Collected Evidence: Collected Evidence: Reduce grazing intensity on pasturesOne replicated trial has shown that reducing the intensity of summer cattle grazing can increase the abundance, but not the species richness of cavity-nesting bees and wasps.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F23https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F23Thu, 20 May 2010 12:44:56 +0100Collected Evidence: Collected Evidence: Reduce inter-specific competition for nest sites of ground nesting seabirds by removing competitor species Four studies from Canada and the UK found increased tern Sterna spp. populations following the control or exclusion of gulls Larus spp. In two studies many interventions were used, making it impossible to tell which was responsible. One study from the UK and one from Canada found that controlling large gulls had no impact on smaller species. Two studies from the USA and UK found that exclusion devices successfully reduced the numbers of gulls at sites, although one found that they were only effective at small colonies and the other found that methods varied in their effectiveness and practicality.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F422https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F422Fri, 17 Aug 2012 16:21:39 +0100Collected Evidence: Collected Evidence: Reduce inter-specific competition for nest sites of woodpeckers by removing competitor species All four studies we captured describe the management of red-cockaded woodpeckers Picoides borealis in open pine forests in the USA. One small study found an increase in woodpecker population following the removal of southern flying squirrels Glaucomys volans, whilst a second found a population increase following squirrel removal, along with other interventions and a third found that reintroductions were  successful when squirrels were controlled. A randomised, replicated and controlled before-and-after study found fewer holes were occupied by squirrels following control efforts, but that occupancy by red-cockaded woodpeckers was no higher.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F423https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F423Fri, 17 Aug 2012 17:09:55 +0100Collected Evidence: Collected Evidence: Reduce inter-specific competition for nest sites of songbirds by removing competitor species Two studies from Australia found increases in bird populations and species richness after the control of noisy miners Manorina melanocephala – a native but hyper-competitive species. A controlled study from Italy found that blue tits Parus caeruleus nested in more nest boxes when hazel dormice Muscardinus avellanarius were excluded from nest boxes over winter.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F424https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F424Fri, 17 Aug 2012 17:28:29 +0100Collected Evidence: Collected Evidence: Reduce inter-specific competition for nest sites by modifying habitats to exclude competitor speciesA replicated controlled study from the USA found no impact of midstorey clearance on the occupation of red-cockaded woodpecker Picoides borealis nesting cavities by southern flying squirrels Glaucomys volans.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F425https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F425Fri, 17 Aug 2012 17:32:51 +0100Collected Evidence: Collected Evidence: Reduce inter-specific competition for food by removing or controlling competitor species Two controlled before-and-after studies from the UK found that six species of wildfowl showed significant increases following the removal of fish from lakes. Three other species did not show increases. A study from France found that grey partridges Perdix perdix increased at a site with several interventions, including the control of competitor species. A before-and-after study from Spain found no change in the rate of kleptoparasitic attacks on herons after the culling of gulls at a colony.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F428https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F428Fri, 17 Aug 2012 17:54:16 +0100Collected Evidence: Collected Evidence: Reduce incidental mortality from birds being attracted to artificial lights We found no evidence for reduced incidental mortality from birds being attracted to artificial lights. '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%2F466https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F466Wed, 29 Aug 2012 16:14:05 +0100Collected Evidence: Collected Evidence: Reduce impact of amphibian trade One review found that reducing trade in two frog species through legislation allowed populations to recover from over-exploitation.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F824https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F824Fri, 23 Aug 2013 11:17:43 +0100Collected Evidence: Collected Evidence: Reduce herbicide use on nearby agricultural/forestry land We found no studies that evaluated the effects of reducing herbicide use on nearby agricultural/forestry land on shrublands. '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%2F1667https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1667Sun, 22 Oct 2017 15:13:10 +0100Collected Evidence: Collected Evidence: Reduce intensity of livestock grazing One study evaluated the effects on peatland vegetation of reducing livestock grazing intensity. This study was in bogs. Vegetation cover (1 study): One replicated, paired, controlled study in bogs in the UK found that total vegetation and shrub cover were greater where grazing intensity was lower. Cottongrass cover was greater where grazing intensity was lower (one species) or unaffected by grazing intensity (one species). Vegetation structure (1 study): The same study found that vegetation biomass was higher where grazing intensity was lower. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1735https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1735Mon, 27 Nov 2017 21:21:21 +0000Collected Evidence: Collected Evidence: Reduce intensity of harvest (of wild biological resources) One study evaluated the effects on peatland vegetation of reducing harvest intensity (of wild biological resources). The study was in a bog. Moss cover (1 study): One replicated, controlled study in a bog in New Zealand reported that Sphagnum moss cover was higher, three years after harvesting, when some Sphagnum was left in plots than when it was completely harvested. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1744https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1744Mon, 27 Nov 2017 21:27:08 +0000Collected Evidence: Collected Evidence: Reduce intensity of grazing by domestic livestock Thirteen studies evaluated the effects on mammals of reducing the intensity of grazing by domestic livestock. Six studies were in the USA, six were in Europe and one was in China. COMMUNITY RESPONSE (3 STUDIES) Richness/diversity (3 studies): Two of three site comparison or controlled studies, in the USA and Norway, found that reduced livestock grazing intensity was associated with increased species richness of small mammals whilst one study did not find an increase in species richness. POPULATION RESPONSE (13 STUDIES) Abundance (13 studies): Six of nine site comparison or controlled studies (including seven replicated studies), in the USA, Denmark, the UK, China, Netherlands and Norway, found that reductions in livestock grazing intensity were associated with increases in abundances (or proxies of abundances) of small mammals, whilst two studies showed no significant impact of reducing grazing intensity and one study showed mixed results for different species. Two replicated studies (including one controlled and one site comparison study), in the UK and in a range of European countries, found that reducing grazing intensity did not increase numbers of Irish hares or European hares. A controlled, before-and-after study, in the USA found that exclusion of cattle grazing was associated with higher numbers of elk and mule deer. A replicated, site comparison study in the USA found that an absence of cattle grazing was associated with higher numbers of North American beavers. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2408https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2408Fri, 29 May 2020 08:14:23 +0100Collected Evidence: Collected Evidence: Reduce hammer energy during pile driving We found no studies that evaluated the effects of reducing hammer energy during pile driving on marine and freshwater mammal 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%2F2900https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2900Mon, 08 Feb 2021 16:10:51 +0000Collected Evidence: Collected Evidence: Reduce intensity of livestock grazing: freshwater marshes Three studies evaluated the effects, on vegetation, of reducing livestock grazing intensity in freshwater marshes (without stopping grazing entirely). Two studies were in the USA and the other was in Ireland. In all three studies, livestock were cattle. VEGETATION COMMUNITY Community composition (1 study): One site comparison study in Ireland found that lightly and heavily grazed wet meadows contained a similar overall mix of plant species. Relative abundance (1 study): One replicated, randomized, paired, controlled study in the USA found that seasonally and continuously grazed ephemeral pools had similar cover of grasses relative to forbs. Overall richness/diversity (1 study): One site comparison study in Ireland found that lightly and heavily grazed wet meadows had similar overall plant species richness. Native plant richness/diversity (1 study): One replicated, randomized, paired, controlled study in the USA found that seasonally and continuously grazed ephemeral pools experienced similar changes in native plant species richness over three years. VEGETATION ABUNDANCE Overall abundance (1 study): One site comparison study in Ireland reported that lightly and heavily grazed wet meadows had similar overall vegetation cover. Herb abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study in the USA found that lightly and moderately grazed springs/creeks had similar herb cover. Individual species abundance (1 study): One study quantified the effect of this action on the abundance of individual plant species. The site comparison study in Ireland reported, for example, that lightly grazed wet meadows had greater cover of black sedge Carex nigra, and lower cover of creeping bent Agrostis stolonifera, than more heavily grazed wet meadows. VEGETATION STRUCTURE Height (1 study): One site comparison study in Ireland found that lightly grazed wet meadows contained taller vegetation than heavily grazed wet meadows. Vegetation was measured in the summer, during the grazing season. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2970https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2970Thu, 25 Mar 2021 14:15:51 +0000Collected Evidence: Collected Evidence: Reduce intensity of livestock grazing: brackish/salt marshes Nine studies evaluated the effects, on vegetation, of reducing livestock grazing intensity in brackish/salt marshes (without stopping grazing entirely). Five studies were in Germany. Four studies were in the Netherlands. Livestock were cattle, sheep or horses. There was overlap in the sites used in two of the German studies and three of the Dutch studies. VEGETATION COMMUNITY Overall extent (1 study): One controlled study of a salt marsh in Germany reported that the total vegetated area was slightly larger in plots grazed at a lower intensity, for eight years, than plots grazed at a higher intensity. Community types (4 studies): Two controlled studies of salt marshes in Germany and the Netherlands reported similar coverage, or similar change in coverage, of plant community types under different grazing intensities. Two studies of brackish and salt marshes in the Netherlands and Germany reported that reducing grazing intensity (along with other interventions) affected coverage of plant community types. In one study, the precise effect varied with environmental conditions. Community composition (1 study): One replicated, randomized, paired, before-and-after study on a salt marsh in the Netherlands found that plots grazed under different grazing intensities experienced a similar turnover of plant species over six years, and had a similar overall plant community composition after six years. Overall richness/diversity (5 studies): Three replicated, paired, controlled studies on salt marshes in Germany and the Netherlands found that plots grazed at lower intensities never had greater plant species richness, after 1–22 years, than plots grazed at higher intensities. One controlled study on a salt marsh in Germany found that paddocks grazed at low intensity had greater plant species richness, after 16–18 years, than paddocks grazed at higher intensities. Two studies of salt marshes in the Netherlands found that plant species richness increased over 6–14 years of reduced grazing intensity (sometimes along with other interventions). VEGETATION ABUNDANCE Overall abundance (1 study): One controlled study on a salt marsh in Germany reported that overall vegetation cover was greater in lightly and moderately grazed paddocks than in a heavily grazed paddock – with the highest cover of all in the moderately grazed paddock. Individual species abundance (6 studies): Six studies quantified the effect of this action on the abundance of individual plant species. For example, three studies (including two controlled) on salt marshes in Germany and the Netherlands reported that plots under different grazing intensities supported a similar abundance (frequency or cover) of saltmarsh grass Puccinellia maritima – but with a tendency for greater abundance under lower intensities. VEGETATION STRUCTURE Height (6 studies): Six controlled studies (three also replicated and paired) in salt marshes in Germany and the Netherlands reported that vegetation was taller on average (or contained taller vegetation patches) in areas that had been grazed at lower intensities. However, in one of the studies, this was only true for canopy height: understory grasses were a similar height under all grazing intensities. One of the replicated, paired, controlled studies found that, after two summers, variation in vegetation height between patches was similar under all grazing intensities. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2971https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2971Thu, 25 Mar 2021 14:16:01 +0000Collected Evidence: Collected Evidence: Reduce intensity of livestock grazing: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of reducing livestock grazing intensity in freshwater swamps (without stopping grazing entirely).   ‘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%2F2972https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2972Thu, 25 Mar 2021 14:16:10 +0000Collected Evidence: Collected Evidence: Reduce intensity of livestock grazing: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of reducing livestock grazing intensity in brackish/saline swamps (without stopping grazing entirely).   ‘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%2F2973https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2973Thu, 25 Mar 2021 14:16:22 +0000Collected Evidence: Collected Evidence: Reduce intensity of vegetation harvest: freshwater marshesWe found no studies that evaluated the effects, on vegetation, of reducing the intensity of harvest in freshwater marshes (or harvesting at different intensities).   ‘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%2F3001https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3001Wed, 31 Mar 2021 13:26:27 +0100Collected Evidence: Collected Evidence: Reduce intensity of vegetation harvest: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of reducing the intensity of harvest in brackish/salt marshes (or harvesting at different intensities).   ‘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%2F3002https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3002Wed, 31 Mar 2021 13:26:40 +0100Collected Evidence: Collected Evidence: Reduce intensity of vegetation harvest: freshwater swamps One study evaluated the effects, on vegetation, of reducing the intensity of harvest in freshwater swamps (or harvesting at different intensities). The study was in China. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Herb abundance (1 study): One replicated, controlled study in a freshwater swamp in China reported that overall herb biomass was statistically similar in plots logged at different intensities five years previously. Tree/shrub abundance (1 study): The same study reported that overall tree biomass was greatest in plots logged at the lowest intensity five years previously. In contrast, overall shrub biomass was greatest in plots logged at medium intensity. Individual species abundance (1 study): The same study reported that the density of the two most common tree species typically declined with increasing logging intensity. VEGETATION STRUCTURE Diameter/perimeter/area (1 study): One replicated, controlled study in a freshwater swamp in China reported that the diameter of the two most common tree species typically declined with increasing logging intensity. Basal area (1 study): The same study reported that the basal area of the two most common tree species typically declined with increasing logging intensity. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3003https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3003Wed, 31 Mar 2021 13:27:11 +0100Collected Evidence: Collected Evidence: Reduce intensity of vegetation harvest: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of reducing the intensity of harvest in brackish/saline swamps (or harvesting at different intensities).   ‘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%2F3004https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3004Wed, 31 Mar 2021 13:27:31 +0100Collected Evidence: Collected Evidence: Reduce intensity of hunting/collecting animalsWe found no studies that evaluated the effects, on vegetation, of reducing the intensity of hunting/collecting animals in marshes or 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%2F3016https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3016Wed, 31 Mar 2021 14:24:32 +0100Collected Evidence: Collected Evidence: Reduce intensity of cutting/mowingWe found no studies that evaluated the effects, on vegetation, of reducing the intensity of cutting/mowing in marshes or swamps (or cutting/mowing them at different intensities).   ‘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%2F3068https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3068Fri, 02 Apr 2021 13:29:11 +0100Collected Evidence: Collected Evidence: Reduce intensity of prescribed burningWe found no studies that evaluated the effects, on vegetation, of reducing the intensity of prescribed burning in marshes or swamps (or burning them at different intensities).   ‘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%2F3073https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3073Fri, 02 Apr 2021 14:44:31 +0100Collected Evidence: Collected Evidence: Reduce grazing intensity on grassland by seasonal removal of livestock Seven studies evaluated the effects on butterflies and moths of reducing grazing intensity on grassland by seasonal removal of livestock. Five studies were in the UK, one was in France and one was a review across Europe. COMMUNITY RESPONSE (3 STUDIES) Richness/diversity (3 studies): Two of three replicated, controlled studies (including one randomized, paired study and one randomized study) in the UK found that upland pasture where cattle were removed in the summer, and silage fields where cattle were not grazed in September, had a similar species richness of butterflies to pasture grazed throughout the growing season and silage fields grazed in September. The other study found that grasslands where cattle were removed in the summer had a greater species richness of butterflies (and other pollinators) than grasslands grazed throughout the summer. POPULATION RESPONSE (7 STUDIES) Abundance (7 studies): Three controlled studies (including two replicated, randomized studies) in the UK found that grasslands where cattle or cattle and sheep were removed in the summer, or sheep were removed in the winter, had a higher abundance of butterflies (and other pollinators) and caterpillars than grasslands grazed throughout the summer or all year. Three replicated, controlled studies (including one randomized study and one paired study) in the UK and France found that upland pasture where cattle were removed in the summer, silage fields where cattle were not grazed in September, and semi-natural grasslands where sheep were removed during the peak flowering period, had a similar abundance of butterflies, burnet moths and caterpillars to pasture grazed throughout the growing season, silage fields grazed in September, and rotationally grazed grassland. One review of studies in Europe reported that reducing grazing intensity benefitted 41 out of 67 butterfly species of conservation concern, but did not distinguish between the seasonal removal of livestock and reducing stocking density. BEHAVIOUR (0 STUDIES)  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3960https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3960Sun, 14 Aug 2022 10:37:27 +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.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust
For a full list of, and information about, our champions:
All Evidence Champions
About our champions, why and how to become one:
Become an Evidence Champion

This website uses Cookies

We use limited Cookies to run the site and to analyse our traffic (none for site vendors). By using this site, you will be providing your consent to our use of Cookies.

Accept & continue