©
2004, ELSEVIER (Pedobiologia)C.N.R.S., U.M.R. 6553 “Ecobio”, University of Rennes
I
Biological
Field Research Station, F-35380 Paimpont, France.
Most
work considering the effects of landscape structure and heterogeneity on
biodiversity in farmland has been devoted to mammals or birds. Despite their
worldwide distribution in many different soil types, the ecology of terrestrial
Chironomidae is still poorly known. The influence of landscape heterogeneity on
the short-range spatial distribution of adult terrestrial Chironomidae within
three agricultural landscapes was investigated in Brittany (France). One hundred
and twenty-eight yellow pan traps collecting flying individuals emerging from
surrounding habitats were set in pairs on the soil surface of crop fields at the
bottom of bordering hedges throughout the three sites. Chironomids abundance
data were related to nine environmental factors using co-inertia analyses. The
terrestrial chironomid community, which included 11 species, was dominated
numerically by a semi-terrestrial species, Limnophyes
minimus (Mg.), and a true terrestrial species, Smittia pratorum (G.). Amongst environmental factors, disturbance
level, land cover, soil hydromorphy, and vegetation height had a significant
influence on the distribution of species at all sites. Hedge quality and soil
flooding were also significant factors at two of the three sites. Specific
life-history traits (including larval and adult ecological requirements)
interact with landscape heterogeneity to determine the short-range spatial
patterning of species. This work, which provides the first detailed study of
adult terrestrial chironomids in farmland, shows that management of crop fields
and hedges by farmers has a strong influence on landscape heterogeneity and,
consequently, on the spatial distribution of species.
Keywords
Agriculture; Biodiversity; Disturbance; Hedgerow;
Field margin; Landscape heterogeneity; Soil fauna
©
2004, ELSEVIER (Pedobiologia)
