservation measures. This paper highlights the need for innovative solutions that balance the protection of endangered species with the realities of a changing world.

With the tourism industry picking up and marching towards the post-pandemic era, the growth of tourism and associated development has again placed significant pressure on Hawaii's natural resources, threatening the long-term sustainability of both its economy and endangered species. Smith et al. [29] examines the impact of the COVID-19 pandemic on conservation science, including the disruption to fieldwork, funding, and scientific collaboration. They argue that the pandemic has highlighted the need for more resilient and adaptive conservation practices, as well as the importance of interdisciplinary approaches to conservation science. This article provides insights into the impact of the pandemic on conservation science and highlights the need for innovative and adaptive conservation strategies in the post-pandemic era.

In the face of climate change, Hawaii Island's survival is contingent upon embracing sustainability as a crucial element. Some potential solutions to ensure the long-term sustainability of Hawaii's endangered species and economy include (1) habitat restoration: the restoration of native habitats can help create safe and suitable environments for endangered species as well as opportunities for eco-tourism, which can provide revenue for local communities while protecting the environment. Habitat restoration efforts can be challenging, requiring significant resources, including funding, expertise, and time. Additionally, restoration efforts must be carefully planned and executed to avoid unintended consequences, such as the introduction of non-native species or the disruption of ecosystems. Despite the challenges, habitat restoration efforts in Hawaii have had some notable successes. For example, the restoration of the Hakalau Forest National Wildlife Refuge on the Big Island has led to the recovery of several endangered bird species. Additionally, the restoration of Kāne'ohe Bay on Oahu has resulted in the return of numerous marine species, including sea turtles and monk seals. (2) Invasive species management: invasive species pose a significant threat to Hawaii's biodiversity. One solution to manage invasive species is through effective control and eradication programs. Several methods have been used

to control invasive species in Hawaii, including mechanical, chemical, and biological control methods. Mechanical methods involve physically removing invasive species, such as through hand-pulling or mowing. Chemical methods involve the use of herbicides or pesticides to control invasive species. Biological control methods involve the introduction of natural enemies of invasive species, such as predators, parasites, or diseases. Eradication programs are designed to eliminate invasive species from a particular area. These programs often require intensive efforts and significant resources. One example of an eradication program in Hawaii is the effort to eradicate the coqui frog, a highly invasive species that has spread across the islands. The program involves the use of a variety of control methods, including hand capture, habitat modification, and the use of acoustic deterrents. Prevention programs often focus on early detection and rapid response to new invasive species introductions. Hawaii has implemented several prevention programs, including the Clean, Drain, and Dry program, which aims to prevent the spread of invasive species through watercraft. Despite the challenges of controlling invasive species, there have been some notable successes in Hawaii. For example, the successful eradication of the Miconia plant from Maui has resulted in the recovery of several native bird species. Additionally, the implementation of the Little Fire Ant Eradication Program has prevented the spread of this invasive species to other islands. (3) Sustainable tourism: tourism is a significant driver of Hawaii's economy, but it can also be a source of environmental degradation. One potential solution is to shift towards sustainable tourism practices that prioritize the preservation of Hawaii's natural and cultural resources. This can include promoting eco-tourism, encouraging responsible tourism practices, and implementing sustainable development initiatives. Agriculture is an essential part of Hawaii's economy, but it can also have a significant impact on endangered species. Sustainable agriculture practices, such as crop rotation and the use of organic fertilizers, can help to reduce the impact of agriculture on endangered species. In addition, sustainable agriculture can help to promote biodiversity by preserving natural habitats and supporting the growth of native plants. (4) Local community engagement: local communities play a vital role in protecting Hawaii's endangered species and economy. One potential solution is to engage local communities in conservation efforts. This can include providing education and training on sustainable practices, involving local communities in conservation planning and decision-making, and creating economic opportunities that promote conservation. (5) Research and technology: advancements in technology can provide innovative solutions to protect Hawaii's endangered species and economy. Additionally, research into sustainable tourism practices and conservation strategies can inform policy decisions and help identify effective solutions.

#### **7. Conclusion**

Hawaiian culture has a strong connection to the land and the environment, with the concept of "malama aina" emphasizing the importance of caring for and protecting the land. Malama Aina is a central concept in Hawaiian culture, emphasizing the importance of living in harmony with the environment and protecting it for future generations. Native Hawaiians recognized this relationship in the proverb "He ali'i ka 'aina; he kauwa ke kanaka (The land is a chief; man is its servant [30]. The recognition of limited resources, the cultural ethic of conservation (malama i ka 'aina, literally to care for that which feeds), and a cultural emphasis on recognizing and documenting changes in Hawaiian ecosystems support active ecological literacy

#### *The Economics of Endangered Species in Hawaii during the COVID-19 Pandemic DOI: http://dx.doi.org/10.5772/intechopen.110861*

oriented to sustainability [31]. Traditional conservation practices include the concept of "ahupua'a," which is a system of land management that recognizes the interconnectedness of land, water, and people. In this system, each ahupua'a was managed to ensure the sustainability of resources such as water, fish, and plants. This system helped to prevent overexploitation and ensured the long-term health of ecosystems. Hawaii has one of the highest rates of species extinction in the world, with many of its native species facing extinction due to habitat loss, invasive species, and climate change. Protecting endangered species in Hawaii is critical to preserving the state's biodiversity and ensuring the long-term health of ecosystems. Current conservation efforts in Hawaii include the restoration of native habitats, the removal of invasive species, and the protection of endangered species through conservation programs and partnerships with local communities. These efforts align with the principles of "malama aina", emphasizing the importance of caring for the land and preserving its natural resources. Protecting endangered species in Hawaii is critical to preserving the state's biodiversity and ensuring the long-term health of ecosystems. It is essential to continue promoting and implementing sustainable conservation practices that balance economic, social, and environmental goals and preserve the unique culture and biodiversity of Hawaii for future generations.

### **Author details**

Patricia Yu University of Hawaii—West Oahu, Hawaii

\*Address all correspondence to: pyu@hawaii.edu

© 2023 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.

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### *Edited by Mohammad Manjur Shah*

The book provides comprehensive information on the importance of conserving endangered animal and plant species. There are many species categorized as very likely to become extinct in their own native ranges in the near future. In fact, thousands of species are lost every year, and their numbers continue to increase annually at an alarming rate. The book is organized into two sections on animal species and plant species. The first section discusses endangered animal species such as Chinese pangolins, Pompa cats Galapagos pinnipeds (sea lions and fur seals), and more. The second section discusses endangered plant species such as dragon blood trees and plants native to Hawaii. The book emphasizes species conservation and proposes various strategies adopted and recommended by experts.

### *J. Kevin Summers, Environmental Sciences Series Editor*

Published in London, UK © 2023 IntechOpen © Jian Fan / iStock

Endangered Species - Present Status

IntechOpen Series

Environmental Sciences, Volume 13

Endangered Species

Present Status

*Edited by Mohammad Manjur Shah*