Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Actively manage water level before/after planting non-woody plants: freshwater wetlands Three studies evaluated the effects, on vegetation, of actively managing water levels in freshwater wetlands planted with emergent, non-woody plants. All three studies were in the USA. Two studies used the same experimental wet basins but planted different species. VEGETATION COMMUNITY Overall richness/diversity (1 study): One study in a freshwater marsh in the USA found that amongst plots amended with wetland soil, those flooded for longer contained fewer emergent plant species over the rest of the growing season following drawdown. Characteristic plant richness/diversity (1 study): The same study found that amongst plots amended with wetland soil, those flooded for longer contained fewer wetland-characteristic plant species over the rest of the growing season following drawdown. VEGETATION ABUNDANCE Overall abundance (1 study): One study in a freshwater marsh in the USA found that amongst plots amended with wetland soil, those flooded for longer developed more submerged vegetation biomass before drawdown, but developed less emergent vegetation (biomass and stem density) over the rest of the growing season after drawdown. Individual species abundance (2 studies): Two studies quantified the effect of this action on the abundance of individual plant species. For example, one controlled, before-and-after study in wet basins in the USA found that the effect of mimicking a natural (falling) water regime on lake sedge Carex lacustris biomass and density, in the three years after planting, depended on the year and various environmental factors (e.g. planting density, elevation and weeding of competitors). VEGETATION STRUCTURE Height (2 studies): Two controlled studies in wet basins in the USA examined the effect of mimicking a natural (falling) water regime, compared to a stable or rising regime, on the height of sedges over three years after planting. One of the studies found no significant effect on the height of tussock sedge Carex stricta in three of three years. The other study found that the effect on the height of lake sedge Carex lacustris varied within and between years. OTHER Survival (2 studies): Two controlled studies in wet basins in the USA examined the effect of mimicking a natural (falling) water regime, compared to a stable or rising regime, on the survival of sedges Carex over three years after planting. The precise effect depended on the year and/or plot elevation. In the first year, sedge survival was typically lower under the falling regime. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3281https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3281Sat, 10 Apr 2021 17:15:30 +0100Collected Evidence: Collected Evidence: Actively manage water level before/after planting non-woody plants: brackish/saline wetlandsWe found no studies that evaluated the effects, on vegetation, of actively managing water levels in brackish/saline wetlands planted with emergent, non-woody plants. ‘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%2F3282https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3282Sat, 10 Apr 2021 17:15:48 +0100Collected Evidence: Collected Evidence: Actively manage water level before/after planting trees/shrubs: freshwater wetlandsWe found no studies that evaluated the effects, on vegetation, of actively managing water levels in freshwater wetlands planted with trees/shrubs. ‘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%2F3283https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3283Sat, 10 Apr 2021 17:15:55 +0100Collected Evidence: Collected Evidence: Add below-ground organic matter before/after planting non-woody plants: freshwater wetlands Seven studies evaluated the effects, on vegetation, of adding below-ground organic matter to freshwater wetlands planted with emergent, non-woody plants. All seven studies were in the USA. Two of the studies were in a greenhouse. VEGETATION COMMUNITY Overall richness/diversity (1 study): One replicated study of marshes alongside a stream in the USA found that adding compost before planting wetland herbs typically reduced overall plant species richness over the following three growing seasons. Richness was negatively related to the amount of soil organic matter in plots. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated study of marshes alongside a stream in the USA found that adding compost before planting wetland herbs had no significant effect on total vegetation biomass after three growing seasons. Biomass was not significantly related to the amount of soil organic matter in plots. Characteristic plant abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study in an experimental wet basin in the USA found that adding sawdust to plots before sowing a mixture of target sedge meadow species had no significant effect on the density of target species overall or target grass-like species. Adding sawdust sometimes affected the density of target forbs, depending on the presence/diversity of a nurse crop. Individual species abundance (2 studies): Two replicated, randomized, paired, controlled studies in wetlands in the USA quantified the effect of this action on the abundance of individual plant species. One study found that incorporating woodchips into soil mounds before planting tussock sedge Carex stricta reduced total tussock sedge cover after two growing seasons. The other study reported varying effects of sawdust addition on the abundance of individual plant species, depending on factors such as the species and presence/diversity of a nurse crop. VEGETATION STRUCTURE Individual plant size (4 studies): Three replicated, controlled studies (one also paired) in the USA found that mixing compost into the substrate before planting tussock sedge Carex stricta seedlings typically increased the biomass and/or number of shoots they developed over 2–3 months. However, in one of the studies, compost typically had no significant effect on top of other soil amendments. One replicated, randomized, paired, controlled study in a wetland in the USA found that incorporating woodchips into soil mounds had no significant effect on the biomass of planted tussock sedge Carex stricta, over two growing seasons. OTHER Germination/emergence (1 study): One replicated, randomized, paired, controlled study in an experimental wet basin in the USA found that seeds of mixed sedge meadow species had a similar germination rate, over 16 weeks after sowing, in plots with or without added sawdust. Survival (2 studies): One replicated, randomized, controlled study in an excavated wetland in the USA found that planted lurid sedge Carex lurida tubers had a higher survival rate, after one year, in plots that had been amended with leaf litter than in unamended plots. One replicated, randomized, paired, controlled study in a wetland in the USA found that incorporating woodchips into soil mounds increased survival of planted tussock sedge Carex stricta in a drier area, but reduced its survival in a wetter area. Growth (1 study): One replicated, randomized, paired, controlled study in a wetland in the USA found that incorporating woodchips into soil mounds had no significant effect on the growth rate of planted tussock sedge Carex stricta, over two growing seasons. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3308https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3308Sun, 11 Apr 2021 09:50:48 +0100Collected Evidence: Collected Evidence: Add below-ground organic matter before/after planting non-woody plants: brackish/saline wetlands Six studies evaluated the effects, on vegetation, of adding below-ground organic matter to brackish/saline wetlands planted with emergent, non-woody plants. Five studies were in the USA and one was in China. Two studies were in the same marsh, but used different experimental set-ups. VEGETATION COMMUNITY VEGETATION ABUNDANCE Individual species abundance (5 studies): Three replicated, randomized, controlled studies in the USA found that adding organic matter before/after planting cordgrasses Spartina spp. typically had no significant effect on cordgrass abundance (biomass and/or density) after 1–2 growing seasons. One replicated, paired, controlled study in an estuary in the USA found that mixing kelp compost into the sediment before planting California cordgrass Spartina foliosa increased its density, three growing seasons later. One replicated, controlled, before-and-after study in an estuary in China found that mixing reed debris into the sediment before sowing seablite Suaeda salsa increased its biomass, but not its density, five months later. VEGETATION STRUCTURE Individual plant size (1 study): One replicated, randomized, paired, controlled study in an estuary in the USA found that tilling compost into plots before planting salt marsh vegetation typically increased the overall size of plants surviving after 1–2 growing seasons. Size was reported as a combination of height and lateral spread. Height (5 studies): Four replicated, controlled studies in the USA and China found that adding organic matter before/after introducing salt marsh plants (cordgrasses Spartina spp. or seablite Suaeda salsa) had no significant effect on their height after 1–2 growing seasons. One replicated, paired, controlled study in an estuary in the USA found that mixing kelp compost into the sediment before planting California cordgrass Spartina foliosa increased its height, three growing seasons later. OTHER Survival (1 study): One replicated, randomized, paired, controlled study in an estuary in the USA found that plots amended with kelp compost supported a higher survival rate of planted salt marsh vegetation over 1–2 growing seasons, with a similar but typically insignificant trend for survival rates of individual species. Growth (1 study): One replicated, randomized, controlled study in a greenhouse in the USA found that adding alginate after planting cordgrasses had no significant effect on the average number of shoots per plant, nine weeks later. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3309https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3309Sun, 11 Apr 2021 09:50:58 +0100Collected Evidence: Collected Evidence: Add below-ground organic matter before/after planting trees/shrubs: freshwater wetlands One study evaluated the effects, on vegetation, of adding below-ground organic matter to freshwater wetlands planted with trees/shrubs. The study was in the USA. VEGETATION COMMUNITY Community composition (1 study): One replicated, randomized, paired, controlled study in a created wetland in the USA found that amongst plots planted with tree seedlings, those amended with large amounts compost contained a plant community characteristic of drier conditions, three years later, than the community in unamended plots. The lowest compost dose had no significant effect on this outcome. Overall richness/diversity (1 study): The same study found that amongst plots planted with tree seedlings, those amended with a large amount of compost had lower plant species richness and diversity, three years later, than unamended plots. Lower compost doses had no significant effect on either outcome. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, randomized, paired, controlled study in a created wetland in the USA found that amongst plots planted with tree seedlings, those amended with compost supported a similar overall vegetation biomass, three years later, to unamended plots. VEGETATION STRUCTURE Individual plant size (1 study): One replicated, randomized, paired, controlled study in a created wetland in the USA found that birch Betula saplings were larger, three years after planting seedlings, in plots amended with large amounts of compost than in unamended plots. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3310https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3310Sun, 11 Apr 2021 09:51:11 +0100Collected Evidence: Collected Evidence: Add below-ground organic matter before/after planting trees/shrubs: brackish/saline wetlands One study evaluated the effects, on vegetation, of adding below-ground organic matter to brackish/saline wetlands planted with trees/shrubs. The study was in Brazil. VEGETATION COMMUNITY VEGETATION ABUNDANCE VEGETATION STRUCTURE OTHER Survival (1 study): One replicated, randomized, controlled study in a coastal swamp in Brazil reported that adding manure to plots planted with tree seedlings had mixed effects on their survival over three years, depending on the species of tree and dose of manure. Growth (1 study): The same study reported that adding manure to plots planted with tree seedlings had mixed effects on their growth over three years, depending on the species of tree and dose of manure. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3311https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3311Sun, 11 Apr 2021 09:51:23 +0100Collected Evidence: Collected Evidence: Add cover other than mulch before/after planting non-woody plants: freshwater wetlands One study evaluated the effects, on vegetation, of adding cover other than mulch to freshwater wetlands planted with emergent, non-woody plants. The study was in Australia. VEGETATION COMMUNITY VEGETATION ABUNDANCE Tree/shrub abundance (1 study): One replicated, randomized, paired, controlled study in floodplain swamps in Australia found that covering plots with plastic or jute mats before planting native understory herbs increased their overall cover, one year later. Individual species abundance (1 study): The same study found that covering plots with plastic or jute mats before planting native understory herbs reduced the cover of two problematic herb species, one year later. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3316https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3316Sun, 11 Apr 2021 12:19:16 +0100Collected Evidence: Collected Evidence: Add cover other than mulch before/after planting non-woody plants: brackish/saline wetlandsWe found no studies that evaluated the effects, on vegetation, of adding cover other than mulch to brackish/saline wetlands planted with emergent, non-woody plants. ‘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%2F3317https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3317Sun, 11 Apr 2021 12:19:32 +0100Collected Evidence: Collected Evidence: Add cover other than mulch before/after planting trees/shrubs: freshwater wetlands One study evaluated the effects, on vegetation, of adding cover other than mulch to freshwater wetlands planted with trees/shrubs. The study was in Australia. VEGETATION COMMUNITY VEGETATION ABUNDANCE Tree/shrub abundance (1 study): One replicated, randomized, paired, controlled study in floodplain swamps in Australia found that covering plots with plastic or jute mats before planting native shrubs had no significant effect on their overall cover, one year later. Individual species abundance (1 study): The same study found that covering plots with plastic or jute mats before planting swamp gum Eucalyptus camphora seedlings had no significant effect on swamp gum cover, one year later. Covering plots with mats also reduced cover of two problematic herb species. VEGETATION STRUCTURE Height (1 study): One replicated, randomized, paired, controlled study in floodplain swamps in Australia found that planted swamp gum Eucalyptus camphora seedlings reached a similar height, after one year, in covered and uncovered plots. Covers were plastic or jute mats. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3318https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3318Sun, 11 Apr 2021 12:19:45 +0100Collected Evidence: Collected Evidence: Add cover other than mulch before/after planting trees/shrubs: brackish/saline wetlands One study evaluated the effects, on vegetation, of adding cover other than mulch to brackish/saline wetlands planted with trees/shrubs. The study was in Mexico. VEGETATION COMMUNITY VEGETATION ABUNDANCE VEGETATION STRUCTURE OTHER Growth (1 study): One controlled study on a sandflat in Mexico reported that planted black mangrove Avicennia germinans seedlings grew more in height, over six months, when shaded with black mesh than when not shaded. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3319https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3319Sun, 11 Apr 2021 12:19:58 +0100