Individual study: More butterfly species in low input grasslands and wildflower strips than intensively managed grasslands and wheat fields, in Switzerland
Jeanneret P., Schupbach B. & Pfiffner L. (2003) Arthropod reaction to landscape and habitat features in agricultural landscapes. Landscape Ecology, 18, 253-263
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Reduce management intensity on permanent grasslands (several interventions at once)
A site comparison study in the regions of Ruswil, northwest of Lucerne, Switzerland (Jeanneret et al. 2003a) found the number of butterfly (Lepidoptera) species, but not spider (Araneae) or ground beetle (Carabidae) species, was significantly higher in low input meadows than in intensively managed meadows. Twenty-three low input grasslands, around 400 m2 in size and managed as Ecological Compensation Areas were surveyed. There were two types: 16 ‘extensively used meadows’ with late mowing and no fertilizer and seven ‘low-input meadows, with late mowing and restricted fertilization (up to 60 kg N/ha/year). For comparison, fifteen intensively managed meadows were surveyed: seven conventional grasslands and eight Ecological Compensation Area meadows in traditional orchards with no restrictions on cutting or fertilizer use. Spiders and ground beetles were monitored using pitfall traps set over five weeks of May and June 1997. Butterflies were observed for ten minute periods on 0.25 ha of each site, on five occasions from May to August 1998, between 10:00 and 17:30 on sunny days with temperatures of at least 18°C. More detailed results (in German) are presented in (Jeanneret et al. 2000).
Plant nectar flower mixture/wildflower strips
A site comparison study in 1997 and 1998 in the region of Rafz, Switzerland (Jeanneret et al. 2003) (part of the same study as Jeanneret et al. 2000) found that butterfly (Lepidoptera) species richness was significantly higher in wildflower strips planted as Ecological Compensation Areas than in intensively managed wheat fields. Eleven wildflower strips and 20 wheat fields were sampled. Butterflies were observed for ten minute periods on 0.25 ha of each site, on five occasions from May to August 1998, between 10:00 and 17:30 h on sunny days with temperatures of at least 18 °C.