Whats species diversity got to do with it?
Organic fields accomodate a greater variety of plants, animals and microorganisms. The organic agroecosystem is thus more resistant to stress and disturbance. Enhanced microbial diversity improves the utilization of the available energy and resources.
Healthy ecosystems, well adapted to the site conditions, are distinguished by species diversity. The element cycles and foodweb structures are closed and the nutrients are bound biologically.
Ecosystem theory is in accordance with the principles of organic farming: the closed nutrient cycle on the farm level. The DOK-trial is showing impressively, even without the intention to enhance species diversity, that organic land-management allows development of a relatively rich weed-flora as compared to conventional systems. In conventional farming, weeds are considered competitive to the crop and are eliminated by herbicides and dense crop stands. In organic systems, however, some of the «accompanying plants» of a crop are desired and considered useful.
The presence of a versatile flora attracts beneficial herbivore and other air-borne or above-ground organisms. Their presence improves the nourishment of the predatory arthropods Populations of the very mobile ground beetles (carabids) in the DOK-trial not only differed in number and species composition.
Of a total of 39 species identified, some specialized and particularly demanding species were exclusively present in the bio-organic field plots. |
