Biodiversity and Organic Agriculture

Nadia El-Hage Scialabba and Caroline Hattam

Biodiversity FOR organic agriculture

Organic agriculture manages locally available resources to optimize competition for food and space between different plant and animal species. The manipulation of the temporal and spatial distribution of biodiversity is the main productive "input" of organic farmers. Instead of using mineral fertilisers, synthetic pesticides, pharmaceuticals and genetically modified seeds and breeds, adapted biodiversity is relied upon to maintain soil fertility and prevent pests and diseases.

Biodiversity FROM organic agriculture

Organic farmers are both custodians and users of biodiversity at all levels:

Gene level: locally adapted seeds and breeds are preferred for their greater resistance to diseases and resilience to climatic stress;
Species level: diverse combinations of plants and animals optimize nutrient and energy cycling for agricultural production;
Ecosystem level: the maintenance of natural areas within and around organic fields and absence of chemical inputs create suitable habitats for wildlife. Reliance on natural control methods maintains species diversity and avoids the selection of pest species resistant to chemical control methods.

Food production, income generation and biodiversity in harmony

The dual aim of organic agriculture of food production and biodiversity conservation is acknowledged at the international level (e.g., IUCN recognizes the potential of organic agriculture in managing several protected areas categories).

The organic standards and certification schemes of some European countries incorporate plans for the management of biodiversity on organic farms (e.g., Sweden, UK) or reward biodiversity on farms (e.g. Germany's Nature Balance Scheme , Bio-Ecological Agri-Tourism in Italy).

Organic agriculture is encouraged in several national and regional protected areas and their buffer zones (e.g., the "Terra Capital Investors" 10 year project in Latin America) where it is expected to support the objectives of the Convention on Biological Diversity in conserving and using biodiversity in maintaining soil ecosystems, using native species and creating habitats for wildlife and agricultural production.

Organic farmers are pioneering practical solutions for the sustainable use of biodiversity. However, extensive research is needed to better understand - and acknowledge - the complex relationships between agriculture and wild biodiversity (especially undomesticated species within the agro-ecosystem). Public policies and investments can unlock this potential.

Organic agriculture and soil ecosystems

Natural soil fertility must be relied upon in organic systems. Practices such as crop rotations, symbiotic association, cover crops, organic fertilisers and minimum tillage create suitable conditions for soil fauna and flora. Twenty years of scientific research have demonstrated that organic agriculture significantly increases the density and species richness of indigenous invertebrates, specialized endangered soil species, beneficial arthropods, earthworms, symbionts and microbes.¹

A living soil generates ecological services

Soil forming and conditioning: invertebrates (e.g., earthworms and termites) decompose plant litter and create conditions that allow nutrients, oxygen and water to circulate;
Waste disposal: micro-organisms (e.g., bacteria and fungi) reduce organic detritus to elemental nutrients and recycle nutrients and detoxify ecosystems;
Soil stabilization: invertebrates and micro-organisms influence the physical, chemical and biological characteristics of soils and thereby play a key role against erosion and floods;
Carbon sequestration: the higher biomass and diversity of microbial population in organic systems contributes to the carbon retention potential of soils.

Organic agriculture and agro-ecosystems

Natural disease resistance and pest predation must be strengthened in organic systems. Crop rotation is considered the cornerstone of organic management, functioning as a tool for pest management and soil fertility. This, together with inter-cropping, integrated crop-tree-animal systems, the use of traditional and under-utilized food and fodder species and the creation of habitats attracts pest enemies and pollinators and spreads the risk of crop failure across the agro-ecosystem. Agro-biodiversity is conserved and developed through the use of locally adapted landraces and the improvement of genotypes of many plant varieties and animal races near extinction.²

Diversified organic farms enhance ecological services

Nitrogen cycling: atmospheric nitrogen is fixed by legumes and other nitrogen-fixing plants (e.g., Azolla) which are used during rotations;
Symbiosis and parasitism: symbionts (e.g., rhizobia and mycorrhiza) play a most important role in absorbing nutrients and reducing pathogen invasions. Parasitism is used in the biological control of insects;
Predation: inter-specific competition between predator and prey populations keeps pest in check;
Pollination: enhanced habitats and absence of chemical use on organic farms reverse the trend of pollinator population decline. One third of agricultural crops and the majority of flowering plants are pollinated by insects (e.g., bees, butterflies, beetles) and other animals (e.g., bats).

Organic agriculture and nature conservation

The maintenance of natural areas of vegetation adjacent to crops and plant corridors is common in organic systems, providing alternative food and refuge for many insect predators, wild flora, birds and other wildlife. The absence of pesticide drifts and herbicides and on-farm integration of natural habitats (e.g., productive perennial plants, hedgerows) and other structures (e.g., stepping stones and corridors for migrating species) attract new or re-colonizing species to the area. Ultimately, the diversity of landscape and wildlife brings people in the form of eco-tourism, providing an important source of off-farm income.³

Organic habitats conserve wildlife

Studies have shown that organic field margins conserve weed species at risk of extinction. On-farm diversity and biomass of arable flora was found to be higher in organic fields (e.g., vineyards and olive groves in Greece);
The abundance of food sources and habitats attracts micro and macro fauna to organic farms. Surveys have found that the quantity of organic land is very important for migratory birds. The abundance of birds in organic shade coffee is 90% more than in sun-grown coffee plantations. Organic agriculture has been found to have positive effects on declining ground-breeding bird species (e.g., skylark, whinchat and yellow wagtail).
Where agriculture is a dominant land-use in buffer zones, the use of organic farming is encouraged for wildlife conservation. For example, the Meso American Biological Corridor stretches over seven countries and envisages organic agriculture within the buffer zones and linking areas.

1 FiBL, 2000. Organic Farming Enhances Soil Fertility and Biodiversity. Results from a 21-year-old field trial. Research Institute of Organic Farming (FiBL), Frick, Switzerland, Dossier no. 1, August 2000.

2 IFOAM, 2000. The Relationship between Nature Conservation, Biodiversity and Organic Agriculture. Proceedings of an international workshop held in Vignola, Italy, by IUCN, IFOAM, WWF and AIAB. Stolton S., B. Geier and J.A. Mc Neely (eds.) .

3 Mc Neely J.A. and S.J. Scherr, 2001. Common Ground, Common Future. How Ecoagriculture can Help Feed the World and Save Wild Biodiversity. IUCN and Future Harvest, May 2001.