Regulating services

Maintaining the quality of air and soil, providing flood and disease control, or pollinating crops are some of the regulating services provided by ecosystems. They are often invisible and therefore mostly taken for granted. When they are damaged, however, the resulting losses can be substantial and difficult to restore.

Local climate and air quality

Ecosystems influence the local climate and air quality. For example, trees provide shade whilst forests influence rainfall and water availability both locally and regionally. Trees or other plants also play an important role in regulating air quality by removing pollutants from the atmosphere.

Air pollutants have an effect on agricultural crops, including annual and perennial species as they may affect processes within individual plants that control or alter growth and reproduction, thereby influencing yield. Crops, as other plants, also have a potential to clean the air. For example, lines of coniferous trees on a field edge may shield a farmer’s crop from pesticide drift from adjacent fields.

Livestock can have a negative influence on local air quality, especially through ammoniac (NH3) emission coming from high density livestock systems. Installing filters in barns can help reducing this impact.

Fisheries and aquaculture are directly impacted by water and air temperature changes through impacts to reproduction cycles, spatial ranges, disease risks and fish habitats, such as coral reefs, which are susceptible to temperature changes.

Urban trees can affect air quality in the following ways: firstly converting carbon dioxide to oxygen through photosynthesis. Secondly by intercepting particulate pollutants (dust, ash, pollen and smoke) and absorbing toxic gases such as ozone, sulphur dioxide, and nitrogen dioxide. Thirdly by emitting various volatile organic compounds contributing to ozone formation in cities. At last by lowering local air temperatures and reducing building temperature extremes in both summer and winter and consequently reduce pollution emissions from power-generating facilities.

Carbon sequestration and storage

Ecosystems regulate the global climate by storing greenhouse gases. For example, as trees and plants grow, they remove carbon dioxide from the atmosphere and effectively lock it away in their tissues.

Historically, land-use conversion and soil cultivation have been an important source of greenhouse gases to the atmosphere. It is estimated that they are responsible for about one-third of greenhouse gas emissions. However, improved agricultural practices can help mitigate climate change by reducing emissions from agriculture and other sources and by storing carbon in plant biomass and soils.

Greenhouse gas emissions associated with livestock supply chains add up to 7.1 giga tonnes of carbon dioxide equivalent per year, or 14.5% of all human-caused green house gass releases. Part of the green house gas emissions from livestock are associated with direct and indirect land use change which affect carbon stocks in soil and vegetation and their sequestration potential. Conversely, grassland carbon sequestration could significantly offset emissions, with global estimates of about 0.6 gigatonnes carbon dioxide equivalent per year.

The oceans and aquatic systems are important green house gass sequesters and sinks: oceans presently take up about one-third of the excess CO2 released into the air and some 93% of the earth’s carbon dioxide is stored in the oceans. Related global warming and acidification can impact fisheries and aquaculture through changes biological processes and distributions, sea level rise, coral bleaching, extreme events, disease and post-harvest risks, for example. Fisheries and aquaculture can support carbon sequestration and storage through maintaining ‘blue carbon’ sinks (peatlands, mangrove forests, seagrass beds, other vegetated ocean habitats) as well as through carbon sequestering products, such as molluscs and seaweed.

Urban trees can affect air quality in the following ways: firstly converting carbon dioxide to oxygen through photosynthesis. Secondly by intercepting particulate pollutants (dust, ash, pollen and smoke) and absorbing toxic gases such as ozone, sulphur dioxide, and nitrogen dioxide. Thirdly by emitting various volatile organic compounds contributing to ozone formation in cities. At last by lowering local air temperatures and reducing building temperature extremes in both summer and winter and consequently reduce pollution emissions from power-generating facilities.

Hazard regulation

Ecosystems and living organisms create buffers against natural disasters. They reduce damage from floods, storms, tsunamis, avalanches, landslides and droughts.

In recent years, increasing climate variability has caused even more serious and frequent drought spells, which influence agricultural systems in all stages of growth and consequently the crop yields. Diversification and adjustment of cropping patterns are among ways to reduce losses, thus mitigating the impact of droughts on the lives of the rural poor.

Livestock is extremely affected by events such as drought. In a world threatened by climate change, breeds that are resistant to drought, extreme heat or tropical diseases are of major potential importance. It is important to keep these traditional breed diversity alive to resist to extreme events. Diversified systems are also more resilient to extreme events. Through vegetation control, livestock also contribute to fire or avalanche control.

Healthy mangroves and coral reef systems are important elements to protect coastal populations from extreme weather events. Fisheries and aquaculture can support the moderation of extreme events through, for example, integrated mangrove-aquaculture ponds, sustainable direct use of mangroves in the sector, and reduction of harmful practices impacting coral reef systems.

Extreme weather events and natural disasters are posing an increasing threat to the world’s forests. The condition of forests themselves can have an influence on the extreme events. For example, deforestation or poor management can increase flooding and landslides during cyclones. However, the extent of large scale flooding in the lower parts of major river basins does not seem to be linked to the degree of forest cover and the management practices in the catchment area. Similarly, forests cannot prevent large scale landslides and mass movements which are triggered by tectonic or extraordinary rainfall events.

(Waste-)Water treatment

Ecosystems such as wetlands filter effluents, decompose waste through the biological activity of microorganisms, and eliminate harmful pathogens.

Agricultural effluents are a big source of water pollution. Agricultural systems can be designed to promote waste water treatment via wetlands or buffer strips. Working on reducing these effluents can help putting less pressure on the ecosystem. Agricultural systems can also be designed to reduce the use of agricultural chemicals which may end up in run-off and water bodies.

Livestock are a producer of waste water and can cause water pollution. Livestock’s influence on water quality is related to concentration in the landscape, either of water points where animals gather, or pollution from manure and fertilizer for feed crops or both. Management practices can be adopted to avoid water pollution.

Many fish species are key to functional wetlands which are the main natural waste-water treatment mechanism. Fish, molluscs and other aquatic animals as well as fish habitats are vital parts of ecosystem functioning and processes that are essential for water quality. Spatial planning for sustainable fisheries and aquaculture can minimize negative effects to those ecosystems.

Trees contribute heavily to waste-water treatment through their root system and their role in nutrient cycling.

Erosion prevention and soil fertility

Vegetation cover prevents soil erosion and ensures soil fertility through natural biological processes such as nitrogen fixation. Soil erosion is a key factor in the process of land degradation, loss of soil fertility and desertification, and contributes to decreased productivity of downstream fisheries.

Reversing the degradation of soil, water and biological resources are essential components in achieving food and livelihood security. Symptoms of soil degradation are numerous and include decline of soil fertility, development of acidity, salinization, alkalization, deterioration of soil structure, accelerated wind and water erosion, loss of organic matter and biodiversity. As a result, socio-economic impacts include that farm labour productivity and revenues from agriculture are falling, migration to urban areas is increasing and rural poverty is exacerbated. Efforts to restore productivity of degraded soils must be coupled with other measures that affect the land use practices, in particular conservation agriculture, good agricultural practices and irrigation management and integrated plant nutrient management.

Animal excreta can be an important source of nutrient and maintain soil fertility in grazed grasslands and croplands, especially in developing countries. Globally, about 15% of the nutrients applied to crops comes from livestock manure. Conversely, livestock can cause soil erosion and degradation as a combination between over grazing, pedo-climatic factors, and other management practices (fire suppression, clear cutting). Livestock exclusion, rotational or rational grazing can be necessary to avoid soil degradation or promote their restoration.

Fish are important for the maintenance of sediment processes and proper spatial planning and integrated systems in fisheries and aquaculture, for example, can work to minimize soil erosion along rivers, lakes and coastal areas.

Studies have shown that the more closely an agricultural system resembles a natural forest in its canopy structure, tree spacing and ground cover, the less chance there is of soil erosion. Traditional agroforestry techniques, which provide natural cover, have been used for centuries to produce food without causing long-term damage to the environment.

Pollination

Insects and wind pollinate plants and trees which is essential for the development of fruits, vegetables and seeds. Animal pollination is an ecosystem service mainly provided by insects but also by some birds and bats. In agro-ecosystems, pollinators are essential for orchard, horticultural and forage production, as well as the production of seed for many root and fibre crops. Pollinators such as bees, birds and bats affect 35% of the world’s crop production, increasing outputs of around 75% of the leading food crops worldwide.

Food security, food diversity, human nutrition and food prices all rely strongly on animal pollinators, and yet animal pollination is under stress from factors including habitat destruction and unsustainable agricultural practices such as intensification and pesticide misuse. There is a renewed interest in helping nature provide pollination services through best agricultural management practices that support wild pollinators, such as planting hedgerows, encouraging plant diversity, mulching, or the wise/reduced use of pesticides.

Grassland are an important habitat for pollinators when they are sustainably managed. Also, the enhancement of their floristic diversity has a huge potential to benefit insect pollinators.

Important freshwater plants, such as water lilies need pollinators to reproduce. Pollinators are therefore also important in freshwater systems, helping the balance of the system, indirectly supporting fisheries.

Natural forests are important habitat for pollinators, providing refuge and food. Given the choice, wild honeybees chose nesting places in trees rather than in an open landscape. When enough bees are present in a forest, they provide a better pollination that leads to improved regeneration of trees and conservation of the forest’s biodiversity.

Biological control

The activities of predators and parasites in ecosystems that act to control populations of potential pest and disease vector.

Agricultural production relies not only on crops but on associated biodiversity in agro-ecosystems. Pests, diseases and weeds limit crop production, and are themselves limited by the action of their natural enemies, mostly arthropods and micro-organisms. Biological control, through an ecosystem approach, is a way to reduce pesticide use and enhance biodiversity while ensuring production.

Animal diseases cause heavy economic losses both for individual farmers and at national or regional levels. Gastro-intestinal nematode parasitism is one of the most important disease constraints to small ruminant production in the sub-tropics and tropics. It is possible to biologically control of gastro-intestinal nematodes of ruminants using predacious fungi. Also, poultry are used for controlling ticks and other vectors of animal and human disease.

Fish populations serve as regulator of food webs and can influence community structure of other species and thereby also regulate pests and diseases. However, unintended consequences may occur so, when using biological control, either enhancing an existing population or bringing a new population, it is key to well understand the ecosystem interactions to avoid promoting a species over another and changing the ecosystem balance. Sustainable fisheries and stock management can support balancing different populations and making the best use of biological control.

In forest, when needed, the biological control of pest is often the chosen methodology since the relatively stable environment of a forest guarantees freedom from such adverse effects as interference by pesticides or disturbing agricultural practices. Natural or sustainably managed forests are also great reservoir of natural pest eradicators.

Water regulation

Water flow regulation is a key service provided by land cover and configuration, but its dynamics are poorly understood by most policy makers and land management organisations.

Agriculture is a large consumer of water, and at the same has strong impacts on water flow regulation. Management of agricultural land can both contribute to flooding, or potentially be seen as a region-wide mechanism to control water flows.

Livestock is a large consumer of water, and at the same has strong impacts on water flow regulation. Grassland management can both contribute to flooding, or be seen as a region-wide mechanism to control water flows.

Fish and other aquatic species are sensitive to changes in water flows, therefore, inclusion of the sector in water flow management discussions is imperative for sustainable development of fisheries and aquaculture.

Forests influence the amount of water available and the timing of water delivery. Stream-flow regulation by forests is the result of processes in the forest canopy, on the surface and below the ground, a combination of interception, transpiration, evaporation, evapotranspiration and infiltration. Accordingly, sustainable forest management is key to the regulation of water flows.