Ecosystem services as natural resources

Defra defines ecosystem services as ‘what nature gives us - Nature provides us with the very essentials of life. It gives us clean air and water; enables us to produce and gather food, fuel and raw materials from the land and sea; regulates our climate; stems flood waters and it filters pollution’. Ecosystem services provide us with natural resources. However, intensive agriculture can put many of these at risk (Tilman et al., 2002).

SOIL - plays vital roles in biogeochemical cycles and the water cycle. They provide nutrients, which enables plant growth and they play a part in flood control, and water filtration among many other processes. ‘Since 1945 approximately 17% of vegetated land has undergone human-induced soil degradation and loss of productivity’ (Tilman et al., 2002). Monocultures and continuous cropping remove nutrients from the soils and reduce soil organic matter, which reduces the stability and fertility of the soil. The reduction of this ecosystem service then results in larger fertilizer and irrigation requirements.

FORESTS- ecosystem services include - minimizing flooding, moderating regional climate, removing atmospheric carbon dioxide and aiding regeneration of fertile soils (Tilman et al., 2002). Greater food demands has led to deforestation to increase land available for agriculture. With continued population growth this will continue, with most deforestation in developing countries, which will have a major impact on the extent of tropical forests and the ecosystem services they provide (Eickhout et al 2006).

BIODIVERSITY – is vital to the maintenance of all ecosystem services. One of the main services provided by biodiversity is disease and pest resistance (Tilman et al., 2002). As previously explained, monocultures remove these protective ecosystem services. Pesticides are therefore used to reduce this problem. However, they have many adverse affects. Rachel Carson’s book silent spring explains the problems associated with increased use of chemical pesticides including the problems associated with non target species ingesting pesticides. Especially the toxic side effects of organochloride insecticides (DDT), which fueled the green revolution. The high persistence of DDT means it moves up the food chain causing more severe effects at successive trophic levels (Krebs et al. 1999). Pesticides can therefore lead to reduction of biodiversity by affecting non-target species and therefore further reduction in ecosystem services. Pollination and seed dispersal by insects and birds are vital ecosystem services that are vulnerable to destruction due to the use of pesticides. These losses would have direct adverse affects to agriculture.

FRESHWATER – has many obvious ecosystem services including water for human consumption, irrigation, power and transport. However, the use of fertilizers and pesticides in agriculture jeopardizes these ecosystem services by causing eutrophication (Eickhout et al., 2006). As shown in this very simplistic but informative video…

In turn eutrophication will reduce the availability of freshwater and the ecosystem services it provides for agriculture.

It is clear that maintaining ecosystem services is crucial for sustainable agricultural production and this is vital if we are to meet the demands of food production in the future. Some ecosystem services such as pollination or control of pests are of direct benefit to the farmer but others may be beneficial to people in general, therefore less care is taken over their preservation. Tilman et al. (2002) state that ‘Agriculturalists are the principle managers of global ‘usable’ lands’. This highlights the great control farmers have over our ecosystem services and therefore our natural resources.