Collected Evidence: Collected Evidence: Provide artificial nest sites for bumblebees We have captured 11 replicated trials of bumblebee nest boxes. Several different types of nest box have been shown to be acceptable to bumblebees, including wooden or brick and tile boxes at the ground surface, underground tin, wooden or terracotta boxes and boxes attached to trees.   Three replicated trials since 1989 in the UK have shown very low uptake rates (0-2.5%) of various nest box designs (not including underground nest boxes), while seven trials in previous decades in the UK, USA or Canada, and one recent trial in the USA, showed overall uptake rates between 10% and 48%.   Wooden surface or above ground nest boxes of the kind currently marketed for wildlife gardening are not the most effective design. Eight studies test this type of nest box. Five (pre-1978, USA or Canada) find 10-40% occupancy. Three (post-1989, UK) find very low occupancy of 0-1.5%. The four replicated trials that have directly compared wooden surface nest boxes with other types all report that underground, false underground or aerial boxes are more readily occupied.   Nest boxes entirely buried 5-10 cm underground, with a 30-80 cm long entrance pipe, are generally the most effective. Seven replicated trials in the USA, Canada or the UK have tested underground nest boxes and found between 6% and 58% occupancy.   We have captured no evidence for the effects of providing nest boxes on bumblebee populations.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F48https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F48Thu, 20 May 2010 02:19:20 +0100Collected Evidence: Collected Evidence: Exclude grazers from semi-natural habitats Two replicated (one controlled) studies from the USA found higher species richnesses on sites with grazers excluded; a replicated and controlled study from Argentina found lower species richness in ungrazed sites and a study from the USA found no difference. Seven studies from the USA (three controlled, two replicated) found that overall bird abundance, or the abundances of some species were higher in sites with grazers excluded; seven studies from the USA and Argentina found that overall abundance or the abundances of some species were lower on sites without grazers, or did not differ between treatments. Three studies from the USA investigated productivity and found it higher in sites with grazers excluded. In one study this difference was only found on improved, not unimproved pastures.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F236https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F236Tue, 17 Jul 2012 15:59:50 +0100Collected Evidence: Collected Evidence: Restore or create inland wetlands Of eleven studies captured, 11, from the mainland USA, Guam, Canada and Hawaii, found that birds used artificially restored or created wetlands. Two found that rates of use and species richness were similar or higher than on natural wetlands. One found that use rates were higher than on unrestored wetlands. Three studies from the USA and Puerto Rico found that restored wetlands held lower densities and fewer species of birds than natural wetlands. A replicated study from the USA found that least bittern productivity was similar in restored and natural wetlands. Two replicated studies examined wetland characteristics: one from the USA found that semi-permanent restored wetlands were used more than temporary or seasonal ones. A study from Hawaii found that larger restored wetlands were used more than smaller sites.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F366https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F366Mon, 06 Aug 2012 13:34:38 +0100Collected Evidence: Collected Evidence: Remove ectoparasites from nests to increase survival or reproductive success Six of the seven studies that investigated infestation rates found lower rates in nests treated for ectoparasites, one (that used microwaves to treat nests) did not find fewer parasites. Two studies from the USA found higher survival or lower abandonment in nests treated for ectoparasites, whilst seven studies from across the world found no differences in survival, fledging rates or productivity between nests treated for ectoparasites and controls. Two studies from the USA and the UK found that chicks from nests treated for ectoparasites were in better condition than those from control nests. Four studies found no such effect.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F438https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F438Wed, 22 Aug 2012 18:20:13 +0100Collected Evidence: Collected Evidence: Scare or otherwise deter mammals from human-occupied areas to reduce human-wildlife conflict Ten studies evaluated the effects of scaring or otherwise deterring mammals from residential areas to reduce human-wildlife conflict. Six studies were in the USA, three were in Canada and one was in Tanzania. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (10 STUDIES) Human-wildlife conflict (10 studies): Two of four studies (including one randomized and controlled study) in the USA, found that a range of noise and pain deterrents did not prevent black bears from returning to urban areas or other human-occupied sites. The other two studies found that such actions did deter them from seeking food at human-occupied sites. Two of three studies, in the USA and Canada, found that chasing nuisance black bears with dogs and chasing elk with people or dogs caused them to stay away longer or remain further from human occupied areas. The other study found that attempts to scare coyotes did not cause them to avoid human occupied areas. A before-and-after study in Canada found that an electric fence prevented polar bear entry to a compound. A study in Canada found that chemical and acoustic repellents did not deter polar bears from baits in most cases. A replicated study in Tanzania found that drones caused African savanna elephants to quickly leave residential areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2347https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2347Fri, 22 May 2020 14:14:50 +0100Collected Evidence: Collected Evidence: Use loud noises to deter crop damage (e.g. banger sticks, drums, tins, iron sheets) by mammals to reduce human-wildlife conflict Ten studies evaluated the effects of using loud noises to deter crop damage by mammals to reduce human-wildlife conflict. Three studies were in the USA, two were in Zimbabwe and Kenya and one each was in the UK, Namibia, and India. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (10 STUDIES) Human-wildlife conflict (10 studies): Five of six studies (including two controlled, one replicated and two before-and-after studies), in the USA, Namibia, Kenya and India, found that loud noises activated when an animal was in the vicinity reduced or partially reduced crop damage or crop visits by white-tailed deer, black-tailed deer (when combined with using electric shock collars) and elephants. The other study found that using loud noises (along with chili fences and chili smoke) did not reduce crop-raiding by African elephants. Three studies (including two controlled studies), in the UK and the USA, found that regularly sounding loud noises did not repel European rabbits or white-tailed deer. Two replicated studies, in Zimbabwe, found that, from among a range of deterrents, African elephants were repelled faster from crop fields when scared by firecrackers or by a combination of deterrents that included drums. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2460https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2460Tue, 02 Jun 2020 11:34:12 +0100Collected Evidence: Collected Evidence: Use fencing to exclude predators or other problematic species Ten studies evaluated the effects on mammals of using fencing to exclude predators or other problematic species. Four studies were in Australia, four were in the USA and two were in Spain. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): A site comparison study in Australia found that fencing which excluded feral cats, foxes and rabbits increased small mammal species richness. POPULATION RESPONSE (10 STUDIES) Abundance (4 studies): Two of three studies (including two replicated, controlled studies), in Spain, Australia and the USA, found that abundances of European rabbits and small mammals were higher within areas fenced to exclude predators or other problematic species, compared to in unfenced areas. The third study found that hispid cotton rat abundance was not higher with predator fencing. A replicated, controlled study in Spain found that translocated European rabbit abundance was higher in fenced areas that excluded both terrestrial carnivores and raptors than in areas only accessible to raptors. Reproductive success (1 study): A replicated, controlled study in USA found that predator exclosures increased the number of white-tailed deer fawns relative to the number of adult females. Survival (7 studies): Four of six studies (including four replicated, controlled studies) in Spain, Australia and the USA, found that fencing to exclude predators did not increase survival of translocated European rabbits, hispid cotton rats, southern flying squirrels or western barred bandicoots. The other two studies found that persistence of populations of eastern barred bandicoots and long-haired rats was greater inside than outside fences. A controlled, before-and-after study in the USA found that electric fencing reduced coyote incursions into sites frequented by black-footed ferrets. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2497https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2497Thu, 04 Jun 2020 15:36:46 +0100Collected Evidence: Collected Evidence: Install rope bridges between canopies Ten studies evaluated the effects on mammals of install rope bridges between canopies. Eight studies were in Australia, one was in Brazil and one in Peru. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): A study in Australia found that arboreal marsupials using rope bridges did not suffer high predation rates when doing so. BEHAVIOUR (9 STUDIES) Use (9 studies): Nine studies (including three replicated studies and a site comparison), in Australia, Brazil and Peru found that rope bridges were used by a range of mammals. Seven of these studies found between three and 25 species using rope bridges, one found that that they were used by squirrel gliders and one that they were used by mountain brushtail possums and common ringtail possums but not by koalas and squirrel gliders. One of the studies found that crossing rates were higher over the canopy bridges than at ground level. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2556https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2556Tue, 09 Jun 2020 10:50:37 +0100Collected Evidence: Collected Evidence: Remove or control predators Ten studies evaluated the effects on non-controlled mammals of removing or controlling predators. Seven studies were in North America, one was in Finland, one in Portugal and one in Mexico. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (10 STUDIES) Abundance (6 studies): Three of six studies (including three controlled, one before-and-after and one replicated, paired sites study), in Finland Portugal, Mexico and the USA, found that removing predators increased abundances of pronghorns, moose and European rabbits and Iberian hares. One of these studies also found that mule deer abundance did not increase. The other three studies found that removing predators did not increase mountain hare, caribou or desert bighorn sheep abundance. Reproductive success (2 studies): Two replicated, before-and-after studies (one also controlled), in the USA, found that predator removal was associated with increased breeding productivity of white-tailed deer and less of a productivity decline in pronghorns. However, one of these studies also found that there was no change in breeding productivity of mule deer. Survival (5 studies): Two of five before-and-after studies (including two controlled studies and one replicated study), in the USA, Canada and the USA and Canada combined, found that controlling predators did not increase survival of caribou calves, or of calf or adult female caribou. Two studies found that moose calf survival and woodland caribou calf survival increased with predator control. The other study found mixed results with increases in white-tailed deer calf survival in some but not all years with predator control. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2613https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2613Thu, 11 Jun 2020 17:19:37 +0100Collected Evidence: Collected Evidence: Cease or prohibit mobile fishing gears that catch bottom (demersal) species and are dragged across the seafloor Ten studies examined the effects of ceasing or prohibiting mobile fishing gears that catch bottom (demersal) species and are dragged across the seafloor on marine fish populations. Two studies were in each of the North Atlantic Ocean (Canada, Portugal), the Indian Ocean (Tasmania, Kenya) and the Mediterranean Sea. One study was in each of the North Sea (Denmark), the Arafura Sea (Australia), the Coral Sea (Australia) and the Gulf of Mexico (USA). COMMUNITY RESPONSE (3 STUDIES)  Richness/diversity (3 studies): Two of three site comparison studies (one replicated and randomized, and one before-and-after) in the North Sea, Indian Ocean and Gulf of Mexico found that the number of fish species, the fish assemblage and overall species richness and diversity (fish and invertebrates combined) varied between areas with different exposures to bottom trawling, and was also dependent on bottom depth and habitat type. The other study reported no effect of closing an area to all towed bottom fishing gears on the species richness of bottom-dwelling fish after 10 years and compared to areas open to trawling.  POPULATION RESPONSE (8 STUDIES) Abundance (5 studies): Two of three replicated studies (one controlled and before-and-after, and two site comparison) and one of two before-and-after studies (one site comparison) in the North Sea, Arafura Sea, North Atlantic Ocean and the Mediterranean Sea found that ceasing or prohibiting fishing with towed bottom gears resulted in higher total fish biomass after 15 years, higher biomass of adult red mullet after 14 years and increased abundances of long-snouted, but not short-snouted, seahorses after one year, compared to openly fished areas. The other two studies found that a ban on towed bottom fishing gears for five and 10 years had no effect on the abundance of bottom-dwelling fish species after closure compared to before, or the abundance and biomass of fish and invertebrate species (combined) compared to areas open to towed gears/trawling. Reproductive success (2 studies): One of two before-and-after studies (one site comparison) in the North Atlantic Ocean and Mediterranean Sea found that after the closure of an area to all bottom-towed fishing gears for 14 years, recruitment of young red mullet had increased. The other study found that an area closed to bottom trawling did not have higher recruitment of young haddock seven years after closure and compared to a trawled area. Survival (1 study): One before-and-after, site comparison study in the North Atlantic Ocean found that closing an area to bottom trawling did not increase the survival of young haddock seven years after closure, and compared to a trawled area. Condition (5 studies): One of four replicated studies (two site comparison and one randomized, site comparison) and one before-and-after study in the Arafura Sea, Mediterranean Sea, Gulf of Mexico and the Indian Ocean found that areas prohibiting bottom towed fishing gears had larger sizes of adult red mullet 14 years after closure than before. Two studies found that the effect on fish size of closing areas to towed bottom gears for 3–6 years or areas with no bottom fishing activity varied between individual fish groups and with habitat type, compared to fished areas. The other two found that areas closed to bottom trawling for five years and 15 years had no effect on the overall size of fish and invertebrate species combined or average fish weight, compared to trawled areas. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduce unwanted catch (1 study): One randomized, replicated, site comparison study in the Coral Sea found no reduction in the biomass of non-commercial unwanted catch (fish and invertebrate discard) or in the number of ‘common’ and ‘rare’ discard species in areas closed to trawling for seven years compared to trawled areas. Catch abundance (1 study): One replicated, before-and-after study in the Indian Ocean found that areas prohibiting beach and all other seine nets for 3–6 years found overall fish catch rates were higher, and catch rates of individual fish groups were variable, compared to unrestricted areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2673https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2673Fri, 20 Nov 2020 12:12:24 +0000Collected Evidence: Collected Evidence: Modify the configuration of a mesh escape panel/window in a trawl net Ten studies examined the effects of modifying the configuration (position/size and increased mesh size) of a mesh escape panel/window in a trawl net on marine fish populations. Four studies were in the Baltic Sea (Sweden/Poland). Two studies were in each of the North Sea (UK), the Irish Sea (UK) and the Kattegat and Skagerrak (Northern Europe). One study was in the Atlantic Ocean (Portugal).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled study in the Baltic Sea found that modifying the position of a mesh escape panel in a trawl net had no effect on the survival rate of cod. BEHAVIOUR (0 STUDIES) OTHER (9 STUDIES) Reduction of unwanted catch (5 studies): Three of five replicated, paired studies (one controlled) in the Irish Sea, Atlantic Ocean and Kattegat-Skagerrak found that modifying the position or mesh size of a mesh escape panel/window in a trawl net reduced the unwanted catches of whiting in one of two cases, haddock and whiting, and boarfish, but caught similar amounts of horse mackerel and blue whiting. The other studies found that catches of unwanted cod or other fish were not reduced. Improved size-selectivity of fishing gear (4 studies): Two of four replicated, controlled studies in the North Sea and Baltic Sea found that modifying the position and/or size of a mesh escape panel in a trawl net improved size-selectivity of haddock and whiting. One of these studies also found that increasing the mesh size of the panel had no effect on size-selectivity for haddock. The other two studies found that size-selectivity was similar for cod compared to standard trawls. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2717https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2717Tue, 05 Jan 2021 14:46:39 +0000Collected Evidence: Collected Evidence: Exclude or remove livestock from historically grazed freshwater marshes Ten studies evaluated the effects, on vegetation, of excluding or removing livestock from historically grazed freshwater marshes. Seven studies were in the USA, two were in Morocco and one was in Australia. In all 10 studies the focal livestock included cattle (mixed with sheep in the two studies in Morocco). Two studies in the USA were based on the same experimental set-up, and the two studies in Morocco shared some study sites. VEGETATION COMMUNITY Community composition (4 studies): Two site comparison studies in Morocco and the USA reported that marshes/pools fenced to exclude livestock for 3–30 years contained a different overall plant community to grazed sites. In the USA, the precise effect depended on the time since exclusion. Two replicated, randomized, paired, controlled studies in marshes in Australia and the USA found that fencing to exclude cattle typically had no significant effect on the overall plant community composition after 1–14 years. One of the studies also found that the plant community in fenced and grazed marshes was of similar quality, relative to pristine local marshes. Relative abundance (3 studies): Of three replicated, randomized, paired, controlled studies that reported data on the relative abundance of plant groups, two studies (based on one experimental set-up) in the USA found that ephemeral pools fenced to exclude cattle for 1–10 years had similar or greater cover of grasses relative to forbs than pools that remained grazed. The other study, also in the USA, found that the relative abundance of forbs, grass-like plants and shrubs was similar in marshes fenced to exclude cattle for 1–3 years and marshes that remained grazed. Overall richness/diversity (6 studies): Four replicated studies (two also randomized, paired, controlled) in the USA, Morocco and Australia found that marshes/pools fenced to exclude cattle, for 1–30 years, typically had similar overall plant species richness to sites that remained grazed. One of the studies found that the same was true for overall plant diversity. One replicated, site comparison study of ephemeral pools in Morocco found that pools fenced to exclude livestock for >30 years had similar (in a dry year) or greater (in a wet year) plant species richness compared to pools that remained grazed. One site comparison study in the USA found that marshes fenced to exclude cattle for 3–13 years contained fewer plant species than grazed marshes, and had similar or lower plant diversity. Characteristic plant richness/diversity (1 study): One site comparison study of ephemeral pools in Morocco found that pools fenced to exclude livestock for >30 years contained a similar number of wetland-characteristic plant species to pools that remained grazed. Native/non-target richness/diversity (3 studies): Of three replicated, randomized, paired, controlled studies that reported data on native plant species richness, two studies (based on one experimental set-up) in the USA found that fencing ephemeral pools to exclude cattle for 1–10 years typically reduced native plant species richness. The other study, also in the USA, found that native plant species richness was similar in marshes fenced to exclude cattle for 1–3 years and marshes that remained grazed. VEGETATION ABUNDANCE Overall abundance (3 studies): Two replicated, site comparison studies in the USA and Morocco found that ponds/pools fenced to exclude cattle for >10 years contained more vegetation than sites that remained grazed. This was measured in terms of emergent cover around pond margins or peak above-ground biomass in ephemeral pools. One replicated, randomized, paired, controlled study in Australia found that marshes fenced to exclude cattle for ≤4 years contained similar above-ground vegetation biomass to marshes that remained grazed. Characteristic plant abundance (1 study): One site comparison study of ephemeral pools in Morocco found that the overall abundance of wetland-characteristic plant species was greater in pools fenced to exclude livestock for >30 years than in pools that remained grazed. Herb abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study in the USA found that fencing pastures to exclude cattle typically increased herb cover in wetlands along creeks, but had no significant effect on herb cover within spring wetlands. Individual species abundance (2 studies): Two replicated, randomized, paired, controlled studies in freshwater marshes in Australia and the USA quantified the effect of this action on the abundance of individual plant species (see original papers for data). VEGETATION STRUCTURE Visual obstruction (1 study): One replicated, site comparison study in the USA found that ponds fenced to exclude cattle for >10 years had greater horizontal vegetation cover, around their margins, than ponds that remained grazed. Height (2 studies): Two replicated studies (one also randomized, paired, controlled, before-and-after) in the USA found that fencing ponds to exclude cattle, for 1–3 or >10 years, increased the height of vegetation around their margins. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2966https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2966Thu, 25 Mar 2021 14:14:57 +0000Collected Evidence: Collected Evidence: Actively manage water level: freshwater marshes Ten studies evaluated the effects, on vegetation, of active water level management in freshwater marshes. Eight studies were in the USA. One study was in Cameroon and one study was in the Netherlands. VEGETATION COMMUNITY Community composition (1 study): One before-and-after study in the USA found that directly pumping water into drained marshes and wet meadows generated plant communities characteristic of wetter conditions. This change was reversed in some plots when the pump output was moved further away from the focal wetlands. Relative abundance (2 studies): One replicated, randomized, controlled study of freshwater marshes in the USA reported that irrigated and non-irrigated marshes supported a similar relative abundance of the most common plant species. One before-and-after study on a floodplain in Cameroon found that the relative abundance of some key plant species changed over four years after restoring wet-season flooding. There was also an increase in the cover of perennial relative to annual herbs. Overall richness/diversity (4 studies): One before-and-after study of a marsh/swamp in the USA found that overall plant diversity was higher in the autumn following a managed flood/drawdown than in the autumn before. Two before-and-after studies of marshes and wet meadows in the USA reported that plant species richness and/or diversity declined over 5–6 years of water level management (fluctuation or water addition). One study in the USA simply reported the number of plant species that colonized a floodplain, over three weeks after lowering the river level. VEGETATION ABUNDANCE Overall abundance (3 studies): One study of riparian moist/wet meadows in the USA reported that vascular plant biomass increased in two of three meadow types, over the second year of artificially augmented streamflow. Meanwhile, vascular plant cover declined in two of three meadow types. Two studies in the Netherlands and the USA simply quantified overall vegetation abundance after 1–9 growing seasons of active water level management (sometimes along with other interventions). Characteristic plant abundance (2 studies): Two before-and-after studies of marshes and wet meadows in the USA reported increases in abundance of some individual wetland- or habitat-characteristic species over 5–6 years of water level management (fluctuation or water addition). Moss abundance (1 study): One study of riparian moist/wet meadows in the USA reported that moss cover did not significantly change in two of three meadow types, over the second year of artificially augmented streamflow. It declined in the other meadow type. Individual species abundance (7 studies): Seven studies quantified the effect of this action on the abundance of individual plant species. For example, one before-and-after study of a marsh/swamp in the USA reported mixed effects of a managed flood/drawdown on species cover, including increased cover of Pacific willow Salix lucida and reduced cover of reed canarygrass Phalaris arundinacea. One controlled study of freshwater marshes in the USA found that irrigated marshes developed a greater biomass of pink smartweed Polygonum pensylvanicum, after one growing season, than marshes that were left dry. VEGETATION STRUCTURE Vegetation height (1 study): One replicated, randomized, controlled study of freshwater marshes in the USA reported that four common plant species were taller in irrigated than non-irrigated marshes. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3038https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3038Thu, 01 Apr 2021 10:02:54 +0100Collected Evidence: Collected Evidence: Actively manage water level: brackish/salt marshes Ten studies evaluated the effects, on vegetation, of active water level management in brackish/salt marshes. Six studies were in the USA. There was overlap in the sites used in two of these studies. Two studies were in Canada and based on the same experimental set-up. One study was in France and one was in Tunisia. VEGETATION COMMUNITY Community types (1 study): One before-and-after study of a lakeshore brackish/salt marsh in Tunisia reported an increase in coverage of bulrush-dominated vegetation over nine years of freshwater releases into the lake (to increase its level and restore winter flooding of the marsh). Community composition (3 studies): One replicated, paired, controlled, before-and-after study of brackish marshes in France reported that artificially flooded marshes developed different plant communities, over five years, to fields with unmanaged flooding. One before-and-after, site comparison study of brackish/salt marshes in the USA reported that the overall plant community composition changed more, over four years, in a marsh directly irrigated with treated wastewater than in downstream marshes. One replicated, paired, site comparison study of brackish/salt marshes in the USA reported that that marshes in which water levels were drawn down each spring/autumn (along with disking soils) shared only 24–34% of plant species with marshes that were not drawn down (or disked). Overall richness/diversity (5 studies): Two replicated, site comparison studies of brackish/salt marshes in the USA found that marshes in which water levels were managed (sometimes along with other interventions) had similar plant species richness and/or diversity to marshes without water level management. One replicated, site comparison study of brackish and salt marshes in the USA reported that marshes in which water levels were managed had similar or higher plant species richness, in winter, than marshes without water level management. One before-and-after, site comparison study of brackish/salt marshes in the USA reported that plant species richness increased, over four years, in marshes directly irrigated with treated wastewater – but only to similar levels as in downstream marshes. One replicated, paired, controlled, before-and-after study of brackish marshes in France reported that the effects of artificial flooding on plant species richness depended on whether the marshes were grazed. VEGETATION ABUNDANCE Overall abundance (2 studies): Two replicated, site comparison studies of brackish and salt marshes in the USA reported that marshes in which water levels were managed typically had similar overall vegetation cover to marshes without water level management. One of the studies also reported that cover of standing dead vegetation was higher in the managed marshes than in the unmanaged marshes. Individual species abundance (6 studies): Six studies quantified the effect of this action on the abundance of individual plant species. For example, four replicated, site comparison studies of brackish and salt marshes in the USA reported mixed effects of water level management on the abundance of saltmeadow cordgrass Spartina patens. One replicated, paired, controlled, before-and-after study of brackish marshes in France reported that the effects of artificial flooding on the cover of individual plant species depended on the flooding (and grazing) regime. VEGETATION STRUCTURE   OTHER Germination/emergence (2 studies): Two replicated studies of brackish marshes in Canada reported that seedlings of wetland plants germinated in the spring/summer following drawdowns, after a period of deep flooding. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3039https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3039Thu, 01 Apr 2021 10:03:10 +0100Collected Evidence: Collected Evidence: Use prescribed fire to maintain or restore disturbance: brackish/salt marshes Ten studies evaluated the effects, on vegetation, of using prescribed fire to maintain or restore disturbance in brackish/salt marshes. Seven studies were in the USA. Two studies were in Argentina but based on the same experimental set-up. One study was in Guadeloupe. VEGETATION COMMUNITY Community composition (1 study): One replicated, paired, controlled study in a salt marsh in Argentina reported that burned plots had a different overall plant community composition to unburned plots, five months after burning. The same was true in one of two comparisons 17 months after burning. Overall richness/diversity (5 studies): Three studies (including one replicated, paired, controlled) in brackish marshes in the USA and Guadeloupe reported that burning had no significant effect on overall plant species richness, measured approximately 10 weeks to 2 years after the latest burn. In one of the studies, the effects of burning and legal protection were not separated. One replicated, randomized, paired, controlled, before-and-after study in brackish marshes in the USA reported that burning typically had no significant effect on changes in plant species richness over two years. One replicated, paired, controlled study in a salt marsh in Argentina reported that burned plots had greater overall plant species richness and diversity than unburned plots, 5–17 months after burning. Characteristic plant richness/diversity (1 study): One study of a coastal marsh in the USA reported that over three years after restoration – involving a prescribed burn along with restoration of tidal exchange – the number of salt-tolerant plant species increased, whilst the number of freshwater plant species decreased. VEGETATION ABUNDANCE Overall abundance (5 studies): Three replicated studies (one also randomized, paired, controlled) in brackish marshes in the USA found that overall vegetation biomass was lower in burned than unburned plots, 10 weeks or 1 year after the latest burn. One replicated, randomized, paired, controlled, before-and-after study in alkali marshes in the USA found that a single prescribed burn had no significant effect on overall vegetation biomass: there was a similar change over two years in burned and unburned plots. One replicated, paired, controlled study in a salt marsh in Argentina found that the effect of a single prescribed burn on the frequency of seedlings depended on the time since burning, but that seedlings were more frequent in burned than unburned plots after 9–12 months. Characteristic plant abundance (1 study): One study of a coastal marsh in the USA found that over three years after restoration – involving a prescribed burn along with restoration of tidal exchange – the cover of salt-tolerant plant species increased, whilst the cover of freshwater plant species decreased. Individual species abundance (7 studies): Seven studies quantified the effect of this action on the abundance of individual plant species. For example, five studies quantified the effects of prescribed burning on the abundance of dominant cordgrasses Spartina sp. in brackish and salt marshes in the USA and Argentina. Two replicated, paired, controlled studies found that cordgrass abundance (biomass or cover) was lower in burned than unburned plots, between 10 weeks and 17 months after the latest burn. However, one replicated, paired, site comparison study found that burning typically had no significant effect on cordgrass biomass or density after 2–8 months. One replicated, before-and-after study found that cordgrass biomass was lower, but cover greater, one year after burning than before. One study reported mixed effects on cordgrass cover across two marshes. VEGETATION STRUCTURE Height (2 studies): Two studies (one controlled, one site comparison) in brackish marshes in the USA and Guadeloupe reported that the height of dominant grass-like plants was lower in burned than unburned areas for up to 1–2 years after the latest burn. The study in the USA reported recovery, to a slightly greater height than in unburned areas, after three years. The study in Guadeloupe also reported that the tallest trees in burned marshes were shorter than the tallest trees in unburned marshes. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3055https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3055Fri, 02 Apr 2021 08:57:38 +0100Collected Evidence: Collected Evidence: Transplant or replace wetland soil: freshwater marshes Ten studies evaluated the effects, on vegetation, of transplanting wetland soil to restore or create freshwater marshes. Nine studies were in the USA. One study was in Guam. Two studies were in the same region but used different sites. VEGETATION COMMUNITY Community composition (3 studies): Two replicated, controlled studies in rewetted marshes in the USA found that areas amended with wetland soil contained a plant community characteristic of wetter conditions than unamended plots after one growing season – but not after two. One replicated, randomized, controlled study in a recently excavated marsh in the USA found that amended and unamended plots contained a plant community of similar overall wetness after both one and two growing seasons. Overall richness/diversity (10 studies): Eight studies (including four at least replicated and controlled) in freshwater marshes in the USA reported that areas amended with wetland soil had greater plant richness and/or diversity than unamended areas and/or nearby natural marshes. One replicated, paired, controlled study in rewetted freshwater marshes in the USA found that plots amended with sieved marsh soil contained a similar number of wetland plant species to unamended plots, after 1–2 growing seasons. One before-and-after study of freshwater pool in Guam simply quantified plant species richness one year after adding wetland soil (along with other interventions). Characteristic plant richness/diversity (1 study): One replicated, randomized, paired, controlled study in a freshwater marsh in the USA reported that plots amended with wetland soil developed a greater richness of wetland-characteristic plant species than unamended plots, at the end of the growing season. VEGETATION ABUNDANCE Overall abundance (6 studies): Six controlled studies in freshwater marshes in the USA reported that plots amended with wetland soil typically contained more vegetation overall than unamended plots, after 1–2 growing seasons. This was true for cover and biomass, but not stem density. Individual species abundance (7 studies): Seven studies (including one replicated, randomized, paired, controlled, site comparison) in freshwater marshes, meadows and pools in the USA and Guam quantified the effect of this action (sometimes along with others) on the abundance of individual plant species. Results were mixed and likely depended on the composition of the donor wetland. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3270https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3270Sat, 10 Apr 2021 15:48:02 +0100Collected Evidence: Collected Evidence: Mow before or after seeding/planting Ten studies examined the effects of mowing before or after seeding/planting on grassland vegetation. Nine studies were in Europe and one was in China. VEGETATION COMMUNITY (5 STUDIES) Community composition (1 study): One replicated, site comparison study in Hungary found that annual mowing after sowing seeds increased plant community similarity to that of natural grassland. Overall richness/diversity (1 study): One replicated, controlled study in the UK found that cutting vegetation yearly after sowing seeds increased plant species richness compared to grazing with livestock. Characteristic plant richness/diversity (1 study): One replicated, controlled study in Germany found that cutting vegetation three times/year after sowing seeds increased the richness of characteristic grassland species compared to cutting once/year. Sown/planted species richness/diversity (2 studies): One replicated, randomized, paired, controlled study in the UK found that mowing after sowing seeds increased the richness of sown species. One replicated study in the UK found that cutting sown plots each year and removing cut vegetation increased sown grass and forb species richness compared to cutting and not removing cut vegetation. VEGETATION ABUNDANCE (4 STUDIES) Sown/planted species abundance (3 studies): One replicated, randomized, paired, controlled study in the UK found that mowing after sowing seeds increased the abundance of sown forb species. One replicated, randomized, paired, controlled study in Germany found that mowing more frequently after sowing seeds increased the abundance of five of seven sown forb species. One replicated study in the UK found that cutting sown plots each year and removing cut vegetation reduced the cover of sown grass and forb species compared to cutting and not removing cut vegetation. Individual plant species abundance (1 study): One replicated, controlled study in Germany found that mowing after planting increased the biomass of transplanted ragged robin and birdsfoot trefoil plants at 2–3 of seven sites. VEGETATION STRUCTURE (0 STUDIES) OTHER (4 STUDIES) Germination/Emergence (3 studies): One of three replicated, controlled studies (including two randomized and one paired study) in the UK, Germany and China found that mowing after sowing seeds increased the germination of four grassland plant species. One study found that mowing after sowing seeds increased the number of ragged robin and birdsfoot trefoil seedlings at 1–2 of seven sites. One study found that cutting grass after sowing seeds did not alter the emergence rate or density of seedlings. Survival (2 studies): One of two replicated, randomized, paired, controlled studies in Germany and China found that cutting grass after sowing seeds did not alter seedling survival. The other study found that cutting grass after sowing seeds did not alter seedling survival. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3419https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3419Fri, 25 Jun 2021 16:29:54 +0100Collected Evidence: Collected Evidence: Transplant or seed organisms onto intertidal artificial structures Ten studies examined the effects of transplanting or seeding species onto intertidal artificial structures on the biodiversity of those structures. Seven studies were in estuaries in southeast Australia and Hong Kong, two were on island coastlines in the Singapore Strait and one was in a port and on an open coastline in southeast Spain. COMMUNITY RESPONSE (5 STUDIES) Overall community composition (3 studies): Three replicated, randomized, controlled studies in Hong Kong and Australia reported that oysters transplanted onto intertidal artificial structures supported macroalgae, mobile invertebrate, non-mobile invertebrate and fish species that were absent from on and around structure surfaces without transplanted oysters. Overall richness/diversity (3 studies): Three replicated, randomized, controlled studies in Hong Kong and Australia found that transplanting oysters onto intertidal artificial structures had mixed effects on the combined macroalgae and invertebrate species richness and/or diversity on structure surfaces, depending on the site and/or the presence and size of grooves and small ridges or ledges on surfaces. Invertebrate richness/diversity (1 study): One replicated, randomized, controlled study in Australia found that transplanting oysters onto intertidal artificial structures increased the mobile invertebrate species richness on structure surfaces. Fish richness/diversity (3 studies): Two of three replicated, randomized studies (including two controlled studies) in Australia found that transplanting oysters and/or coralline algae onto intertidal artificial structures did not increase the fish species richness on and around structure surfaces. One found mixed effects of transplanting oysters, depending on the presence and size of grooves and small ridges on surfaces and the site. POPULATION RESPONSE (10 STUDIES) Overall abundance (2 studies): One of two replicated, randomized, controlled studies in Australia found that transplanting oysters onto intertidal artificial structures did not increase the combined macroalgae and invertebrate abundance on structure surfaces. One study found mixed effects depending on the presence and size of grooves and small ridges/ledges on structure surfaces. Invertebrate abundance (3 studies): Two of three replicated, randomized, controlled studies in Hong Kong and Australia found that transplanting oysters onto intertidal artificial structures had mixed effects on the mobile invertebrate abundance on structure surfaces, depending on the presence of grooves and small ridges or ledges on surfaces and/or the site. One of the studies also found that transplanting oysters increased the non-mobile invertebrate and oyster recruit abundance and decreased barnacle abundance. One found increased oyster and mobile invertebrate abundance. Fish abundance (3 studies): Two of three replicated, randomized studies (including two controlled studies) in Australia found that transplanting oysters and/or coralline algae onto intertidal artificial structures did not increase the fish abundance on and around structure surfaces. One found that fish abundance around transplanted oysters was similar regardless of the presence and size of grooves and small ridges on structure surfaces. Algal survival (1 study): One replicated study in Singapore found that macroalgae transplanted onto an intertidal artificial structure were more likely to survive at mid- and highshore than at lowshore. Invertebrate survival (8 studies): Six of eight studies (including six replicated, three randomized and two controlled studies) in Australia, Spain, Singapore and Hong Kong reported that the survival of mobile invertebrates (seasnails, starfish and/or urchins and anemones) or non-mobile invertebrates (limpets, corals and sponges or oysters) transplanted onto intertidal artificial structures varied depending on the species, site, and/or the presence and size of grooves and small ridges or ledges on structure surfaces. One of the studies found that oyster survival was higher when transplanted into grooves compared with on ridges, while one found that survival in grooves and on ledges varied depending on the site. Two studies simply reported that a proportion of transplanted oysters survived. Algal condition (1 study): One replicated study in Singapore found that the growth of macroalgae transplanted onto an intertidal artificial structure was similar at lowshore, midshore and highshore. Invertebrate condition (2 studies): One study in Singapore reported that the growth of corals and sponges transplanted onto an intertidal artificial structure varied depending on the species. One replicated study in Spain simply reported that transplanted limpets grew. BEHAVIOUR (1 STUDY) Fish behaviour change (1 study): One replicated, randomized, controlled study in Australia found that transplanting oysters and/or coralline algae onto intertidal artificial structures did not increase the time fishes spent interacting with structure surfaces or the number of bites they took, but that benthic fishes took more bites from surfaces with transplanted oysters than from those with transplanted algae and oysters together. These results were true regardless of whether there were grooves and small ridges on structure surfaces. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3472https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3472Fri, 17 Sep 2021 16:55:42 +0100Collected Evidence: Collected Evidence: Legally protect habitat Ten studies evaluated the effects on butterflies and moths of legally protecting habitat. Six studies were in the UK and one was in each of Australia, Singapore and Ireland and the USA. Three of the studies used data from the same national monitoring scheme across different years. COMMUNITY RESPONSE (3 STUDIES) Richness/diversity (3 studies): One replicated, site comparison study in Singapore found that protected primary or secondary forest reserves had a higher species richness of butterflies than unprotected forest fragments. One replicated, paired, site comparison study in Ireland reported that raised bogs protected as Special Areas of Conservation (where restoration had sometimes taken place) had a similar species richness of moths to unprotected bogs. One replicated, site comparison study in the UK found that, in the first three years after protection as Sites of Special Scientific Interest (SSSI), woodland, grassland and heathland sites lost a similar proportion of 29 threatened butterfly species to unprotected sites. POPULATION RESPONSE (8 STUDIES) Abundance (7 studies): Three of five site comparison studies (including four replicated studies and one before-and-after study) in the UK and Ireland found that sites protected as National Nature Reserves or Sites of Special Scientific Interest (SSSI) (in one case also managed by coppicing), or surrounded by SSSIs, had a higher abundance of heath fritillary, all butterflies and 30/57 species of butterfly than unprotected sites. However, one of these studies only found the result using one of two sets of sites. The other two studies found that grasslands protected as National Nature Reserves or SSSIs and raised bogs protected as Special Areas of Conservation had a similar total abundance of moths, and change in abundance of chalkhill blue butterflies, to unprotected sites. However, one of these studies found mixed results for individual moth species. One replicated, site comparison study in the USA found that, at sites with the highest levels of protection, abundances of Karner blue, frosted elfin and Persius duskywing did not change over time, whereas they decreased at sites with lower levels of protection. One replicated, site comparison study in the UK found that protected grasslands assessed as being in “Favourable” habitat condition had worse population trends for 4/8 butterfly species but better for 1/8 species than grasslands in “Unfavourable” condition. One study in Australia reported that after a grassland was designated as a local reserve, populations of golden sun-moth and pale sun-moth persisted for at least four years. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3831https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3831Mon, 04 Jul 2022 13:36:18 +0100Collected Evidence: Collected Evidence: Remove, control or exclude vertebrate herbivores Ten studies evaluated the effects on butterflies and moths of removing, controlling or excluding vertebrate herbivores. Three studies were in the USA, two were in the UK, one was in each of Mauritius, the Netherlands, Canada and Japan, and one was a global systematic review. COMMUNITY RESPONSE (6 STUDIES) Richness/diversity (6 studies): Two of four replicated studies (including three controlled studies and one site comparison study) in the USA, Mauritius and Canada found that forest plots fenced to exclude, or reduce the density of, non-native pigs and deer (in one case along with weeding of invasive plants) had a greater species richness of butterflies and macro-moths than unfenced plots. The other two studies found that forest plots fenced to exclude elk had mixed effects on the species richness of butterflies and arthropods including moths depending on fire intensity and year. One of these studies also found that grassland plots fenced to exclude elk had a similar species richness of butterflies to unfenced plots in all years. One global systematic review found that reducing or removing grazing or browsing by wild or domestic herbivores in temperate and boreal forests did not affect the species richness of butterflies and moths. POPULATION RESPONSE (10 STUDIES) Abundance (9 studies): Five of eight studies (including five controlled studies, one before-and-after study, and two site comparison studies) in the UK, the USA, Mauritius, Canada and Japan found that forest and grassland plots fenced to exclude, or reduce the density of, deer, sheep, pigs and large herbivores (in one case along with weeding of invasive plants) had a higher abundance of butterflies, moths, caterpillars, rare macro-moths and New Forest burnet moths than unfenced plots. One of these studies also found that the total abundance of macro-moths was similar in fenced and unfenced plots. Two studies found that forest plots fenced to exclude elk had mixed effects on the abundance of butterflies and arthropods including moths depending on fire intensity and year. One of these studies also found that grassland plots fenced to exclude elk had a similar abundance of butterflies to unfenced plots in all years. The eighth study found that a forest fenced to exclude sika deer had a similar abundance of all moths, but a lower abundance of tree-feeding moths, than unfenced forest. One global systematic review found that reducing or removing grazing or browsing by wild or domestic herbivores in temperate and boreal forests increased the abundance of butterflies and moths. Survival (1 study): One paired, controlled study in the Netherlands reported that all Glanville fritillary caterpillar nests survived in grassland fenced to exclude sheep, compared to 88% in a grazed area. Condition (1 study): One paired, controlled study in the Netherlands found that fewer Glanville fritillary caterpillar nests were damaged in grassland fenced to exclude sheep than in a grazed area. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3891https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3891Tue, 09 Aug 2022 11:49:20 +0100Collected Evidence: Collected Evidence: Restore arable land to permanent grassland Ten studies evaluated the effects on butterflies and moths of restoring arable land to permanent grassland. Six studies were in the UK, two were in Finland, and one was in each of Switzerland and Taiwan. COMMUNITY RESPONSE (9 STUDIES) Community composition (2 studies): One of two replicated, site comparison studies in the UK and Finland found that grasslands restored from bare soil by seeding developed butterfly communities that were increasingly similar to existing high-quality grasslands over the first 10 years after establishment. The other study found that older grasslands established by sowing with competitive seed mixes had a greater proportion of specialist butterflies than newer grasslands sown with less competitive species which required re-seeding every 4–5 years. Richness/diversity (8 studies): Three replicated, site comparison studies (including two paired studies) in Switzerland, the UK and Taiwan found that 4–5-year-old created grasslands and abandoned cropland had a greater species richness of butterflies, burnet moths and all moths than conventionally managed grassland or cultivated farms. Two of three replicated studies (including one randomized, paired, controlled study and two site comparison studies) in the UK and Finland found that grasslands established by sowing grasses, legumes and other non-woody, broadleaved plants (forbs), or perennial grass mixes, had a higher species richness of butterflies (in one case including other pollinators) than grasslands established with grass-only mixes or less competitive species. The third study found that grasslands established by sowing complex or simple seed mixes, or by natural regeneration, all had a similar species richness of butterflies and day-flying moths, but species richness was higher on grasslands created <10 years ago than on grasslands created >20 years ago. One before-and-after study in the UK found that after the adoption of an Environmentally Sensitive Areas scheme, including reverting arable land to permanent grassland, the species richness of large moths on a farm increased. One replicated, site comparison study in the UK found that over 10 years after restoration, the number of species of butterfly on seeded grassland remained similar each year. POPULATION RESPONSE (7 STUDIES) Abundance (7 studies): Two of three replicated, paired, site comparison studies in the UK and Taiwan found that restored grassland had a higher abundance of moths than conventional grassland or unrestored crop fields, and a similar abundance to semi-natural grasslands, but abundance did not increase with time since restoration. The third study found that abandoned cropland had a similar abundance of butterflies to cultivated farms. Two of three replicated studies (including one randomized, paired, controlled study and two site comparison studies) in the UK and Finland found that grasslands established by sowing grasses, legumes and other non-woody, broadleaved plants (forbs), or perennial grass mixes, had a higher abundance of butterflies (in one case including other pollinators) than grasslands established with grass-only mixes or less competitive species. The third study found that grasslands restored by sowing complex or simple seed mixes, or by natural regeneration, all had a similar abundance of caterpillars. One before-and-after study in the UK found that after the adoption of an Environmentally Sensitive Areas scheme on a farm, including reverting arable land to permanent grassland, the abundance of large moths and five species of butterfly increased, but the abundance of two species of butterfly decreased. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3929https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3929Thu, 11 Aug 2022 18:15:43 +0100Collected Evidence: Collected Evidence: Restore or create forest or woodland Ten studies evaluated the effects on butterflies and moths of restoring or creating forest or woodland. Three studies were in the UK, two studies were in Brazil and one was in each of the USA, Cameroon, Mexico, Malaysia and Costa Rica. COMMUNITY RESPONSE (6 STUDIES) Community composition (4 studies): Three site comparison studies (including two replicated studies) in Mexico, Costa Rica and Brazil found that naturally generating or secondary forest had a different community composition of caterpillars6, geometrid and arctiine moths and butterflies to replanted forest, oil palm plantations, pasture or remnant primary forest. One site comparison study in Brazil found that a 54-year-old restored forest had a higher proportion of fruit-feeding forest butterfly species than 11–22-year-old restored forests, and a similar community composition to a remnant forest. Richness/diversity (6 studies): Three replicated, site comparison studies in Cameroon, Costa Rica and Brazil found that secondary forest had a similar species richness of butterflies and geometrid and arctiine moths to agroforestry plantations, pasture and remnant forest. Two of these studies also found that secondary forest had a greater species richness of butterflies and geometrid and arctiine moths than cropland or oil palm plantations. One of two site comparison studies (including one replicated study) in Brazil and Malaysia found that a 54-year-old restored forest had a lower species richness of fruit-feeding butterflies than 11–22-year-old restored forests. The other study found that 5–60-year-old restored forests had a greater species richness of butterflies than newly restored forests (<3-years-old), but restored forests had a lower species richness than primary forests. One site comparison study in Mexico found that a forest restored by natural regeneration had a similar diversity of caterpillars to a forest restored by planting. POPULATION RESPONSE (6 STUDIES) Abundance (6 studies): Two replicated, site comparison studies in Cameroon and Costa Rica found that secondary forest had a higher abundance of butterflies and geometrid and arctiine moths than cropland or oil palm plantations. One of these studies also found that secondary forest had a similar abundance of butterflies to coffee and cocoa agroforestry, and the other study also found that secondary forest had a lower abundance of geometrid and arctiine moths than primary forest. One site comparison study in Mexico found that a forest restored by natural regeneration had a similar abundance of caterpillars to a forest restored by planting. Two of three studies in the UK reported that where forest had been restored with coppicing, felling and ride management, the number of populations of high brown fritillary, pearl-bordered fritillary, wood white and grizzled skipper stayed the same or increased. The other study found that the number of heath fritillary colonies decreased after management. BEHAVIOUR (3 STUDIES) Use (3 studies): Two studies (including one paired study) in the USA and the UK found that in forest restored with selective logging or coppicing, felling and ride widening orange sulphur and heath fritillary butterflies, but not pine white butterflies, flew into restored areas more than unrestored areas and occupied a greater area than before the sites were restored. One replicated, before-and-after study in the UK reported that in forest restored with coppicing, felling and ride management, high brown fritillary presence was the same or higher than before restoration, and after restoration the butterflies were more likely to be present at sites with high brash and bracken litter coverage.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3936https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3936Sat, 13 Aug 2022 14:54:54 +0100Collected Evidence: Collected Evidence: Coppice woodland Ten studies evaluated the effects on butterflies and moths of coppicing woodland. Eight studies were in the UK and one was in each of France and Germany. COMMUNITY RESPONSE (4 STUDIES) Community composition (3 studies): Two replicated, site comparison studies in the UK and France found that coppiced woodland of different ages supported different communities of moths and butterflies. One replicated, site comparison study in the UK found that coppiced woodland contained more unique species of macro-moth than mature forest. Richness/diversity (4 studies): One of two replicated, site comparison studies in the UK found that coppiced woodland had a greater species richness of butterflies than unmanaged woodland. The other study found that coppiced woodland had a lower species richness of macro-moths than mature forest, and there was no change in species richness with the age of coppice. One of two replicated, site comparison studies in the UK and France found that woodland coppiced two years ago had a greater species richness of butterflies than woodland coppiced >15 years ago. The other study found that the species richness of moths was similar in woodland coppiced 1–4, 5–8 and 12–20 years ago. POPULATION RESPONSE (10 STUDIES) Abundance (9 studies): Two of four site comparison studies (including three replicated studies and one before-and-after study) in the UK found that coppiced woodland (in one case also legally protected) had a higher abundance of butterflies generally, and of heath fritillary specifically, than unmanaged woodland. One study found that pearl-bordered fritillary and small pearl-bordered fritillary populations were more likely to persist for up to 20 years in coppiced woodland (or woodland with young plantations) than in mature conifer woodland. The fourth study found that the abundance of macro-moths was lower in coppiced woodland than in mature forest, and there was no change in abundance with the age of coppice. Three of four replicated, site comparison studies (including one before-and-after study) in the UK, France and Germany found that the abundance of butterflies generally, heath fritillary specifically, and eastern eggar moth and scarce fritillary caterpillar webs, was higher in woodland coppiced two, two–four, five–seven or 12–15 years ago than in woodland coppiced 5–11 or >15 years ago. The fourth study reported that the abundance of moths was similar in woodland coppiced 1–4, 5–8 and 12–20 years ago. One before-and-after study in the UK reported that after coppicing, along with scrub control, tree felling and grazing, high brown fritillary and small pearl-bordered fritillary abundance increased. Reproductive success (1 study): One before-and-after study in the UK reported that pearl-bordered fritillaries released into coppiced woodland bred at least once. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3939https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3939Sat, 13 Aug 2022 14:56:58 +0100Collected Evidence: Collected Evidence: Use rotational mowing Ten studies evaluated the effects on butterflies and moths of using rotational mowing. Two studies were in each of the USA, the Czech Republic and Switzerland, and one was in each of the UK, Germany, Europe and Japan. COMMUNITY RESPONSE (6 STUDIES) Community composition (1 study): One replicated, site comparison study in the Czech Republic found that grasslands managed with “mixed management”, which included mowing parts of a site at different times and leaving some areas uncut, had a similar community composition of butterflies, but a different community composition of moths, to grasslands managed by complete annual mowing. Richness/diversity (6 studies): Three of four replicated studies (including two paired, controlled studies and two site comparison studies) in Germany, Switzerland, Japan and the Czech Republic found that grasslands managed by mowing strips in alternate years, by mowing and burning one half of the meadow each year, or by mowing parts of a site at different times and leaving some areas uncut, had a greater species richness and diversity of butterflies than grasslands cut in full once/year. However, one of these studies also found that grasslands managed by mowing parts of a site at different times and leaving some areas uncut had a lower species richness of moths than grasslands cut in full once/year. The fourth study found that grasslands managed by leaving a rotational area uncut on each mow had a similar species richness of butterflies and burnet moths to grasslands cut in full twice/year. One replicated, site comparison study in the USA found that rotationally managed grasslands, including some rotationally mown grasslands, which were last managed longer ago had a higher species richness of butterflies than more recently managed grasslands. One replicated, site comparison study in Switzerland found that farms managed with more in-field agri-environment scheme (AES) options, including staggered mowing dates, had a similar species richness of butterflies to farms with fewer AES options. POPULATION RESPONSE (7 STUDIES) Abundance (7 studies): Two replicated, paired, controlled studies (including one randomized study) in Germany and Switzerland found that grasslands managed by mowing strips in alternate years, or by leaving a rotational area uncut on each mow, had a higher abundance of butterflies and burnet moths than grasslands cut in full once or twice per year. One of two replicated, site comparison studies in the USA found that rotationally managed grasslands, including some rotationally mown grasslands, which were last managed longer ago had a higher abundance of butterflies than more recently managed grasslands. The other study found that rotationally mown grasslands had a lower abundance of butterflies in the second year after they were last cut than in the first year after mowing. One replicated, site comparison study in the UK reported that two heath fritillary populations survived on rotationally mown grasslands while six populations went extinct on unmanaged grasslands. One review in Europe reported that rotationally mowing grassland benefitted 27 out of 67 butterfly species of conservation concern. One replicated, site comparison study in Switzerland found that farms managed with more in-field agri-environment scheme (AES) options, including staggered mowing dates, had a similar abundance of butterflies to farms with fewer AES options. BEHAVIOUR (1 STUDY) Use (1 study): One replicated, controlled study in the Czech Republic found that 29 out of 32 butterfly species preferred meadows which were half mown in June and August to meadows cut in full twice/year. The other three species were woodland species which only visited meadows temporarily. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3966https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3966Sun, 14 Aug 2022 10:38:31 +0100Collected Evidence: Collected Evidence: Create uncultivated margins around intensive arable or pasture fields Ten studies evaluated the effects on butterflies and moths of creating uncultivated margins around intensive arable or pasture fields. Six studies were in the UK, two were in Sweden, and one was in each of Finland and Germany. COMMUNITY RESPONSE (9 STUDIES) Richness/diversity (9 studies): Two of five studies (including four replicated, one randomized, one paired, two controlled and two site comparison studies) in Sweden, the UK and Finland, found that uncultivated margins had a lower species richness or diversity of butterflies than margins sown with grasses and non-woody broadleaved plants (forbs) or wildflowers. One other study found that the species richness of butterflies and day-flying moths was higher in permanent uncultivated margins than in sown fallow plots, and the other two found that the species richness of butterflies and moths was similar in uncultivated and sown margins. Three replicated studies (including one randomized, controlled study and two site comparison studies) in the UK and Germany found that uncultivated margins which were not grazed or cut, or were only cut in spring or autumn, had a higher species richness of butterflies than margins which were cut in summer. Two site comparison studies (including one replicated study) in the UK and Germany found that the species richness of butterflies was higher in longer or wider uncultivated margins than in shorter, narrower or conventional width margins. One of two replicated studies (including one controlled study and one site comparison study) in the UK and Finland found that uncultivated margins had a higher species richness of butterflies and day-flying moths than cereal fields, but the other found that the species richness of butterflies was similar between regenerating margins and cropped field edges. One replicated, paired, site comparison study in Sweden found that uncultivated margins had a higher species richness of butterflies and burnet moths if they were located closer to existing grassland. POPULATION RESPONSE (9 STUDIES) Abundance (9 studies): Six of seven studies (including six replicated, two randomized, four controlled and three site comparison studies) in Sweden, the UK and Finland found that the abundance of butterflies and moths, and of adult but not caterpillar meadow brown, was lower in uncultivated margins than in margins sown with grasses, or grasses and non-woody broadleaved plants (forbs) or wildflowers, or a mixture of grasses and wildflowers. However, one of these studies found that uncultivated margins had similar abundance of butterflies to margins sown with grasses or cereal crop. The other study found that the abundance of butterflies and day-flying moths was higher in permanent uncultivated margins than in sown fallow plots. Two of three replicated, site comparison studies (including two randomized studies) in the UK found that uncultivated margins which were not cut, or were only cut in spring and autumn, had a higher abundance of butterflies, and adult but not caterpillar meadow brown, than margins cut in summer. The other study found that margins which were not cut and grazed had a similar abundance of butterflies to margins which were cut and grazed. Two replicated studies (including one controlled study and one site comparison study) in the UK and Finland found that uncultivated margins had a higher abundance of butterflies and day-flying moths than cereal fields or cropped field edges. One site comparison study in the UK found that the abundance of butterflies in wide uncultivated margins was higher than in conventional margins. One replicated, paired, site comparison study in Sweden found that uncultivated margins had a higher abundance of butterflies and burnet moths if they were located closer to existing grassland. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3981https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3981Thu, 18 Aug 2022 11:06:18 +0100
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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