Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Change type of livestock Two replicated, before-and-after studies and one controlled study in Spain and the UK found changing the type of livestock led to mixed effects on shrub cover. However, in two of these studies changing the type of livestock reduced the cover of herbaceous species. One replicated, controlled, before-and-after study in the UK found that grazing with both cattle and sheep, as opposed to grazing with sheep, reduced cover of purple moor grass, but had no effect on four other plant species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1608https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1608Sun, 22 Oct 2017 10:05:25 +0100Collected Evidence: Collected Evidence: Cut trees One randomized, replicated, controlled study in the UK found that cutting birch trees increased density of heather seedlings but not that of mature common heather plants. One replicated, controlled study in South Africa found that cutting non-native trees increased herbaceous plant cover but did not increase cover of native woody plants. One site comparison study in South Africa found that cutting non-native Acacia trees reduced shrub and tree cover. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1630https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1630Sun, 22 Oct 2017 11:44:14 +0100Collected Evidence: Collected Evidence: Cut trees and use prescribed burning One replicated, before-and-after trial in the USA found that cutting western juniper trees and using prescribed burning increased the cover of herbaceous plants. One replicated, randomized, controlled, before-and-after trial in the USA found that cutting western juniper trees and using prescribed burning increased cover of herbaceous plants but had no effect on the cover of most shrubs. One controlled study in South Africa found that cutting followed by prescribed burning reduced the cover of woody plants but did not alter herbaceous cover. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1637https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1637Sun, 22 Oct 2017 12:07:21 +0100Collected Evidence: Collected Evidence: Cut/mow to control grass and sow seed of shrubland plants One randomized, replicated, controlled study in the USA found that the biomass of sagebrush plants in areas where grass was cut and seeds sown did not differ from areas where grass was not cut, but seeds were sown. One randomized controlled study in the USA found that cutting grass and sowing seeds increased shrub seedling abundance and reduced grass cover One randomized, replicated, controlled study in the USA found that sowing seeds and mowing did not change the cover of non-native plants or the number of native plant species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1639https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1639Sun, 22 Oct 2017 13:11:17 +0100Collected Evidence: Collected Evidence: Plant individual plants One replicated, randomized, controlled study in the USA found that planting California sagebrush plants did not increase the cover of native plant species compared to sowing of seeds or a combination of planting and sowing seeds. One replicated, randomized, controlled study in South Africa found that planting Brownanthus pseudoschlichtianus plants increased plant cover, but not the number of plant species. One study in the USA found that a majority of planted plants survived after one year. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1697https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1697Mon, 23 Oct 2017 10:55:44 +0100Collected Evidence: Collected Evidence: Plant turf Two randomized, controlled studies in the UK found that planting turf from intact heathland sites increased the abundance or cover of heathland species. One of these studies also found that planting turf increased the seedling abundance for a majority of heathland plant species. One randomized, controlled study in the UK found that planting turf increased forb cover, and reduced grass cover. One randomized, replicated, controlled study in Iceland found that planting large turves from intact heathland sites increased the number of plant species, but smaller turves did not. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1703https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1703Mon, 23 Oct 2017 11:28:15 +0100Collected Evidence: Collected Evidence: Add sulphur to soil (alongside planting/seeding) A randomized, replicated, controlled study in the UK found that adding sulphur to soil alongside sowing seeds did not increase heather cover in a majority of cases. One replicated, controlled study in the UK found that adding sulphur and spreading heathland clippings had mixed effects on cover of common heather, perennial rye-grass, and common bent. One randomized, controlled study in the UK found that adding sulphur to soil alongside planting of heather seedlings increased their survival, though after two years survival was very low. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1710https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1710Mon, 23 Oct 2017 13:17:21 +0100Collected Evidence: Collected Evidence: Strip/disturb topsoil (alongside planting/seeding) Two replicated, controlled studies in the UK found that removal of topsoil and addition seed/clippings increased cover of heathland plants or cover of heather and gorse. One controlled study in the UK found that soil disturbance using a rotovator and spreading clippings of heathland plants (alongside mowing) increased the number of heathland plants. One replicated, controlled study in the UK found that stripping the surface layers of soil and adding seed reduced the cover of perennial rye-grass. One randomized, replicated, paired, controlled study in the UK found that removal of topsoil and addition of the clippings of heathland plants did not alter the cover of annual grasses but led to a decrease in cover of perennial grasses. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1711https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1711Mon, 23 Oct 2017 13:29:32 +0100Collected Evidence: Collected Evidence: Physically remove problematic plants Three studies evaluated the effects on peatland vegetation of removing problematic plants. All three studies were in fens. Characteristic plants (1 study): One replicated, randomized, controlled study in a fen in Ireland reported that cover of fen-characteristic plants increased after mossy vegetation was removed. Herb cover (3 studies): Three replicated, controlled studies in fens in the Netherlands and Ireland reported mixed effects of moss removal on herb cover after 2–5 years. Results varied between species or between sites, and sometimes depended on other treatments applied to plots (i.e. drainage or isolation from the surrounding bog). Moss cover (3 studies): One replicated, randomized, controlled study in a fen in Ireland reported that removing the moss carpet reduced total bryophyte and Sphagnum moss cover for three years. Two replicated, controlled, before-and-after studies in fens in the Netherlands reported that removing the moss carpet had no effect on moss cover (after 2–5 years) in wet plots, but reduced total moss and Sphagnum cover in drained plots. Overall plant richness/diversity (1 study): One replicated, controlled, before-and-after study in a fen in the Netherlands reported that moss removal increased plant species richness, but only in a drained area. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1768https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1768Mon, 27 Nov 2017 21:41:10 +0000Collected Evidence: Collected Evidence: Divert/replace polluted water source(s) Three studies evaluated the effects, on peatland vegetation, of diverting or replacing polluted water source(s). Two studies were in bogs and one was in a fen. Characteristic plants (1 study): One study in a fen in the Netherlands found that after a nutrient-enriched water source was replaced (along with other interventions to reduce pollution), cover of mosses characteristic of low nutrient levels increased. Vegetation cover (2 studies): Two studies (one before-and-after) in bogs in the UK and Japan reported that after polluting water sources were diverted (sometimes along with other interventions), Sphagnum moss cover increased. Both studies reported mixed effects on herb cover, depending on species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1779https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1779Tue, 28 Nov 2017 08:14:06 +0000Collected Evidence: Collected Evidence: Fill/block ditches to create conditions suitable for peatland plants (without planting) Three studies evaluated the effects of filling or blocking ditches (without planting) on peatland vegetation within them. Two studies were in bogs and one was in a fen. Vegetation cover (3 studies): Two studies in a bog in the UK and a fen in the USA reported that blocked or filled ditches were colonized by herbs and bryophytes within 2–3 years. In the USA, vegetation cover (total, bryophyte, forb, grass and sedge) was restored to natural, undisturbed levels. One replicated study in bogs in the UK reported that plants had not colonized blocked gullies after six months. Overall plant richness/diversity (1 study): One site comparison study in a fen in the USA found that a filled ditch contained more plant species than adjacent undisturbed fen, after two years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1805https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1805Tue, 28 Nov 2017 08:29:55 +0000Collected Evidence: Collected Evidence: Add inorganic fertilizer (without planting) Three studies evaluated the effects of adding inorganic fertilizer (without planting) on peatland vegetation. Two studies were in bogs and one was in a fen meadow. Vegetation cover (1 study): One replicated, randomized, paired, controlled, before-and-after study in a bog in New Zealand reported that fertilizing typically increased total vegetation cover. Vegetation structure (1 study): One replicated, paired, controlled study in a fen meadow in the Netherlands found that fertilizing with phosphorous typically increased total above-ground vegetation biomass, but other chemicals typically had no effect. Overall plant richness/diversity (1 study): One replicated, randomized, paired, controlled, before-and-after study in a bog in New Zealand reported that fertilizing typically increased plant species richness. Growth (1 study): One replicated, controlled, before-and-after study in a bog in Germany found that fertilizing with phosphorous typically increased herb and shrub growth rate, but other chemicals had no effect. Other (3 studies): Three replicated, controlled studies in a fen meadow in Germany and bogs in Germany and New Zealand reported that effects of fertilizer on peatland were more common when phosphorous was added, than when nitrogen or potassium were added. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1812https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1812Tue, 28 Nov 2017 08:37:10 +0000Collected Evidence: Collected Evidence: Introduce nurse plants (to aid focal peatland plants) Three studies evaluated the effects, on peatland vegetation, of introducing nurse plants to aid focal peatland plants. Two studies were in bogs. One was in a tropical peat swamp. Survival (1 study): One replicated, paired, controlled study in Malaysia reported that planting nurse trees had no effect on survival of planted peat swamp tree seedlings (six species). Cover (2 studies): Two replicated, randomized, paired, controlled, before-and-after studies in bogs in the USA and Canada found that planting nurse herbs had no effect on cover, after 2–3 years, of other planted vegetation (mosses/bryophytes, vascular plants or total cover). Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1830https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1830Tue, 28 Nov 2017 08:52:11 +0000Collected Evidence: Collected Evidence: Create mounds or hollows (before planting) Three studies evaluated the effects, on peatland vegetation, of creating peat mounds or hollows before planting peatland plants. Two studies were in bogs. One was in a tropical peat swamp. Growth (1 study): One controlled study in a peat swamp in Thailand reported that trees planted into mounds of peat grew thicker stems than trees planted at ground level. Cover (2 studies): Two replicated, randomized, paired, controlled, before-and-after studies in bogs in Canada found that roughening the peat surface (by harrowing, ploughing, creating vehicle tracks or adding peat blocks) did not significantly affect cover of planted Sphagnum moss after 1–3 growing seasons. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1834https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1834Tue, 28 Nov 2017 08:53:57 +0000Collected Evidence: Collected Evidence: Add root-associated fungi to plants (before planting) Three studies evaluated the effects of adding root-associated fungi to planted peatland vegetation. All three studies involved peat swamp tree seedlings: two in the wild and one in a nursery. Survival (2 studies): Two controlled studies (one also replicated, paired, before-and-after) in peat swamps in Indonesia found that adding root fungi did not affect survival of planted red balau or jelutong in all or most cases. However, one fungal treatment increased red balau survival in one study. Growth (3 studies): Two replicated, controlled, before-and-after studies (one also paired) of peat swamp trees in Indonesia found that adding root fungi to seedlings had no effect on growth: for red balau and jelutong or the majority of 15 tested species. However, one controlled study in Indonesia found that adding root fungi increased growth of red balau seedlings. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1841https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1841Tue, 28 Nov 2017 08:55:55 +0000Collected Evidence: Collected Evidence: Reduce intensity of livestock grazing: freshwater marshes Three studies evaluated the effects, on vegetation, of reducing livestock grazing intensity in freshwater marshes (without stopping grazing entirely). Two studies were in the USA and the other was in Ireland. In all three studies, livestock were cattle. VEGETATION COMMUNITY Community composition (1 study): One site comparison study in Ireland found that lightly and heavily grazed wet meadows contained a similar overall mix of plant species. Relative abundance (1 study): One replicated, randomized, paired, controlled study in the USA found that seasonally and continuously grazed ephemeral pools had similar cover of grasses relative to forbs. Overall richness/diversity (1 study): One site comparison study in Ireland found that lightly and heavily grazed wet meadows had similar overall plant species richness. Native plant richness/diversity (1 study): One replicated, randomized, paired, controlled study in the USA found that seasonally and continuously grazed ephemeral pools experienced similar changes in native plant species richness over three years. VEGETATION ABUNDANCE Overall abundance (1 study): One site comparison study in Ireland reported that lightly and heavily grazed wet meadows had similar overall vegetation cover. Herb abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study in the USA found that lightly and moderately grazed springs/creeks had similar herb cover. Individual species abundance (1 study): One study quantified the effect of this action on the abundance of individual plant species. The site comparison study in Ireland reported, for example, that lightly grazed wet meadows had greater cover of black sedge Carex nigra, and lower cover of creeping bent Agrostis stolonifera, than more heavily grazed wet meadows. VEGETATION STRUCTURE Height (1 study): One site comparison study in Ireland found that lightly grazed wet meadows contained taller vegetation than heavily grazed wet meadows. Vegetation was measured in the summer, during the grazing season. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2970https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2970Thu, 25 Mar 2021 14:15:51 +0000Collected Evidence: Collected Evidence: Change season/timing of livestock grazing: freshwater marshes Three studies evaluated the effects, on vegetation, of grazing freshwater marshes in different seasons or at different times. Two studies were in the USA and one was in Canada. In all three studies, the livestock were cattle. VEGETATION COMMUNITY Community composition (1 study): One replicated, randomized, paired, controlled, before-and-after study of freshwater marshes and wet meadows in the USA reported that plots grazed in the summer and autumn experienced similar changes in overall plant community composition over a year. Relative abundance (1 study): One replicated, randomized, paired, controlled study of ephemeral pools in the USA found that pools grazed in the dry or wet seasons had similar cover of grasses relative to forbs over three years. Overall richness/diversity (1 study): One replicated, site comparison study of freshwater marshes in Canada found that in summer, marshes grazed in the summer/autumn contained more plant genera than marshes grazed in the spring/summer. Native/non-target richness/diversity (1 study): One replicated, randomized, paired, controlled study of ephemeral pools in the USA found that pools grazed in the dry and wet seasons experienced similar changes in native plant richness over three years. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study of freshwater marshes and wet meadows the USA found that, in three of four habitat types, summer- and autumn-grazed plots experienced similar changes in live vegetation biomass over one year. VEGETATION STRUCTURE Height (1 study): One replicated, site comparison study of freshwater marshes in Canada found that in summer, marshes grazed in the summer/autumn contained taller emergent vegetation than marshes grazed in the spring/summer. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2974https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2974Thu, 25 Mar 2021 14:17:41 +0000Collected Evidence: Collected Evidence: Change type of livestock grazing: brackish/salt marshes Three studies evaluated the effects, on vegetation, of allowing different types of livestock to graze brackish/salt marshes. There was overlap in the sites used in the studies, which all compared cattle and horse grazing on one salt marsh in the Netherlands. VEGETATION COMMUNITY Community types (1 study): One replicated, randomized, paired, controlled, before-and-after study on a salt marsh in the Netherlands found that plots experienced similar changes in the area of a couch-grass-dominated community, over four years, whether grazed by cattle or horses. Community composition (1 study): One replicated, randomized, paired, controlled, before-and-after study on a salt marsh in the Netherlands found that plots grazed by cattle and plots grazed by horses experienced a similar turnover of plant species over six years, and had a similar overall plant community composition after six years. Overall richness/diversity (2 studies): Two replicated, randomized, paired, controlled studies on one salt marsh in the Netherlands found that plots grazed by cattle and plots grazed by horses had similar plant species richness after 1–6 years. One of the studies also reported similar increases in species richness over six years, whether plots were grazed by cattle or horses. VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, randomized, paired, controlled, before-and-after study on a salt marsh in the Netherlands3 found that plots grazed by cattle and plots grazed by horses experienced similar changes in the cover of two salt marsh herb species, over six years. VEGETATION STRUCTURE Height (2 studies): Of two replicated, paired, controlled studies on one salt marsh in the Netherlands, one found that horses maintained shorter late-summer vegetation than cattle after two years of grazing. The other study found that horses and cattle maintained late-summer vegetation of a similar height, over four years. The first study also examined variation in height between vegetation patches, and found no significant difference between horse- and cattle-grazed plots. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2979https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2979Thu, 25 Mar 2021 15:05:17 +0000Collected Evidence: Collected Evidence: Backfill canals or trenches: freshwater marshes Three studies evaluated the effects, on vegetation, of backfilling canals or trenches in freshwater marshes. All three studies were in the USA. There was overlap in the canals used in two of the studies. VEGETATION COMMUNITY Overall extent (3 studies): Three replicated studies in freshwater marshes in the USA reported coverage of emergent marsh vegetation between 6 months and 25 years after backfilling. All three studies reported that coverage was greater on former spoil areas alongside canals than within the partly filled canal channels. Relative abundance (1 study): One replicated, paired, site comparison study in a freshwater marsh in the USA reported that in levelled former spoil areas alongside backfilled canals, the relative abundance of some key plant species differed from natural marshland. Vegetation was surveyed three years after backfilling. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2987https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2987Thu, 25 Mar 2021 21:10:33 +0000Collected Evidence: Collected Evidence: Reduce frequency of vegetation harvest: freshwater marshes Three studies evaluated the effects, on vegetation, of reducing the frequency of harvest in freshwater marshes (or harvesting at different frequencies). There was one study in each of the USA, Belgium and Italy. VEGETATION COMMUNITY Overall richness/diversity (1 study): One replicated, paired, controlled, before-and-after study in wet grasslands in Belgium reported that overall plant species richness was similar in plots harvested once or twice/year. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, paired, controlled, before-and-after study in wet grasslands in Belgium reported that the effect of harvesting twice/year (in July and October) on total above-ground biomass was intermediate between the effects of harvesting once/year in July or October. Individual species abundance (3 studies): All three studies quantified the effect of this action on the abundance of individual plant species. For example, one replicated, paired, controlled study in freshwater marshes in the USA reported that cattail Typha biomass was greater, nine months after the last harvest, in plots harvested every six weeks than in plots harvested every three weeks. One paired, controlled, before-and-after study in reedbeds in Italy found that the common reed Phragmites australis biomass was similar in plots harvested once or twice/year, when measured at least five months after the last harvest. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2997https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2997Wed, 31 Mar 2021 13:15:36 +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%2Fwww.conservationevidence.com%2Factions%2F3005https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3005Wed, 31 Mar 2021 13:33:45 +0100Collected Evidence: Collected Evidence: Use grazing to control problematic plants: freshwater marshes Three studies evaluated the effects, on vegetation, of using grazing to control problematic plants in freshwater marshes. Two studies were in the USA. One study was in Costa Rica. VEGETATION COMMUNITY Community composition (1 study): One replicated, randomized, paired, controlled study in Costa Rica found that amongst plots where cattail-dominated vegetation had been crushed, grazing had no significant effect on the overall plant community composition over 15 months. Relative abundance (1 study): One replicated, paired, controlled, before-and-after study in a canarygrass-invaded marsh in the USA found that grazing had no significant effect on the relative abundance of the invader: over two years, it declined similarly in grazed and ungrazed plots. Overall richness/diversity (3 studies): Of three replicated, paired, controlled studies in invaded marshes/wet meadows in the USA and Costa Rica, two found that grazing typically had no significant effect on plant species richness and/or diversity over approximately two years. The other study found that grazed areas had higher plant species richness than ungrazed areas after two months. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, paired, controlled, before-and-after study in a canarygrass-invaded marsh in the USA found that grazing had no significant effect on total vegetation cover at the ground surface, over two years. Native/non-target abundance (1 study): One replicated, paired, controlled, before-and-after study in an invaded wet meadow in the USA found that two months of grazing increased cover of non-invasive grass-like plants. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3112https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3112Sun, 04 Apr 2021 15:42:11 +0100Collected Evidence: Collected Evidence: Introduce fragments of non-woody plants: brackish/saline wetlands Three studies evaluated the effects, on vegetation, of introducing fragments of emergent, non-woody plants to brackish/saline wetlands. Two studies were in one bog in Canada. One study was in China. VEGETATION COMMUNITY VEGETATION ABUNDANCE Overall abundance (2 studies): Two replicated, paired, controlled, before-and-after studies in salt-contaminated bogs in Canada found that plots planted with rhizomes or sown with fragments of salt marsh herbs had similar overall vegetation biomass, after one year, to plots that had not been planted or sown. Herb abundance (1 study): One replicated, paired, controlled, before-and-after studies in salt-contaminated bogs in Canada found that plots sown with fragments of salt marsh herbs had greater overall cover of the introduced species, after one year, to unsown plots. However, biomass of the introduced species did not significantly differ between sown and unsown plots. Individual species abundance (2 studies): Two replicated studies (one also before-and-after) in brackish/saline wetlands in Canada and China simply quantified the abundance of herb species, over one year or growing season after planting herb fragments. VEGETATION STRUCTURE OTHER Germination/emergence (1 study): One replicated study on a tidal flat in China reported that at least 25% of bulrush Scirpus mariqueter corms (bulb-like organs) produced shoots within the first growing season after planting. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3261https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3261Sat, 10 Apr 2021 13:28:14 +0100Collected 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%2Fwww.conservationevidence.com%2Factions%2F3281https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3281Sat, 10 Apr 2021 17:15:30 +0100Collected Evidence: Collected Evidence: Create mounds or hollows before planting trees/shrubs: freshwater wetlands Three studies evaluated the effects, on vegetation, of creating mounds or hollows in freshwater wetlands before planting trees/shrubs. All three studies were in the USA. VEGETATION COMMUNITY Community composition (1 study): One replicated, site comparison study of 10-year-old restored/created freshwater wetlands in the USA reported that adding coarse woody debris to wetlands before planting trees/shrubs affected the composition of the ground vegetation layer, but not the tree layer. Overall richness/diversity (2 studies): Two studies in freshwater wetlands in the USA reported that creating mounds or hollows before planting trees/shrubs had no clear or significant effect on plant species richness and diversity 10–12 years later. In one of the studies, the same was true for bryophyte, herb and woody plants richness separately. VEGETATION ABUNDANCE VEGETATION STRUCTURE Height (1 study): One replicated, paired, controlled study in created freshwater wetlands in the USA found that the average height of white cedar Thuja occidentalis saplings typically increased more, between two and five years after planting, in created mounds than on lower (occasionally flooded) ground. OTHER Survival (1 study): One replicated, paired, controlled study in created freshwater wetlands in the USA found that white cedar Thuja occidentalis seedlings had higher survival rates when planted into created mounds than on lower (occasionally flooded) ground. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3288https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3288Sat, 10 Apr 2021 17:35:08 +0100