Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Integrate marshes or swamps into developed areasWe found no studies that evaluated the effects, on vegetation, of incorporating marshes or swamps into developed areas. ‘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%2F2948https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2948Mon, 01 Mar 2021 16:15:08 +0000Collected Evidence: Collected Evidence: Implement ‘mosaic management’ of farmlandWe found no studies that evaluated the effects, on marsh/swamp vegetation, of implementing mosaic management in agricultural systems. ‘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%2F2949https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2949Mon, 01 Mar 2021 16:15:18 +0000Collected Evidence: Collected Evidence: Retain/create habitat linkages in farmed areasWe found no studies that evaluated the effects, on marsh/swamp vegetation, of retaining or creating habitat linkages in farmed areas. ‘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%2F2950https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2950Mon, 22 Mar 2021 13:40:33 +0000Collected Evidence: Collected Evidence: Regulate farming to allow gradual regeneration of marshes or swampsWe found no studies that evaluated the effects, on marsh/swamp vegetation, of regulating farming to allow gradual habitat regeneration. ‘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%2F2951https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2951Mon, 22 Mar 2021 13:40:41 +0000Collected Evidence: Collected Evidence: Abandon cropland: allow freshwater marshes or swamps to recover without active intervention Four studies evaluated the effects, on vegetation, of abandoning cropland with the expectation that freshwater marshes or swamps would recover spontaneously. There was one study in each of Spain, South Korea, China and Japan. The studies involved former rice fields, soybean fields or pastures. VEGETATION COMMUNITY Community composition (2 studies): Two site comparison studies in South Korea and Japan reported that the overall plant community composition in abandoned cropland became more like natural swamps and/or marshes over time. Overall richness/diversity (2 studies): One site comparison study on a floodplain in Japan found that pastures abandoned for 5–25 years contained a higher richness of vascular, wetland plant species than pastures that remained in use. One study in South Korea simply reported the number of plant species in abandoned rice paddies increased over time. Characteristic plant richness/diversity (1 study): One site comparison study on a floodplain in Japan found that pastures abandoned for 5–25 years typically contained more marsh-indicator and swamp-indicator species than pastures that remained in use. VEGETATION ABUNDANCE Overall abundance (2 studies): One site comparison study in China found that vegetation biomass in abandoned soybean fields was lower than in natural wet meadows after three years, similar to natural wet meadows after six years, and higher than in natural wet meadows after 12 years. One study in Spain simply quantified the peak biomass and density of vegetation in rice fields abandoned for up to six years. Biomass, but not density, increased with time since abandonment. VEGETATION STRUCTURE Height (1 study): One site comparison study in China found that soybean fields abandoned for 3–12 years contained vegetation of a similar height to natural wet meadows. Diameter/perimeter/area (1 study): One site comparison study in South Korea reported that rice fields abandoned for 10 years contained thinner-stemmed Japanese alder Alnus japonica than mature alder forests. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2952https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2952Mon, 22 Mar 2021 13:41:02 +0000Collected Evidence: Collected Evidence: Abandon cropland: allow brackish/saline marshes or swamps to recover without active interventionWe found no studies that evaluated the effects, on vegetation, of abandoning cropland with the expectation that brackish/saline marshes or swamps would recover spontaneously. ‘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%2F2953https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2953Mon, 22 Mar 2021 13:41:20 +0000Collected Evidence: Collected Evidence: Flood cropland when fallow to conserve freshwater marshes One study evaluated the effects, on freshwater marsh vegetation, of flooding cropland during fallow seasons or years. The study was in Brazil. VEGETATION COMMUNITY Community composition (1 study): One replicated, site comparison study in Brazil found that flooding rice fields during their fallow period affected the overall community composition of wetland plants, but that the nature of the effect depended on when fields were surveyed. Overall richness/diversity (1 study): The same study found that flooding rice fields during their fallow period had no significant effect on wetland plant species richness per site and per survey, although fewer species were recorded in the flooded fields over the year of the study. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2954https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2954Thu, 25 Mar 2021 13:44:32 +0000Collected Evidence: Collected Evidence: Flood cropland when fallow to conserve brackish/salt marshesWe found no studies that evaluated the effects, on brackish/salt marsh vegetation, of flooding cropland during fallow seasons or years. ‘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%2F2955https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2955Thu, 25 Mar 2021 13:54:21 +0000Collected Evidence: Collected Evidence: Abandon plantations: allow marshes or swamps to recover without active interventionWe found no studies that evaluated the effects, on vegetation, of abandoning plantations with the expectation that marshes or swamps would recover spontaneously. ‘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%2F2956https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2956Thu, 25 Mar 2021 13:56:05 +0000Collected Evidence: Collected Evidence: Cut/remove/thin forest plantations: freshwater marshes One study evaluated the effects, on vegetation, of cutting/removing/thinning forest plantations to restore freshwater marshes. The study was in the USA. VEGETATION COMMUNITY Characteristic plant richness/diversity (1 study): One replicated, controlled study in the USA reported that the effect of thinning/clearing forest plantations on wetland-characteristic plant species richness depended on soil moisture. After three growing seasons, wetter thinned/cleared sites generally contained more wetland-characteristic plant species than drier thinned/cleared sites or sites that remained afforested. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2958https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2958Thu, 25 Mar 2021 13:56:32 +0000Collected Evidence: Collected Evidence: Cut/remove/thin forest plantations: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of cutting/removing/thinning forest plantations to restore 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%2F2959https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2959Thu, 25 Mar 2021 13:56:46 +0000Collected Evidence: Collected Evidence: Cut/remove/thin forest plantations: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of cutting/removing/thinning forest plantations to restore 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%2F2960https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2960Thu, 25 Mar 2021 13:56:54 +0000Collected Evidence: Collected Evidence: Cut/remove/thin forest plantations: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of cutting/removing/thinning forest plantations to restore 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%2F2961https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2961Thu, 25 Mar 2021 13:57:00 +0000Collected Evidence: Collected Evidence: Use barriers to keep livestock off ungrazed freshwater marshesWe found no studies that evaluated the effects, on vegetation, of using barriers to keep livestock off freshwater marshes that have never (or not recently) been grazed. ‘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%2F2962https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2962Thu, 25 Mar 2021 14:13:27 +0000Collected Evidence: Collected Evidence: Use barriers to keep livestock off ungrazed brackish/salt marshes One study evaluated the effects, on vegetation, of using barriers to keep livestock off brackish/salt marshes that have never (or not recently) been grazed. The study was in the UK. VEGETATION COMMUNITY Overall richness/diversity (1 study): One replicated, controlled study in a salt marsh in the UK reported that plots fenced to exclude sheep contained more plant species, after four years, than plots that became grazed by sheep. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, controlled study in a salt marsh in the UK reported that plots fenced to exclude sheep contained more vegetation biomass, after two years, than plots that became grazed by sheep. Individual species abundance (1 study): The same study also quantified the effect of this action on the abundance of individual plant species. For example, plots fenced to exclude sheep contained more cordgrass Spartina and less saltbush Atriplex hastata, after four years, than plots that became grazed by sheep. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2963https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2963Thu, 25 Mar 2021 14:14:07 +0000Collected Evidence: Collected Evidence: Use barriers to keep livestock off ungrazed freshwater swampsWe found no studies that evaluated the effects, on vegetation, of using barriers to keep livestock off freshwater swamps that have never (or not recently) been grazed. ‘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%2F2964https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2964Thu, 25 Mar 2021 14:14:26 +0000Collected Evidence: Collected Evidence: Use barriers to keep livestock off ungrazed brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of using barriers to keep livestock off brackish/saline swamps that have never (or not recently) been grazed. ‘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%2F2965https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2965Thu, 25 Mar 2021 14:14:42 +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: Exclude or remove livestock from historically grazed brackish/salt marshes Fifteen studies evaluated the effects, on vegetation, of excluding or removing livestock from historically grazed brackish/salt marshes. There were five studies in Germany. There were two studies in the UK, Denmark and the Netherlands. There was one study in each of the USA, Sweden, France and Argentina. Livestock were sheep, cattle, sheep and cattle, cattle and horses, or unspecified. There was overlap in the sites used in two studies. Two other studies took place in one marsh, but with different experimental set-ups. VEGETATION COMMUNITY Overall extent (1 study): One controlled study of a salt marsh in Germany reported that in a plot fenced to exclude cattle for eight years, the total vegetated area was greater than in a plot that remained grazed. Community types (1 study): One site comparison study of brackish and salt marshes in Germany reported that reducing (or stopping) grazing affected the nature of transitions between vegetation types over time, but that the precise effect varied with environmental conditions. Community composition (5 studies): Three paired studies (two also replicated and controlled) in brackish/salt marshes in France, Argentina and the Netherlands reported that the effect of excluding livestock for 5–30 years on the overall plant community composition depended on plot elevation/flooding regime. In one of these studies, the effect of livestock exclusion was not separated from the effect of general legal protection. Two studies in one salt marsh in Denmark reported that excluding livestock had little effect on the identity of plant species in the community after six years. Overall richness/diversity (6 studies): Two studies (one controlled, one before-and-after) in one salt marsh in Denmark reported that excluding sheep and cattle for 6–7 years had no effect on overall plant species richness. One replicated, paired, controlled study in a salt marsh in the Netherlands reported that plots fenced to exclude cattle for seven years had lower plant species richness than areas that remained grazed. Two controlled studies (one also replicated and paired) in salt marshes in Germany found that the effect of removing sheep on overall plant species richness depended on the scale of measurement and the grazing intensity used for comparison – with inconsistent results across these studies even for similar scales and intensities. One paired, site comparison study of salt marshes in Argentina found that the effect of excluding cattle (along with legal protection) increased plant species richness at lower elevations, but did not significantly affect plant diversity at any elevation. VEGETATION ABUNDANCE Overall abundance (4 studies): Three studies (two controlled, one before-and-after) in salt marshes in the UK and Denmark reported that excluding livestock for 2–6 years maintained or increased overall vegetation abundance (although in one study, only by a small amount). One controlled study in a salt marsh in Germany found that a paddock left ungrazed for 16–18 years had greater overall vegetation cover than lightly or heavily grazed paddocks, but lower cover than a moderately grazed paddock. Individual species abundance (11 studies): Eleven studies quantified the effect of this action on the abundance of individual plant species. For example, five studies (four controlled, one before-and-after) on salt marshes in the UK, Denmark, Germany and the Netherlands reported that excluding livestock for 2–8 years reduced (or prevented increases in) cover of saltmarsh grass Puccinellia maritima. However, two controlled studies (one also replicated and paired) on salt marshes in Denmark and Sweden reported greater saltmarsh grass cover in areas fenced to exclude livestock for 1–6 years than in areas that remained grazed. Four studies (three controlled, one before-and-after) on salt marshes in Denmark and Germany reported that excluding or removing livestock for 4–16 years increased cover of sea purslane Halimione portulacoides. VEGETATION STRUCTURE Height (5 studies): Five controlled studies (two also replicated and paired) in salt marshes in Sweden and Germany, and brackish wet grassland in the UK, found that ungrazed plots (livestock excluded or removed) contained taller vegetation than plots that remained grazed. Vegetation was surveyed after one month, 1–8 years or 16–22 years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2967https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2967Thu, 25 Mar 2021 14:15:09 +0000Collected Evidence: Collected Evidence: Exclude or remove livestock from historically grazed freshwater swampsWe found no studies that evaluated the effects, on vegetation, of excluding or removing livestock from historically grazed 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%2F2968https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2968Thu, 25 Mar 2021 14:15:24 +0000Collected Evidence: Collected Evidence: Exclude or remove livestock from historically grazed brackish/saline swamps One study evaluated the effects, on vegetation, of excluding or removing livestock from historically grazed brackish/saline swamps. The study was in South Africa and the focal livestock were cattle. VEGETATION COMMUNITY VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, paired, controlled study in South Africa reported that more grey mangrove Avicennia marina seedlings appeared in plots fenced to exclude cattle for two years, than in plots left open to cattle. VEGETATION STRUCTURE Height (1 study): One replicated, paired, controlled study in South Africa reported that mangrove trees fenced off from cattle were taller, after two years, than trees accessible to cattle. OTHER Growth (1 study): One replicated, paired, controlled study in South Africa found that mangrove trees fenced off from cattle grew more over two years – in height, diameter and crown volume –than trees accessible to cattle. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2969https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2969Thu, 25 Mar 2021 14:15:41 +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 +0000