Early succession of butterfly and plant communities on set-aside fields
Published source details
Steffan-Dewenter I. & Tscharntke T. (1997) Early succession of butterfly and plant communities on set-aside fields. Oecologia, 109, 294-302.
Published source details Steffan-Dewenter I. & Tscharntke T. (1997) Early succession of butterfly and plant communities on set-aside fields. Oecologia, 109, 294-302.
This study is summarised as evidence for the following.
Provide or retain set-aside areas in farmlandAction Link
Provide or retain set-aside areas in farmland
A site comparison study of set-aside in southern Germany (Steffan-Dewenter & Tscharntke 1997) found that numbers of plant and butterfly species were higher in naturally regenerated set-aside than cereal or set-aside sown with Phacelia tanacetifolia, but that number of plant species decreased and butterfly species composition changed with set-aside age (1-4 year-old). Numbers of plant species were higher in four naturally regenerated set-aside fields (20-30 species) than in a cereal field (1) or 1-year-old set-aside sown with P. tanacetifolia (3). The number of species decreased significantly with age of naturally regenerated set-aside fields from one (30 plant species) to three-years-old (20 species). Cover of annual herbs declined rapidly in the 3rd to 4th year of set-aside. The number of butterfly species was higher in naturally regenerated set-aside (11-13 species) than cereal (4) or sown set-aside (7). Butterfly species richness did not differ with set-aside age (11-13 species), but species composition changed greatly. Butterfly body size tended to decrease with set-aside age (from 24 mm to 23 mm) and mean life-span of caterpillars increased (from 61 days to 105 days). Plant species and cover were sampled in 49 m² plots in September 1992 and flowering plant abundance was estimated nine times from May-October. Adult butterflies were counted along transects, nine times per field (May-October 1992) and caterpillars were sampled twice in September 1992 by sweep-netting.