Collected 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: Design transportation or service corridors to maintain water flowWe found no studies that evaluated the effects, on vegetation, of designing infrastructure to maintain water flow into/out of 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%2F2995https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2995Mon, 29 Mar 2021 12:29:29 +0100Collected Evidence: Collected Evidence: Cut/mow herbaceous plants to maintain or restore disturbance: freshwater marshes Twenty studies evaluated the effects, on vegetation, of cutting/mowing to maintain or restore disturbance in freshwater marshes. There were four studies in Belgium, three of which took place in one wetland area so probably shared some experimental plots. There were two studies in each of the UK, the USA and Estonia. There was one study in each of seven other European countries, Japan, Mexico and Brazil. In 15 of the studies vegetation was measured at least six months after the last cut. VEGETATION COMMUNITY Community composition (6 studies): Four replicated, paired, controlled studies (two also randomized and before-and-after) of freshwater marshes and wet meadows in Belgium, Switzerland, Mexico and Estonia reported that the overall plant community composition differed between cut and uncut sites after 1–5 years, or typically diverged in cut and uncut areas over 3–10 years. One before-and-after study in a freshwater marsh in Belgium reported that the overall plant community composition changed over seven years after resuming annual mowing. One replicated, paired, controlled, before-and-after study in wet grasslands in Germany reported that over 20 years, mowing increased the average moisture preference of the vegetation. Overall richness/diversity (11 studies): Seven studies (including two replicated, paired, controlled) in freshwater marshes in Belgium, the UK, Mexico and Estonia reported that cut marshes had higher plant species richness than uncut marshes. Two of these studies reported the same result for diversity. One before-and-after study in a freshwater marsh in Belgium reported that plant species richness increased over seven years after resuming annual mowing. Three replicated, paired, controlled studies in reedbeds in the UK and wet meadows in Germany and Estonia reported that cutting typically had no clear or significant effect on plant species richness, after 3–5 months or over 5–20 years. The two studies in the UK and Estonia found the same result for diversity. Characteristic plant richness/diversity (1 study): One replicated, paired, controlled, before-and-after study in a temporary marsh in France reported that two years of annual autumn cutting increased the number of habitat-characteristic plant species present. VEGETATION ABUNDANCE Overall abundance (3 studies): Two replicated, controlled studies (one also randomized, paired, before-and-after) in freshwater marshes in the USA found that cutting had no significant effect on overall vegetation cover over 72 days or three years. One replicated, paired, controlled study in wet grasslands in Belgium reported that plots mown annually for two years contained less above-ground biomass, just before mowing, than unmown plots. Herb abundance (1 study): One replicated, paired, controlled, before-and-after study in wet grasslands in Germany reported that mowing increased sedge cover over 20 years, but had no clear effect on cover of rushes, forbs, ferns, grasses and legumes. Tree/shrub abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study in a wet prairie in the USA found that cutting had no significant effect on woody plant cover: there were similar increases, over three years, in cut and uncut plots. Bryophyte abundance (1 study): One replicated study in a freshwater marsh in Belgium reported that total moss cover increased over five years after resuming annual mowing. Individual species abundance (15 studies): Fifteen studies quantified the effect of this action on the abundance of individual plant species. For example, five studies (including one replicated, randomized, paired, controlled) in freshwater marshes in Belgium, the UK and the Czech Republic reported that common reed Phragmites australis was more abundant in cut than uncut areas. Two studies (one site comparison, one before-and-after) in fresh/brackish marshes in Belgium and Denmark reported that cutting reduced common reed cover or density. The two studies in Belgium reported that cutting had no clear effect on common reed frequency. Four studies (including one replicated, randomized, paired, before-and-after) in freshwater marshes in the Netherlands, Switzerland, Japan and Italy found that the effect of cutting on common reed abundance depended on factors such as the year, plant community type, cutting season, cutting intensity and time since mowing. VEGETATION STRUCTURE Overall structure (1 study): One replicated, randomized, paired, controlled study in wet meadows in Switzerland reported that mown plots experienced a shift in vegetation cover towards lower vegetation layers, over 3–4 years, compared to a shift to upper layers in unmown plots. Visual obstruction (1 study): One replicated, controlled study in a freshwater marsh in Belgium reported that summer-cut plots had lower horizontal vegetation cover than uncut plots (or winter-cut plots) over six years after resuming annual mowing. Height (6 studies): Three replicated, controlled studies (one also randomized and paired) in freshwater marshes in Belgium, the UK and the USA reported that cut marshes had shorter vegetation than uncut marshes. This was true for vegetation overall, vegetation other than common reed Phragmites australis, and for common reed cut in winter or spring (but not summer). Two replicated, paired, controlled, before-and-after studies in a marsh in Mexico and wet grasslands in Germany reported that cutting/mowing had no significant or clear effect on vegetation height, after 12 months or over 20 years. One site comparison study in the Czech Republic found that common reed was taller, when measured in the summer, in a winter-mown reedbed than in an unmown reedbed. Diameter/perimeter/area (5 studies): Two studies (one site comparison, one before-and-after) in fresh/brackish marshes in Belgium and Denmark reported that cutting, or time since last cutting, had no significant or clear effect on the stem diameter of common reed Phragmites australis. Two studies (including one replicated, randomized, paired, controlled) of reedbeds in the UK and the Czech Republic found that cut areas contained thicker reed stems than uncut areas, after one growing season. One replicated, randomized, paired, controlled, before-and-after study in wet meadows in Switzerland found that the effect of cutting on common reed shoot diameter depended on the plant community type and season of mowing. Basal area (1 study): One site comparison study in a fresh/brackish marsh in Denmark found that the basal area of common reed Phragmites australis stems was smaller in a reedbed cut two years previously than in a reedbed cut seven years previously. Only “tall” stems were sampled. OTHER Survival (1 study): One replicated, randomized, paired, controlled study in a wet prairie in the USA found that mowing had no significant effect on woody plant survival over the following year. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3044https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3044Thu, 01 Apr 2021 15:18:37 +0100Collected Evidence: Collected Evidence: Cut/mow herbaceous plants to maintain or restore disturbance: brackish/salt marshes Six studies evaluated the effects, on vegetation, of cutting/mowing to maintain or restore disturbance in brackish/salt marshes. Two studies were in France. There was one study in each of the USA, Denmark, South Africa and Estonia. VEGETATION COMMUNITY Community composition (1 study): One replicated, randomized, controlled, before-and-after study in brackish wet grasslands in Estonia found that annual cutting affected overall plant community composition, with significant differences between cut and uncut plots after four years. Overall richness/diversity (3 studies): Two replicated, site comparison studies in France found that cut and uncut reedbeds had similar overall plant species richness. One replicated, randomized, controlled, before-and-after study in brackish wet grasslands in Estonia found that cut and uncut plots typically had similar plant species richness and diversity over four years. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, site comparison study in France found that cut and uncut reedbeds had similar cover of plants other than common reed Phragmites australis. Individual species abundance (5 studies): Five studies quantified the effect of this action on the abundance of individual plant species. For example, two replicated, randomized, controlled, before-and-after studies in brackish marshes or grasslands in South Africa and Estonia found that cutting had mixed effects on the abundance of common reed Phragmites australis after 1–4 years, depending on the water level of the plots. One site comparison study in Denmark found that a fresh/brackish reedbed cut two years previously contained fewer “tall” common reed stems than a reedbed cut seven years previously. Two replicated, site comparison studies in France found that cut reedbeds contained a similar number (and, in one study, biomass) of live reed stems than uncut reedbeds, but far fewer dead stems. VEGETATION STRUCTURE Height (4 studies): Two controlled studies (one also replicated, randomized, before-and-after) in brackish marshes in the USA and South Africa reported that rushes or reeds were shorter in cut plots than in uncut plots, for up to one year after cutting. Two replicated, site comparison studies in France found that live reed stems were a similar height in cut and uncut reedbeds. Diameter/perimeter/area (3 studies): Two site comparison studies (one replicated) in fresh/brackish reedbeds in Denmark and France found that common reed Phragmites australis stems were a similar diameter in cut and uncut reedbeds. One replicated, randomized, controlled, before-and-after study in a brackish marsh in South Africa found that cutting reduced the diameter of common reed stems present one year later. Basal area (1 study): One site comparison study in a fresh/brackish marsh in Denmark found that the basal area of common reed Phragmites australis stems was smaller in a reedbed cut two years previously than in a reedbed cut seven years previously. Only “tall” stems were sampled. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3045https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3045Thu, 01 Apr 2021 15:21:23 +0100Collected Evidence: Collected Evidence: Cut large trees/shrubs to maintain or restore disturbance: freshwater marshes Four studies evaluated the effects, on vegetation, of cutting large trees/shrubs to maintain or restore disturbance in freshwater marshes. Three studies were in the USA. One was in Germany. VEGETATION COMMUNITY Community types (1 study): One study of a riparian wet meadow in Germany reported changes in the area of plant community types over four years after cutting trees/shrubs (along with grazing). Community composition (1 study): One replicated, randomized, controlled, before-and-after study aiming to restore freshwater marshes in the USA found that cutting trees (along with other interventions) significantly affected the overall plant community composition over the following five years. Overall richness/diversity (1 study): One study of a riparian wet meadow in Germany reported that plant species richness increased over four years after cutting trees/shrubs (along with grazing). VEGETATION ABUNDANCE Overall abundance (2 studies): Of two replicated, randomized, paired, controlled, before-and-after studies in the USA, one found that cutting and removing woody plants from a degraded wet prairie had no significant effect on overall vegetation cover three years later. The other study was in wet patches of a pine forest and found that understory vegetation cover increased more, over one year, where trees were thinned than where they were not thinned. Characteristic plant abundance (1 study): One replicated, randomized, controlled, before-and-after study of overgrown freshwater marshes in the USA reported that of 26 plant taxa that became more frequent after cutting trees (along with other interventions), 16 were obligate wetland taxa. Herb abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study in wet patches of a pine forest in the USA found that cover of sedges Carex increased more, over one year, where trees were thinned than where they were not thinned. Tree/shrub abundance (2 studies): One replicated, randomized, paired, controlled, before-and-after study of a wet prairie in the USA found that woody plant cover declined, over three years, in plots where trees/shrubs were cut – but increased in plots where trees/shrubs were not cut. One study of a riparian wet meadow in Germany simply reported that some trees/shrubs regrew over four years after cutting trees/shrubs (along with grazing). Individual species abundance (1 study): One study quantified the effect of this action on the abundance of individual plant species. The replicated, randomized, paired, controlled, before-and-after study of a wet prairie in the USA found, for example, that cutting trees and shrubs had no significant effect on cover of the dominant herbaceous plant, tussock grass Deschampsia cespitosa, three years later. VEGETATION STRUCTURE Height (1 study): One site comparison study of a riparian wet meadow in Germany reported that an area in which trees/shrubs were cut back (along with reinstating cattle grazing) contained shorter vegetation than an adjacent unmanaged area. OTHER Survival (2 studies): One replicated, randomized, paired, controlled study in a wet prairie in the USA found that cutting woody plants did not significantly affect their survival in the following year. One study of a riparian wet meadow in Germany simply 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%2F3046https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3046Thu, 01 Apr 2021 19:06:56 +0100Collected Evidence: Collected Evidence: Cut large trees/shrubs to maintain or restore disturbance: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of cutting large trees/shrubs to maintain or restore disturbance 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%2F3047https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3047Thu, 01 Apr 2021 19:10:37 +0100Collected Evidence: Collected Evidence: Cut large trees/shrubs to maintain or restore disturbance: freshwater swamps One study evaluated the effects, on vegetation, of cutting large trees/shrubs to maintain or restore disturbance in freshwater swamps. The study was in the USA. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Herb abundance (1 study): One replicated, randomized, controlled, before-and-after, site comparison study of freshwater swamps in the USA found that cutting woody vegetation (and applying herbicide) had no significant effect on herbaceous ground cover one year later: there were similar changes in treated and untreated swamps. VEGETATION STRUCTURE Basal area (1 study): One replicated, randomized, controlled, before-and-after, site comparison study of freshwater swamps in the USA found that cutting woody vegetation (and applying herbicide) had no significant effect on the basal area of woody vegetation one year later: there were similar changes in treated and untreated swamps. Canopy cover (1 study): The same study found that cutting woody vegetation (and applying herbicide) reduced canopy cover – to similar levels as in high-quality swamps after one year. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3048https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3048Thu, 01 Apr 2021 19:10:54 +0100Collected Evidence: Collected Evidence: Cut large trees/shrubs to maintain or restore disturbance: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of cutting large trees/shrubs 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%2F3049https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3049Thu, 01 Apr 2021 19:11:08 +0100Collected Evidence: Collected Evidence: Cut or burn oil-contaminated vegetation: freshwater marshesWe found no studies that evaluated the effects, on vegetation, of cutting or burning oil-contaminated vegetation in 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%2Fwww.conservationevidence.com%2Factions%2F3174https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3174Tue, 06 Apr 2021 13:40:59 +0100Collected Evidence: Collected Evidence: Cut or burn oil-contaminated vegetation: brackish/salt marshes Two studies evaluated the effects, on vegetation, of cutting or burning oil-contaminated vegetation in brackish/salt marshes. One study reviewed multiple cases from the UK and the USA. The other study was in Brazil. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Overall abundance (1 study): One review of studies in oil-contaminated salt marshes in the UK and the USA reported that in eight of eight cases with quantitative comparisons between cut and uncut areas, cutting had no clear benefit for vegetation abundance (density, biomass or cover) over 8–29 months of recovery. Individual species abundance (1 study): One replicated, paired, controlled, site comparison study in oil-contaminated brackish/salt marshes in Brazil found that smooth cordgrass Spartina alterniflora density and biomass were never greater in cut than uncut plots (and typically similar under each treatment), over nine months after cutting. VEGETATION STRUCTURE Height (1 study): One replicated, paired, controlled, site comparison study in oil-contaminated brackish/saline marshes in Brazil found that smooth cordgrass Spartina alterniflora was never taller in cut than uncut plots (typically similar height under each treatment) over nine months after cutting. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3175https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3175Tue, 06 Apr 2021 13:41:15 +0100Collected Evidence: Collected Evidence: Cut or burn oil-contaminated vegetation: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of cutting or burning oil-contaminated vegetation 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%2F3176https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3176Tue, 06 Apr 2021 13:41:35 +0100Collected Evidence: Collected Evidence: Cut or burn oil-contaminated vegetation: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of cutting or burning oil-contaminated vegetation 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%2F3177https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3177Tue, 06 Apr 2021 13:41:47 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment and introduce vegetation: freshwater marshesWe found no studies that evaluated the combined effects, on vegetation, of depositing soil/sediment to form the physical structure of freshwater marshes and introducing vegetation.   ‘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%2F3194https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3194Wed, 07 Apr 2021 13:40:54 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment and introduce vegetation: brackish/salt marshes Six studies evaluated the combined effects, on vegetation, of depositing soil/sediment to form the physical structure of brackish/salt marshes and introducing vegetation. All six studies were in the USA. Several sites, and even the same data from some sites, were used in multiple studies. VEGETATION COMMUNITY Overall extent (2 studies): Two replicated, site comparison studies of salt marshes in the USA compared the overall area of emergent vegetation in marshes created by depositing sediment and planting vs natural marshes. One study found that created and natural marshes had similar vegetation coverage after 2–23 years. The other study reported that created marshes had slightly lower vegetation coverage than nearby natural marshes after 2–4 years. Community types (1 study): One replicated, site comparison study in the USA found that four of four plant community types had similar coverage in created and natural salt marshes after 3–15 years. For most marshes, creation involved depositing sediment and planting herbs. Community composition (1 study): One replicated, before-and-after, site comparison study in the USA reported that the overall plant community in salt marshes created by depositing sediment and planting herbs/shrubs was <36% similar to nearby natural salt marshes, after 2–4 years. VEGETATION ABUNDANCE Overall abundance (1 study): One paired, site comparison study in the USA found that salt marshes created by depositing sediment and planting/sowing herbs typically contained at least as much vegetation (biomass and density) as natural marshes, after 1–4 years. Individual species abundance (4 studies): Four studies quantified the effect of this action on the abundance of individual plant species. For example, two studies (one review, one site comparison) in the USA found that salt marshes created by depositing sediment and introducing vegetation typically contained a similar amount (density and/or biomass) of cordgrasses Spartina spp. to nearby natural marshes, after 1–9 years. Meanwhile, one paired, site comparison study in the USA reported that whether created marshes contained a higher, lower or similar cordgrass density to natural marshes depended on plot elevation. VEGETATION STRUCTURE Overall structure (2 studies): One replicated, site comparison study in the USA found that salt marshes created (mostly) by depositing sediment and planting herbs contained larger patches of vegetation with straighter edges than natural marshes, after 3–15 years. One replicated, paired, site comparison study in the USA reported that created salt marshes contained a similar proportion of edge habitat to nearby natural salt marshes, after 2–23 years. Height (2 studies): Two site comparison studies in the USA compared the height of cordgrasses Spartina sp. in created and nearby natural marshes. One study (also paired) found that created marshes typically contained cordgrass of similar height to natural marshes, after 1–4 growing seasons. The other study reported that cordgrass was shorter in created than natural marshes, after 7–9 years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3195https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3195Wed, 07 Apr 2021 13:41:27 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment and introduce vegetation: freshwater swampsWe found no studies that evaluated the combined effects, on vegetation, of depositing soil/sediment to form the physical structure of freshwater swamps and introducing vegetation.   ‘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%2F3196https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3196Wed, 07 Apr 2021 13:41:44 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment and introduce vegetation: brackish/saline swampsWe found no studies that evaluated the combined effects, on vegetation, of depositing soil/sediment to form the physical structure of brackish/saline swamps and introducing vegetation.   ‘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%2F3197https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3197Wed, 07 Apr 2021 13:41:58 +0100Collected Evidence: Collected Evidence: Create mounds or hollows: freshwater marshesWe found no studies that evaluated the effects, on vegetation, of creating mounds or hollows in 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%2Fwww.conservationevidence.com%2Factions%2F3217https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3217Fri, 09 Apr 2021 12:52:42 +0100Collected Evidence: Collected Evidence: Create mounds or hollows: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of creating mounds or hollows 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%2F3219https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3219Fri, 09 Apr 2021 12:53:02 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment to form physical structure of freshwater marshes Two studies evaluated the effects, on vegetation, of depositing soil/sediment to form the physical structure of freshwater marshes (without introducing vegetation). One study was in the USA and one was in the Netherlands. VEGETATION COMMUNITY Community types (1 study): One replicated, paired, site comparison study in the Netherlands reported that marshes created by depositing sand at lake margins contained fewer plant community types, after 8–16 years, than mature natural marshes. VEGETATION ABUNDANCE Overall abundance (2 studies): One site comparison study in the USA reported that plant stem density was similar, after 4–10 years, in marshes created by depositing sediment and in natural marshes, but that vegetation cover was lower in the created marshes. One replicated, paired, site comparison study in the Netherlands reported that marshes created by depositing sand at lake margins contained similar vegetation biomass to nearby natural marshes after 8–16 years. VEGETATION STRUCTURE Height (1 study): One site comparison study in the USA reported that a freshwater marsh created by depositing sediment contained vegetation of a similar height to nearby natural marshes after 4–10 years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3235https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3235Fri, 09 Apr 2021 15:01:56 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment to form physical structure of brackish/salt marshes Four studies evaluated the effects, on vegetation, of depositing soil/sediment to form the physical structure of brackish/salt marshes (without introducing vegetation). Three studies were in the USA and one study was in Italy. Two studies took place in the same marsh, but in different areas. VEGETATION COMMUNITY Overall extent (1 study): One replicated study in a lagoon in Italy quantified the area of vegetation on sediment deposited up to 19 years previously (average six years four months, with 61% vegetation coverage). Community types (2 studies): Two replicated studies in coastal wetlands in the USA and Italy quantified the coverage of brackish or salt marsh plant communities on sediment deposited up to 19 years previously. Community composition (1 study): One replicated, site comparison study on the coast of the USA reported that the composition of the plant community that developed on deposited sediment depended on the time since deposition and the elevation of the sediment. Areas of sediment that were of a similar elevation to natural marshes (or slightly lower) developed (or were developing) a similar overall plant community composition to the natural marshes. Overall richness/diversity (1 study): One replicated study in an estuary in the USA reported that 1–2 plant species had colonized areas of deposited sediment after 4–8 years. VEGETATION ABUNDANCE   VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3236https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3236Fri, 09 Apr 2021 15:02:12 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment to form physical structure of freshwater swampsWe found no studies that evaluated the effects on vegetation, of depositing soil/sediment to form the physical structure of freshwater swamps (without introducing vegetation).   ‘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%2F3237https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3237Fri, 09 Apr 2021 15:02:24 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment to form physical structure of brackish/saline swampsWe found no studies that evaluated the effects on vegetation, of depositing soil/sediment to form the physical structure of brackish/saline swamps (without introducing vegetation).   ‘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%2F3238https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3238Fri, 09 Apr 2021 15:02:32 +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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