Collected Evidence: Collected Evidence: Create uncultivated margins around intensive arable or pasture fields Thirty-nine studies (including 13 replicated controlled trials of which three also randomized and four reviews) from eight European countries compared wildlife on uncultivated margins with other margin options. Twenty-four found benefits to some wildlife groups (including 11 replicated controlled trials of which one also randomised, and four reviews). Nineteen studies (including one randomized, replicated, controlled trial) from Germany, Ireland, Lithuania, Norway, the Netherlands and the UK found uncultivated margins support more invertebrates (including bees) and/or higher plant diversity or species richness than conventionally managed field margins or other field margin options. One replicated, controlled study showed that uncultivated margins supported more small mammal species than meadows and farmed grasslands. Four studies (two replicated UK studies, two reviews) reported positive associations between birds and field margins including food provision. A review from the UK found grass margins (including naturally regenerated margins) benefited plants and some invertebrates. Fifteen studies (including one randomized, replicated, controlled trial) from Germany, the Netherlands, Norway and the UK found that invertebrate and/or plant species richness or abundance were lower in naturally regenerated than conventionally managed fields or sown margins. Six studies (including one randomized, replicated, controlled trial) from Belgium, Germany and the UK found uncultivated margins did not have more plant or invertebrate species or individuals than cropped or sown margins. A review found grass margins (including naturally regenerated margins) did not benefit ground beetles. Five studies (including three replicated controlled trials) from Ireland and the UK reported declines in plant species richness and invertebrate numbers in naturally regenerated margins over time. One replicated trial found that older naturally regenerated margins (6-years old) had more invertebrate predators (mainly spiders) than newly established (1-year old) naturally regenerated margins. Five studies (including one replicated, randomized trial) from the Netherlands and the UK found that cutting margins had a negative impact on invertebrates or no impact on plant species. One replicated controlled study found cut margins were used more frequently by yellowhammers when surrounding vegetation was >60 cm tall. Seven studies (including four replicated controlled trials and a review) from Ireland, the Netherlands, Norway and the UK reported increased abundance or biomass of weed species in naturally regenerated margins. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F63https%3A%2F%2Fconservationevidence.com%2Factions%2F63Tue, 04 Oct 2011 14:51:45 +0100Collected Evidence: Collected Evidence: Apply 'cross compliance' environmental standards linked to all subsidy payments We have captured no evidence for the effects of applying 'cross compliance' environmental standards for all subsidy payments on farmland wildlife. '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%2Fconservationevidence.com%2Factions%2F70https%3A%2F%2Fconservationevidence.com%2Factions%2F70Mon, 24 Oct 2011 20:59:15 +0100Collected Evidence: Collected Evidence: Create corn bunting plots We have captured no evidence for the effects of creating corn bunting plots on farmland wildlife. '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%2Fconservationevidence.com%2Factions%2F88https%3A%2F%2Fconservationevidence.com%2Factions%2F88Mon, 24 Oct 2011 21:29:24 +0100Collected Evidence: Collected Evidence: Buffer in-field ponds We have captured no evidence for the effects of buffering in-field ponds on farmland wildlife. '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%2Fconservationevidence.com%2Factions%2F97https%3A%2F%2Fconservationevidence.com%2Factions%2F97Mon, 24 Oct 2011 21:48:25 +0100Collected Evidence: Collected Evidence: Avoid use of lead shot We have captured no evidence for the effects of avoiding the use of lead shot on farmland wildlife. '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%2Fconservationevidence.com%2Factions%2F100https%3A%2F%2Fconservationevidence.com%2Factions%2F100Mon, 24 Oct 2011 21:52:38 +0100Collected Evidence: Collected Evidence: Enforce legislation to protect birds against persecution Two before-and-after studies have evaluated effects of legislative protection on bird species in Europe. Both found that legislation protects bird populations. One found increased population levels of raptors in Scotland, following protective legislation. One found increased survival of kestrels in Denmark stricter protection, but not necessarily population-level responses. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F101https%3A%2F%2Fconservationevidence.com%2Factions%2F101Mon, 24 Oct 2011 21:55:47 +0100Collected Evidence: Collected Evidence: Control invasive non-native plants on farmland (such as Himalayan Balsam, Japanese knotweed) Two randomized, replicated, controlled trials in the Czech Republic found that removing all flower heads of giant hogweed plants at peak flowering time dramatically reduced seed production in giant hogweed.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F104https%3A%2F%2Fconservationevidence.com%2Factions%2F104Mon, 24 Oct 2011 21:59:27 +0100Collected Evidence: Collected Evidence: Control bracken One systematic review found that the herbicide asulam reduced bracken abundance if applied repeatedly, but cutting may be equally effective. A replicated laboratory trial in the UK found that the herbicide asulam inhibited the growth of three common moss species that commonly grow in association with bracken, when exposed over three weeks, but not if only exposed for 24 hours.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F105https%3A%2F%2Fconservationevidence.com%2Factions%2F105Mon, 24 Oct 2011 22:00:36 +0100Collected Evidence: Collected Evidence: Control grey squirrels We have captured no evidence for the effects of controlling grey squirrels on farmland wildlife. '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%2Fconservationevidence.com%2Factions%2F106https%3A%2F%2Fconservationevidence.com%2Factions%2F106Mon, 24 Oct 2011 22:01:22 +0100Collected Evidence: Collected Evidence: Control mink A systematic review found seven studies demonstrating that trapping appears to be an effective method of reducing American mink populations, but firm conclusions could not be made due to limitations in experimental design. A large-scale trapping programme in the UK demonstrated that American mink have been successfully eradicated over a large area and this may have been associated with some localized water vole expansions. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F107https%3A%2F%2Fconservationevidence.com%2Factions%2F107Mon, 24 Oct 2011 22:02:53 +0100Collected Evidence: Collected Evidence: Erect predator-proof fencing around important breeding sites for waders We have captured no evidence for the effects of erecting predator-proof fencing around important breeding sites for waders on farmland wildlife. '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%2Fconservationevidence.com%2Factions%2F109https%3A%2F%2Fconservationevidence.com%2Factions%2F109Mon, 24 Oct 2011 22:06:13 +0100Collected Evidence: Collected Evidence: Control weeds without damaging other plants in conservation areas Two studies looked at the effects of controlling weeds on the surrounding vegetation. One study from the UK found that new populations of rare arable plants established following the control of perennial weeds in a nature conservation area. A replicated, controlled and randomized study in the UK found that using grass-specific herbicide reduced grass diversity and resulted in increases in broadleaved plants. Eleven studies investigated different methods of controlling plants. A review found that specific management regimes can reduce the abundance of pernicious weeds in nature conservation areas. Four replicated controlled studies (one also randomized) from Denmark and Germany found cutting and infection with fungal pathogens were effective methods for controlling creeping thistle and one replicated, randomized, controlled trial from the UK found long-term control was achieved by lenient grazing. A replicated, controlled and randomized study in Germany found weevils could be used to infect creeping thistle with systemic rust. One study found a non-native beetle was unsuitable for controlling creeping thistle because it had poor survival in the UK climate. A replicated controlled study found that spraying a high concentration of herbicide killed less than half of broad-leaved dock plants. A replicated, controlled, randomized study found black grass was eliminated with a December treatment of grass-specific herbicide. A small replicated study found that Hebridean sheep grazed more purple moor grass than Swaledale sheep. Two replicated controlled laboratory and grassland studies found negative impacts of the herbicide asulam on green dock beetles.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F123https%3A%2F%2Fconservationevidence.com%2Factions%2F123Tue, 01 Nov 2011 21:27:23 +0000Collected Evidence: Collected Evidence: Control scrub A replicated study from the UK found a negative relationship between the number of young grey partridge per adult and a combined intervention of scrub control, rough grazing and the restoration of various semi-natural habitats.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F127https%3A%2F%2Fconservationevidence.com%2Factions%2F127Mon, 14 Nov 2011 21:51:12 +0000Collected Evidence: Collected Evidence: Add yellow rattle seed Rhinanthus minor to hay meadows A review of studies from the UK found that adding hay rattle seed helped other sown target meadow species to colonize and that more plant species were found when yellow rattle was present. A randomized, replicated controlled trial in the UK found that yellow rattle could be established on a pasture field by ‘slot seeding’.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F129https%3A%2F%2Fconservationevidence.com%2Factions%2F129Mon, 14 Nov 2011 21:56:48 +0000Collected Evidence: Collected Evidence: Delay mowing or first grazing date on pasture or grassland Eight studies from the Netherlands, Sweden and the UK (three replicated and controlled of which one also randomized and one European systematic review) found that delaying mowing or grazing dates resulted in benefits to some or all plants, invertebrates or birds studied. These benefits included: higher plant species richness, higher densities of two rare arable weeds, more insect species and individuals visiting flowers, greater abundance of some spiders and ground beetles, increased breeding wading bird densities, and increased Eurasian skylark productivity. Three reviews found the UK corncrake population increased after measures including delaying mowing dates were introduced. Six studies from Finland, the Netherlands, Sweden, Switzerland and the UK (including three replicated controlled trials of which one was also randomized and a European systematic review) found that delaying mowing or grazing dates on grassland had no clear effect on plant species richness, ground beetle communities, abundance of some insects and spiders, or population trends of wading bird species. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F131https%3A%2F%2Fconservationevidence.com%2Factions%2F131Mon, 14 Nov 2011 22:17:17 +0000Collected Evidence: Collected Evidence: Exclude livestock from semi-natural habitat (including woodland) Seven studies (including four replicated controlled trials of which one also randomized, and a review) from Ireland, Poland and the UK looked at the effects of excluding livestock from semi-natural habitats. Three studies (including one replicated controlled and randomized study) from Ireland and the UK found that excluding livestock benefited plants and invertebrates. Three studies (one replicated controlled and one replicated paired sites comparison) from Ireland and the UK found that excluding grazing did not benefit plants or birds. Two studies (one replicated and controlled, one review) from Poland and the UK found that the impact of excluding grazing as a tool in habitat restoration was neutral or mixed.    Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F150https%3A%2F%2Fconservationevidence.com%2Factions%2F150Sat, 14 Jan 2012 15:15:55 +0000Collected Evidence: Collected Evidence: Create scrapes and pools Three studies from Sweden and the UK (including two site comparisons one of which was replicated) found that the creation of scrapes and pools provided habitat for a range of plant, invertebrate or bird species and resulted in increased aquatic macroinvertebrate diversity. One of these studies found constructed pools supported locally or nationally scarce species of plant and water beetle. A study in Sweden found that a combination of large surface area, high shoreline complexity and shallow depth resulted in increased bird, bottom-dwelling invertebrate and aquatic plant diversity. However there were fewer fish species than in natural wetlands. Two replicated studies from Ireland and the UK (one controlled paired study and a site comparison) found that bird visit rates were higher but invertebrate numbers varied in ditch-fed paired ponds compared with dry controls and total macroinvertebrate and beetle richness did not differ between artificial and natural ponds, although communities did differ.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F153https%3A%2F%2Fconservationevidence.com%2Factions%2F153Sat, 14 Jan 2012 15:30:46 +0000Collected Evidence: Collected Evidence: Create skylark plots All four studies from the UK and Switzerland (two replicated and controlled, and one review) investigating the effect of skylark plots on Eurasian skylarks, found a positive effect, reporting increases in skylark population size, breeding density, duration or success or a lower likelihood of skylarks abandoning their territory relative to fields without plots. A replicated study from Denmark found that skylarks used undrilled patches within cereal fields more than expected by an even distribution across the landscape. Four studies reported the effect of undrilled patches on wildlife other than skylarks. Three studies from the UK (including two replicated studies, of which one also controlled and a review) found benefits to plants and invertebrates. Whilst two studies (both replicated, one also controlled) from the UK found no significant differences in the number of some invertebrates or seed-eating songbirds between skylark plots and conventional crop fields. One replicated study from the UK investigated different skylark plot establishment techniques. Plots that were undrilled had greater vegetation cover and height than plots established by spraying out with herbicide. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F540https%3A%2F%2Fconservationevidence.com%2Factions%2F540Tue, 11 Sep 2012 16:08:32 +0100Collected Evidence: Collected Evidence: Convert or revert arable land to permanent grassland All seven individual studies (including four replicated studies, of which two also controlled and a review) looking at the effects of reverting arable land to grassland found no clear benefit to wildlife. The studies monitored UK birds in winter and summer, wading birds in Denmark, grey partridges, brown hares in the UK, and plants in the Czech Republic. One of the studies, a controlled before-and-after study from the UK, showed that grey partridge numbers fell significantly following the reversion of arable fields to grassland.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F561https%3A%2F%2Fconservationevidence.com%2Factions%2F561Tue, 25 Sep 2012 12:33:31 +0100Collected Evidence: Collected Evidence: Create open patches or strips in permanent grassland Two studies (both randomized, replicated and controlled) investigated the effects of creating open strips in permanent grassland. One trial from the UK found that more Eurasian skylarks used fields containing open strips, but variations in skylark numbers were too great to draw conclusions from this finding. One trial from Scotland found insect numbers in grassy headlands initially dropped when strips were cleared.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F563https%3A%2F%2Fconservationevidence.com%2Factions%2F563Tue, 25 Sep 2012 17:19:06 +0100Collected Evidence: Collected Evidence: Connect areas of natural or semi-natural habitat All four studies (including one site comparison and two replicated trials) from the Czech Republic, Germany and the Netherlands investigating the effects of habitat corridors or restoring areas of natural or semi-natural habitat between existing patches found some degree of colonization of these areas by invertebrates or mammals. However for invertebrates one unreplicated site comparison reported that the colonization process was slow (Gruttke 1994), and three studies found that the extent of colonization varied between invertebrate taxa. One small, replicated study from the Czech Republic investigated colonization of two bio-corridors by small mammal species. It found more small mammal species in the bio-corridors than in an adjacent forest or arable fields. All three studies from Germany and the Netherlands looking at the effects on invertebrates found mixed results. One replicated study found more species of some wasps (cavity-nesting wasps and caterpillar-hunting wasps) in grass strips connected to forest edges than in isolated strips. An unreplicated study found that the abundance of three ground beetle species substantially increased in an arable field undergoing restoration to heathland but that typical heathland species failed to colonize over the 12 year period. One study found that two out of 85 ground beetle species used a meadow and hedge-island strip extending from semi-natural habitats into arable farmland. In the same study the habitat strip did not function well for ground beetles and harvestmen but was colonized by snails and spiders. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F579https%3A%2F%2Fconservationevidence.com%2Factions%2F579Thu, 04 Oct 2012 11:08:34 +0100Collected Evidence: Collected Evidence: Create rotational grass or clover leys A controlled study in Finland found that creating clover leys resulted in higher spider abundance and fewer pest insects than a barley control plot. A study in the UK found that one-year ley plots had significantly lower earthworm species richness and abundance than three-and-a-half-year leys. A replicated study in the UK found that grass leys had fewer plant species than nine other conservation measures.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F643https%3A%2F%2Fconservationevidence.com%2Factions%2F643Tue, 16 Oct 2012 15:45:06 +0100Collected Evidence: Collected Evidence: Create beetle banks Fourteen reports from eight studies out of a total 24 reports from 12 individual studies (including eight replicated studies of which three controlled and four literature reviews) from Denmark and the UK found that beetle banks provide some benefits to farmland biodiversity. Sixteen reports from eight individual studies looked at invertebrates and beetle banks. Five reports from two replicated studies (of which one controlled) and a review found positive effects on invertebrate densities/numbers, distribution, or higher ground beetle density and species diversity in spring and summer but not winter. Six reports from three replicated studies (of which one randomized and controlled) found that invertebrate numbers varied between specific grass species sown on beetle banks. Two replicated studies (one paired and controlled) found that the effect of beetle banks varied between invertebrate groups or families. Five replicated studies (of which two controlled) found lower or no difference in invertebrate densities or numbers on beetle banks relative to other habitats. One review found lesser marsh grasshopper did not forage on two plant species commonly sown in beetle banks. Six studies looked at birds and beetle banks. Two reviews and one replicated controlled trial found positive effects on bird numbers (in combination with other farmland conservation measures) or evidence that birds used beetle banks. Two studies (one replicated site comparison) found mixed effects on birds. One replicated study found no farmland bird species were associated with beetle banks. One replicated, paired, controlled study and a review looked at the effects of beetle banks on plants and found either lower plant species richness on beetle banks in summer, or that grass margins including beetle banks were generally beneficial to plants but these effects were not pronounced on beetle banks. One controlled study and a review found beetle banks acted as nest sites for harvest mice. Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F651https%3A%2F%2Fconservationevidence.com%2Factions%2F651Tue, 23 Oct 2012 16:24:44 +0100Collected Evidence: Collected Evidence: Employ areas of semi-natural habitat for rough grazing (includes salt marsh, lowland heath, bog, fen) A series of site comparison studies from the UK found that areas of heathland that had been re-seeded with grass to improve livestock grazing were avoided by nesting whimbrels but were the main early spring feeding areas for them. There was no difference in whimbrel chick survival between areas of heathland re-seeded with grass and those that had not. Two replicated studies from the UK found higher butterfly abundance and species richness and a higher frequency of occurrence of songbirds and invertebrate-feeding birds on areas of grazed semi-natural upland grassland than grazed improved pasture. However members of the crow family showed the opposite trend. A review found excluding cattle from fenland reduced the number of plant species, and that low-medium grazing levels could have positive effects on fenland biodiversity but may need to be accompanied by additional management such as mowing. One study from the UK found northern lapwing nest survival and clutch size were greater on ungrazed than grazed marshes. A replicated site comparison from the UK found the proportion of young grey partridges was negatively associated with rough grazing (in combination with several other interventions). Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F697https%3A%2F%2Fconservationevidence.com%2Factions%2F697Fri, 07 Dec 2012 15:57:06 +0000Collected Evidence: Collected Evidence: Control predatory mammals and birds (foxes, crows, stoats and weasels) A total of nine individual studies from France and the UK (including five replicated controlled studies and a systematic review) looked at the effects of removing predators on birds. Three studies found controlling predatory mammals or birds (sometimes alongside other interventions) increased the abundance or population size of some birds. One of these studies from the UK found numbers of nationally declining songbirds increased on a site where predators were controlled, but there was no overall difference in bird abundance, species richness or diversity between predator control and no-control sites. Five studies (two replicated and controlled, two before-and-after trials) from the UK found some evidence for increased productivity, nest or reproductive success or survival of birds following bird or mammal predator control (sometimes alongside other interventions). A randomized, replicated, controlled study found hen harrier breeding success was no different between areas with and without hooded crow removal. A global systematic review including evidence from European farmland found that reproductive success of birds increased with predator removal.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F699https%3A%2F%2Fconservationevidence.com%2Factions%2F699Thu, 20 Dec 2012 13:08:22 +0000
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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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