Collected Evidence: Collected Evidence: Add salt to control problematic plants: freshwater marshesWe found no studies that evaluated the effects, on vegetation, of directly adding salt to control problematic plants in freshwater marshes.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3100https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3100Sun, 04 Apr 2021 09:24:05 +0100Collected Evidence: Collected Evidence: Add salt to control problematic plants: brackish/salt marshes One study evaluated the effects, on vegetation, of directly adding salt to control problematic plants in brackish/salt marshes. The study was in the USA. VEGETATION COMMUNITY   VEGETATION ABUNDANCE   VEGETATION STRUCTURE Height (1 study): One replicated, randomized, paired, controlled, before-and-after study in a salt marsh in the USA found that adding salt to control invasive beardgrass Polypogon monspeliensis had no significant effect on the height the dominant native glasswort Salicornia subterminalis. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3101https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3101Sun, 04 Apr 2021 09:24:29 +0100Collected Evidence: Collected Evidence: Add salt to control problematic plants: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of directly adding salt to control problematic plants in 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%2Fconservationevidencejournal.com%2Factions%2F3102https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3102Sun, 04 Apr 2021 09:25:07 +0100Collected Evidence: Collected Evidence: Add salt to control problematic plants: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of directly adding salt to control problematic plants in brackish/saline swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3103https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3103Sun, 04 Apr 2021 09:25:17 +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%2Fconservationevidencejournal.com%2Factions%2F3157https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3157Tue, 06 Apr 2021 12:16:26 +0100Collected Evidence: Collected Evidence: Add lime or similar chemicals: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of adding neutralizing chemicals to brackish/salt marshes or their catchments.   ‘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%2F3158https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3158Tue, 06 Apr 2021 12:16:51 +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%2Fconservationevidencejournal.com%2Factions%2F3159https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3159Tue, 06 Apr 2021 12:17:03 +0100Collected Evidence: Collected Evidence: Add lime or similar chemicals: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of adding neutralizing chemicals to brackish/saline swamps or their catchments.   ‘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%2F3160https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3160Tue, 06 Apr 2021 12:17:14 +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%2Fconservationevidencejournal.com%2Factions%2F3239https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F3240https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3240Sat, 10 Apr 2021 12:12:30 +0100Collected Evidence: Collected Evidence: Add inorganic fertilizer: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of adding inorganic fertilizer 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%2Fconservationevidencejournal.com%2Factions%2F3241https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3241Sat, 10 Apr 2021 12:12:43 +0100Collected Evidence: Collected Evidence: Add inorganic fertilizer: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of adding inorganic fertilizer 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%2Fconservationevidencejournal.com%2Factions%2F3242https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3242Sat, 10 Apr 2021 12:12:53 +0100Collected Evidence: Collected Evidence: Add lime or similar chemicals before/after planting non-woody plants: freshwater wetlandsWe found no studies that evaluated the effects, on vegetation, of adding neutralizing chemicals to freshwater 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%2F3300https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3300Sun, 11 Apr 2021 08:46:21 +0100Collected Evidence: Collected Evidence: Add lime or similar chemicals before/after planting non-woody plants: brackish/saline wetlands Three studies evaluated the effects, on vegetation, of adding neutralizing chemicals to brackish/saline wetlands planted with emergent, non-woody plants. Two studies were in Canada. One study was in the USA. One study was in a greenhouse. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Characteristic plant abundance (1 study): One replicated, paired, controlled, before-and-after study in salt-contaminated bogs in Canada reported that liming reduced the above-ground biomass of planted salt marsh vegetation after one year. Individual species abundance (2 studies): One controlled study in former borrow pits in the USA found that limed and unlimed plots supported similar biomass of a planted herb species after 1–2 growing seasons. In contrast, one replicated, randomized, paired, controlled study in salt-contaminated peat in Canada found that limed pots supported lower biomass of two sown herb species than unlimed pots, after four months. VEGETATION STRUCTURE   OTHER Germination/emergence (1 study): One replicated, randomized, paired, controlled study in salt-contaminated peat in Canada found that for each of two sown herb species, germination rates were similar in limed and unlimed pots. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3301https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3301Sun, 11 Apr 2021 08:46:32 +0100Collected Evidence: Collected Evidence: Add lime or similar chemicals before/after planting trees/shrubs: freshwater wetlandsWe found no studies that evaluated the effects, on vegetation, of adding neutralizing chemicals 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%2Fconservationevidencejournal.com%2Factions%2F3302https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3302Sun, 11 Apr 2021 08:46:44 +0100Collected Evidence: Collected Evidence: Add lime or similar chemicals before/after planting trees/shrubs: brackish/saline wetlandsWe found no studies that evaluated the effects, on vegetation, of adding neutralizing chemicals 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%2Fconservationevidencejournal.com%2Factions%2F3303https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3303Sun, 11 Apr 2021 08:46:55 +0100Collected Evidence: Collected Evidence: Add inorganic fertilizer before/after planting non-woody plants: freshwater wetlands Four studies evaluated the effects, on vegetation, of adding inorganic fertilizer to freshwater wetlands planted with emergent, non-woody plants. Two studies were in the USA, one was in the Netherlands and one was in Ireland. One of the studies in the USA was in a greenhouse. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, paired, controlled study of lakeshores planted with bulrushes Scirpus spp. in the Netherlands found that fertilized and unfertilized plots contained a similar amount (density and biomass) of each bulrush species over three growing seasons. VEGETATION STRUCTURE Individual plant size (2 studies): Two replicated, controlled studies (one also paired) in the USA found that adding fertilizer to mineral soil increased the biomass and/or number of shoots of tussock sedge Carex stricta seedlings, 2–3 months after planting. However, in both studies, adding fertilizer had no significant or clear effect on sedge size in plots amended with compost and/or topsoil. OTHER Growth (1 study): One replicated, paired, controlled, before-and-after study in tubs of mining waste in Ireland found that adding fertilizer increased growth of planted sweetgrass Glyceria fluitans in one case but had no significant effect in another. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3304https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3304Sun, 11 Apr 2021 08:57:08 +0100Collected Evidence: Collected Evidence: Add inorganic fertilizer before/after planting non-woody plants: brackish/saline wetlands Seven studies evaluated the effects, on vegetation, of adding inorganic fertilizer to brackish/saline wetlands planted with emergent, non-woody plants. Four studies were in the USA. Two of these were based in the same marsh, but used different experimental set-ups. Two studies were in Canada. One study was in China. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Overall abundance (2 studies): One replicated, randomized, paired, controlled study in intertidal brackish marshes in Canada found that adding fertilizer when planting wetland herbs typically had no significant effect on total live vegetation biomass, after two growing seasons. One replicated, paired, controlled, before-and-after study in salt-contaminated bogs in Canada found that overall vegetation biomass and cover were greater in fertilized than unfertilized plots, one year after introducing salt marsh vegetation. Individual species abundance (6 studies): Six studies quantified the effect of this action on the abundance of individual plant species. For example, three replicated, randomized, paired, controlled studies in intertidal areas in the USA found that the abundance of cordgrasses Spartina spp. was typically similar in fertilized and unfertilized plots, 1–2 growing seasons after planting. This was true for density, biomass and/or cover. However, one controlled study on former borrow pits in the USA found that cordgrass Spartina spp. biomass was typically greater in fertilized than unfertilized plots, one growing season after planting. This study also found that fertilization typically reduced black rush Juncus roemarianus biomass, one growing season after planting. VEGETATION STRUCTURE Height (6 studies): Five replicated, controlled studies (four also paired, three also randomized) in brackish/saline wetlands in the USA, China and Canada found that adding fertilizer had no significant effect on the height of planted/sown wetland herbs after 1–2 growing seasons. One controlled study on former borrow pits in the USA found that fertilized smooth cordgrass Spartina alterniflora was taller than unfertilized smooth cordgrass, two growing seasons after planting. OTHER Survival (4 studies): Three replicated, randomized, paired, controlled studies in intertidal areas in the USA and Canada found that adding fertilizer had no significant effect on the survival of planted wetland herbs over 1–2 growing seasons. One controlled study on former borrow pits in the USA reported that adding standard fertilizer to planting holes reduced the survival of planted big cordgrass Spartina cynosuroides, after one growing season. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3305https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3305Sun, 11 Apr 2021 08:57:23 +0100Collected Evidence: Collected Evidence: Add inorganic fertilizer before/after planting trees/shrubs: freshwater wetlands Two studies evaluated the effects, on vegetation, of adding inorganic fertilizer to freshwater wetlands planted with trees/shrubs. Both studies were in the USA. VEGETATION COMMUNITY                  VEGETATION ABUNDANCE   VEGETATION STRUCTURE Height (1 study): One replicated, paired, controlled study in the USA found that adding fertilizer had no significant effect, after two years, on the height of tree saplings planted into floating peat bags. Diameter, perimeter, area (1 study): The same study found that adding fertilizer had no significant effect, after two years, on the diameter of two of three tree species planted into floating peat bags. However, fertilized pond apple Annona glabra saplings had thicker stems than unfertilized saplings. OTHER Growth (1 study): One replicated, randomized, controlled study in the USA found that adding fertilizer increased the growth rate of baldcypress Taxodium distichum seedlings planted into a marsh. This was true for both diameter and height growth. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3306https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3306Sun, 11 Apr 2021 08:57:33 +0100Collected Evidence: Collected Evidence: Add inorganic fertilizer before/after planting trees/shrubs: brackish/saline wetlandsWe found no studies that evaluated the effects, on vegetation, of adding inorganic fertilizer 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%2Fconservationevidencejournal.com%2Factions%2F3307https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3307Sun, 11 Apr 2021 08:57:43 +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 +0100Collected Evidence: Collected Evidence: Add root-associated fungi to plants before plantingWe found no studies that evaluated the effects – on emergent wetland plants – of adding root-associated fungi before planting.   ‘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%2F3350https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3350Sun, 11 Apr 2021 16:59:38 +0100
What Works 2021 cover

What Works in Conservation

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

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