Reduce management intensity on permanent grasslands (several interventions at once)
Overall effectiveness category Awaiting assessment
Number of studies: 12
Background information and definitions
Intensive, conventional grassland management, with high fertilizer input and regular cutting or grazing, creates species-poor plant communities which in turn result in a lower diversity of butterflies and moths (Marini et al. 2009). Reducing management intensity may, therefore, enable species-rich plant and butterfly and moth communities to recover.
This intervention is for studies which look at the effect of a combination of measures to reduce management intensity, including reducing or delaying grazing or mowing, sometimes in combination, and often alongside a reduction or removal of the application of fertilizers, herbicides or pesticides. For individual effects of these actions, see “Reduce grazing intensity on grassland by reducing stocking density”, “Reduce grazing intensity on grassland by seasonal removal of livestock”, “Reduce cutting frequency on grassland”, “Delay cutting or first grazing date on grasslands to create variation in sward height”, “Pollution – Reduce fertilizer, pesticide or herbicide use generally” and “Pollution – Convert to organic farming”.
Marini L., Fontana P., Battisti A. & Gaston K.J. (2009) Agricultural management, vegetation traits and landscape drive orthopteran and butterfly diversity in a grassland-forest mosaic: a multi-scale approach. Insect Conservation and Diversity, 2, 213–220.
Supporting evidence from individual studies
A replicated, site comparison study in 1998 in two agricultural regions in the Swiss Plateau, Switzerland (Jeanneret et al. 2000, same experimental set-up as 2 and partially the same as 4) found that grasslands managed with reduced intensity had a similar species richness of butterflies to conventional grasslands. Butterfly species richness was similar on low intensity meadows, extensively managed meadows and intensively managed meadows. However, butterfly species richness was higher in extensively managed meadows (but not in low intensity meadows) than in cereal fields. See paper for details. Across two arable regions, 109 sites were composed of eight habitat types: Ecological Compensation Areas including 19 extensively managed meadows, 16 low intensity meadows, eight orchard meadows, five hedgerows and eleven wildflower strips on set-aside land, along with seven intensively managed meadows, 20 winter wheat fields, and 23 forest edges. From May–September 1998, butterflies were observed for 10 minutes on each of six visits to each site (0.25 ha/site).Study and other actions tested
A replicated, site comparison study in 1998 in an agricultural region in the Swiss Plateau, Switzerland (Jeanneret et al. 2003, same experimental set-up as 1 and 4) found that butterfly species richness was higher in grassland with reduced management intensity than in intensively managed grassland. The species richness of butterflies was higher in grassland with reduced management intensity than in intensively managed grassland (data not presented). Two types of reduced management intensity grassland, managed as Ecological Compensation Areas, were surveyed: 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). Each was around 400 m2. 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. Butterflies were observed for 10-minute periods on 0.25 ha of each site, on five occasions from May–August 1998, between 10:00–17:30 h on sunny days with temperatures of at least 18 °C. More detailed results (in German) are presented in (1 - Jeanneret et al. 2000).Study and other actions tested
A replicated, controlled study in 2000–2002 in three farmland regions of the Swiss Plateau, Switzerland (Aviron et al. 2005) found more butterfly species on low-input grasslands than on intensively managed grasslands in one of two study years. In 2002, but not in 2000, low-input grasslands had more butterfly species than intensively managed grasslands (actual numbers not given). The identity of the butterfly species found was not significantly influenced by management intensity, but was different in different regions. The low-input grasslands were managed as “Ecological Compensation Areas”, with restricted fertilizer and pesticide use, and delayed mowing. Butterflies were recorded in 56 low-input grasslands and 48 intensively managed grasslands during the summers of 2000 and 2002.Study and other actions tested
Referenced paperAviron S., Berner D. & Bosshart S. (2005) Butterfly diversity in Swiss grasslands: respective impacts of low-input management, landscape features and region. Pages 340-343 in: R. Lillak, R. Viiralt, A. Linke & V. Geherman (eds.) Grassland Science in Europe. 10, Estonian Grassland Society, Tartu.
A replicated, site comparison study in 2000–2004 in two agricultural regions in the Swiss Plateau, Switzerland (Jeanneret et al. 2005, same experimental set-up as 1 and 2) found that butterfly communities on low-input grasslands were distinct and different from those on intensively managed grasslands. Butterfly communities in low-input grasslands were different from those in intensively managed grasslands (data presented as model results). Thirty-three low-input grasslands were managed as Ecological Compensation Areas, comprising 23 extensively used meadows (late mowing and no fertilizer application) and 10 low-input meadows (late mowing and restricted fertilizer application (up to 60 kg N/ha/year)). Twenty-four intensively managed grasslands, where fertilizer application and mowing were unrestricted, comprised eight permanent intensively managed meadows, 14 meadows in traditional orchards, and two seeded meadows. Butterflies were monitored in three years between 2000 and 2004.Study and other actions tested
A replicated, paired, controlled study in 2004 in 13 hay meadows in Aargau, Switzerland (Albrecht et al. 2007) found that meadows managed with low inputs had a higher species richness and abundance of butterflies compared to intensively managed meadows. Species richness and abundance of butterflies was higher in low-input meadows than in intensively managed meadows (data presented as model results). However, species richness and abundance of butterflies in intensively managed meadows did not change with distance from the low-input meadows (data presented as model results). The 13 low-input meadows (0.48–2.15 ha) had been managed as “Ecological Compensation Areas”, with no fertilizer application and not mown until after 15 June, for at least 5 years, and were paired with adjacent intensively managed meadows. In May 2004 four pots, each containing one plant of radish Raphanus sativus, clustered bellflower Campanula glomerata, and common catsear Hypochaeris radicata, were placed in each low-input meadow, and at 25, 50, 100 and 200 m into the adjacent intensive meadow. Flower visiting insects were collected between 10:00 and 16:00 in one 20-minute session/station in each of May, July and August 2004.Study and other actions tested
A replicated, controlled study in 1998–2004 in two farmland regions of the Swiss Plateau, Switzerland (Aviron et al. 2007) found more species of butterfly on low-input grassland than conventional grassland in one of the two areas. In Nuvilly, there was an average of 12 species on low-input grasslands and 11 species on conventional grasslands. In Ruswil, there was an average of 3.4 species on low-input grasslands and 2.6 species on conventional grasslands. When other factors such as number of plant species, coverage of woody plants or distance to forest were taken into account, this difference was only statistically significant in Ruswil, and not in Nuvilly. Low-input grasslands had more ‘specialist’ species – those with only one generation/year, poor dispersal ability or caterpillars that eat only one type of plant. Low-input grasslands, managed as “Ecological Compensation Areas”, were fertilized with an average of 7 kg N/ha and cut on average twice a year. Conventional grasslands were fertilized with an average of 206 kg N/ha and cut on average three times each year. Every two years from 1998–2004, butterflies were surveyed in five 10 minute surveys every 2–3 weeks between May and August, in 20–22 low-input grasslands and 6–16 conventional grasslands.Study and other actions tested
A replicated, controlled study in 1998–2004 in two grassland and mixed farmland regions in central Switzerland (Aviron et al. 2009) found that low-input grasslands contained similar numbers of butterfly species to conventionally managed grasslands. The estimated number of butterfly species on low-input grasslands (36 species) was similar to on conventional grasslands (34 species). The study sampled 315 low-input grasslands managed as “Ecological Compensation Areas” and 216 conventionally managed grasslands. From 1998–2004, butterflies were surveyed every two years between May and September, using five 10-minute observation periods across 0.25 ha/field.Study and other actions tested
A replicated, randomized, controlled study in 2002–2006 on four lowland farms in Devon and Somerset, UK (Potts et al. 2009) found that plots of unfertilized, ungrazed grassland cut once in July or not cut during the summer had a higher abundance, but not species richness, of butterflies than fertilized silage plots cut twice/year. In extensive, unfertilized plots cut in July, or not cut all summer, the abundance of butterflies (1–6 individuals/transect) was higher than in intensively managed plots (0–4 individuals/transect), but the number of species was similar (extensive: 1–2; intensive: 0–2 species/transect). The number of caterpillars in extensive plots (1–8 caterpillars/transect) was higher than in one intensive treatment (0–4 caterpillars/transect), but did not differ significantly from other intensive treatments (0–7 caterpillars/transect). In April 2002, experimental plots (50 × 10 m) were established on permanent pastures (>5-years-old) on four farms. There were seven treatments, with three replicates/farm. Three extensive treatments were not fertilized or grazed, and were either cut to 10 cm once/year in May or July, or topped in early spring and undisturbed in summer. Four intensive treatments included modifications to conventional silage management (reducing fertilizer application or grazing, or raising cutting height), but were all cut twice/year. From June–September 2003–2006, butterflies were surveyed once/month on a 50-m transect through the centre of each plot. In April, June, July and September 2003–2006, caterpillars were counted (but not identified) on two 10-m transects/plot using a sweep net (20 sweeps/transect).Study and other actions tested
A before-and-after study in 1994–2006 on a farm in Oxfordshire, UK (Taylor & Morecroft 2009) found that following adoption of the Environmentally Sensitive Areas scheme, including reducing grazing intensity and stopping the application of fertilizers, herbicides and pesticides, the abundance and species richness of large moths and some species of butterfly increased. After Environmentally Sensitive Area management began, the total abundance (1,000–1,450 individuals) and species richness of large moth species was higher than before (800–1,250 individuals, richness data not presented). One of the five most abundant moth species (lunar underwing Omphaloscelis lunosa) and five of 23 butterfly species (meadow brown Maniola jurtina, brown argus Aricia agestis, common blue Polyommatus icarus, small copper Lycaena phlaeas and red admiral Vanessa atalanta) increased in abundance after the change in management. However, two butterfly species became less abundant (green-veined white Pieris napi and large white Pieris brassicae, data presented as model results). Overall butterfly abundance and species richness increased over the entire monitoring period, but the increase did not just happen after the management change. In 2002, the farm entered the Environmentally Sensitive Areas agri-environment scheme. Fertilizers, herbicides and pesticides were no longer used, the total number of livestock dropped from 180 cows and 1,000 sheep to 120 cows and 850 sheep, and the proportion of grassland increased. Butterflies were monitored weekly from April–September on a fixed 3.6 km transect divided into 13 sections. Moths were monitored nightly from dusk to dawn using a light trap in a fixed position in the middle of the farm.Study and other actions tested
A replicated, paired, site comparison study in 2008 on 32 farms in central Scotland, UK (Fuentes-Montemayor et al. 2011) found that created species-rich grassland managed at low intensity had a higher abundance and species richness of micro- and macro-moths than conventionally-managed grassland or crop fields. In low intensity grasslands, the abundance (156 individuals) and species richness (24 species) of micro-moths, the species richness of all macro-moths (46 species), and the abundance of declining macro-moths (44 individuals) were all higher than in improved grasslands or crop fields on conventional farms (micro-moths: 43 individuals, 19 species; all macro-moths: 33 species; declining macro-moths: 21 individuals). However, the abundance of all macro-moths (366 individuals) and species richness of declining macro-moths (10 species) on low intensity grasslands was not significantly different from improved grasslands or crop fields (all macro-moths: 271 individuals; declining macro-moths: 9 species). In 2004, sixteen farms enrolled in agri-environment schemes, and were paired with 16 similar but conventionally-managed farms, <8 km away. On agri-environment scheme farms, species-rich grassland was created on former arable or improved grassland fields by sowing a low productivity grass and herb seed mix, and managed with fertilizer and pesticide restrictions, and no summer cutting or grazing. Improved pastures and crop fields on conventional farms had no management restrictions. From June–September 2008, moths were collected for four hours, on one night/farm, using a 6 W heath light trap located in one field on each farm. Paired farms were surveyed on the same night.Study and other actions tested
A site comparison study in 2008 in 10 wet grasslands in the Epirus district, Greece (Kati et al. 2012) found that sites with lower grazing intensity or cutting frequency had a higher species richness of butterflies than sites with higher intensity management. The species richness of butterflies was higher at less disturbed sites (10–23 species) than at more disturbed sites (3–11 species). Ten 1-ha wet grasslands, managed by either grazing (by cattle from May–August), mowing (1–2 times/year from June–August), grazing and mowing, or neither, were surveyed (exact grazing and cutting details not provided). From May–July 2008, butterflies were surveyed three times on one 200-m transect/site.Study and other actions tested
A replicated, site comparison study in 2014 in 26 grasslands in Germany (Mangels et al. 2017) found that grasslands managed less intensively had a similar abundance, species richness and diversity of moths to more intensively managed grasslands. The abundance, species richness and diversity of moths on grasslands managed with lower grazing intensity, less frequent cutting and/or less fertilizer input was similar to more intensively managed grasslands (data presented as model results). However, less intensively managed grasslands did support more specialist moth species, and species of greater conservation concern, than more intensively managed grasslands (data presented as model results). Of 87 individual species monitored, 24 species preferred less intensively managed grasslands, and 12 preferred more intensively managed grasslands (see paper for individual species data). From 2006, across three regions, nine grasslands were managed by grazing (by cattle, sheep or horses at 26–520 livestock units/ha/year), nine by mowing (1–2 cuts/year, often with nitrogen fertilization), and eight were grazed and mown (76–163 livestock units/ha/year; 1–2 cuts/year). Eleven of the mown or mown and grazed grasslands were fertilized with 1–138 kg nitrogen/ha. Moths were collected once/month from nine grasslands in each of two regions (May–August 2014), and from eight grasslands in one region (June–July 2014). Each night, a 12 V actinic and black-light trap were placed in the centre of each of three grasslands for 138–317 minutes/night. Moths were classified as specialists based on the number of food plants eaten by their caterpillars.Study and other actions tested