Collected Evidence: Collected Evidence: Deepen, de-silt or re-profile ponds Two before-and-after studies in France and Denmark found that pond deepening and enlarging or re-profiling resulted in the establishment of a breeding population of great crested newts or translocated garlic toads. Two studies (including one replicated, controlled study) in the UK and Denmark found that pond deepening and enlarging or dredging increased a population of common frogs or numbers of calling male tree frogs. Four before-and-after studies in Denmark and the UK found that pond deepening, along with other interventions, maintained newt populations and increased populations of European fire-bellied toads or natterjack toads.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F817https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F817Fri, 23 Aug 2013 09:03:23 +0100Collected Evidence: Collected Evidence: Control invasive plants One before-and-after study in the UK found that aquatic and terrestrial habitat management that included controlling swamp stonecrop, along with release of captive-reared toadlets, tripled a population of natterjack toads. One replicated, controlled study in the USA found that Oregon spotted frogs laid eggs in areas where invasive reed canarygrass had been mown more frequently than where it was not mown.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F823https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F823Fri, 23 Aug 2013 11:04:26 +0100Collected Evidence: Collected Evidence: Create ponds for natterjack toads Five before-and-after studies (including three replicated and one controlled study) in the UK and Denmark found that pond creation, along with other interventions, significantly increased natterjack toad populations, or in two cases maintained or increased populations at 75% of sites. One replicated, site comparison study in the UK found that compared to natural ponds, created ponds had lower natterjack toad tadpole mortality from desiccation, but higher mortality from predation by invertebrates.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F866https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F866Tue, 10 Sep 2013 15:47:29 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use hot water to control plants We found no evidence on the use of hot water to control Crassula helmsii. '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%2F1275https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1275Thu, 30 Jun 2016 08:21:56 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Biological control using fungal-based herbicides We found no evidence for the effects of biological control using specific, non-selective or native herbivores on Crassula helmsii. '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%2F1276https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1276Thu, 30 Jun 2016 13:52:42 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Biological control using herbivores We found no evidence for the effects of biological control using specific, non-selective or native herbivores on Crassula helmsii. '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%2F1277https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1277Tue, 05 Jul 2016 16:21:33 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Physical control using manual/mechanical control or dredging We found no evidence for the effects of physical control, using manual or mechanical control or dredging, on Crassula helmsii. '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%2F1278https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1278Tue, 05 Jul 2016 16:27:37 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Chemical control using herbicides Seven studies (including one replicated and controlled study) in the UK, found that applying glyphosate reduced Crassula helmsii. In one before-and-after study at a single site glyphosate applied in combination with diquat reduced C. helmsii by 98%. Another before-and-after study at a single site found that covering C. helmsii with carpet before treating with glyphosate resulted in an 80% reduction in the plant. Three out of four studies (including one controlled study) in the UK found that applying diquat or diquat alginate reduced cover or eradicated submerged C. helmsii. One before-and-after study at a single site found that applying both diquat and glyphosate reduced C. helmsii by 98%. One small, before-and-after trial found no effect of diquat or diquat alginate on cover of C. helmsii. One out of two studies (including one replicated, controlled study) in the UK, found that treating submerged C. helmsii with dichlobenil in container trials led to partial reduction in its biomass. One small before-and-after field study found no effect of dichlobenil on C. helmsii. One replicated, controlled container trial in the UK found that treatment with terbutryne partially reduced biomass of submerged C. helmsii. The same study found reductions in emergent C. helmsii following treatment with asulam, 2,4-D amine and dalapon. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1279https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1279Tue, 05 Jul 2016 16:29:26 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use hydrogen peroxide to control plants One controlled study in the UK using tank trials found that hydrogen peroxide did not control Crassula helmsii.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1281https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1281Tue, 12 Jul 2016 08:42:23 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use liquid nitrogen to kill plants We found no evidence for the effects of treating Crassula helmsii with liquid nitrogen. '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%2F1282https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1282Tue, 12 Jul 2016 08:51:36 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use hot foam to control plants One replicated, controlled study in the UK found that treatment with hot foam, along with other treatments, did not reduce cover of Crassula helmsii. One before-and-after study in the UK found that applying hot foam partially destroyed C. helmsii.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1286https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1286Tue, 12 Jul 2016 08:56:05 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use salt water to kill plants Two replicated, controlled container trials and two before-and-after field trials in the UK found that seawater eradicated Crassula helmsii.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1288https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1288Tue, 12 Jul 2016 09:14:42 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use flame-throwers to control plants We found no evidence on the use of flame-throwers to control Crassula helmsii. '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%2F1291https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1291Tue, 12 Jul 2016 09:26:14 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use dyes to reduce light levels One replicated, controlled study in the UK found that applying aquatic dye, along with other treatments, did not reduce coverage of Crassula helmsii. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1293https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1293Tue, 12 Jul 2016 09:32:38 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use lightproof barriers to control plants Five before-and-after studies in the UK found that covering Crassula helmsii with black sheeting or carpet strips eradicated or severely reduced the cover of the plant. However, C. helmsii was reported to have progressively recolonized two of the sites where it had been had initially been reported as eradicated.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1294https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1294Tue, 12 Jul 2016 09:39:41 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Alter environmental conditions to control plants No evidence was captured on altering environmental conditions to control Crassula helmsii by using shading, increasing turbidity, re-shaping or re-profiling banks of waterbodies or dredging. '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%2F1296https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1296Tue, 12 Jul 2016 10:38:54 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Plant other species to suppress growth We found no evidence for the effects of using other plant species to control growth of Crassula helmsii. '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%2F1299https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1299Tue, 12 Jul 2016 10:42:46 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use grazing to control plants One of two replicated, controlled studies in the UK found that excluding grazing reduced the abundance and coverage of Crassula helmsii. The other study found no difference in cover of C. helmsii between ungrazed and grazed plots. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1301https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1301Tue, 12 Jul 2016 10:48:03 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Dry out waterbodies to control plants We found no evidence for the effects of draining waterbodies on Crassula helmsii. '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%2F1303https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1303Tue, 12 Jul 2016 10:51:10 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Bury plants We found no evidence on the use of burying with soil alone to control Crassula helmsii. '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%2F1305https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1305Tue, 12 Jul 2016 10:53:24 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Surround with wire mesh We found no evidence that surrounding Crassula helmsii with wire mesh reduced its rate of spread. '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%2F1307https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1307Tue, 12 Jul 2016 10:54:59 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Decontamination to prevent further spread One controlled, replicated container study in the UK found that submerging Crassula helmsii in hot water led to higher mortality than drying out plant fragments or a control.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1308https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1308Tue, 12 Jul 2016 10:57:56 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Public education No evidence was captured on the impact of education programmes on control of Crassula helmsii. '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%2F1311https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1311Tue, 12 Jul 2016 11:01:15 +0100Collected Evidence: Collected Evidence: Crassula helmsii: Use a combination of control measures One before-and-after study at a single pond in the UK found covering Crassula helmsii with carpet, followed by treatment with the herbicide glyphosate, killed 80% of the plant. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1313https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1313Tue, 12 Jul 2016 11:04:35 +0100Collected Evidence: Collected Evidence: Parrot’s feather: Reduction of trade through legislation and codes of conduct One randomized, before-and-after trial in the Netherlands reported that the implementation of a code of conduct reduced the trade of aquatic plants banned from sale (group that included parrot’s feather Myriophyllum aquaticum). One study in the USA found that parrot’s feather plants were still traded despite a state-wise trade ban. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1604https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1604Fri, 20 Oct 2017 15:14:50 +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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