Agro-ecosystems

In agricultural systems biodiversity perform a number of ecosystem services including nutrient recycling, micro climate control, regulation of the local hydrological cycle and pest control. The persistence and health of these services depends on the maintenance of diversity, without which constant human intervention is required (Altieri, 1994).

As a result of expanding human populations, globalisation, and the intensification of agriculture there is increased reliance on a small number of crop species. Across the 1440 million ha of presently cultivated land, only 70 plant species are grown (Perry, 1994). There is also limited genetic variability. For example in the US 72% of the area planted with potato consist of just four species increasing vulnerability to disease and pests (National Academy of Sciences, 1972). 

In agro-ecosystems the degree of biodiversity depends on the diversity of vegetation within and around the agro-ecosystem, the permanence of various crops, the intensity of management and extent of the isolation of the system (Southwood and Way, 1970). As a result, biodiversity can be grouped into productive biota or crops and livestock deliberately selected, resource biota or organisms that contribute e.g. pollinators and pest controllers such as Apis mellifera,the common honeybee, and finally destructive biota such as Phytophthora infestans or potato blight. To promote the required ecosystem services, it is important to determine the best practices that maximise productive and resource biota (Altieri, 1999). 

In 2014 the INSPIA project was initiated, bringing together the European Conservation Agriculture Federation, the Institute for Sustainable Agriculture and the European Crop Protection Association. The project aims to raise awareness about the value of Best Management Practices (BMPs) to both biodiversity and agricultural productivity and how to implement them. These BMPs include the use of minimum soil disturbance practices. This favours the proliferation of  Lumbricus terrestris, the common earthworm, improving soil aeration and water infiltration. They also include the implementation of field margins or buffer strips. These areas enhance agro-biodiversity by providing habitats for birds, other pollinators and soil fauna. They also prevent soil erosion, the transfer of agricultural pollutants from crop land to non crop land and slow runoff.  As it stands, the project promotes 15 BMPs, many of these drawing on more traditional agriculture practices (INSPIA, 2014).

Sources:

Altieri, M. 1994. Biodiversity and Pest Management in Agroecosystems. Haworth Press: New York. p185 

Altieri, M. 1999. Th ecological role of biodiversity in agro-ecosystems. Agriculture, Ecosystems and Environment. vol 74. pp19–31. 

INSPIA. 2014. European Index for sustainable productive agriculture. [online]. Available at: http://www.inspia-europe.eu/ [accessed 28.12.14]. 

National Academy of Sciences. 1972. Genetic vulnerability of major crops. NAS: Washington. p307 

Perry, D.1994. Forest Ecosystems. Johns Hopkins University Press: Baltimore. p649.

Southwood, R and Way, M.J. 1970. Ecological background to pest management. In: Rabb, R and Guthrie, F.E. (Eds.). Concepts of Pest Management. North Carolina State University: Raleigh.  pp. 6–29.