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Individual study: Naturally developed set-aside fields hold a higher diversity of plant and invertebrate species than set-asides sown with Phacelia in the Kraichgau hill-region in southern Germany

Published source details

Greiler H.J. (1994) Insect communities in self-established and sown agricultural fallows. Pages 1-136 in: W. Nentwig (ed.) Agrarokologie. 11, Haupt, Bern.


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Provide or retain set-aside areas in farmland Farmland Conservation

A replicated, controlled site comparison study 1989-1991 in up to 65 arable sites in the Kraichgau region, Germany (Greiler 1994; same study as Gathmann & Tscharntke 1993) found more plant species but fewer invertebrates on naturally developed set-aside fields than on control crop fields. There were more plant species in orchard meadows (50 species/49m2) and naturally developed set-asides (37-45 species/49m2) than in sown set-asides (10-15 species/49m2) and cereal fields (10-17 species/49m2). Plant species richness was also higher in mown than in unmown set-asides. Invertebrate numbers from suction samplers were highest in set-asides sown with clover-grass-mixes (1500 individuals/5 m2), intermediate in naturally developed set-asides and cereal fields (ca. 1000 individuals/5 m2) and lowest in Phacelia-sown set-asides (500 individuals/ 5m2). Invertebrate numbers caught in Malaise-traps were highest in rye fields and clover-grass-mixes (around 3000 individuals) and lowest in naturally developed set-asides (1000 individuals). The effect of field type and set-aside age was strongly species- or family-dependent. Up to 11 field types (four to five replicates each) were investigated: one, two and three-year-old naturally developed set-asides (mown and unmown), 1-year-old set-asides sown with either Phacelia tanacetifolia or a clover-grass mix, conventionally managed cereal fields (rye and barley) and low-intensity orchard meadows (>30 years old). Plant surveys (three visits) were conducted in May to October 1990-1991 on one 49 m2 permanent quadrat (meadows and sown fields) or on 120 m2 (naturally developed fields). Insects were sampled on four to five visits in April to October using Malaise-traps (20 fields) and suction samplers (61 fields; 3 minute suctions of five 0.25m2 plots).

 

Plant nectar flower mixture/wildflower strips Farmland Conservation

A replicated, controlled study in 1989-1991 in up to 65 arable sites in the Kraichgau region, Germany (Greiler 1994) (same study as Gathmann et al. 1994) found lower plant species richness and invertebrate abundance on phacelia Phacelia tanacetifolia sown set-aside fields than on naturally developed set-asides. Plant species richness was lowest in sown set-asides (10-15 species/49 m2) and cereal fields (10-17spp./49 m2) and highest in orchard meadows (50 spp./49 m2) and naturally developed set-asides (37-45 spp./49 m2). Invertebrate numbers from suction samplers were lowest in phacelia-sown set-asides (500 individuals/5 m2), intermediate in naturally developed set-asides and cereal fields (ca. 1,000 ind./5 m2) and highest in set-asides sown with clover-grass-mixes (1,500 ind./5 m2). Invertebrate numbers caught in Malaise traps were highest in rye fields and clover-grass mixes (around 3,000 ind.) and lowest in naturally developed set-asides (1,000 ind.). Further studies and single species comparisons showed that the effect of field type and set-aside age was strongly species/family-dependent. Up to 11 field types (four to five replicates each) were investigated: one, two and three-year-old naturally developed set-asides (mown and unmown), one-year-old set-asides sown with either phacelia or a clover-grass mix, conventionally managed cereal fields (rye and barley), and low-intensity orchard meadows (<30 years old). Plant surveys (three visits) were conducted in May to October 1990-1991 on one 49 m2 permanent quadrat (meadows and sown fields) or on 120 m2 (systematically changed in naturally developed fields). Insects were sampled on four to five visits in April to October using Malaise traps (20 fields) and suction samplers (61 fields, 3 minute suctions in five 0.25 m2 plots).