Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Use high-visibility longlines to reduce seabird bycatch We captured no intervention-based evidence on the impact on seabird bycatch of high-visibility longlines. '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%2F294https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F294Tue, 24 Jul 2012 16:58:27 +0100Collected Evidence: Collected Evidence: Use high-visibility mesh on gillnets to reduce seabird bycatch A repeated, randomised and controlled trial in the USA found that having gillnets made partially from high-visibility mesh was effective in reducing seabird bycatch. Having a greater percentage (25% vs. 10%) of the net made from high-visibility mesh was more effective, but also reduced catch of the target species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F303https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F303Tue, 24 Jul 2012 18:10:09 +0100Collected Evidence: Collected Evidence: Use herbicides to control mid-storey or ground vegetation Three studies (including two randomized, replicated, controlled studies) in the USA found that understory removal using herbicide had no effect or some negative effects on amphibian abundance. One replicated, site comparison study in Canada found that following logging American toad abundance was similar and wood frogs lower in stands with herbicide treatment and planting compared to stands left to regenerate naturally. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F778https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F778Wed, 21 Aug 2013 15:38:27 +0100Collected Evidence: Collected Evidence: Use herbicides to remove understory vegetation to reduce wildfires We found no evidence for the effects of using herbicides to remove understory vegetation to reduce wildfiress. '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%2F1218https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1218Fri, 20 May 2016 14:40:39 +0100Collected Evidence: Collected Evidence: Use herbicides to thin trees One replicated, controlled study in Canada found no effect of using herbicide to thin pine trees on total plant species richness. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1225https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1225Mon, 23 May 2016 10:33:00 +0100Collected Evidence: Collected Evidence: Use herbicides to control invasive plant species One replicated, randomized, controlled study in the USA found no effect of invasive plant control using herbicide on the total native plant species richness. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1229https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1229Mon, 23 May 2016 10:52:27 +0100Collected Evidence: Collected Evidence: Use herbicides after tree planting Two of three studies (including two replicated, randomized, controlled studies) in Sweden and the USA found that using herbicide increased the size of planted trees. One study found no effect on tree size. One replicated, randomized, controlled study in Sweden found no effect of using herbicide on frost damage caused to planted Norway spruce seedlings. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1262https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1262Mon, 06 Jun 2016 13:13:27 +0100Collected Evidence: Collected Evidence: Use herbicides to remove invasive plant species One replicated, randomized, controlled study in the USA found no effect of invasive plant control using herbicide on the total native plant species richness. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1314https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1314Fri, 23 Sep 2016 14:49:03 +0100Collected Evidence: Collected Evidence: Use herbicide to control grass Two randomized, controlled studies in the UK and the USA found that spraying with herbicide did not affect the number of shrub or heathland plant seedlings. One of these studies found that applying herbicide increased the abundance of one of four heathland plants, but reduced the abundance of one heathland species. However, one randomized, controlled study in the UK found that applying herbicide increased cover of heathland species. One randomized, replicated, controlled study in the UK reported no effect on the cover of common heather. One randomized, replicated study in the UK reported mixed effects of herbicide application on shrub cover. Two randomized, controlled studies in the USA and the UK found that herbicide application did not change the cover of forb species. However, one randomized, controlled, study in the USA found that herbicide application increased native forb cover. Four of five controlled studies (two of which were replicated) in the USA found that grass cover or non-native grass cover were lower in areas where herbicides were used to control grass than areas were herbicide was not used. Two randomized, replicated, controlled studies in the UK found that herbicide reduced cover of purple moor grass, but not cover of three grass/reed species. Two randomized, controlled studies in the UK found that herbicide application did not reduce grass cover. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1643https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1643Sun, 22 Oct 2017 13:23:19 +0100Collected Evidence: Collected Evidence: Use herbicide to control bracken One controlled, before-and-after trial in the UK found that applying herbicide to control bracken increased the number of heather seedlings. However, two randomized, controlled studies in the UK found that spraying with herbicide did not increase heather cover. One randomized, controlled study in the UK found that applying herbicide to control bracken increased heather biomass. One replicated, randomized, controlled study in the UK found that the application of herbicide increased the number of plant species in a heathland site. However, one replicated, randomized, controlled study in the UK found that spraying bracken with herbicide had no effect on species richness or diversity. One randomized, controlled study in the UK found that applying herbicide to control bracken increased the cover of wavy hair-grass and sheep’s fescue. One controlled study in the UK found that applying herbicide to control bracken increased the cover of gorse and the abundance of common cow-wheat. One controlled, before-and-after trial in the UK found that the application of herbicide reduced the abundance of bracken but increased the number of silver birch seedlings. Three randomized, controlled studies in the UK found that the application of herbicide reduced the biomass or cover of bracken. However, one controlled study in the UK found that applying herbicide did not change the abundance of bracken. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1652https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1652Sun, 22 Oct 2017 14:09:58 +0100Collected Evidence: Collected Evidence: Use herbicide and sow seed of shrubland plants to control bracken We found no studies that evaluated the effects of controlling bracken by applying herbicide and sowing seed on shrublands. '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%2F1658https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1658Sun, 22 Oct 2017 14:56:07 +0100Collected Evidence: Collected Evidence: Use herbicide and remove leaf litter to control bracken One randomized, controlled study in the UK found that using herbicide and removing leaf litter did not increase total plant biomass after eight years. The same study found that for three of six years, heather biomass was higher in areas where herbicide was sprayed and leaf litter was removed than in areas that were sprayed with herbicide. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1660https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1660Sun, 22 Oct 2017 14:59:23 +0100Collected Evidence: Collected Evidence: Use herbicide and grazing to control bracken We found no studies that evaluated the effects of controlling bracken by using herbicide and grazing on shrublands. '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%2F1661https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1661Sun, 22 Oct 2017 15:02:06 +0100Collected Evidence: Collected Evidence: Use herbicide and prescribed burning to control grass One randomized, replicated, controlled, paired, before-and-after study in the UK found that burning and applying herbicide to reduce the cover of purple moor grass reduced cover of common heather but did not reduce cover of purple moor grass. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1725https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1725Wed, 22 Nov 2017 16:31:55 +0000Collected Evidence: Collected Evidence: Use herbicide to control problematic plants One study evaluated the effects on peatland vegetation of using herbicide to control problematic plants. The study was in fens. Plant community composition (1 study): One replicated, controlled, before-and-after study in fens in the USA found that applying herbicide to shrubs (along with other interventions) changed the overall plant community composition. Tree/shrub cover (1 study): The same study found that applying herbicide to shrubs (along with other interventions) could not prevent increases in shrub cover over time. Overall plant richness/diversity (1 study): The same study found that applying herbicide to shrubs (along with other interventions) prevented increases in plant species richness. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1776https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1776Mon, 27 Nov 2017 21:44:30 +0000Collected Evidence: Collected Evidence: Use guardian animals (e.g. dogs, llamas, donkeys) bonded to livestock to deter predators to reduce human-wildlife conflict Twelve studies evaluated the effects of using guardian animals (e.g. dogs, llamas, donkeys) bonded to livestock to deter mammals from predating these livestock to reduce human-wildlife conflict. Four studies were in the USA, two were in Kenya and one each was in Solvakia, Argentina, Australia, Cameroon, South Africa, and Namibia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (12 STUDIES) Human-wildlife conflict (12 studies): Four of seven studies, (including four site comparison studies), in the USA, Kenya, Solvakia, Australia and Cameroon, found that guardian animals reduced attacks on livestock by predators. The other three studies reported mixed results with reductions in attacks on some but not all age groups or livestock species and reductions for nomadic but not resident pastoralists. Two studies, (including one site comparison study and one before-and-after study), in Argentina and Namibia, found that using dogs to guard livestock reduced the killing of predators by farmers but the number of black-backed jackals killed by farmers and dogs combined increased. A replicated, controlled study in the USA found that fewer sheep guarded by llamas were predated by carnivores in one of two summers whilst a replicated, before-and-after study in South Africa found that using dogs or alpacas to guard livestock reduced attacks by predators. A randomized, replicated, controlled study in USA found that dogs bonded with livestock reduced contact between white-tailed deer and domestic cattle. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2433https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2433Tue, 02 Jun 2020 08:41:54 +0100Collected Evidence: Collected Evidence: Use holding pens at release site prior to release of captive-bred mammals Thirty-one studies evaluated the effects of using holding pens at the release site prior to release of captive-bred mammals. Seven studies were in Australia, and in the USA, four were in the UK, three in Argentina, two in each of Israel, Saudi Arabia and China and one in each of Canada, Namibia, South Africa and Germany. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (30 STUDIES) Abundance (2 studies): A study in Saudi Arabia found that a population of captive-bred Arabian sand gazelles kept in holding pens prior to release nearly doubled in size over four years. A before-and-after study in China found that following release of captive-bred animals from a pre-release enclosure into the semi-wild (free-roaming in summer, enclosed in winter and provided with food), Przewalski’s horses increased in number. Reproductive success (10 studies): Eight studies (one replicated) and one review in the UK, Saudi Arabia, the USA, Israel and Australia found that following the use of holding pens prior to release (and in some cases provision of supplementary food), captive-bred Eurasian otters, Arabian sand gazelles, eastern-barred bandicoots, some swift foxes, some red wolves and over 33% of Persian fallow deer reproduced, Arabian gazelles started breeding in the first year and the reproductive success of female Asiatic wild ass increased over 10 years. A study in Australia found that after being kept in a holding pen, all four mammal populations released into an invasive-species-free fenced enclosure reproduced. Survival (23 studies): One of three studies (two controlled, one replicated) in the UK, Canada and Australia found that using holding pens prior to release of captive-bred (and some translocated) animals resulted in greater post-release survival for water voles compared to animals released directly into the wild. The other two studies found similar survival rates for eastern barred bandicoots and swift foxes compared to animals released directly into the wild. A replicated study in the USA found that captive-bred Allegheny woodrats kept in holding pens prior to release, had higher early survival rates than those not kept in holding pens, but overall survival rates tended to be lower than wild resident woodrats. Three studies in South Africa, USA and Argentina found that released captive-bred (and some translocated) African wild dogs, riparian brush rabbits and guanacos that spent longer in, and in one case in larger, holding pens had a higher survival rate. Three studies (one controlled) in Australia and the USA found that captive-bred animals kept in holding pens prior to release had similar (bridled nailtail wallabies) or lower (black-footed ferret kits) annual survival rate after release to that of wild-born translocated animals and lower (black-footed ferrets) survival rates than resident animals. Ten studies (including one controlled, before-and-after study) and one review in Saudi Arabia, the USA, Argentina, China, Israel, Australia and Germany found that following the use of holding pens prior to release of captive-bred animals (or in some cases captive-reared/rehabilitated, or with provision of supplementary food), four of four mammal populations, 19% of red wolves, Asiatic wild ass, Persian fallow deer, most Arabian sand gazelles, most swift foxes, eastern-barred bandicoots and European mink survived at least 1-10 years, over half of giant anteaters, hare-wallabies and Père David’s deer survived for at least 1.5-6 months. Three studies in Namibia, the USA and Australia found that that following the use of holding pens prior to release of captive-bred or reared animals (some provided with nest boxes and/or supplementary food), red-tailed phascogales, most Mexican wolves and African wild dogs survived less than 6-12 months. Condition (4 studies): A randomized, controlled study in Australia found that eastern barred bandicoots released after time in holding pens lost a similar proportion of body weight and recovered to a similar weight compared to bandicoots released directly. A controlled study in the UK found that common dormice lost weight after being put into holding pens whereas wild translocated dormice gained weight. A controlled, before-and-after study in Australia found that captive-bred rufous hare-wallabies placed in holding pens prior to release lost body condition in holding pens. A before-and-after study in Australia found that captive-bred brush-tailed rock-wallabies placed in a holding pen prior to release maintained good health. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A controlled study in Argentina found that after being kept in holding pens and provided with supplementary food, released captive-bred giant anteaters were less nocturnal in their activity patterns than released wild-born rehabilitated individuals. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2510https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2510Fri, 05 Jun 2020 09:17:56 +0100Collected Evidence: Collected Evidence: Use herbicide to maintain or restore disturbance: freshwater marshes One study evaluated the effects, on vegetation, of using herbicide to maintain or restore disturbance in freshwater marshes. The study was in the USA. VEGETATION COMMUNITY Community composition (1 study): One replicated, randomized, controlled, before-and-after study aiming to restore freshwater marshes in the USA found that applying herbicide to trees (along with other interventions) significantly affected the overall plant community composition over the following five years. VEGETATION ABUNDANCE Characteristic plant abundance (1 study): One replicated, randomized, controlled, before-and-after study aiming to restore freshwater marshes in the USA reported that of the 26 plant taxa that became more frequent after applying herbicide to trees (along with other interventions), 16 were obligate wetland taxa. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3058https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3058Fri, 02 Apr 2021 12:13:44 +0100Collected Evidence: Collected Evidence: Use herbicide to maintain or restore disturbance: brackish/salt marshesWe found no studies that evaluated the effects, on vegetation, of using herbicide to maintain or restore disturbance in brackish/salt 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%2F3059https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3059Fri, 02 Apr 2021 12:13:54 +0100Collected Evidence: Collected Evidence: Use herbicide to maintain or restore disturbance: freshwater swamps One study evaluated the effects, on vegetation, of using herbicide to maintain or restore disturbance in freshwater swamps. The study was in the USA. VEGETATION COMMUNITY VEGETATION ABUNDANCE Herb abundance (1 study): One replicated, randomized, controlled, before-and-after, site comparison study of freshwater swamps in the USA found that applying herbicide to woody vegetation (after cutting it) had no significant effect on herbaceous ground cover one year later: there were similar changes in treated and untreated swamps. VEGETATION STRUCTURE Basal area (1 study): One replicated, randomized, controlled, before-and-after, site comparison study of freshwater swamps in the USA found that applying herbicide to woody vegetation (after cutting it) had no significant effect on the basal area of woody vegetation one year later: there were similar changes in treated and untreated swamps. Canopy cover (1 study): The same study found that applying herbicide to woody vegetation (after cutting it) reduced canopy cover – to similar levels as in high-quality swamps after one year. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3060https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3060Fri, 02 Apr 2021 12:14:06 +0100Collected Evidence: Collected Evidence: Use herbicide to maintain or restore disturbance: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of using herbicide to maintain or restore disturbance 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%2Fwww.conservationevidence.com%2Factions%2F3061https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3061Fri, 02 Apr 2021 12:14:18 +0100Collected Evidence: Collected Evidence: Use herbicide to control problematic plants: freshwater marshes Seventeen studies evaluated the effects, on vegetation, of using herbicide to control problematic plants in freshwater marshes. Twelve studies were in the USA. Two studies were in Australia. There was one study in each of Canada, Mexico and the UK. There was overlap in the sites used in two studies. Two pairs of studies in Australia and the USA used the same general study area, but different plots or experimental set-ups. VEGETATION COMMUNITY Overall extent (3 studies): Two replicated, randomized, controlled, before-and-after studies in the USA found that marshes sprayed with herbicide had lower live vegetation coverage but greater dead vegetation coverage than unsprayed marshes, after 1–2 years. Overall vegetation coverage was lower in sprayed than unsprayed marshes in one study, but similar in sprayed and unsprayed marshes in the other. One study of a dune slack in the UK simply reported an increase in overall vegetation coverage between one and two years after clearing scrub (by cutting and applying herbicide). Overall richness/diversity (6 studies): Three studies (including one replicated, randomized, paired, controlled) in ephemeral marshes/wet meadows in the USA reported that spraying invaded vegetation with herbicide (sometimes along with other interventions) typically increased total plant species richness 1–5 growing seasons later. Two replicated, randomized, paired, controlled studies (one also before-and-after) in freshwater marshes/wet meadows in the USA and Mexico found that plots treated with herbicide (sometimes along with other interventions) had similar overall plant species richness and diversity to untreated plots, after 4–8 months or three years. One study of a dune slack in the UK simply reported a small increase in total plant richness between one and two years after clearing scrub (by cutting and applying herbicide). Characteristic plant richness/diversity (3 studies): Two before-and-after studies of floodplain marshes in the USA reported that cover of wet-prairie indicator species was higher 1–4 years after applying herbicide than before. However, one of these studies reported that the total cover of non-invasive, wetland-characteristic herbs was similar or lower 2–3 years after applying herbicide than before. One study of a dune slack in the UK simply reported an increase the number of slack-characteristic plant species present between one and two years after clearing scrub (by cutting and applying herbicide). Native/non-target richness/diversity (3 studies): One controlled, before-and-after study in a reed-dominated freshwater marsh in the USA found that applying herbicide (along with cutting/mowing) increased non-reed species richness three years later. One replicated, controlled, before-and-after study in cattail-invaded marshes in the USA reported that marshes sprayed with herbicide contained no living native plants one year later: fewer than were present before spraying and in unsprayed marshes. One study of a dune slack in the UK simply reported an increase in native plant richness between one and two years after clearing scrub (by cutting and applying herbicide). VEGETATION ABUNDANCE Overall abundance (4 studies): Three replicated studies (two also randomized, paired, controlled) in freshwater marshes/wet meadows in the USA and Mexico found that applying herbicide (sometimes along with other interventions) had no clear or significant effect on overall vegetation abundance four months to three years later. Cover and density were similar to untreated plots and/or pre-treatment levels. One replicated, randomized, paired, controlled study in the USA found that wet meadows sprayed with herbicide contained less total vegetation biomass than unsprayed marshes, 2–3 growing seasons later. Native/non-target abundance (7 studies): Four studies (including one replicated, randomized, paired, controlled, before-and-after) in marshes/wet meadows in the USA and Australia found that spraying invaded plots with herbicide (sometimes along with other interventions) did not reduce – and often increased – the abundance of native or non-target vegetation 1–3 growing seasons later. One replicated, controlled, before-and-after study in cattail-invaded marshes in the USA reported that marshes sprayed with herbicide contained no living native plants one year later: density and biomass were lower than before spraying and in unsprayed marshes. One replicated, randomized, paired, controlled study in an alligatorweed-invaded marsh in the USA found that spraying vegetation with herbicide had no significant effect on native plant biomass after 1–2 growing seasons. One study of a floodplain marsh in Australia simply reported non-target vegetation cover for up to four years after treating mimosa-invaded vegetation with herbicide (along with other interventions). Herb abundance (4 studies): Two replicated, randomized, paired, controlled studies in wet meadows in the USA found that treating a problematic plant species with herbicide (sometimes along with physical removal) had no significant effect on cover of forbs, grass-like plants or sedges after 2–3 growing seasons. One replicated, randomized, paired, controlled study in a loosestrife-invaded marsh in Canada found that the density of sedges and grasses was not lower in herbicide-sprayed plots, than in unsprayed plots, after 2–3 years. The precise effect depended on dose of herbicide used. One study of a floodplain marsh in Australia simply reported grass/sedge cover for up to four years after treating mimosa-invaded vegetation with herbicide (along with other interventions). Algae/phytoplankton abundance (1 study): One replicated, randomized, controlled study in a reed-invaded marsh in the USA reported that free-growing filamentous algae were more common in plots sprayed with herbicide than unsprayed plots, approximately one year later. However, spraying with herbicide had no significant effect on the density or biomass of biofilm algae. Individual species abundance (3 studies): Three studies quantified the effect of this action on the abundance of individual plant species, other than the species being controlled. For example, one replicated, randomized, paired, controlled study in a grass-invaded marsh in Mexico found that five of five monitored native species had similar cover in herbicide-sprayed and unsprayed plots after 4–8 months. Two of the studies do not distinguish between the effects of applying herbicide and other interventions. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3120https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3120Sun, 04 Apr 2021 17:19:04 +0100Collected Evidence: Collected Evidence: Use herbicide to control problematic plants: brackish/salt marshes Seven studies evaluated the effects, on vegetation, of using herbicide to control problematic plants in brackish/salt marshes. Six studies were in the USA. One study was in South Africa. Two studies shared part of the same experimental set-up. VEGETATION COMMUNITY Relative abundance (1 study): One site comparison study of brackish marshes in the USA found that a marsh sprayed with herbicide for nine years (and burned for three) and a nearby natural marsh supported a similar relative abundance of the dominant plant species, smooth cordgrass Spartina alterniflora. Overall richness/diversity (1 study): One site comparison study of brackish marshes in the USA reported that a marsh sprayed with herbicide for nine years (and burned for three) contained more plant species than an unburned and unsprayed marsh – but also more plant species than a nearby natural marsh. Native/non-target richness/diversity (2 studies): One replicated, randomized, paired, controlled, before-and-after study in a pepperweed-invaded marsh in the USA found that applying herbicide did not increase the richness of non-pepperweed species over two years after intervention. The precise effect depended on the herbicide used. One study of an intertidal area in the USA simply counted the number of native salt marsh plant species that colonized after treating smooth cordgrass Spartina alterniflora stands with herbicide. VEGETATION ABUNDANCE Native/non-target abundance (5 studies): Three replicated, randomized, paired, controlled, before-and-after studies in pepperweed-invaded marshes in the USA found that applying herbicide typically did not increase cover of non-pepperweed vegetation, in the two years following intervention. The precise effect depended on the herbicide used. Two studies on the coasts of South Africa and the USA simply quantified the abundance of native salt marsh vegetation that colonized after treating smooth cordgrass Spartina alterniflora stands with herbicide. Individual species abundance (4 studies): Four studies quantified the effect of this action on the abundance of individual plant species, other than the species being controlled. For example, one site comparison study of brackish marshes in the USA reported that a marsh sprayed with herbicide for nine years (and burned for three) contained more smooth cordgrass Spartina alterniflora than an unburned and unsprayed marsh, and a similar amount of smooth cordgrass to a nearby natural marsh. One replicated, paired, controlled, before-and-after study in a pepperweed-invaded marsh in the USA reported that applying herbicide typically reduced cover of dominant native species over two years. The precise effect depended on the herbicide used. VEGETATION STRUCTURE Height (1 study): One site comparison study of brackish marshes in the USA found that in a marsh sprayed with herbicide for nine years (and burned for three), the dominant plant species (smooth cordgrass Spartina alterniflora) grew to a similar height as in a nearby natural marsh. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3121https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3121Sun, 04 Apr 2021 17:19:16 +0100Collected Evidence: Collected Evidence: Use herbicide to control problematic plants: freshwater swamps Four studies evaluated the effects, on vegetation, of using herbicide to control problematic plants in freshwater swamps. All four studies were in the USA. VEGETATION COMMUNITY Overall richness/diversity (2 studies): One replicated, randomized, paired, controlled study aiming to restore canarygrass-invaded swamps in the USA found that plots sprayed with herbicide typically had greater plant species richness and diversity than unsprayed plots, after 1–2 growing seasons. One replicated, randomized, controlled study in a petunia-invaded floodplain swamp in the USA found that plots sprayed with herbicide had similar overall plant species richness to unsprayed plots over 15 months after spraying. Native/non-target richness/diversity (3 studies): Three replicated, controlled studies (also paired and/or randomized) in invaded freshwater swamps in the USA found that applying herbicide typically had no significant effect on native plant species richness, over 3–24 months after spraying. VEGETATION ABUNDANCE Tree/shrub abundance (2 studies): Two replicated, controlled studies in the USA evaluated the effects, on tree/shrub abundance, of managing canarygrass-invaded vegetation by applying herbicide. One study found that plots sprayed with herbicide contained more non-planted tree seedlings than unsprayed plots, after 1–2 growing seasons. The other study found that managed plots (cut, disked and sprayed with herbicide) contained more non-planted tree seedlings than unmanaged plots, after 1–3 years. Native/non-target abundance (2 studies): Two replicated, controlled studies in swamps in the USA reported that spraying invaded vegetation with herbicide (sometimes along with other interventions) typically had no clear or significant effect on native/non-target vegetation cover 1–3 years later. Cover was typically similar to unmanaged plots or before intervention. Individual species abundance (1 study): One replicated, randomized, paired, controlled study aiming to restore a canarygrass-invaded swamp in the USA reported that spraying the vegetation with herbicide affected the abundance of some individual plant species – other than the target problematic species – two growing seasons later. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3122https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3122Sun, 04 Apr 2021 17:19:27 +0100Collected Evidence: Collected Evidence: Use herbicide to control problematic plants: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of using herbicide 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%2Fwww.conservationevidence.com%2Factions%2F3123https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3123Sun, 04 Apr 2021 17:19:48 +0100