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《Mammalian Biology》2014,79(3):176-182
Rapid changes in agricultural landscape structure and composition affect many different farmland biotas, including carnivores, which are a key element of ecosystem stability, yet little is known about their distribution and habitat use. In this study, we evaluated how habitat characteristics on two different spatial scales (local and landscape scale) affected the forest-edge utilization by small and medium-sized carnivores in fragmented central European farmland. Based on an indirect method for detecting carnivores (scent stations), we sampled 212 forest fragments of different sizes (1–7864 ha) during April to May from 2006 to 2009. Our results indicate that carnivore utilization of forest-edge habitats was driven by landscape rather than local characteristics even though the overall extent of explained variation was small. The most important factors that determined response of the carnivore community were the area of farmland and that of urban land on a landscape scale. The corridor connectivity between small forest fragments and other spatial elements played a crucial role in the occurrence of red fox. Our results suggest that comprehensive studies on multi-species carnivore assemblage using scent station might be useful in evaluating species-specific response to habitat characteristics, especially if large numbers of stations visited by carnivores are available. 相似文献
3.
D. E. Chamberlain A. Joys P. J. Johnson L. Norton R. E. Feber R. J. Fuller 《Biology letters》2010,6(1):82-84
The generally higher biodiversity on organic farms may be influenced by management features such as no synthetic pesticide and fertilizer inputs and/or by differences in uncropped habitat at the site and landscape scale. We analysed bird and habitat data collected on 48 paired organic and conventional farms over two winters to determine the extent to which broad-scale habitat differences between systems could explain overall differences in farmland bird abundance. Density was significantly higher on organic farms for six out of 16 species, and none on conventional. Total abundance of all species combined was higher on organic farms in both years. Analyses using an information-theoretic approach suggested that both habitat extent and farm type were important predictors only for starling and greenfinch. Organic farming as currently practised may not provide significant benefits to those bird species that are limited by winter food resources, in particular, several declining granivores. 相似文献
4.
Andrew B. Stein Todd K. Fuller Laurie L. Marker 《Biodiversity and Conservation》2008,17(14):3579-3587
In northcentral Namibia, Waterberg Plateau Park (WPP) is a protected area that acts as a refuge for rare and endangered species,
while the farmlands surrounding the Park are managed for livestock production, but support populations of wildlife for game
farming, trophy hunting, and conservation. During June–October 2006, camera-traps were set within and surrounding WPP to assess
leopard (Panthera pardus) density (n = 19 camera stations and 946 camera-trap-nights). Fortuitously, photographic results (2,265 photos of identifiable mammal
(n = 37) and bird (n = 25) species) allowed us to assess aspects of species diversity and differences among the Park, the farmland areas along
the Waterberg Plateau escarpment, and the flatlands surrounding the escarpment. Species composition among the three areas
was markedly different, and made sense with respect to differences in habitat and management features. Camera-trapping efforts,
although intended for a narrow purpose, may also provide a rather robust record of differences in mammal and bird diversity
in adjacent habitats and can be incorporated into long-term monitoring programs. 相似文献
5.
Although modern agriculture generally relies on homogeneous varieties that are usually grown in pure stands, crop variety mixtures have been used for a long time, notably to improve resistance to fungal diseases. A growing number of studies suggest that intraspecific plant diversity may also enhance the abundance and diversity of wild species and thereby some ecosystem services such as biological control by natural predators. However, positive effects of the genetic diversity of plant species on the diversity of associated communities have mostly been documented in natural systems, with only a handful of studies targeting crop species in agroecosystems. Here, we investigated the ecological effects of the number of winter wheat varieties (Triticum aestivum) on aboveground arthropods and particularly predatory species. We manipulated the number of wheat varieties (1, 2, 4 or 8) in 120 plots (80 m2 each) to examine how wheat diversity and stand characteristics impact communities of three dominant aboveground arthropod groups that include many predatory species: ground beetles, rove beetles and spiders. The number of wheat varieties had a weak, but positive effect on predator abundance, notably spider abundance. In contrast, wheat functional diversity, as assessed by the number of wheat functional groups, was only negatively related to the diversity of spiders. Among wheat stand characteristics, the variance in plant height, wheat biomass and the Green Area Index were weakly correlated with ground beetle, rove beetle and predatory diversity, respectively. The Green Area Index was also weakly correlated with ground beetle abundance. Our study suggests that wheat variety mixtures have variable and limited effects on aboveground arthropods and probably low effectiveness to enhance biological control, but these results should be further tested under low-input agriculture in real fields. 相似文献
6.
(强)热带风暴条件下农田林网对防止棉花倒伏及减产的效应 总被引:2,自引:0,他引:2
研究结果表明 ,林带背风面 2 7H范围内 ,林网具有不同程度减轻棉株倒伏及产量损失的功能 ,有效防护范围为 0 .42~ 2 3H ,最大籽棉产量和衣分率效果区为 1 0~ 1 3H .与受灾区相比 ,保护区的籽棉产量增加 45.0 1 % ,皮棉产量增加 52 .69% .整个林网内的籽棉产量增加 2 9 94% ,皮棉产量增加 35 0 6% . 相似文献
7.
Farmland bird population trends were examined on a sample of lowland English farms to assess the relative importance of habitat
loss and habitat degradation. Data were extracted from 11 farms surveyed by territory mapping between 1966 and 1986 as part
of the British Trust for Ornithology's Common Birds Census. The population size of 38 bird species was quantified for each
farm in each year. The extents of five non-crop habitats were measured at 4-yearly intervals on each farm. The farms were
selected because some had undergone extensive removal of non-crop habitats while others had undergone little or none. Although
declines were commonest on farms where the severest habitat loss had taken place, we found no evidence that habitat loss was
the main factor causing population declines: all 11 farms had significant numbers of declining species, even where habitat
loss was minimal. Furthermore, general linear modelling found no significant effects of habitat loss on population trends
and principal-components analysis found limited effects of habitat extent on community composition. These results suggest
that habitat loss is of secondary importance in causing farmland bird population declines. We suggest that other processes,
such as habitat degradation, may have caused a baseline population decline in at least 10 farmland bird species and that declines
may have been exacerbated by localised habitat loss.
Received: 4 February 1998 / Accepted: 1 April 1998 相似文献
8.
Different nest predator faunas and nest predation risk on ground and shrub nests at forest ecotones: an experiment and a review 总被引:1,自引:0,他引:1
This study examined predator faunas of artificial ground and shrub nests and whether nest predation risk was influenced by
nest site, proximity to forest edge, and habitat structure in 38 grassland plots in south-central Sweden. There was a clear
separation of predator faunas between shrub and ground nests as identified from marks in plasticine eggs. Corvids accounted
for almost all predation on shrub nests whereas mammals mainly depredated ground nests. Nest predation risk was significantly
greater for shrub than for ground nests at all distances (i.e. 0, 15 and 30 m) from the forest edge. However, nest predation
risk was not significantly related to distance to forest edge, but significantly increased with decreasing distance to the
nearest tree. Different corvid species robbed nests at different distances from the forest edge, with jays robbing nests closest
to edges. We conclude that the relationship between the predation risk of grassland bird nests and distance to the forest
edge mainly depends on the relative importance of different nest predator species and on the structure of the forest edge
zone. A review of published articles on artificial shrub and ground nest predation in the temperate zone corroborated the
results of our own study, namely that shrub nests experienced higher rates of depredation in open habitats close to the forest
edge and that avian predators predominantly robbed shrub nests. Furthermore, the review results showed that predation rates
on nests in general are highest <50 m inside the forest and lower in open as well as forest interior habitats (≥50 m from
the edge).
Received: 16 March 1998 / Accepted: 30 July 1998 相似文献
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10.
林带空间配置与布局优化研究 总被引:20,自引:1,他引:19
农田防护林(林带)的空间配置与布局是影响防护林结构和防护效益发挥并持续的关键因素.为达到农田防护林防护效益最大并持续的经营目标。在保证林分多样性和稳定性的条件下.林带必须具有空间上布局的合理性和时间上的连续性.经过多年防护林营林研究实践.在对1992年于辽宁省昌图县双井子乡设计营造的试验示范林带调查的基础上.对农田防护林单条林带方向的设置、带内树木的空间搭配方式、树种组成形式,多条林带或林网的带间距离以及大面积或区域防护林体系的空间景观布局等进行了综合研究.结果表明,单条林带和林网走向都应以垂直主害风作为设计的原则;林带内树木的空间搭配以“品”字型为佳,在不同树种混交的同一条林带中,可利用“边行优势”将生长相对缓慢的树种配置于边行.生长相对迅速的树种配置于内行;多条林带或林网空间配置参数——带间距离的设计应以林带达到初始防护成熟龄时的树高作为成林高.以林带结构变化规律和降低害风比例作为林带设计关键参数;区域防护林体系的空间布局应以景观生态学原理为基础.对林网体系进行评价与调控. 相似文献