Collected 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%2Fconservationevidencejournal.com%2Factions%2F2951https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2951Mon, 22 Mar 2021 13:40:41 +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%2Fconservationevidencejournal.com%2Factions%2F2970https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2971https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2972https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F2973https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2973Thu, 25 Mar 2021 14:16:22 +0000Collected Evidence: Collected Evidence: Reduce frequency of vegetation harvest: freshwater marshes Three studies evaluated the effects, on vegetation, of reducing the frequency of harvest in freshwater marshes (or harvesting at different frequencies). There was one study in each of the USA, Belgium and Italy. VEGETATION COMMUNITY Overall richness/diversity (1 study): One replicated, paired, controlled, before-and-after study in wet grasslands in Belgium reported that overall plant species richness was similar in plots harvested once or twice/year. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, paired, controlled, before-and-after study in wet grasslands in Belgium reported that the effect of harvesting twice/year (in July and October) on total above-ground biomass was intermediate between the effects of harvesting once/year in July or October. Individual species abundance (3 studies): All three studies quantified the effect of this action on the abundance of individual plant species. For example, one replicated, paired, controlled study in freshwater marshes in the USA reported that cattail Typha biomass was greater, nine months after the last harvest, in plots harvested every six weeks than in plots harvested every three weeks. One paired, controlled, before-and-after study in reedbeds in Italy found that the common reed Phragmites australis biomass was similar in plots harvested once or twice/year, when measured at least five months after the last harvest. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2997https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2997Wed, 31 Mar 2021 13:15:36 +0100Collected Evidence: Collected Evidence: Reduce frequency of vegetation harvest: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of reducing the frequency of harvest in brackish/salt marshes (or harvesting at different frequencies).   ‘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%2Fconservationevidencejournal.com%2Factions%2F2998https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2998Wed, 31 Mar 2021 13:16:12 +0100Collected Evidence: Collected Evidence: Reduce frequency of vegetation harvest: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of reducing the frequency of harvest in freshwater swamps (or harvesting at different frequencies).   ‘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%2Fconservationevidencejournal.com%2Factions%2F2999https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2999Wed, 31 Mar 2021 13:16:35 +0100Collected Evidence: Collected Evidence: Reduce frequency of vegetation harvest: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of reducing the frequency of harvest in brackish/saline swamps (or harvesting at different frequencies).   ‘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%2Fconservationevidencejournal.com%2Factions%2F3000https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3000Wed, 31 Mar 2021 13:16:57 +0100Collected 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%2Fconservationevidencejournal.com%2Factions%2F3001https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F3002https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F3003https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F3004https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3004Wed, 31 Mar 2021 13:27:31 +0100Collected Evidence: Collected Evidence: Reduce frequency of hunting/collecting animalsWe found no studies that evaluated the effects, on vegetation, of reducing the frequency 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%2Fconservationevidencejournal.com%2Factions%2F3015https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3015Wed, 31 Mar 2021 14:23:23 +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%2Fconservationevidencejournal.com%2Factions%2F3016https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3016Wed, 31 Mar 2021 14:24:32 +0100Collected Evidence: Collected Evidence: Reintroduce overharvested animalsWe found no studies that evaluated the effects, on marsh/swamp vegetation, of reintroducing overharvested animals.   ‘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%2Fconservationevidencejournal.com%2Factions%2F3018https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3018Wed, 31 Mar 2021 14:26:34 +0100Collected Evidence: Collected Evidence: Reduce frequency of cutting/mowing: freshwater marshes Four studies evaluated the effects, on vegetation, of reducing the frequency of cutting/mowing in freshwater marshes (or cutting/mowing them at different frequencies). There was one study in each of USA, the Netherlands, Belgium and Italy. VEGETATION COMMUNITY Community composition (1 study): One replicated, randomized, paired, controlled study of farmland ditches in the Netherlands found that marshy areas cut once, twice or three times/year had a similar overall plant community composition, when surveyed in July. Overall richness/diversity (2 studies): Two replicated, paired, controlled studies in farmland ditches in the Netherlands and wet grasslands in Belgium reported that overall plant species richness was similar in plots cut once or twice/year (and three times/year in the Netherlands). VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, paired, controlled, before-and-after study in wet grasslands in Belgium reported that the effect of cutting twice/year (in July and October) on total above-ground biomass was intermediate between the effects of cutting once/year in July or October. Individual species abundance (4 studies): All four studies quantified the effect of this action on the abundance of individual plant species. For example, one replicated, paired, controlled study in freshwater marshes in the USA reported that cattail Typha spp. biomass was greater, nine months after the last cut, in plots cut every six weeks than in plots cut every three weeks. One paired, controlled, before-and-after study in reedbeds in Italy found that common reed Phragmites australis biomass was similar in plots mown once or twice/year, when measured at least five months after the last cut. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3066https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3066Fri, 02 Apr 2021 13:14:38 +0100Collected Evidence: Collected Evidence: Reduce frequency of cutting/mowing: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of reducing the frequency of cutting/mowing in brackish/salt marshes (or cutting/mowing them at different frequencies).   ‘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%2Fconservationevidencejournal.com%2Factions%2F3067https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3067Fri, 02 Apr 2021 13:17:06 +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%2Fconservationevidencejournal.com%2Factions%2F3068https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3068Fri, 02 Apr 2021 13:29:11 +0100Collected Evidence: Collected Evidence: Reduce frequency of prescribed burningWe found no studies that evaluated the effects, on vegetation, of reducing the frequency of prescribed burning in marshes or swamps (or burning them at different frequencies).   ‘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%2Fconservationevidencejournal.com%2Factions%2F3072https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3072Fri, 02 Apr 2021 14:40:50 +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%2Fconservationevidencejournal.com%2Factions%2F3073https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3073Fri, 02 Apr 2021 14:44:31 +0100Collected Evidence: Collected Evidence: Remove debris from freshwater marshesWe found no studies that evaluated the effects, on vegetation, of removing debris from freshwater 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%2Fconservationevidencejournal.com%2Factions%2F3161https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3161Tue, 06 Apr 2021 12:48:54 +0100Collected Evidence: Collected Evidence: Remove debris from brackish/salt marshes Two studies evaluated the effects, on vegetation, of removing debris from brackish/salt marshes. Both studies were in the USA. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, paired, site comparison study in a salt marsh in the USA found that overall vegetation cover in patches where debris had been removed remained lower than in undisturbed marsh for one growing season, but had recovered to match undisturbed marsh after two growing seasons. Individual species abundance (2 studies): Two studies quantified the effect of this action on the abundance of individual plant species. For example, the two replicated, site comparison studies in salt marshes in the USA found that the abundance of dominant herb species in impacted vegetation patches was typically lower than in undisturbed marsh one growing season after removing debris, but was sometimes similar to undisturbed marsh. The results depended on the species, metric and type of debris removed. One of the studies also monitored until the second growing season after removing debris; at this point, the cover of both dominant herb species had recovered to match undisturbed marsh. VEGETATION STRUCTURE Height (1 study): One replicated, before-and-after, site comparison study in a salt marsh in the USA found that the maximum height of smooth cordgrass recovered, to match undisturbed marsh, within 45 weeks of removing debris. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3162https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3162Tue, 06 Apr 2021 12:49:05 +0100Collected Evidence: Collected Evidence: Remove debris from freshwater swampsWe found no studies that evaluated the effects, on vegetation, of removing debris from 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%2Fconservationevidencejournal.com%2Factions%2F3163https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3163Tue, 06 Apr 2021 12:49:15 +0100Collected Evidence: Collected Evidence: Remove debris from brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of removing debris from 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%2Fconservationevidencejournal.com%2Factions%2F3164https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3164Tue, 06 Apr 2021 12:49:30 +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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