Collected Evidence: Collected Evidence: Plant parks and gardens with appropriate flowersTwo replicated trials in the USA and Canada have found more wild bees (either more species or more individuals) in gardens planted with bee forage or native plants, relative to conventionally managed gardens. Another USA trial found more bee species after the addition of bee forage plants to a community garden. Three trials in the UK or USA have shown that native flowering plants or bee forage plants are well used by wild bees when planted in gardens. A UK trial demonstrated that some popular non-native or horticulturally modified garden flowers are not frequently visited by insects, despite providing nectar in some cases.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1Tue, 18 May 2010 15:19:40 +0100Collected Evidence: Collected Evidence: Plant wild bird seed or cover mixture All seven studies (based on five replicated experiments and a review) that investigated species richness or diversity were from the UK and found that fields or farms with wild bird cover had higher bird diversity than those without, or that more species were found in wild bird cover than in surrounding habitats. Thirty-two studies out of 33 from the UK and North America that examined abundance and population data, found that bird densities, abundances, nesting densities or use of wild bird cover was higher than in other habitats or management regimes, or that sites with wild bird cover had higher populations than those without. These studies included a systematic review and seven randomised, replicated and controlled studies. Some studies found that this was the case across all species or all species studied, while others found that only a subset showed a preference. Four studies investigated other interventions at the same time. Thirteen of the 33 studies (all replicated and from Europe and the USA), found that bird populations or densities were similar on wild bird cover and other habitats, that some species were not associated with wild bird cover or that birds rarely used wild bird cover. Three studies from the UK and Canada, two replicated, found higher productivities for some or all species monitored on wild bird cover, compared to other habitats. Two replicated and controlled studies from Canada and France found no differences in reproductive success between wild bird cover and other habitats for some or all species studied. Three studies from Europe and the USA investigated survival, with two finding higher survival of grey partridge Perdix perdix released on wild bird cover or of artificial nests in some cover crops. The third found that survival of grey partridge was lower on farms with wild bird cover, possibly due to high predation. Five studies from the UK, three replicated, found that some wild bird cover crops were preferred to others. A randomised, replicated and controlled study and a review from the UK found that the landscape surrounding wild bird cover and their configuration within it affected use by birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F187https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F187Sun, 10 Jun 2012 13:10:33 +0100Collected Evidence: Collected Evidence: Plant trees to act as windbreaks One of two before-and-after studies, from the UK, found that the local population of European nightjars increased following several interventions including the planting of windbreaks. A before-and-after study, from the USA, found that erecting a windbreak appeared to disrupt lekking behaviour in greater prairie chicken territories nearby.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F351https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F351Sun, 29 Jul 2012 15:42:39 +0100Collected Evidence: Collected Evidence: Plant wild bird seed or cover mixture Thirty individual studies investigated the effects on birds of sowing wild bird seed or cover mixture, 21 studies found positive effects. Fourteen studies from the UK (including one systematic review and nine replicated controlled trials of which four randomized, and three reviews) found that fields sown with wild bird cover mix had higher abundance, density, species diversity and species richness of birds than other farmland habitats. Six studies from the UK (including one review and two replicated studies) found that birds showed a preference for wild bird cover and used it significantly more than other habitats. One review found the grey partridge population increased substantially on farms where conservation measures including cover crops were in place. Nine replicated studies from France and the UK reported mixed or negative effects of wild bird cover on birds compared to other farmland habitats. Six studies found that mixtures including kale or a mixture of kale and/or other species attracted the largest number of bird species or highest bird abundance. Twelve studies from the UK looked at the effects of wild bird cover strips on invertebrates. Seven studies from the UK (including one review and four replicated controlled studies of which two were also randomized) found positive effects. Farmland habitats sown with wild bird cover mix were used more by butterflies, and had a higher abundance or species richness of butterflies and/or bees than other farmland habitats. One review found wild bird cover benefited invertebrates. Four studies (including one review and two replicated trials) reported mixed or negative effects of wild bird cover on invertebrate numbers compared with other farmland habitats. One study found that bees and butterflies showed preferences for particular plant species. Eight studies from the UK looked at plants and wild bird cover. Six studies (including two reviews and two replicated controlled trials) found that planting wild bird cover mix was one of the three best options for conservation of annual herbaceous plant communities, benefited plants and resulted in increased plant diversity and species richness. However two replicated studies (of which one a site comparison) found mixed/negative effects for plant species richness. One replicated trial from the UK found that small mammal activity was higher in wild bird cover than in the crop in winter but not in summer.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F594https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F594Fri, 12 Oct 2012 14:56:56 +0100Collected Evidence: Collected Evidence: Plant riparian buffer strips One replicated, controlled study in the USA found that planting buffer strips along streams did not increase amphibian abundance, numbers of species, or the ratio of adults to tadpoles.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F819https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F819Fri, 23 Aug 2013 09:57:29 +0100Collected Evidence: Collected Evidence: Plant trees after wildfire We found no evidence for the effects of planting trees after wildfire on forests. '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%2F1235https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1235Fri, 03 Jun 2016 08:29:53 +0100Collected Evidence: Collected Evidence: Plant spiny shrubs to act as barriers to people We found no studies that evaluated the effects of planting spiny shrubs to act as barriers to people 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%2F1621https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1621Sun, 22 Oct 2017 10:37:20 +0100Collected Evidence: Collected Evidence: Plant vegetation to act as a buffer to exclude pollution We found no studies that evaluated the effects of planting vegetation to act as a buffer to exclude pollution 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%2F1665https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1665Sun, 22 Oct 2017 15:11:46 +0100Collected Evidence: Collected Evidence: Plant turf Two randomized, controlled studies in the UK found that planting turf from intact heathland sites increased the abundance or cover of heathland species. One of these studies also found that planting turf increased the seedling abundance for a majority of heathland plant species. One randomized, controlled study in the UK found that planting turf increased forb cover, and reduced grass cover. One randomized, replicated, controlled study in Iceland found that planting large turves from intact heathland sites increased the number of plant species, but smaller turves did not. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1703https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1703Mon, 23 Oct 2017 11:28:15 +0100Collected Evidence: Collected Evidence: Plant seed balls A randomized, replicated, controlled study in the USA found that planting seed balls resulted in lower seedling numbers than sowing seed. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1712https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1712Mon, 23 Oct 2017 13:30:52 +0100Collected Evidence: Collected Evidence: Plant shrubs in clusters A randomized, controlled study in South Africa found that when shrubs were planted in clumps more of them died than when they were planted alone. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1715https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1715Mon, 23 Oct 2017 13:57:53 +0100Collected Evidence: Collected Evidence: Plant shelter belts to protect peatlands from wind We found no studies that evaluated the effects, on peatland vegetation, of planting shelter belts to protect peatlands from wind. ‘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%2F1793https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1793Tue, 28 Nov 2017 08:19:25 +0000Collected Evidence: Collected Evidence: Plant riparian buffer strips We found no studies that evaluated the effects of planting riparian buffer strips on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2016https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2016Wed, 05 Dec 2018 17:43:25 +0000Collected Evidence: Collected Evidence: Plant trees on farmland Four studies evaluated the effects on mammals of planting trees on farmland. Two studies were in the UK, one was in Italy and one was in Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): Two replicated studies (including one controlled, and one site comparison study), in the UK, found that farm woodland supported a higher small mammal abundance than on arable land or similar abundance compared to uncultivated field margins and set-aside. BEHAVIOUR (2 STUDIES) Use (2 studies): A study in Italy found that tree stands were used more by European hares compared to the wider farmed landscape. A replicated study in Australia found that trees planted on farmland were used by koalas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2386https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2386Wed, 27 May 2020 15:47:33 +0100Collected Evidence: Collected Evidence: Plant trees following clearfelling One study evaluated the effects on mammals of planting trees following clearfelling. This study was in Canada. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY) Use (1 study): A replicated, site comparison study in Canada found that forest stands subject to tree planting and herbicide treatment after logging were used more by American martens compared to naturally regenerating stands. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2631https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2631Fri, 12 Jun 2020 12:45:40 +0100Collected Evidence: Collected Evidence: Plant non-woody plants into moisture-retaining peat pots: freshwater wetlands One study evaluated the effects of using moisture-retaining peat pots when planting emergent, non-woody vegetation in freshwater wetlands. The study was in the USA. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, randomized, paired, controlled study in a wetland in the USA found that tussock sedge Carex stricta cover was similar across plots, after two growing seasons, whether sedges were planted into peat pots or into existing wetland soil. VEGETATION STRUCTURE Individual plant size (1 study): One replicated, randomized, paired, controlled study in a wetland in the USA found that the biomass of tussock sedge Carex stricta plants was similar, after two growing seasons, whether they were planted into peat pots or into existing wetland soil. OTHER Survival (1 study): One replicated, randomized, paired, controlled study in a wetland in the USA found that the survival rate of tussock sedge Carex stricta plants was similar, after two growing seasons, whether they were planted into peat pots or into existing wetland soil. Growth (1 study): The same study found that the growth rate of tussock sedge Carex stricta was typically similar, over two growing seasons, when planted into peat pots or into existing wetland soil. However, in a dry area and in a dry year, planting in peat pots did increase the growth rate. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3341https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3341Sun, 11 Apr 2021 16:45:47 +0100Collected Evidence: Collected Evidence: Plant non-woody plants into moisture-retaining peat pots: brackish/saline wetlandsWe found no studies that evaluated the effects of using moisture-retaining peat pots when planting emergent, non-woody vegetation in brackish/saline wetlands.   ‘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%2F3342https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3342Sun, 11 Apr 2021 16:46:08 +0100Collected Evidence: Collected Evidence: Plant trees/shrubs into moisture-retaining peat pots: freshwater wetlandsWe found no studies that evaluated the effects of using moisture-retaining peat pots when planting trees/shrubs in freshwater wetlands.   ‘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%2F3343https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3343Sun, 11 Apr 2021 16:46:17 +0100Collected Evidence: Collected Evidence: Plant trees/shrubs into moisture-retaining peat pots: brackish/saline wetlandsWe found no studies that evaluated the effects of using moisture-retaining peat pots when planting trees/shrubs in brackish/saline wetlands.   ‘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%2F3344https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3344Sun, 11 Apr 2021 16:46:35 +0100Collected Evidence: Collected Evidence: Plant vegetation into heavy containersWe found no studies that evaluated the effects of planting emergent wetland vegetation into heavy containers.   ‘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%2F3345https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3345Sun, 11 Apr 2021 16:55:25 +0100Collected Evidence: Collected Evidence: Plant trees on farmland Two studies evaluated the effects of planting trees on farmland to benefit reptiles. Both studies were in Australia. COMMUNITY RESPONSE (2 STUDIES) Richness/diversity (2 studies): One replicated, paired sites study in Australia found that pastures with tree plantings had similar rare reptile species richness compared to pastures with no trees, but that more rare species were present with 50% canopy cover compared to 5% cover. One replicated, site comparison study in Australia found that farms with restoration planting (of native ground cover and trees) had lower reptile species richness than farms with remnant vegetation (of old growth woodland or natural regrowth). POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, paired sites study in Australia found that pastures with tree plantings had higher abundance of rare reptiles than pastures with no trees, and that rare reptiles were more abundant with 50% canopy cover compared to 5% cover. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3527https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3527Tue, 07 Dec 2021 15:32:49 +0000Collected Evidence: Collected Evidence: Plant riparian buffer strips One study evaluated the effects of planting riparian buffer strips on reptile populations. The study was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY) Use (1 study): One replicated study in the USA found that grassed riparian buffer strips were used by up to five snake species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3586https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3586Wed, 08 Dec 2021 15:46:10 +0000Collected Evidence: Collected Evidence: Plant trees to reduce temperatures in cities We found no studies that evaluated the effects of planting trees to reduce temperatures in cities on butterflies and moths. ‘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%2F3838https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3838Mon, 04 Jul 2022 15:35:33 +0100Collected Evidence: Collected Evidence: Plant parks, gardens and road verges with appropriate native species Eight studies evaluated the effects on butterflies and moths of planting parks and gardens with appropriate native species. Seven were in the USA and one was in Germany. COMMUNITY RESPONSE (5 STUDIES) Richness/diversity (5 studies): Three of five replicated studies (including three paired, three controlled and two site comparison studies) in Germany and the USA found that gardens and road verges planted with native species had a greater species richness of butterfly and moth adults and caterpillars than gardens or verges with mixed or exclusively non-native plant species. The other two studies found that the species richness of adult butterflies was similar in areas planted with native or non-native flowers. POPULATION RESPONSE (6 STUDIES) Abundance (4 studies): Two of three replicated studies (including two paired and two controlled studies) in the USA found that gardens planted with native species had a higher abundance of butterfly and moth caterpillars than gardens with mixed or exclusively non-native plant species. The third study found that the abundance of adult butterflies was similar in areas planted with native or non-native flowers. One replicated, randomized, controlled study in the USA found that when taller native milkweed species were planted, they had a higher abundance of monarch butterfly eggs and caterpillars than shorter milkweed species. Survival (2 studies): One of two replicated, site comparison studies in the USA found that the survival of pipevine swallowtail eggs and caterpillars was lower on California pipevine planted in gardens than in natural sites. The other study found that the survival of monarch butterfly caterpillars was similar on common milkweed planted in gardens and meadows. Condition (1 study): One replicated, randomized, controlled study in the USA found that the growth of monarch butterfly caterpillars was similar on eight different native milkweed species. BEHAVIOUR (2 STUDIES) Use (2 studies): One of two replicated, site comparison studies in the USA found that monarch butterfly adults used common milkweed planted in gardens more than milkweed planted in meadows. The other study found that pipevine swallowtail adults used California pipevine planted in gardens less than in natural sites. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3842https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3842Tue, 05 Jul 2022 09:53:23 +0100Collected Evidence: Collected Evidence: Plant wild bird seed or cover mixture Seven studies evaluated the effects of planting wild bird seed or cover mixture on butterflies and moths. All seven were in the UK. COMMUNITY RESPONSE (4 STUDIES) Richness/diversity (4 studies): Two of three replicated, controlled studies (including two randomized and one paired study) in the UK found that plots sown with wild bird seed mixture had a greater species richness of butterflies than wheat crop or extensively or conventionally managed grassland. The other study found that land managed under an agri-environment scheme, including wild bird seed plots, had a similar species richness of butterflies to conventional farmland. One replicated, randomized, controlled study in the UK found that plots sown with lucerne had a greater species richness of butterflies than plots sown with borage, chicory, sainfoin and fodder radish. POPULATION RESPONSE (7 STUDIES) Abundance (7 studies): Two replicated, controlled studies (including one randomized study) in the UK­ found that plots sown with wild bird seed had a higher abundance of butterflies than wheat crop or extensively or conventionally managed grassland, but that caterpillar abundance was lower in wild bird seed plots than either grassland. Two replicated, site comparison studies in the UK found that the abundance of butterfly and moth caterpillars in wild bird seed plots was similar to a range of other cropped and non-cropped farm habitats. Two replicated, randomized, controlled studies (including one paired study) in the UK found that farms with wild bird seed plots (along with other agri-environment scheme options) had a higher abundance of some butterflies and micro-moths, a similar abundance of macro-moths, but a lower abundance of other butterflies, than farms without agri-environment scheme management. One replicated, randomized, controlled study in the UK found that plots sown with lucerne and red clover had a higher abundance of butterflies than plots sown with borage, chicory and sainfoin. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3930https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3930Thu, 11 Aug 2022 19:22:03 +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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