Collected Evidence: Collected Evidence: Plant in-field trees (not farm woodland)We have captured no evidence for the effects of planting in-field trees 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%2F76https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F76Mon, 24 Oct 2011 21:08:23 +0100Collected Evidence: Collected Evidence: Plant nettle strips A small study from Belgium found that planting nettle strips in the margins of three arable fields resulted in a higher number of aphid predator species. The number of aphid predators on a natural patch of nettles was higher than on crops, however there were fewer predators on nettle strips than on crops. Three insect families, including green lacewings, were only found on nettles.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F118https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F118Tue, 01 Nov 2011 20:40:45 +0000Collected Evidence: Collected Evidence: Plant more than one crop per field (intercropping) Three replicated, controlled and randomized studies from the Netherlands, Poland and the UK found that intercropping cabbage with French beans or clover resulted in increased ground beetle abundance. A trial from Switzerland found increased earthworm abundance in a maize plot immediately followed by a rye grass crop. A review found ground beetle numbers were enhanced by intercropping relative to single crops.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F124https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F124Tue, 01 Nov 2011 21:30:53 +0000Collected Evidence: Collected Evidence: Plant new hedgesA small study from the USA found that the population of northern bobwhites increased following several interventions including the planting of new hedges.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F178https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F178Wed, 30 May 2012 14:09:27 +0100Collected Evidence: Collected Evidence: Plant nectar flower mixture/wildflower strips for birds Two replicated and controlled studies from the UK (one randomised) and a European review out of seven studies captured found that more birds used nectar/wildflower strips than crops or land under other management. Two studies of a replicated and controlled experiment in the UK found that no more birds used nectar/wildflower strips in winter than used land under other management. A replicated, controlled study from Switzerland found that Eurasian skylarks Alauda arvensis were more likely to nest in patches of fields sown with annual weeds than in crops, and were less likely to abandon nests in these patches. A randomised, replicated and controlled study from the UK found that field margin management affected their use by birds more than the seed mix used on them.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F189https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F189Sat, 16 Jun 2012 19:33:52 +0100Collected Evidence: Collected Evidence: Plant nettle strips We found no evidence for the effects of planting nettle strips on bird populations. '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%2F205https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F205Sun, 15 Jul 2012 17:08:57 +0100Collected Evidence: Collected Evidence: Plant more than one crop per field (intercropping)A study from the USA found that 35 species of bird used fields with intercropping, with four nesting, but that productivity from the fields was very low.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F209https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F209Sun, 15 Jul 2012 17:42:11 +0100Collected Evidence: Collected Evidence: Plant nesting cover to reduce nest predation We found no evidence of planting nesting cover to reduce nest predation for bird populations. '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%2F405https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F405Thu, 16 Aug 2012 15:01:47 +0100Collected Evidence: Collected Evidence: Plant nectar flower mixture/wildflower strips A total of 80 individual studies have in some way investigated the effects of flowering strips on biodiversity. Sixty-four individual studies show some benefits to one or more wildlife groups. Sixty-five individual studies reported the effects of flower strips on invertebrates. Of these, fifty reported positive effects. Forty-one studies from eight European countries (including five reviews and twenty-three replicated controlled studies, of which one randomized and two site comparisons) found evidence that flower strips had a positive influence on invertebrate numbers with increased abundance, species richness/diversity, or both. Ten studies (nine replicated of which two controlled) found invertebrates visited or foraged on flower strips but did not specify increases/decreases in numbers. Two studies found effects on ground beetles other than changes in numbers. One replicated controlled study showed that ground beetles were more active or had enhanced feeding/reproductive conditions in flower strips. A review found flower strips supported ground beetle species that were rarely found in crops. Fifteen studies reported mixed or negative effects of flower strips on invertebrates. Six studies found no significant effects. Twenty-one studies looked at the effects of flower strips on plants. Sixteen studies from seven European countries (including ten replicated controlled studies of which one randomized) found evidence that flower strips had higher plant cover, number of flowers, diversity, and species richness. One review found flower strips benefited plants but did not specify how. Four studies found negative or no effects of flower strips on the number or diversity of plant species. Five studies described the effects of different margin establishment or management techniques on plants. Seven studies investigated birds and wildflower strips. Four replicated, controlled studies from Switzerland and the UK (two of which were randomized) and one review of European studies found evidence that plots sown with a wildflower or legume seed mix had a positive influence on birds. Flower strips attracted more birds or bird species and the number of birds using flower strips increased over time. Eurasian skylarks preferentially foraged in, and nested in or near, sown weed patches and were less likely to abandon their territories when they included sown weed patches. However one replicated trial in Switzerland found barn owls avoided sown wildflower areas. Two winter recording periods of the same replicated, controlled study in the UK found there were not more bird species or individuals on wildflower plots compared to control margins. All five studies investigating the effects of wildflower strips on small mammals (four replicated studies from Switzerland and one review of studies from north-western Europe) found evidence that small mammals benefit from strips sown with wildflowers or flowers rich in pollen and nectar, with increases in abundance, density and species richness. One replicated study from Switzerland reported that most common vole home ranges and core regions of their territories were found within a wildflower strip. Nineteen studies (of which eight replicated, controlled) reported positive effects on biodiversity of sowing specific plant species including phacelia, and/or other plant species such as borage and red clover. Three replicated studies (two also controlled) found negative impacts or no effects on biodiversity of sowing phacelia. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F442https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F442Thu, 23 Aug 2012 15:37:16 +0100Collected Evidence: Collected Evidence: Plant new hedges Two studies from France and the UK compared newly planted hedges with control areas. Both (including one replicated trial) found newly planted hedges had higher abundance, species richness or diversity of beetles or spiders than crop fields or field margins. The replicated study also found vascular plant species diversity and grass species richness were higher in newly planted hedges than recently established grass field margins. A review found newly established hedges supported more ground beetles than older hedges. A small-scale study from the UK found that local hawthorn plants exhibited better growth and were more stock proof than those of eight other provenances. A literature review found lower pest outbreaks in areas with new hedges. A replicated study in the UK found that the diversity of arthropods supported by newly planted hedges varied between seven different plant species An unreplicated site comparison study in Germany found that two out of 85 ground beetle species used newly planted hedges as stepping stones for dispersal. Results from the same study found that invertebrates that moved passively (attached to mammals and birds), such as snails, benefited most from the hedge-islands compared to actively moving ground beetles and harvestmen. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F538https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F538Tue, 11 Sep 2012 15:38:22 +0100Collected Evidence: Collected Evidence: Plant new hedgesFive studies in Slovakia, Kenya and Thailand measured the effects of planting grass or shrub hedgerows on soil animals and soil fertility. All five found hedgerows to maintain or improve soil fertility and soil animal activity. Of these, three replicated studies found reduced soil erosion and higher soil organic matter levels. Another replicated trial found a higher diversity of soil animals near to the hedgerows. One of the replicated studies and one review found that adding woody species to the hedgerows improved many factors contributing to soil fertility. SOIL TYPES COVERED: Alluvial, clay, sandy-loam.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F744https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F744Tue, 04 Jun 2013 16:25:36 +0100Collected Evidence: Collected Evidence: Plant new hedgesNatural enemies: One randomised, replicated, controlled study from China compared plots with and without hedges and found no effect on spiders in crops. One of two studies from France and China found more natural enemies in a hedge than in adjacent crops while one study found this effect varied between crop types, hedge species and years. Two randomised, replicated, controlled studies from France and Kenya found natural enemy abundance in hedges was affected by the type of hedge shrub/tree planted and one also found this effect varied between natural enemy groups. Pests: One randomised, replicated, controlled study from Kenya compared fallow plots with and without hedges and found effects varied between nematode (roundworm) groups. Crops studied were barley, beans, maize and wheat.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F752https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F752Thu, 01 Aug 2013 09:28:37 +0100Collected Evidence: Collected Evidence: Plant new hedges We found no evidence for the effects of planting hedges on amphibian populations. '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%2F791https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F791Thu, 22 Aug 2013 14:34:21 +0100Collected Evidence: Collected Evidence: Plant nesting trees/shelter for primates within agricultural fields We found no evidence for the effects of planting nesting trees/shelter for primates within agricultural fields on primate populations. '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%2F1431https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1431Tue, 17 Oct 2017 09:54:24 +0100Collected Evidence: Collected Evidence: Plant indigenous trees to re-establish natural tree communities in clear-cut areas One site comparison study in Kenya found that two out of three primate species had lower group densities in planted forests than in natural forests. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1584https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1584Fri, 20 Oct 2017 13:07:25 +0100Collected Evidence: Collected Evidence: Plant indigenous fast-growing trees (will not necessarily resemble original community) in clear-cut areas We found no evidence for the effects of planting indigenous fast-growing trees in clear-cut areas on primate populations. '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%2F1586https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1586Fri, 20 Oct 2017 13:09:25 +0100Collected Evidence: Collected Evidence: Plant individual plants One replicated, randomized, controlled study in the USA found that planting California sagebrush plants did not increase the cover of native plant species compared to sowing of seeds or a combination of planting and sowing seeds. One replicated, randomized, controlled study in South Africa found that planting Brownanthus pseudoschlichtianus plants increased plant cover, but not the number of plant species. One study in the USA found that a majority of planted plants survived after one year. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1697https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1697Mon, 23 Oct 2017 10:55:44 +0100Collected Evidence: Collected Evidence: Plant new hedges We found no studies that evaluated the effects of planting new hedges on bat populations. ‘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%2F1942https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1942Tue, 04 Dec 2018 09:51:33 +0000Collected Evidence: Collected Evidence: Plant new or maintain existing hedgerows on farmland Three studies evaluated the effects on mammals of planting new or maintaining existing hedgerows on farmland. Two studies were in the UK and one was in Switzerland. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): One of two replicated, site comparison studies, in the UK and Switzerland, found that retaining and enhancing hedgerows along with other field boundary features was associated with higher brown hare density in arable sites but not in grassland sites while the other study found that Irish hare numbers did not increase. A replicated, site comparison study in the UK found that establishing hedgerows alongside arable land increased small mammal abundance. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2383https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2383Wed, 27 May 2020 14:36:44 +0100Collected Evidence: Collected Evidence: Plant native species for reptile habitat in urban areas We found no studies that evaluated the effects of planting native species for reptile habitat in urban areas on reptile populations. ‘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%2F3479https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3479Fri, 03 Dec 2021 11:53:01 +0000Collected Evidence: Collected Evidence: Plant native species Two studies evaluated the effects of planting native species on reptile populations. Both studies were in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Occupancy/range (1 study): One before-and-after study in the USA found that an area reseeded and replanted with native vegetation was colonized and abandoned at different times by two snake and one lizard species, and one other lizard species may have remained, but in low numbers. BEHAVIOUR (1 STUDY) Use (1 study): One replicated, site comparison study in the USA found that grasslands reseeded with both native and non-native grasses were used by Texas horned lizards. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3709https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3709Mon, 13 Dec 2021 13:49:56 +0000Collected Evidence: Collected Evidence: Plant nectar flower mixture/wildflower strips Twenty-three studies evaluated the effects of planting nectar flower mixtures, or wildflower strips, on butterflies and moths. Eleven studies were in the UK, six were in Switzerland, two were in the USA, and one was in each of Sweden, Finland and Germany. COMMUNITY RESPONSE (20 STUDIES) Richness/diversity (20 studies): Eight of thirteen studies (including twelve replicated studies, two randomized studies, five controlled studies, one before-and-after study, and eight site comparison studies) in the UK, Switzerland, Finland and Germany found that sown wildflower strips had a higher species richness and diversity of all butterflies, generalist butterflies, and moths than conventional field margins, unsown margins, cropped fields or conventional grassland. One of these studies also found that the species richness of specialist butterflies was similar in sown wildflower strips, cropped fields and conventional grassland. Four studies found that the species richness of butterflies was similar between sown wildflower strips and cropped fields, cropped margins, unsown strips or extensively managed meadows. The other study found that, five years after sowing wildflower strips, butterfly species richness, but not diversity had increased at one of two study sites. One replicated, randomized, paired, controlled study in the UK found that the species richness of butterflies and moths was similar on farms managed under agri-environment schemes, including with sown wildflower strips, and on conventionally managed farms. Two replicated studies (including one randomized, controlled study and one site comparison study) in the UK and Sweden found that field margins sown with wildflowers had a greater species richness of butterflies than grass-only field margins. One of two replicated, paired, controlled studies (including one randomized study) in the USA and the UK found that plots sown with a mix of wildflowers had a greater species richness of caterpillars than plots sown with a single flower species. The other study found that plots sown with either complex or simpler flower mixes had a similar species richness of butterflies. Two replicated studies (including one randomized, controlled study) in the UK found that wildflower plots sown with phacelia, borage or lucerne had a higher species richness or diversity of butterflies and moths than plots sown with other flower species. POPULATION RESPONSE (16 STUDIES) Abundance (17 studies): Ten studies (including nine replicated studies, three randomized studies, three controlled studies and seven site comparison studies) in the UK, Switzerland and Finland found that sown wildflower strips had a higher abundance of all butterflies, generalist butterflies, specialist butterflies and meadow brown butterflies than conventional field margins, unsown margins, cropped fields, cropped margins, conventional grassland or extensively managed meadows. However, one of these studies only found this effect in one of two study years. Two of these studies also found that the abundance of specialist butterflies and meadow brown caterpillars was similar in sown wildflower strips and unsown margins, cropped fields and conventional grassland, and one found that the abundance of caterpillars was lower in sown wildflower strips than in conventional grassland. One replicated, randomized, paired, controlled study in the UK found that the abundance of butterflies and micro-moths was higher on farms managed under agri-environment schemes, including with sown wildflower strips, than on conventionally managed farms, but the abundance of other moths was similar. Two replicated studies (including one randomized, controlled study and one site comparison study) in the UK and Sweden found that field margins sown with wildflowers had a higher abundance of butterflies than grass-only field margins. One replicated, randomized, controlled study in the UK found that farms with wildflower strips (along with other enhanced agri-environment scheme options) had a higher abundance of some butterflies, but a lower abundance of other butterflies, than farms with simpler agri-environment scheme management such as grass-only margins. One of two replicated, paired, controlled studies (including one randomized study) in the USA and the UK found that plots sown with one of three wildflower mixes had a higher abundance of moths than plots sown with two other mixes or a single flower species. The other study found that plots sown with either complex or simple flower mixes had a similar abundance of butterflies. One replicated, randomized, controlled study in the UK found that wildflower plots sown with lucerne had a higher abundance of butterflies than plots sown with borage, chicory or sainfoin. BEHAVIOUR (2 STUDIES) Use (2 studies): Two studies (including one replicated study) in the UK and the USA reported that sown nectar flower plots and tropical milkweed plots were used by six species of butterflies and moths and monarch butterflies and caterpillars. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3932https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3932Fri, 12 Aug 2022 06:26:40 +0100Collected Evidence: Collected Evidence: Plant new hedges Seven studies evaluated the effects of planting new hedges on butterflies and moths. Five studies were in the UK and one was in each of Ireland and Canada. COMMUNITY RESPONSE (5 STUDIES) Richness/diversity (5 studies): Three of four site comparison studies (including three replicated and three paired studies) in the UK, Ireland and Canada found that established hedgerows had a higher species richness of butterflies and macro-moths than in-field beetle banks, crops or pasture. The other study found that hedgerows had a similar species richness of butterflies to grass banks between fields. One replicated study in the UK found that gorse, oak and blackthorn planted within hedgerows had more species of arthropods, including caterpillars, than more commonly planted hawthorn. POPULATION RESPONSE (6 STUDIES) Abundance (6 studies): Five of six studies (including one replicated, controlled study, three paired, site comparison studies and two site comparison studies) in the UK, Ireland and Canada found that the abundance of butterflies, moths, macro-moths and gatekeepers was higher along hedgerows than on beetle banks, grass margins without hedgerows, in field interiors, or 5–10 metres away from hedgerows.The other study found that the abundance of butterflies along hedgerows was similar to grass banks between fields without hedgerows. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One site comparison study in the UK found that moths recorded close to hedgerows were more likely to be flying parallel to it than moths recorded further away. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3976https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3976Thu, 18 Aug 2022 10:00:38 +0100Collected Evidence: Collected Evidence: Plant in-field trees (e.g. copses) We found no studies that evaluated the effects of planting in-field trees 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%2F3979https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3979Thu, 18 Aug 2022 10:41:45 +0100Collected Evidence: Collected Evidence: Plant more than one crop per field (intercropping) One study evaluated the effects on butterflies and moths of planting more than one crop per field. The study was in Malaysia. COMMUNITY RESPONSE (1 STUDY) Community composition (1 study): One replicated, site comparison study in Malaysia found that smallholdings planted with oil palm and other crops did not differ in butterfly community composition from those planted with oil palm alone. Richness/diversity (1 study): One replicated, site comparison study in Malaysia found that smallholdings planted with oil palm and other crops did not have greater butterfly species richness than those planted with oil palm alone. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in Malaysia found that smallholdings planted with oil palm and other crops did not have higher overall butterfly abundance than those planted with oil palm alone. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3983https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3983Sat, 20 Aug 2022 19:18:11 +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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