Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Use prescribed burning on deciduous forests Of four studies found, one paired sites study from the USA found that bird species richness was similar in burned and unburned aspen forests, although there were significant changes in the relative abundances of some species. A replicated, controlled study in the USA found no evidence for changes in community composition in oak and hickory forests following burning. A replicated controlled trial from the USA found no differences in wood thrush nest survival in burned compared to unburned areas. Another replicated controlled trial from the USA found a reduction in the number of black-chinned hummingbird nests following fuel reduction treatments that included burning. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F317https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F317Thu, 26 Jul 2012 12:53:13 +0100Collected Evidence: Collected Evidence: Use prescribed burning on pine forests Two studies of the 28 captured (all from the USA) found higher bird species richness in sites with prescribed burning, tree thinning and mid- or understorey control or just burning and tree thinning, compared to control sites. Five studies found no differences in species richness or community composition between sites with prescribed burning; prescribed burning, tree thinning and mid- or understorey control; or prescribed burning and tree thinning only, compared to control sites, or those with other management. Eight studies found that some species or guilds (such as open habitat species) were more abundant or more likely to be found in burned areas of pine forest than control areas. One study found that the responses of Henslow’s sparrows to burning varied considerably with geography and habitat. Three studies found that some species were more abundant in thinned and burned stands, compared to controls or other management. Three studies found that overall bird densities or abundances of red-cockaded woodpeckers were higher in open pine forests with prescribed burning, tree thinning and mid- or understorey control, compared with control areas or those thinned but not burned. One found differences were more marked in spring. A study found that a red-cockaded woodpecker population increased following the start of intensive management consisting of prescribed burning and other interventions. Ten studies found that total bird densities or those of some species was the same or lower in sites with prescribed burning compared to control sites, or those with other management. Five studies investigated several interventions at once. Generally, closed-forest species and ground nesters appeared to be adversely affected by burning. Three studies found higher productivities or survival of species in burned or burned and thinned areas, compared to control areas or those burned less recently. Seven studies found no differences in productivity, behaviour or survival (including of artificial nests) in burned areas or burned and thinned areas, compared to controls. One study found that northern bobwhite chicks had lower foraging success in burned areas, compared to other management regimes, whilst another found that different predators were dominant under different management. The three studies that investigated it found that burning season did not appear to affect the effects of burning. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F318https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F318Thu, 26 Jul 2012 13:02:39 +0100Collected Evidence: Collected Evidence: Use prescribed burning on Australian sclerophyll forest Two of three studies from Australia found no differences in bird species richness in burned sites compared to unburned areas. Three studies found differences in species assemblages in burned and unburned areas, with some species lost and others gained from areas after fire. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F319https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F319Thu, 26 Jul 2012 14:44:29 +0100Collected Evidence: Collected Evidence: Use prescribed burning on savannas A replicated and controlled study from Kenya, of five studies captured, found that burned areas of savanna tended to have more birds and more species than control or grazed areas. However, the authors note that differences were not present during drought years and burned sites showed significant annual variation, unlike grazed sites. A replicated and controlled study from Australia found that the effects of burning on bird abundances depended on burn season, and habitat type. Two replicated studies in the USA found that some open country species were more common in burned areas than unburned, whilst other species were less so. A small study from the USA found that two eastern bluebird Sialia sialis successfully raised chicks after the habitat around their nest boxes was subject to a prescribed burn. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F320https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F320Thu, 26 Jul 2012 14:58:00 +0100Collected Evidence: Collected Evidence: Use prescribed burning on shrublands One controlled study from the USA, of eight captured, found that overall bird densities were similar between burned and unburned areas, whilst a replicated and controlled study found that species numbers and bird densities did not vary between areas burned in summer and those burned in winter. Three studies found that some species were more abundant on areas that were burned, compared to those managed differently, or not at all. Four studies found that the densities of individual species were similar or lower on burned areas compared to control areas or those under different management. A before-and-after study found that sage sparrows chose different nest sites before burning compared to after. A controlled study found no differences in greater sage grouse movement between burned and unburned areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F321https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F321Thu, 26 Jul 2012 15:10:30 +0100Collected Evidence: Collected Evidence: Use prescribed burning on grasslands Four studies from the USA, of 21 studies captured, found that overall species richness did not vary between burned areas, or areas burned recently, and unburned sites. One study found that community composition was also similar whilst others found that species showed individual responses. Nine studies from across the world found that at least some study species were found at higher densities or were more abundant in burned areas than in unburned areas or areas under different management. One study investigated multiple interventions at once. Fourteen studies found that at least one study species was less abundant or found at similar abundances on burned areas of grassland, compared to unburned areas or those under different management. However, four studies found that apparent responses varied depending on how soon after fires measurements were taken. Care should therefore be taken when interpreting the results of studies on prescribed burning. One study from the USA found that Florida grasshopper sparrow had significantly higher reproductive success soon after plots were burned, whilst another American study founds that dickcissel reproductive success was higher in patch-burned areas than burned and grazed areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F322https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F322Thu, 26 Jul 2012 15:38:18 +0100Collected Evidence: Collected Evidence: Use prescribed burning on coastal habitats Of three studies captured, one replicated, controlled, paired sites study from the USA found that there was a fall in breeding seaside sparrow numbers on a burned site in the year it was burned. The next year, numbers were higher than on an unburned site. A controlled study in Argentina found that tall-grass specialist species were lost from burned areas in the year of burning, but that some habitats recovered by the following year. A replicated controlled study from the USA found no differences in nest predation rates between burned and unburned areas for two years after burning. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F323https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F323Thu, 26 Jul 2012 16:24:19 +0100Collected Evidence: Collected Evidence: Use fire suppression/control Two out of three before-and-after studies, from Australia and the UK, found that five species of bird (including noisy scrub-bird, the target species of one study) increased following fire suppression measures. A before-and-after study in the USA found that open habitat species declined in a pine forest site after fire exclusion, whilst mesic woodland species appeared. A before-and-after study from the UK found that five bird species declined following fire suppression. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F324https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F324Thu, 26 Jul 2012 16:35:35 +0100Collected Evidence: Collected Evidence: Thin trees within forests Of 13 studies, one from the USA which used several interventions found higher species richness in managed sites. Three studies from the USA and the UK found no differences between thinned and control sites. Seven studies from the USA and Sweden found that total bird abundance, or that of some species, were higher in thinned plots than control plots or those under different management. Four of these used other interventions as well. Five studies found that abundances were similar, or that some species were less abundant in areas with thinning. Two studies from the USA found no effect of thinning on wood thrushes, a species thought to be sensitive to it. A controlled before-and-after study found that more nests were in nest boxes in a thinned site, compared to a control site. A replicated randomised, controlled study in the USA found no differences in bird abundances between burned sites with high-retention thinning, compared to low-retention. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F328https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F328Thu, 26 Jul 2012 17:16:33 +0100Collected Evidence: Collected Evidence: Use patch retention harvesting instead of clearcutting One before-and-after study of two from the USA found that areas under patch retention harvesting contained more birds of more species than clearcut areas, retaining similar numbers to unharvested areas. Two studies from the USA found that forest specialist species were found with greater frequency in patch retention plots than other management types. One found that habitat generalists increased on other management types, relative to patch retention areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F330https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F330Fri, 27 Jul 2012 15:02:03 +0100Collected Evidence: Collected Evidence: Use selective harvesting/logging instead of clearcutting Six studies of seven from the USA and Canada found that some species were more abundant in selective-logged forests, whilst others were less abundant, compared to both control stands and other managements. One study found that there were no consistent differences between selectively harvested and clearcut stands. A replicated study from the USA found a lower species richness of cavity-nesting birds in snags in selectively-logged stands, compared to clearcuts. A replicated study from the USA found that brood parasitism of two species by brown-headed cowbirds was higher in harvested stands compared to controls, but it was lower for two others. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F331https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F331Sat, 28 Jul 2012 13:49:15 +0100Collected Evidence: Collected Evidence: Use variable retention management during forestry operationsA replicated, controlled study from the USA found that nine bird species occurred at higher densities in stands under variable retention management, compared to control stands. Five were found at lower densities. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F332https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F332Sat, 28 Jul 2012 14:02:54 +0100Collected Evidence: Collected Evidence: Use shelterwood cutting instead of clearcuttingA replicated study from the USA found that community composition of birds in shelterwood stands differed from other forestry practices, with some species more abundant and others less so. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F333https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F333Sat, 28 Jul 2012 14:08:41 +0100Collected Evidence: Collected Evidence: Use ring-barking (girdling), cutting or silvicides to produce snags Of five studies found, one replicated and controlled study from the USA found that forest plots provided with snags had higher bird diversity and abundance than plots without snags added. Three studies from the USA and UK found that woodpeckers and other species used artificially-created snags for nesting and foraging. One study from the USA found that use increased with how long a snag had been dead. A UK study found that no crested tits used snags created for them, possibly because they were not rotted enough, or because they were too close to the ground. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F343https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F343Sat, 28 Jul 2012 20:29:12 +0100Collected Evidence: Collected Evidence: Treat wetlands with herbicideThree of four studies, one replicated and controlled, found that numbers of terns, American coot and waders were found at higher densities on wetland areas sprayed with herbicide, compared to unsprayed areas. However, one study found that wader numbers were not as high as on ploughed areas. One replicated and controlled study found that songbird densities were lower on sprayed than unsprayed areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F347https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F347Sun, 29 Jul 2012 14:26:26 +0100Collected Evidence: Collected Evidence: Use environmentally sensitive flood management One of two studies, a before-and-after study from the UK, found that there were significantly more bird territories in a stretch of river with ‘flood beams’ installed, compared to a channelized river. A replicated site comparison study in the USA found that 13 of 20 bird species increased at sites with the restoration of river dynamics and vegetation. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F356https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F356Sun, 29 Jul 2012 16:58:18 +0100Collected Evidence: Collected Evidence: Use greentree reservoir managementA site comparison study from the USA found significantly lower numbers of breeding mid- and under-storey birds at a greentree reservoir site than at a control site. Canopy nesting species were not affected. The species investigated were not gamebirds or wildfowl. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F357https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F357Sun, 29 Jul 2012 17:02:09 +0100