PARENT SESSION
Oral Session #21: Conservation of Biodiversity: Human landscapes, reserve design. Presiding: C. Meine.
Tuesday, August 7, 2001. 8:00 AM to 12:00 PM. Madison Ballroom D.

The common biodiversity in agroecosystems.

Östman, Örjan¹, Weibull, Ann-Christin¹, ¹

ABSTRACT- Society's interest in biodiversity has much focused on how to preserve endangered species. Biodiversity however, is not just rare species. Currently, scientists are debating whether biodiversity enhances some ecosystem functions or not. Most biodiversity studies have treated only one or a few taxonomic groups, often within the same guild. In agricultural ecosystems, biodiversity has been suggested to depend on both the landscape and farming practice, but studies of biodiversity where landscape features or farming practices are considered at the same time are rare. We have studied the species richness of plants, day-active butterflies, carabids, rove beetles, and spiders at 16 commercial farms at two provinces in Central East Sweden. The 16 farms were divided into eight pairs of one conventional and one organic farm in order to separate the effect of landscape and farming practice on biodiversity. The pairing was based on landscape features, location and land use. There were generally no correlations between biodiversities of different taxonomic groups. Total biodiversity increased with landscape heterogeneity, but we found no effect of farming practice. Moreover, we could not find evidence that biodiversity was important for biological pest control.

KEY WORDS: species richness, tri-trophic levels, conservation ecology, landscape ecology