Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Reduce fertilizer or herbicide use: freshwater marshes One study evaluated the effects, on vegetation in freshwater marshes, of reducing the amount of fertilizer or herbicide used in the marshes or adjacent areas. The study was in Brazil. VEGETATION COMMUNITY Community composition (1 study): One replicated, site comparison study of rice fields in Brazil found that the overall plant community composition (excluding rice) was similar in organically farmed fields and conventionally farmed fields, but different from the community in nearby natural marshes. Overall richness/diversity (1 study): The same study found that organically farmed rice fields contained a similar average richness and diversity of wetland plants (at any single point in time) to conventionally farmed rice fields, although more species were recorded in the organic fields over the year of the study. Organically farmed rice fields had lower wetland plant richness and diversity than nearby natural marshes. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, site comparison study of rice fields in Brazil found that organically farmed fields contained more wetland plant biomass than conventionally farmed fields over the year of the study, but less wetland plant biomass than nearby natural marshes. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3152https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3152Mon, 05 Apr 2021 15:48:02 +0100Collected Evidence: Collected Evidence: Add lime or similar chemicals: freshwater marshes One study evaluated the effects, on vegetation, of adding neutralizing chemicals to freshwater marshes or their catchments. The study was in the USA. VEGETATION COMMUNITY Relative abundance (1 study): One replicated, controlled, before-and-after study of marsh vegetation in the USA found that liming had little effect on the relative abundance of plant taxa. For 48 of 49 taxa, differences or similarities in relative abundance between limed and unlimed areas before intervention persisted over two years after intervention. VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, controlled, before-and-after study of marsh vegetation in the USA found that for most plant taxa, differences or similarities in abundance between limed and unlimed areas before intervention persisted over two years following intervention. This was true for 33 of 38 herbaceous plant taxa, eight of eight woody plant taxa, and two of three moss taxa. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3157https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3157Tue, 06 Apr 2021 12:16:26 +0100Collected Evidence: Collected Evidence: Add lime or similar chemicals: freshwater swamps One study evaluated the effects, on vegetation, of adding neutralizing chemicals to freshwater swamps or their catchments. The study was in the USA. VEGETATION COMMUNITY Relative abundance (1 study): One replicated, controlled, before-and-after study of shrubby wetland vegetation in the USA found that liming had no significant effect on the relative abundance of plant taxa. For 49 of 49 taxa, differences or similarities in relative abundance between limed and unlimed areas before intervention persisted over two years after intervention. VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, controlled, before-and-after study of shrubby wetland vegetation in the USA found that for most plant taxa, differences or similarities in abundance between limed and unlimed areas before intervention persisted over two years following intervention. This was true for 31 of 31 herbaceous plant taxa, 16 of 16 woody plant taxa, and one of two moss taxa. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3159https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3159Tue, 06 Apr 2021 12:17:03 +0100Collected Evidence: Collected Evidence: Modify crop farming practices in watershed to reduce pollution: freshwater marshes One study evaluated the effects, on vegetation in freshwater marshes, of modifying crop farming practices in the watershed to reduce pollution. The study was in the USA. VEGETATION COMMUNITY Community composition (1 study): One replicated, site comparison study in the USA reported that freshwater marshes being restored by abandoning cropland in the watershed (along with removing topsoil from the marshes) contained a different overall plant community, after 1–12 years, to both natural and degraded marshes nearby. Overall richness/diversity (1 study): The same study reported that freshwater marshes being restored by abandoning cropland in the watershed (along with removing topsoil from the marshes) contained fewer wetland plant species, after 1–12 years, than nearby natural marshes. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3166https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3166Tue, 06 Apr 2021 13:17:51 +0100Collected Evidence: Collected Evidence: Restore/create brackish/saline swamps in areas that will be climatically suitable in the future One study evaluated the effects, on vegetation, of restoring or creating brackish/saline swamps in areas expected to be climatically suitable in the future. The study was in South Africa. VEGETATION COMMUNITY Overall extent (1 study): One before-and-after study in an estuary in South Africa reported that over 42 years after planting mangrove trees just beyond their current range, the area of mangrove forests increased. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3189https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3189Tue, 06 Apr 2021 17:11:31 +0100Collected Evidence: Collected Evidence: Create mounds or hollows: brackish/saline swamps One study evaluated the effects, on vegetation, of creating mounds or hollows in brackish/saline swamps. The study was in Indonesia. VEGETATION COMMUNITY VEGETATION ABUNDANCE Tree/shrub abundance (1 study): One study in Indonesia simply reported the number of mangrove tree seedlings that had colonized a pile of branches placed in a disused aquaculture pond, around seven months after depositing the branches (and releasing mangrove propagules). VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3220https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3220Fri, 09 Apr 2021 12:55:02 +0100Collected Evidence: Collected Evidence: Remove surface soil/sediment: brackish/salt marshes One study evaluated the effects, on vegetation, of removing surface soil/sediment to restore or create brackish/salt marshes. The study was in the Netherlands. VEGETATION COMMUNITY Overall richness/diversity (1 study): One study in the Netherlands reported that 23 plant species colonized over two years after stripping topsoil from coastal farmland. VEGETATION ABUNDANCE Individual species abundance (1 study): One study in the Netherlands reported the frequency of plant species that colonized over two years after stripping topsoil from coastal farmland. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3222https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3222Fri, 09 Apr 2021 13:08:28 +0100Collected Evidence: Collected Evidence: Disturb soil/sediment surface: brackish/salt marshes One study evaluated the effects, on vegetation, of disturbing the surface of brackish/salt marshes. The study was in the USA. VEGETATION COMMUNITY Community composition (1 study): One replicated, paired, site comparison study of brackish/salt marshes in the USA reported that marshes disked every spring for at least six years (and drawn down during spring/autumn) shared only 24–34% of plant species with marshes that were not disked (or drawn down). Overall richness/diversity (1 study): The same study found that overall plant species richness and diversity were similar in managed marshes (disked every spring and drawn down during spring/autumn, for at least six years) and unmanaged marshes (neither disked nor drawn down). VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3227https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3227Fri, 09 Apr 2021 14:04:14 +0100Collected Evidence: Collected Evidence: Add sediment: freshwater marshes One study evaluated the effects, on vegetation, of adding sediment to existing freshwater marshes. The study was in the USA. VEGETATION COMMUNITY Overall richness/diversity (1 study): One replicated, randomized, paired, controlled study in the USA reported that adding sediment to freshwater marshes typically reduced plant species richness after one growing season. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, randomized, paired, controlled study in the USA found that adding sediment to freshwater marshes had no significant effect on total live vegetation biomass after one growing season. Individual species abundance (1 study): The same study found that adding sediment to freshwater marshes had no significant effect on the biomass of most of the dominant herbaceous species after one growing season. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3230https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3230Fri, 09 Apr 2021 14:26:32 +0100Collected Evidence: Collected Evidence: Add inorganic fertilizer: freshwater marshes One study evaluated the effects, on vegetation, of adding inorganic fertilizer to restore or create freshwater marshes. The study was in Germany. VEGETATION COMMUNITY Community composition (1 study): One replicated, paired, controlled, before-and-after study in wet grasslands in Germany reported that the effect of annual fertilization (for 20 years) on the average moisture preference of the vegetation varied between sites. Overall richness/diversity (1 study): The same study reported that the effect of annual fertilization (for 20 years) on total plant species richness varied between sites. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, paired, controlled study in wet grasslands in Germany reported that plots fertilized every spring contained more vegetation biomass, after 4–18 years, than unfertilized plots. Herb abundance (1 study): The same study reported that the effect of annual fertilization (for 20 years) on cover of herb groups (sedges, rushes, forbs, ferns, grasses and legumes) varied between sites. VEGETATION STRUCTURE Height (1 study): One replicated, paired, controlled, before-and-after study in wet grasslands in Germany reported that the effect of annual fertilization (for 20 years) on vegetation height varied between sites. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3239https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3239Sat, 10 Apr 2021 12:11:20 +0100Collected Evidence: Collected Evidence: Add inorganic fertilizer: brackish/salt marshes One study evaluated the effects, on vegetation, of adding inorganic fertilizer to restore or create brackish/salt marshes. The study was in Canada. VEGETATION COMMUNITY VEGETATION ABUNDANCE Characteristic plant abundance (1 study): One replicated, paired, controlled, before-and-after study in salt-contaminated bogs in Canada found that adding fertilizer had no significant effect on cover of salt marsh vegetation, in unplanted plots, after one year. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3240https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3240Sat, 10 Apr 2021 12:12:30 +0100Collected Evidence: Collected Evidence: Add below-ground organic matter: brackish/salt marshes One study evaluated the effects, on vegetation, of adding below-ground organic matter to restore or create brackish/salt marshes. The study was in the USA. VEGETATION COMMUNITY VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, randomized, controlled, before-and-after study in a salt marsh in the USA found that plots amended with alginate contained a greater density of smooth cordgrass Spartina alterniflora than unamended plots after 6–52 weeks. However, amended and unamended plots contained similar smooth cordgrass biomass when it was sampled after 52 weeks. VEGETATION STRUCTURE Height (1 study): One replicated, randomized, controlled, before-and-after study in a salt marsh in the USA found that amending plots with alginate had no significant effect on smooth cordgrass height in the first 16 weeks after intervention, but that amended plots contained taller smooth cordgrass than unamended plots after 28–52 weeks. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3244https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3244Sat, 10 Apr 2021 12:33:05 +0100Collected Evidence: Collected Evidence: Add surface mulch: brackish/salt marshes One study evaluated the effects, on vegetation, of using organic mulch to restore or create brackish/salt marshes. The study was in Australia. VEGETATION COMMUNITY Overall richness/diversity (1 study): One replicated, paired, controlled study on a sandflat in Australia found that mulched and unmulched plots had similar plant species richness over two years. VEGETATION ABUNDANCE Herb abundance (1 study): One replicated, paired, controlled study on a sandflat in Australia found that mulched plots were more likely to contain glasswort Sarcocornia quinqueflora than unmulched plots, after 20 months. However, mulching had no significant effect on glasswort biomass after 20 months, and typically had no significant effect on glasswort cover over two years. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3248https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3248Sat, 10 Apr 2021 12:51:36 +0100Collected Evidence: Collected Evidence: Introduce nurse plants: brackish/saline swamps One study evaluated the effects, on naturally colonizing vegetation, of introducing nurse plants to restore or create brackish/saline swamps. The study was in India. VEGETATION COMMUNITY VEGETATION ABUNDANCE VEGETATION STRUCTURE Height (1 study): One study on an estuarine mudflat in India reported that the average height of mangrove propagules trapped by nurse grasses increased by 21–90% (depending on the species) over the first month after establishment. OTHER Germination/emergence (1 study): One study on an estuarine mudflat in India reported that 60–80% (depending on the species) of mangrove propagules trapped by nurse grasses developed into seedlings. Saltmarsh grasses trapped 1,200–1,372 mangrove propagules/m2/week, approximately 1–2 years after they were planted. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3255https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3255Sat, 10 Apr 2021 13:04:30 +0100Collected Evidence: Collected Evidence: Introduce fragments of trees/shrubs: freshwater wetlands One study evaluated the effects, on vegetation, of introducing tree/shrub fragments to freshwater wetlands. The study was in the USA. VEGETATION COMMUNITY VEGETATION ABUNDANCE VEGETATION STRUCTURE OTHER Survival (1 study): One study in a floodplain swamp clearing in the USA reported 12% overall survival of planted unrooted tree cuttings over two years. For two of four species, no monitored seedlings survived. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3262https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3262Sat, 10 Apr 2021 13:28:25 +0100Collected Evidence: Collected Evidence: Transplant or replace blocks of vegetation: brackish/salt marshes One study evaluated the effects, on vegetation, of transplanting or replacing blocks of brackish/salt marsh vegetation. The study was in Australia. VEGETATION COMMUNITY Community composition (1 study): One replicated, controlled, site comparison study in an estuarine salt marsh in Australia found that areas where sods of saltwater couch Sporobolus virginicus were transplanted had a similar overall plant community composition to areas without transplants, after 3–4 years. The plant community in the transplanted areas was >70% similar to natural areas in only 4 of 12 comparisons. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3269https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3269Sat, 10 Apr 2021 15:36:47 +0100Collected Evidence: Collected Evidence: Create mounds or hollows before planting non-woody plants: brackish/saline wetlands One study evaluated the effects, on vegetation, of creating mounds or hollows in brackish/saline wetlands before planting emergent, non-woody plants. The study was in the USA. VEGETATION COMMUNITY VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, randomized, paired, controlled study in an estuarine salt marsh in the USA found that amongst plots sown/planted with dwarf saltwort Salicornia bigelovii, those that had been excavated into depressions had lower cover of dominant pickleweed Salicornia virginica – over the first growing season – than plots left at ground level. VEGETATION STRUCTURE OTHER Germination/emergence (1 study): One replicated, randomized, paired, controlled study in an estuarine salt marsh in the USA found that there were no more (sometimes fewer) dwarf saltwort Salicornia bigelovii seedlings in excavated depressions than in level plots, two months after sowing saltwort seeds. Survival (1 study): The same study found that the survival rate of dwarf saltwort Salicornia bigelovii transplants was not greater (sometimes lower) in excavated depressions than in level plots. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3287https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3287Sat, 10 Apr 2021 17:34:58 +0100Collected Evidence: Collected Evidence: Create mounds or hollows before planting trees/shrubs: brackish/saline wetlands One study evaluated the effects, on vegetation, of creating mounds or hollows in brackish/saline wetlands before planting trees/shrubs. The study was in Brazil. VEGETATION COMMUNITY VEGETATION ABUNDANCE VEGETATION STRUCTURE OTHER Survival (1 study): One replicated, controlled study in a degraded coastal swamp in Brazil reported that planting tree seedlings into mounds had mixed effects on survival over three years, depending on the species. Growth (1 study): The same study reported that tree seedlings planted into mounds typically grew at a similar rate, over three years, to seedlings planted at ground level. Growth was measured in terms of diameter, height and canopy area. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3289https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3289Sat, 10 Apr 2021 17:35:23 +0100Collected Evidence: Collected Evidence: Disturb soil/sediment surface before planting trees/shrubs: brackish/saline wetlands One study evaluated the effects, on vegetation, of disturbing the surface of brackish/saline wetlands before planting trees/shrubs. The study was in Australia. VEGETATION COMMUNITY VEGETATION ABUNDANCE VEGETATION STRUCTURE Height (1 study): One replicated, controlled study on an estuarine mudflat in Australia found that ploughing the substrate before planting grey mangrove Avicennia marina propagules had no significant effect on their height after two growing seasons. OTHER Survival (1 study): One replicated, controlled study on an estuarine mudflat in Australia found that ploughing the substrate before planting grey mangrove propagules had no significant effect on their survival over two growing seasons. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3295https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3295Sun, 11 Apr 2021 07:57:16 +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%2Fwww.conservationevidence.com%2Factions%2F3310https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F3311https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3311Sun, 11 Apr 2021 09:51:23 +0100Collected Evidence: Collected Evidence: Add surface mulch before/after planting non-woody plants: freshwater wetlands One study evaluated the effects, on vegetation, of mulching freshwater wetlands planted with emergent, non-woody plants. The study was in Australia. VEGETATION COMMUNITY VEGETATION ABUNDANCE Herb abundance (1 study): One replicated, randomized, paired, controlled study in floodplain swamps in Australia found that mulching with woodchips before planting native understory herbs either increased or had no significant effect on their overall cover, one year later. Individual species abundance (1 study): The same study found that mulching with woodchips before planting native understory herbs reduced the cover of one problematic species (common reed Phragmites australis) one year later, but had no significant effect on another (reed canarygrass Phalaris arundinacea). VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3312https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3312Sun, 11 Apr 2021 12:05:44 +0100Collected Evidence: Collected Evidence: Add surface mulch before/after planting non-woody plants: brackish/saline wetlands One study evaluated the effects, on vegetation, of mulching brackish/saline wetlands planted with emergent, non-woody plants. The study was in Canada. VEGETATION COMMUNITY VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, randomized, paired, controlled study in intertidal brackish marshes in Canada found that adding surface mulch after planting wetland herbs typically had no significant effect on total live vegetation biomass, two growing seasons later. Individual species abundance (1 study): The same study found that adding surface mulch increased the cover of one of two planted herb species (creeping alkaligrass Puccinellia phryganodes) but had no significant effect on cover of the other species (estuary sedge Carex subspathacea). Cover was monitored over the second growing season after planting/mulching. VEGETATION STRUCTURE OTHER Survival (1 study): One replicated, randomized, paired, controlled study in intertidal brackish marshes in Canada found that adding surface mulch had no significant effect on the survival of two of two planted herb species, after two growing seasons. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3313https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3313Sun, 11 Apr 2021 12:05:55 +0100Collected Evidence: Collected Evidence: Add surface mulch before/after planting trees/shrubs: freshwater wetlands One study evaluated the effects, on vegetation, of mulching 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 mulching with woodchips 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 mulching with woodchips before planting swamp gum Eucalyptus camphora seedlings had no significant effect on swamp gum cover, one year later. Mulching reduced cover of the problematic herb species in one of two swamps, but had no significant effect in the other. 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 mulched and unmulched plots. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3314https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3314Sun, 11 Apr 2021 12:06:05 +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%2Fwww.conservationevidence.com%2Factions%2F3316https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3316Sun, 11 Apr 2021 12:19:16 +0100