Collected Evidence: Collected Evidence: Add specific plants to aquatic habitats We found no evidence for the effects of adding specific plants, such as emergent vegetation, to aquatic habitats on amphibian populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.      Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F816https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F816Thu, 22 Aug 2013 15:10:49 +0100Collected Evidence: Collected Evidence: Add topsoil Two randomized, controlled studies in the UK found that the addition of topsoil increased the cover or abundance of heathland plant species. One replicated, site comparison in Spain found an increase in the abundance of woody plants. One randomized, controlled study in the UK found an increase in the number of seedlings for a majority of heathland plants. One controlled study in Namibia found that addition of topsoil increased plant cover and the number of plant species, but that these were lower than at a nearby undisturbed site. One randomized, controlled study in the UK found an increase in the cover of forbs but a reduction in the cover of grasses. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1686https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1686Mon, 23 Oct 2017 09:45:51 +0100Collected Evidence: Collected Evidence: Add sulphur to soil One randomized, replicated, controlled study in the UK found that adding sulphur to the soil of a former agricultural field did not increase the number of heather seedlings in five of six cases. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1691https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1691Mon, 23 Oct 2017 10:40:15 +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: Add water to peatlands to compensate for drought We found no studies that evaluated the effects, on peatland vegetation, of adding water to peatlands to compensate for drought. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1792https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1792Tue, 28 Nov 2017 08:19:08 +0000Collected Evidence: Collected Evidence: Add topsoil (alongside planting/seeding) One randomized, replicated, paired, controlled study in the USA found that addition of topsoil alongside sowing of seed increased the biomass of grasses but reduced the biomass of forbs in comparison to addition of topsoil alone. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1857https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1857Fri, 01 Dec 2017 14:27:24 +0000Collected Evidence: Collected Evidence: Add water to marshes or swamps to compensate for droughtWe found no studies that evaluated the effects, on vegetation, of adding water to marshes or swamps to compensate for drought.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3180https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3180Tue, 06 Apr 2021 16:13:02 +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 sediment: brackish/salt marshes Five studies evaluated the effects, on vegetation, of adding sediment to existing brackish/salt marshes. All five studies were in the USA. Two studies were based on one experimental set-up and two studies were based on another. VEGETATION COMMUNITY Relative abundance (1 study): One replicated, site comparison study in the USA found that salt marshes amended with sediment typically supported a greater relative abundance of smooth cordgrass Spartina alterniflora than degraded marshes after two years, but that this typically remained lower than in natural marshes. Overall richness/diversity (1 study): The same study found that salt marshes amended with sediment typically had greater plant species richness than degraded marshes, and statistically similar richness to natural marshes, after two years. VEGETATION ABUNDANCE Overall abundance (1 study): One replicated, site comparison study in the USA found that salt marshes amended with sediment typically had greater total vegetation cover than degraded marshes, and statistically similar cover to natural marshes, after two years. Individual species abundance (4 studies): Four studies quantified the effect of this action on the abundance of individual plant species. For example, all four studies (including two replicated, randomized, paired, controlled) of salt marshes in the USA found that adding sediment typically increased the abundance of smooth cordgrass Spartina alterniflora, over approximately 1–5 years. This is based on total biomass, density and/or cover. One of the studies reported that adding sediment increased the cover of three other species after one year. VEGETATION STRUCTURE Height (1 study): One replicated, randomized, paired, controlled study in a salt marsh in the USA found that the height of the dominant plant species, smooth cordgrass Spartina alterniflora, did not significantly differ between plots amended with sediment and unamended plots. Height was measured 16 months after sediment amendment began. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3231https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3231Fri, 09 Apr 2021 14:26:47 +0100Collected Evidence: Collected Evidence: Add sediment: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of adding sediment to existing freshwater swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3232https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3232Fri, 09 Apr 2021 14:27:03 +0100Collected Evidence: Collected Evidence: Add upland topsoilWe found no studies that evaluated the effects, on vegetation, of adding upland topsoil to restore/create marshes or swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3234https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3234Fri, 09 Apr 2021 15:01:20 +0100Collected Evidence: Collected Evidence: Add surface mulch: freshwater marshesWe found no studies that evaluated the effects, on vegetation, of using organic mulch to restore or create freshwater marshes.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3247https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3247Sat, 10 Apr 2021 12:51:29 +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: Add surface mulch: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of using organic mulch to restore or create freshwater swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3249https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3249Sat, 10 Apr 2021 12:51:52 +0100Collected Evidence: Collected Evidence: Add surface mulch: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of using organic mulch to restore or create brackish/saline swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3250https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3250Sat, 10 Apr 2021 12:52:03 +0100Collected Evidence: Collected Evidence: Add upland topsoil before/after planting non-woody plants: freshwater wetlands Three studies evaluated the effects, on vegetation, of adding upland topsoil to freshwater wetlands planted with emergent, non-woody plants. Two studies were in the USA and one was in Canada. One study was in a greenhouse. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, randomized, paired, controlled study in freshwater trenches in Canada found that adding a mixture of mineral soil and peat to pots of mine tailings before planting water sedge Carex aquatilis typically increased its above-ground biomass two growing seasons later. VEGETATION STRUCTURE Individual plant size (2 studies): One replicated, controlled study in a greenhouse in the USA found that mixing topsoil into pots of mineral soil/compost before planting tussock sedge Carex stricta seedlings typically increased the biomass and number of shoots they developed over three months. However, one replicated, paired, controlled study in a wet meadow restoration site in the USA reported that mixing topsoil into the mineral soil/compost substrate before planting tussock sedge seedlings had no clear effect on the number of shoots they developed over two months. OTHER Survival (1 study): One replicated, randomized, paired, controlled study in freshwater trenches in Canada found that adding a mixture of mineral soil and peat to pots of mine tailings either increased or had no significant effect on survival of planted water sedge Carex aquatilis over two growing seasons. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3296https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3296Sun, 11 Apr 2021 08:11:14 +0100Collected Evidence: Collected Evidence: Add upland topsoil before/after planting non-woody plants: brackish/saline wetlandsWe found no studies that evaluated the effects, on vegetation, of adding upland topsoil 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%2Fwww.conservationevidence.com%2Factions%2F3297https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3297Sun, 11 Apr 2021 08:11:32 +0100Collected Evidence: Collected Evidence: Add upland topsoil before/after planting trees/shrubs: freshwater wetlandsWe found no studies that evaluated the effects, on vegetation, of adding upland topsoil to 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%2Fwww.conservationevidence.com%2Factions%2F3298https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3298Sun, 11 Apr 2021 08:11:43 +0100Collected Evidence: Collected Evidence: Add upland topsoil before/after planting trees/shrubs: brackish/saline wetlandsWe found no studies that evaluated the effects, on vegetation, of adding upland topsoil to brackish/saline 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%2Fwww.conservationevidence.com%2Factions%2F3299https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3299Sun, 11 Apr 2021 08:11:53 +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 surface mulch before/after planting trees/shrubs: brackish/saline wetlandsWe found no studies that evaluated the effects, on vegetation, of mulching brackish/saline 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%2Fwww.conservationevidence.com%2Factions%2F3315https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3315Sun, 11 Apr 2021 12:06:27 +0100Collected Evidence: Collected Evidence: Add topsoil before seeding/planting One study examined the effects of adding topsoil before seeding/planting on grassland vegetation. The study was in the USA. VEGETATION COMMUNITY (1 STUDY) Overall richness/diversity (1 study): One replicated, controlled study in the USA found that adding topsoil before sowing seeds increased plant species richness. VEGETATION ABUNDANCE (1 STUDY) Sown/planted species abundance (1 study): One replicated, controlled study in the USA found that adding topsoil before sowing seeds increased the biomass of sown species in most cases. VEGETATION STRUCTURE (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3420https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3420Fri, 25 Jun 2021 16:37:29 +0100Collected Evidence: Collected Evidence: Add sulphur to soil before seeding/planting Two studies examined the effects of adding sulphur to soil before seeding/planting on grassland vegetation. One study was in the UK and one was in the USA. VEGETATION COMMUNITY (2 STUDIES) Overall richness/diversity (1 study): One of two replicated, controlled studies (one of which was randomized and paired) in the UK and USA found that adding sulphur to soil before sowing seeds reduced plant species richness. The other study found no change in overall plant species richness. Native/non-target species richness/diversity (1 study): One replicated, controlled study in the USA found that adding sulphur to soil before sowing seeds did not alter the number of native plant species. VEGETATION ABUNDANCE (2 STUDIES) Overall abundance (1 study): One replicated, randomized, paired, controlled study in the UK found that adding sulphur to soil before sowing seeds reduced overall vegetation cover. Sown/planted species abundance (1 study): One replicated, randomized, paired, controlled study in the UK found that adding low amounts of sulphur to soil before sowing seeds increased the cover of three of six sown species. Native/non-target species abundance (1 study): One replicated, controlled study in the USA found that adding sulphur to soil before sowing seeds did not alter the cover of native plant species. VEGETATION STRUCTURE (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3428https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3428Mon, 28 Jun 2021 10:48:32 +0100
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What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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