Collected Evidence: Collected Evidence: Use greentree reservoir managementA site comparison study from the USA found significantly lower numbers of breeding mid- and under-storey birds at a greentree reservoir site than at a control site. Canopy nesting species were not affected. The species investigated were not gamebirds or wildfowl.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F357https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F357Sun, 29 Jul 2012 17:02:09 +0100Collected Evidence: Collected Evidence: Use gloves to handle amphibians We found no evidence for the effects of using gloves on the spread of disease between amphibian populations or individuals. A review for Canada and the USA found that there were no adverse effects of handling 22 amphibian species using disposable gloves. However, three replicated studies (including one controlled study) in Australia and Austria found that deaths of tadpoles were caused by latex gloves for all four species tested, by vinyl gloves for three of five species and by nitrile gloves for the one species tested.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F769https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F769Mon, 19 Aug 2013 15:45:10 +0100Collected Evidence: Collected Evidence: Use grazing instead of cutting for pasture or grassland managementNatural enemies: Two studies (one before-and-after and one replicated trial) from Australia and the UK found grazing instead of cutting had mixed effects on natural enemies, with some species and groups affected on some dates but not others. One replicated study from New Zealand found no effect. Pests and diseases: One of five studies (including three replicated trials) from Australia, New Zealand, the UK and the USA found more pests, and two studies found effects varied between pest groups and sampling dates. Two studies found no effect on pests. One study found no effect on disease when grazing was used in addition to cutting. Pasture damage and plant survival: One randomised study found more ryegrass shoots were attacked by pests. One study found lower survival of alfalfa plants but another found no effect. Yield: One of four randomised, replicated studies (one also controlled) found lower yields and two found no effect. One study found lower ryegrass and higher clover yields, but no difference between clover varieties. Another randomised study found more ryegrass shoots. Crops studied were alfalfa, cock’s-foot, perennial ryegrass, other grasses and white clover.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F885https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F885Wed, 18 Sep 2013 15:54:32 +0100Collected Evidence: Collected Evidence: Use genetically modified alternatives Three controlled, replicated (two randomised) studies in Norway found no difference in growth rate of Atlantic salmon that were fed diets containing either GM or non-GM soybeans. One randomised, replicated, controlled study in Norway found no differences in fish fed diets containing either GM or non- GM soybeans on the histology of the fish.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F928https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F928Fri, 25 Oct 2013 13:50:59 +0100Collected Evidence: Collected Evidence: Use grazing to remove invasive plant species We found no evidence for the effects of using grazing to remove invasive plant species on forests. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1195https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1195Thu, 19 May 2016 13:10:18 +0100Collected Evidence: Collected Evidence: Use group-selection harvesting Four of eight studies (including one replicated, controlled study) in Australia, Canada, Costa Rica and the USA found that group-selection harvesting increased cover and diversity of understory plants and the density of young trees. Two studies found it decreased understory species richness2 and biomass.Two studies found no effect on understory species richness and diversity and two found no effect of group-selection harvest on tree density and growth-rate.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1224https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1224Mon, 23 May 2016 09:45:25 +0100Collected Evidence: Collected Evidence: Use GPS and/or VHF tracking devices on individuals of problem troops to provide farmers with early warning of crop raiding We found no evidence for the effects of tracking devices on crop-raiding primates to provide farmers with early warning of crop raiding on primate populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1443https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1443Tue, 17 Oct 2017 11:17:37 +0100Collected Evidence: Collected Evidence: Use grazing to control trees One randomized, controlled, before-and-after study in Italy found that grazing to reduce tree cover reduced cover of common heather and the basal area of trees, but did not alter cover of purple moor grass. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1634https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1634Sun, 22 Oct 2017 11:59:55 +0100Collected Evidence: Collected Evidence: Use grazing or alter livestock to control grass One replicated, controlled, before-and-after study in the Netherlands found that grazing to reduce grass cover had mixed effects on cover of common heather and cross-leaved heath. One replicated, controlled, before-and-after study in the Netherlands found that cover of wavy-hair grass increased and one before-and-after study in Spain found a reduction in grass height. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1646https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1646Sun, 22 Oct 2017 13:34:04 +0100Collected Evidence: Collected Evidence: Use grazing to maintain or restore disturbance Four studies evaluated the effects, on peatland vegetation, of using grazing to maintain or restore disturbance. All four studies were in fens or fen meadows. N.B. Grazing in peatlands with no history of disturbance is considered as a separate action. Plant community composition (1 study): One replicated, paired, site comparison study in Germany found that the overall plant community composition differed between grazed and mown fen meadows. Characteristic plants (3 studies): One replicated, paired, controlled study in Germany reported that the abundance of bog/fen-characteristic plants was similar in grazed and ungrazed fen meadows. One replicated before-and-after study in a fen in the UK reported that cover of fen-characteristic mosses did not change after grazers were introduced. One replicated, paired, site comparison study, also in Germany, found that grazed fen meadows contained fewer fen-characteristic plant species than mown meadows. Herb cover (2 studies): Two before-and-after studies in fens in the UK reported that grazing increased cover of some herb groups (cottongrasses, sedges or all grass-like plants). One of the studies found that grazing reduced purple moor grass cover, but the other found that grazing typically had no effect. Moss cover (2 studies): One replicated before-and-after study in a fen in the UK reported that cover of fen-characteristic mosses did not change after grazers were introduced. One controlled, before-and-after study in a fen in the UK found that grazing reduced Sphagnum moss cover. Tree/shrub cover (2 studies): Of two before-and-after studies in fens in the UK, one found that grazing reduced shrub cover but the other found that grazing typically had no effect on shrub cover. Overall plant richness/diversity (3 studies): Of two before-and-after studies in fens in the UK, one found that plant species richness increased after grazing was reinstated but the other reported that there was typically no effect. One replicated, paired, site comparison study in Germany found that grazed fen meadows contained fewer plant species than mown meadows. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1762https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1762Mon, 27 Nov 2017 21:36:40 +0000Collected Evidence: Collected Evidence: Use grazing to control problematic plants We found no studies that evaluated the effects, on peatland vegetation, of using grazing to control problematic plants. N.B. Grazing in different contexts is considered in separate actions here, here and here. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1773https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1773Mon, 27 Nov 2017 21:43:22 +0000Collected Evidence: Collected Evidence: Use glazing treatments to reduce light spill from inside lit buildings We found no studies that evaluated the effects of using glazing treatments to prevent light spill from inside lit buildings on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2022https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2022Wed, 05 Dec 2018 18:07:22 +0000Collected Evidence: Collected Evidence: Use green engineering techniques on artificial structures - Modify rock dump to make it more similar to natural substrate We found no studies that evaluated the effects of modifying rock dump to make it more similar to natural substrate on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2254https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2254Wed, 23 Oct 2019 10:03:28 +0100Collected Evidence: Collected Evidence: Use green engineering techniques on artificial structures - Cover subsea cables with artificial reefs We found no studies that evaluated the effects of covering subsea cables with artificial reefs on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2255https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2255Wed, 23 Oct 2019 10:04:11 +0100Collected Evidence: Collected Evidence: Use green engineering techniques on artificial structures - Cover subsea cables with materials that encourage the accumulation of natural sediments We found no studies that evaluated the effects of covering subsea cables with materials that encourage the accumulation of natural sediments on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2256https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2256Wed, 23 Oct 2019 10:04:53 +0100Collected Evidence: Collected Evidence: Use grazing to maintain or restore disturbance: freshwater marshes Five studies evaluated the effects, on vegetation, of using grazing to maintain or restore disturbance in freshwater marshes. Two studies were in the UK. There was one study in each of the Netherlands, Germany and the USA. VEGETATION COMMUNITY Community types (2 studies): One study of a riparian wet meadow in Germany reported changes in the area of plant community types over four years of grazing (after cutting trees/shrubs). One replicated, before-and-after study of dune slacks in the UK reported that the plant community type within plots remained stable over 16 years of grazing. Community composition (3 studies): Two replicated, randomized, paired, controlled, studies in freshwater marshes/wet meadows in the UK and the USA reported that the overall plant community composition was similar in grazed and ungrazed plots after 2–9 years. One replicated study of dune slacks in the Netherlands simply reported changes in the overall plant community composition after resuming grazing (along with other interventions). Overall richness/diversity (4 studies): Two studies (one replicated, before-and-after) in wetlands in Germany and the UK reported that after resuming grazing (and cutting trees/shrubs in one study), there were increases in total plant species richness and/or diversity. One replicated, randomized, paired, controlled, before-and-after study in the UK reported that grazing had no significant effect on overall plant species richness in wet grassland and flush vegetation: there were similar declines over nine years in grazed and ungrazed plots. One replicated study of dune slacks in the Netherlands simply quantified total plant species richness over three years after resuming grazing (along with other interventions). Characteristic plant richness/diversity (2 studies): One replicated, before-and-after study in dune slacks in the UK reported that after resuming grazing, the number of dune-slack indicator species increased. One replicated study of dune slacks in the Netherlands simply quantified the richness of characteristic plant species – typical of dune slacks or nutrient-rich marshes – over three years after resuming grazing (along with other interventions). VEGETATION ABUNDANCE Overall abundance (2 studies): One replicated, randomized, paired, controlled, before-and-after study in freshwater marshes/wet meadows in the USA found that grazing typically had no significant effect on overall vegetation biomass after 1–2 years. One replicated study of dune slacks in the Netherlands simply quantified total vegetation cover over three years after resuming grazing (along with other interventions). Cover never exceeded 50%. Herb abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study in the UK reported that grazing had no significant effect on the cover of forbs or grass-like plants in wet grassland and flush vegetation: there were similar declines over nine years in grazed and ungrazed plots. Tree/shrub abundance (1 study): One study of a riparian wet meadow in Germany reported that some trees/shrubs regrew over four years of grazing (after cutting trees/shrubs). Bryophyte abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study in the UK reported that grazing had no significant effect on bryophyte cover in wet grassland and flush vegetation: there were similar changes over nine years in grazed and ungrazed plots. Individual species abundance (1 study): One replicated study of dune slacks in the Netherlands simply quantified the cover of individual species present over three years after resuming grazing (along with other interventions). Only two species had >1% cover in any slack. VEGETATION STRUCTURE Height (2 studies): One site comparison study of a riparian wet meadow in Germany reported that an area grazed by cattle (after cutting trees/shrubs) contained shorter vegetation than an adjacent unmanaged area. One replicated, randomized, paired, controlled study in wet grassland and flush vegetation in the UK found that the maximum vegetation height was typically similar, over four years, in plots grazed by cattle and plots from which cattle were excluded. OTHER Survival (1 study): One study of a riparian wet meadow in Germany reported that 20% of black alder Alder glutinosa trees were still alive after being cut back and grazed for four years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3050https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3050Thu, 01 Apr 2021 19:34:04 +0100Collected Evidence: Collected Evidence: Use grazing to maintain or restore disturbance: brackish/salt marshes Four studies evaluated the effects, on vegetation, of using grazing to maintain or restore disturbance in brackish/salt marshes. The studies were in the UK, Denmark, France and the USA. VEGETATION COMMUNITY Community composition (1 study): One replicated, paired, controlled, before-and-after study of brackish marshes in France reported that the overall plant community composition diverged, over five years, in plots where grazing was maintained and plots where grazing ceased. The precise effect depended on the flooding regime. Overall richness/diversity (2 studies): One controlled study on a salt marsh in Denmark reported that an area where grazing was maintained had identical plant species richness, after six years, to an area where grazing had ceased. One replicated, paired, controlled, before-and-after study of brackish marshes in France reported that the effect of continued grazing on plant species richness depended on the flooding regime. VEGETATION ABUNDANCE Overall abundance (3 studies): Two controlled studies on salt marshes in the UK and Denmark reported that areas where grazing was maintained contained less vegetation overall, after 2–6 years, than areas where grazing ceased. This was measured in terms of biomass or cover. One replicated, randomized, paired, controlled, before-and-after study in alkali marshes in the USA found that grazing had no significant effect on total vegetation biomass after 1–2 years. Individual species abundance (3 studies): Three studies quantified the effect of this action on the abundance of individual plant species. For example, one replicated, paired, controlled, before-and-after study of brackish marshes in France reported that continued grazing strongly limited colonization by common reed Phragmites australis over five years. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3051https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3051Thu, 01 Apr 2021 19:35:04 +0100Collected Evidence: Collected Evidence: Use grazing to maintain or restore disturbance: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of using grazing to maintain or restore disturbance in freshwater swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3052https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3052Thu, 01 Apr 2021 19:57:56 +0100Collected Evidence: Collected Evidence: Use grazing to maintain or restore disturbance: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of using grazing to maintain or restore disturbance in brackish/saline swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3053https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3053Thu, 01 Apr 2021 19:58:30 +0100Collected Evidence: Collected Evidence: Use grazing to control problematic plants: freshwater marshes Three studies evaluated the effects, on vegetation, of using grazing to control problematic plants in freshwater marshes. Two studies were in the USA. One study was in Costa Rica. VEGETATION COMMUNITY Community composition (1 study): One replicated, randomized, paired, controlled study in Costa Rica found that amongst plots where cattail-dominated vegetation had been crushed, grazing had no significant effect on the overall plant community composition over 15 months. Relative abundance (1 study): One replicated, paired, controlled, before-and-after study in a canarygrass-invaded marsh in the USA found that grazing had no significant effect on the relative abundance of the invader: over two years, it declined similarly in grazed and ungrazed plots. Overall richness/diversity (3 studies): Of three replicated, paired, controlled studies in invaded marshes/wet meadows in the USA and Costa Rica, two found that grazing typically had no significant effect on plant species richness and/or diversity over approximately two years. The other study found that grazed areas had higher plant species richness than ungrazed areas after two months. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, paired, controlled, before-and-after study in a canarygrass-invaded marsh in the USA found that grazing had no significant effect on total vegetation cover at the ground surface, over two years. Native/non-target abundance (1 study): One replicated, paired, controlled, before-and-after study in an invaded wet meadow in the USA found that two months of grazing increased cover of non-invasive grass-like plants. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3112https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3112Sun, 04 Apr 2021 15:42:11 +0100Collected Evidence: Collected Evidence: Use grazing to control problematic plants: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of using grazing to control problematic plants in brackish/salt marshes.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3113https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3113Sun, 04 Apr 2021 15:42:40 +0100Collected Evidence: Collected Evidence: Use grazing to control problematic plants: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of using grazing to control problematic plants in freshwater swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3114https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3114Sun, 04 Apr 2021 15:47:05 +0100Collected Evidence: Collected Evidence: Use grazing to control problematic plants: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of using grazing to control problematic plants in brackish/saline swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3115https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3115Sun, 04 Apr 2021 15:47:21 +0100Collected Evidence: Collected Evidence: Use genetically modified crops which produce pesticide to replace conventional pesticide application          One study evaluated the effects on butterflies and moths of using genetically modified crops which produce pesticide to replace conventional pesticide application. This study was in a laboratory. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One controlled study in a laboratory found that pollen from genetically modified maize expressing the Bacillus thuringiensis kurstaki (Btk) toxin against European corn borer did not reduce the survival of eastern tiger swallowtail or spicebush swallowtail caterpillars more than pollen from non-genetically modified maize. Condition (1 study): One controlled study in a laboratory found that pollen from genetically modified maize expressing the Bacillus thuringiensis kurstaki (Btk) toxin against European corn borer did not reduce the growth of eastern tiger swallowtail or spicebush swallowtail caterpillars more than pollen from non-genetically modified maize. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3895https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3895Tue, 09 Aug 2022 13:21:11 +0100Collected Evidence: Collected Evidence: Use glazing treatments to reduce light spill from inside lit buildings We found no studies that evaluated the effects on butterflies and moths of using glazing treatments to reduce light spill from inside lit buildings. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3905https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3905Tue, 09 Aug 2022 15:15:56 +0100
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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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