**4. Challenges on soil ecosystem services: implications of global change drivers**

Majority of ecosystem services required for humans'survival and development are resulted from soil processes and functions mainly mediated by biodiversity. This is due to involvement in soil biogeochemical and physicochemical processes, as well as in shaping the aboveground biodiversity and terrestrial ecosystem functioning through liaising nutrient cycles and turnover [48]. Once their structure can be influenced by environmental (soil physicochemical properties) and climatic conditions [68], they are considered as a relevant indicator of soil health and ecosystem sustainability. Thereby, soil biota is the main pillar that sustains and maintains the soil ecosystem. They are pivotal in supporting services such as soil organic matter decomposition, nutrient cycling, and organic and inorganic compounds degradation.

*Global Change Drivers Impact on Soil Microbiota: Challenges for Maintaining Soil… DOI: http://dx.doi.org/10.5772/intechopen.111585*

**Figure 2.** *Interrelationship between microbiota mediated and other soil functions and ecosystem services.*

Through these, they contribute to soil fertility and quality. Microbiota sustains soil provisioning services by producing a wide range of organic compounds (e.g., polysaccharides, mucilage) that cohere soil particles. This influences soil supporting services as soil structure formation and development in time, through soil particle cementation. Further, soil structure stabilization is sustained by fungal filaments. Microbiota components are at the same time producers and consumers of soil organic carbon; thus, it is linked with supporting and regulating services of soil. Many studies underlay that soil microbiota could be a serious element in regulating services such as reducing atmospheric greenhouse gases. In this manner, they could limit climate change amplitude in future. Under favorable microhabitat conditions (optimal nutrient and carbon sources, available inorganic nutrients, proper acidity/alkalinity, temperature, aeration, moisture, etc.) microbial activity could considerably favoring and facilitating soil functions, and consequently the provision of soil ecosystem services at a higher amplitude. Niego et al., [69] reported that changes in soil microbiota diversity and abundance impact soil ecosystem processes. One of them is involvement in nutrient retention and cycling. These processes are related to the ability of soil microbiota components to break down organic matter and to release resources back into aboveground biota. Both plant litter decomposition as well N release back into aboveground plant diversity decrease with soil biodiversity shift in structure and abundance. Moreover, phosphorous, after increased rain events, could be lost through leaching. This is positively correlated with soil microbiota transformation and/or decline. Loss of soil biota become a great concern due to global change-related drivers induced pressures on it. Shift or loss of soil biota communities and abundance are thought to threaten soil ecosystem performance, further reducing the provision of ecosystem services [70]. Although it starts to become more clearer the importance of

soil microbiota community structure and abundance in provision of soil ecosystem services, at the moment it is unclear how global change drivers will impact that. According to literature, until now most studies have focused on global change drivers' ecological consequences on aboveground biodiversity loss and less on belowground biodiversity. This is mostly attributed to the soils hidden diversity and heterogeneity. There are studies performed on land use and land management potential impact on soil microbiota. Usually, these connected soil microbiotas threaten with lower cycling of nutrients and other resources. Moreover, most studies focused on the effects and implications of a specific group or species. While soil microbiota components interact within complex food webs, which also contribute to changes in structure, abundance, and distribution within on trophic group or functional guild it is assumed that these may cause changes in the abundance, diversity, and functioning of another [70]. Therefore, become emergent to understand and get knowledge on how loss of soil microbiota will impact soil functions performance in providing ecosystem services.

Concurrent use with intensified management of the soil for agriculture, forestry, grazing, urbanization, mining, etc. purposes has serious outcomes on the provision of soil ecosystem services. Climate change-related events such as extreme meteorological events, higher temperature, and altered precipitation frequency amplify the effects. Although not fully elucidated which species in which manner has an impact on soil ecosystem services provision, it started to become clearer that soil microbiota components have a relevant role in soil functions and processes. Consequently, this could influence the provision of ecosystem services. It was reported that generally, microorganisms could manifest resistance, resilience, or extinction against some abiotic and biotic disturbance or stress. However, even in that cases the mechanisms are not completely understood. The impact amplitude seems to depend directly on the type of stress or disturbance, combinations of these, and their end influence on micro and macrohabitat properties.

#### **4.1 Climate change impact on soil ecosystem services**

It is acknowledged that soil biodiversity from all geoclimatic regions is affected by climate change. There are several reports that attest to the impact of various climate change drivers on several aboveground biodiversity components' health, functioning, and distribution. Considering literature, often reported that selected species have become extinct while others are endangered [71, 72]. However, both extinctions as well changes in health and functional status of species can alter seriously important ecological processes because they control, and mediate functions related to it. However, plants and animals respond in different ways at the pressures of climate change drivers. Usually, species have a tendency to cope with them. This is because of their evolutionary and ecological properties. Low-altitude inhabiting species extend their distribution at higher elevations while species from higher altitudes reorganize their relationships between community structure. Therefore, species range expansion poleward in latitude and upward in elevation is a common feature under changing climate properties. Generally, species are vulnerable due to their native habitat fragmentation and the negative effects of climate change drivers. They present individualistic responses to these challenges, but these will present a more pronounced and extended impact on the composition and functioning of future ecosystems [73]. Projected data reported in the literature consider macro-biodiversity. Information on how climate change impacts soil belowground microbiota, their involvement in ecosystem services provision as well how soil ecosystem will change, are scarce at present.

*Global Change Drivers Impact on Soil Microbiota: Challenges for Maintaining Soil… DOI: http://dx.doi.org/10.5772/intechopen.111585*

#### *4.1.1 Atmosphere composition*

Soils play a fundamental role in climate maintenance under favorable conditions, one of the major regulating services. Soil processes, mainly mediated by soil biodiversity, regulate climate through a balance of thermal and moisture exchange ratio, and greenhouse gases (H2O, CO2, CH4, and N2O) emission and retention [74]. Threatening of soil biodiversity can alter atmosphere quality and composition, which consequently will amplify climate change drivers further.

#### *4.1.2 Temperature and precipitation regime*

Degradation of soil ecosystem become frequent in many regions of the world. Changes in temperature, seasonality, and precipitation patterns have the potential to exacerbate soil ecosystem degradation. Many times, this results in lowering of ecosystem services' amount and efficiency. The high quality and quantity of ecosystem services are correlated with the health, complexity, and abundance of ecosystem species. However, species are limited in their adaptation to pressures such as temperature rise. Dow et al., [75] reported that an increase in average night temperature by 1° C decreased rice yield by 10%. Thus, changes in both temperature and precipitation regimes are often linked with food and other provisioning services decline. Alteration of evapotranspiration contribute also in the decline of primary productivity and food production [73]. These are supporting and provisioning services.

#### *4.1.3 Extreme climate events*

As changes in meteorological parameters could induce an alteration of the soil system's ability to translate the various ecosystem functions that support crop growth into provisioning services such as food, feed, and fiber, it becomes obvious that extreme climate events such as flood, drought, heat waves, and others, will have a more pronounced and dramatic effect.

#### **4.2 Anthropogenic impact on soil ecosystem services**

The prevalence of anthropogenic disturbance in the surrounding environment is obvious. These are highlighted through the soil physical and chemical properties decline. Soil properties decline manifest mainly through loss of its key constituents (clay, silt, soil organic carbon), diminution of water availability and holding capacity, abatement of key nutrients content, truncation of soil profile, and shallowing of topsoil depth as well through chemicals contamination and runoff. These deplete ecosystem C pool, enhance GHG reemission, and could induce anaerobiosis in soil layers. In part or in combination they could threaten soil microbiota through damage to their functioning, reduction in richness and abundance, or even in the extinction of species. The microbiology within soils supports a wide range of ecosystems underpinning the productive capacity and environmental sustainability of land use. Ample occupation of forests, grasslands, and wetlands for various purposes as the extension of living space and agricultural land resulted predominantly in the loss of biodiversity. This loss registered negative consequences on the soil chemical, biochemical, and physical properties. Ecosystem services are in high percent the end-result of interactions between plants, animals, and microorganisms from an ecosystem; biotic and abiotic properties of system; and human-engineered components of social-ecological

systems. Ecosystem services provision, both in terms of quality and quantity, directly depends on land use type and use intensity, production system, and applied management [76]. These have an extensive impact on soil ecosystem services. Anthropogenic drivers and induced environmental stressors impact natural ecosystems through propagation of ecosystem functions that hamper ecosystem services provision [13, 30].

*Land use change* links human activities with ecological processes change that is closely connected with ecosystem services provision. Modification of land with aim of other use changes seriously soil ecosystem and its native biota abundance and spatial distribution. For example, in agriculture farms diversity (crops and/or livestock) is characterized mainly as "planned biodiversity." This always modifies soil ecological system structure and function, which end in failure of soil ecosystem ability to provide services. Therefore, the way of the use of soils has a decisive role on soil ecosystem services provision. Changes in natural land systems into agricultural or urban environment hampered soil ecosystem development, thereby reducing or stopping the provision of most support, provision, regulating and cultural services. Such alteration of services often amplifies soil issues such as erosion, poor fertility, desertification, and salinization [77]. Removal of forests for feedstock production for biofuels changed and damaged most services provided originally by the forest soil ecosystem. These are regulating services such as climate and water regulation through functions connected with carbon sequestration and accumulation, regulation of the atmospheric chemical composition and climate processes, as well functions linked to regulation of hydrological flows, buffering, and moderation of hydrological cycles. Provisioning services such as fiber, timber, genetic resources, and biochemicals are also reduced or totally shifted due to habitat modification and properties alteration. Such alterations extend their impact also on supporting and cultural services as well. Urban expansion is pronounced all around the world. This is also a driver associated with habitat loss and soil system degradation. Moreover, He et al., [78] and Wu et al., [79] reported that the continued expansion of urban areas will decrease significantly regional carbon storage, fostering thus climate change continuum and amplitude.

#### *4.2.1 Land management*

Intensive farming, mining, and industrial activities; as well as extended urbanization endangers local ecosystem services across landscapes. Soil erosion is a common feature of these activities. These reduce soil nutrient content which made microorganisms sensitive to this disturbance. Hereby, microbiota functions related to supporting services provision as nutrients element cycling and organic matter decomposition will decline [27, 32]. Until that moment farm diversity (crops and/or livestock) was characterized as "planned biodiversity." Although it comprised also "unplanned diversity," as weeds and pests, most of the time measures have been taken against them. Applied management practices were directed either to eliminate (e.g., pests) or promote (e.g., cultivated crops) populations or to enhance specific ecosystem processes (e.g., N fixation). Today, these practices and their effects at the macrolevel made us to suppose that actions were felt also by associated species and functional diversity (e.g., soil belowground diversity), and consequently by their function performances in soil. The amplitude at which these were felt by soil belowground microbiota is not clearly acknowledged although there are evidence of their importance in several soil functions and processes performance. Crop diversification through crop rotations, cover crops, or intercropping enhanced regulation and

#### *Global Change Drivers Impact on Soil Microbiota: Challenges for Maintaining Soil… DOI: http://dx.doi.org/10.5772/intechopen.111585*

sustainability of provided services. This was achieved through the facilitation of pest, weeds, and disease control by minimizing considerably or avoiding the use of agrochemicals. Furthermore, crop diversification stimulates soil microbial abundance and, in turn, soil biodiversity. Also, it supports carbon sequestration, which provides additional ecosystem services. Brussard et al., [80] stated in their paper that after abiotic disturbances or stresses, soil ecosystem and its inhabiting diversity could either restart succession from the stage to which it was set back or transcend into a new stability level. They assumed that after release from disturbance or stress, the reversion could take a long time. The required time usually could depend on spatial heterogeneity where recolonization must take place, and on microorganism restoration and dispersal abilities. However, studies in this sense are at early stage at this moment and the mechanisms and multilevel effects are not fully understood. Soil microbiota community resistance against stress and resilience from disturbance are important to be acknowledged for the proper management of biodiversity and provisions of linked ecosystem services. Crop production is associated with soil carbon content decline. This impacts soil functions as water and nutrient retention. The application of high amount of chemical N for intensive crops and vegetable cultivation caused an array of soil and connected ecosystem services alterations associated mainly with ecosystem pollution. These could be summarized in reactive N losses and greenhouse gas emissions. According to literature tilled agroecosystems without crop rotation decrease microbiota abundance and certain species richness. Opposite, agricultural practices such as crop-rotation, no-tillage and use of organic amendments enhance diversity abundance and community structure richness [81]. However, based on applied organic matter quality, the effects on microbiota could be either positive or negative. Drainage and irrigation, in proper manner, could enhance soil microbiota diversity and abundance. Tillage, a usual field operation practice modifies soil structure favoring agronomic processes (seed contact, root proliferation, water infiltration, etc.). Under conventional tillage, soil microbiota is altered structurally, morphologically, and functionally. This reduces microbial biomass, nutrient cycling, and enzymatic activities. Tillage reduces especially bacteria abundance and AMF diversity.

#### *4.2.2 Chemicals and other extraneous elements addition to soil ecosystem*

Pesticides and fertilizers can adversely impact selected soil biota species. This could result in the diminishment of their functionality, lower health status, or extinction. Such threat to soil biodiversity species will damage soil food webs, thereby underpinning the diversity of higher trophic levels. Moreover, modified interactions among soil species as well as a lower abundance or altered functioning of biota will significantly reduce supporting (nutrient cycling, soil formation, primary production) and regulating services (disease regulation pollination, climate, and water regulation). These consequently will negatively impact soil provisioning and cultural services. Municipal compost and animal slurries application to agricultural soils were considered as means to replace fertilizers used in conventional agricultural practices, and to reduce waste deposition in landfill sites. Acceptance of this practice was sustained also by other potential benefits such as the reduction of carbon emissions linked with mineral fertilizers production and use and with reduction of greenhouse gases emission through organic material decomposition and degradation in storing landfills. However, once with application of these management procedure on agricultural lands, new studies were performed assessing their impact. These evidenced several

new safety issues linked to them. Most of these issues are related to the higher loads to the soil of potentially toxic chemicals, crops phytotoxicity, higher CH4 and N2O emission, as well as high potential in the introduction of alien and potential toxic microbiota components (e.g., pathogens). However, understanding and knowledge related to the impacts of applying organic waste materials to agricultural lands is developing at moment. There is information that introduction of alien species and/or pathogens in soil have the potential to change physical environment properties but is not clear how will this modify microbiota community structure and abundance that are involved in several key soil functions. EA published a report in 2008 [82] highlighted that organic waste material with higher Zn content shifted rhizobium bacteria abundance, which is responsible for nitrogen fixation into the soil. Considering agricultural and organic wastes, Garcia et al., [83] published that they could degrade the local ecosystem in multiple ways, reducing and altering therefore the provision of ecosystem services. They mentioned that swine manure ends up in nearby waters (rivers, streams, creeks, etc.) impacting fish diversity health and abundance, and water quality as well. However, more experimental and confirmatory data are still required in order to comprehend relations and connections between organic waste materials application to agricultural lands and changes in soil microbiota and ecosystem services, respectively.

## **5. Conclusions**

Collectively, soil microbiota has key roles in soil ecosystem functioning processes, such as organic matter decomposition, nutrient cycling, and soil fertilizing. Through these, they assure soil with essential nutrients and elements with that soil could sustain the continuation and development of living organisms. As producer and consumer of soil organic carbon, they could sequester C into soil for a large period. They contribute to atmospheric greenhouse gas reduction and have the potential to limit the effects caused by greenhouse gases generated by climate change. Microbiota through their biochemical reactions assures in large part soil structure development and soil water retention capacity. With released polysaccharides and mucilage help to cement soil aggregates and consequently, reduce aggregates crumble when exposed to water. Summarizing all involvement and effects of soil microbiota components in soil processes and reactions, it could be concluded that most microbiota community components break down organic matter, recycle nutrients in soil, create humus, influence soil structure, fix nitrogen, promote plant development and growth as well protect them against pests and diseases. It is obvious that soil biodiversity is a critical element that assures soil ecosystem functioning and sustainability. Soil belowground microbiodiversity is as valuable as aboveground biodiversity, as they are being involved in many soils' biochemical and physicochemical processes. The effects of global change drivers on aboveground species are acknowledged through literature but knowledge on these how will impact soil microbiota and how a change in their structure and functioning will modify the sustainability of soil ecosystem functioning and ecosystem services delivery require additional research. In this context, exploring the influences of global change drivers on soil microbiota involved in key functions that contribute to and deliver ecosystem services is significant for understanding potential changes in regional soil ecosystem, ecology, and environment; enhancing soil ecosystem and ecology security; to promote a sustainable development maintaining in safe limits soil environment resources.

*Global Change Drivers Impact on Soil Microbiota: Challenges for Maintaining Soil… DOI: http://dx.doi.org/10.5772/intechopen.111585*
