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%2Fwww.conservationevidence.com%2Factions%2F63https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F70https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F70Mon, 24 Oct 2011 20:59:15 +0100Collected Evidence: Collected Evidence: Implement food labelling schemes relating to biodiversity-friendly farming (organic, LEAF marque) We have captured no evidence for the effects of implementing food labelling schemes relating to biodiversity-friendly farming (organic, LEAF marque) 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%2Fwww.conservationevidence.com%2Factions%2F71https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F71Mon, 24 Oct 2011 21:01:42 +0100Collected Evidence: Collected Evidence: Maintain in-field elements such as field islands and rockpiles We have captured no evidence for the effects of maintaining in-field elements such as field islands and rockpiles, 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%2Fwww.conservationevidence.com%2Factions%2F77https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F77Mon, 24 Oct 2011 21:09:32 +0100Collected Evidence: Collected Evidence: Introduce nest boxes stocked with solitary bees We have captured no evidence for the effects of introducing nest boxes stocked with solitary bees 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%2Fwww.conservationevidence.com%2Factions%2F81https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F81Mon, 24 Oct 2011 21:17:25 +0100Collected Evidence: Collected Evidence: Manage ditches to benefit wildlife Five out of a total eight studies from the Netherlands and the UK (including one replicated, controlled paired study and three replicated site comparisons) looking at the effects of managing ditches on biodiversity, found that this intervention resulted in increased invertebrate biomass or abundance, plant species richness, emergent plant cover, amphibian diversity and abundance, bird visit rates and higher numbers of some bird species or positive impacts on some birds in plots with ditches managed under agri-environment schemes. One replicated controlled and paired study from the Netherlands found higher plant diversity on ditch banks along unsprayed edges of winter wheat compared to those sprayed with pesticides. Three studies from the Netherlands and the UK (including two replicated site comparisons) found that ditch management had negative or no clear effects on some farmland bird species or plants.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F135https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F135Thu, 17 Nov 2011 21:35:00 +0000Collected Evidence: Collected Evidence: Increase the proportion of semi-natural habitat in the farmed landscapeFive studies monitored the effects of the Swiss Ecological Compensation Areas scheme at a landscape scale, including three replicated site comparisons. Of these, one found an increase in numbers of birds of some species. Two found no effect on the number of bird species or population densities of farmland birds. Three studies found mixed effects, with some species or groups of species increasing and others decreasing.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F145https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F145Sat, 14 Jan 2012 13:48:09 +0000Collected Evidence: Collected Evidence: Make direct payments per clutch for farmland birds Two replicated and controlled studies from the Netherlands found limited evidence for increased wading bird populations on farms with per-clutch payments. One study found no population effects over three years. The second found slightly higher breeding densities of wading birds, but not higher overall numbers. A replicated and controlled study found higher hatching success of northern lapwing and black-tailed godwit on farms with payment schemes than control farms. A replicated site comparison from the Netherlands that looked at the effects of per-clutch payments in combination with postponed agricultural activities found more birds bred on 12.5 ha plots under the per-clutch payment and postponed agricultural activities scheme but found no differences at the field-scale.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F146https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F146Sat, 14 Jan 2012 14:46:56 +0000Collected 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%2Fwww.conservationevidence.com%2Factions%2F579https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F579Thu, 04 Oct 2012 11:08:34 +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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