Collected 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: Change season/timing of vegetation harvest: freshwater marshes Three studies evaluated the effects, on vegetation, of harvesting vegetation from freshwater marshes in different seasons or at different times. There was one study in Switzerland, one in Belgium and one in Japan. VEGETATION COMMUNITY Community composition (1 study): One replicated, randomized, paired, controlled study in wet meadows in Switzerland reported that summer-harvested and winter-harvested plots experienced similar changes in their overall plant community composition, over 3–4 years. Overall richness/diversity (1 study): One replicated, paired, controlled study of wet grasslands in Belgium reported that the effect of a single harvest between June and November on overall plant species richness depended on the month of harvesting. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, paired, controlled study of wet grasslands in Belgium reported that the effect of a single harvest between June and November on overall vegetation abundance (including litter) depended on the month of harvesting. Individual species abundance (3 studies): All three studies quantified the effect of this action on the abundance of individual plant species. The studies all reported that individual species’ abundances responded differently to harvesting in different seasons. For example, the controlled, before-and-after study in Japan reported that harvesting in June reduced the abundance of common reed Phragmites australis, in the following summer, more than harvesting in July. VEGETATION STRUCTURE Overall structure (1 study): One replicated, randomized, paired, controlled study in wet meadows in Switzerland reported that summer-harvested and winter-harvested plots both experienced a shift in vegetation cover towards lower vegetation layers, over 3–4 years. Diameter/perimeter/area (1 study): The same study reported that summer harvesting and winter harvesting had opposite effects on the diameter of common reed Phragmites australis shoots: they became thinner over four years of summer harvests but thicker over three years of winter harvests. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3005https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3005Wed, 31 Mar 2021 13:33:45 +0100Collected Evidence: Collected Evidence: Change season/timing of vegetation harvest: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of harvesting brackish/salt marshes in different seasons or at different times.   ‘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%2F3006https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3006Wed, 31 Mar 2021 13:34:28 +0100Collected Evidence: Collected Evidence: Change season/timing of vegetation harvest: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of harvesting freshwater swamps in different seasons or at different times.   ‘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%2F3007https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3007Wed, 31 Mar 2021 13:34:40 +0100Collected Evidence: Collected Evidence: Change season/timing of vegetation harvest: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of harvesting brackish/saline swamps in different seasons or at different times.   ‘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%2F3008https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3008Wed, 31 Mar 2021 13:34:53 +0100Collected Evidence: Collected Evidence: Use low-impact methods to harvest vegetation: freshwater marshesWe found no studies that evaluated the effects, on vegetation, of using supposedly low-impact methods to harvest 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%2Fconservationevidencejournal.com%2Factions%2F3009https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3009Wed, 31 Mar 2021 14:09:59 +0100Collected Evidence: Collected Evidence: Use low-impact methods to harvest vegetation: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation of using supposedly low-impact methods to harvest vegetation 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%2Fconservationevidencejournal.com%2Factions%2F3010https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3010Wed, 31 Mar 2021 14:10:09 +0100Collected Evidence: Collected Evidence: Use low-impact methods to harvest vegetation: freshwater swamps One study evaluated the effects, on vegetation, of using supposedly low-impact methods to harvest vegetation in freshwater swamps. The study was in the USA. VEGETATION COMMUNITY Overall richness/diversity (1 study): One controlled study in a freshwater swamp in the USA reported that after seven years, a plot where logs had been extracted by helicopter only contained fewer plant species than a plot where logs had been extracted by helicopter and ground vehicles. VEGETATION ABUNDANCE Overall abundance (1 study): One controlled study in a freshwater swamp in the USA reported that after seven years, a plot where logs had been extracted by helicopter only contained less overall plant biomass than a plot where logs had been extracted by helicopter and ground vehicles. This was also true for the overstory and ground layers separately. However, overstory tree density did not significantly differ between helicopter-extracted and vehicle-extracted plots. Individual species abundance (1 study): The same study found that the abundance of some individual plant species – particularly swamp ash Fraxinus caroliniana and water tupelo Nyssa aquatica – significantly differed between helicopter-extracted and vehicle-extracted plots. VEGETATION STRUCTURE Height (1 study): One controlled study in a freshwater swamp in the USA found that after seven years, the average height of the overstory was similar in a plot where logs had been extracted by helicopter only and a plot where logs had been extracted by helicopter and ground vehicles. Diameter, perimeter, area (1 study): The same study found that after seven years, the average stem diameter of overstory trees was similar in helicopter-extracted and vehicle-extracted plots. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3011https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3011Wed, 31 Mar 2021 14:10:30 +0100Collected Evidence: Collected Evidence: Use low-impact methods to harvest vegetation: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of using supposedly low-impact methods to harvest 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%2Fconservationevidencejournal.com%2Factions%2F3012https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3012Wed, 31 Mar 2021 14:10:48 +0100Collected Evidence: Collected Evidence: Implement ‘mosaic management’ when harvesting wild vegetationWe found no studies that evaluated the effects, on vegetation, of implementing mosaic management when harvesting wild vegetation from 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%2F3013https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3013Wed, 31 Mar 2021 14:20:54 +0100Collected Evidence: Collected Evidence: Provide new technologies to reduce harvesting pressure on vegetationWe found no studies that evaluated the effects, on vegetation or human behaviour, of providing new technologies to reduce harvesting pressure on vegetation 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%2F3014https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3014Wed, 31 Mar 2021 14:22:01 +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: Use low-impact methods to hunt/collect animalsWe found no studies that evaluated the effects, on vegetation, of using supposedly low-impact methods to hunt/collect 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%2F3017https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3017Wed, 31 Mar 2021 14:25:33 +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: Restrict vehicle useWe found no studies that evaluated the effects, on vegetation, of restricting vehicle use in or near 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%2F3019https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3019Wed, 31 Mar 2021 14:39:31 +0100Collected Evidence: Collected Evidence: Physically exclude vehiclesWe found no studies that evaluated the effects, on vegetation, of physically excluding vehicles from 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%2F3020https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3020Wed, 31 Mar 2021 14:40:09 +0100Collected Evidence: Collected Evidence: Build barriers to protect littoral areas from boat wakesWe found no studies that evaluated the effects, on vegetation, of building barriers to protect littoral marshes or swamps from boat wakes.   ‘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%2F3021https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3021Wed, 31 Mar 2021 14:41:04 +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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