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As an increasingly dominant feature in the landscape, transportation corridors are becoming a major concern for bats. Although wildlife–vehicle collisions are considered to be a major source of mortality, other negative implications of roads on bat populations are just now being realized. Recent studies have revealed that bats, like many other wildlife species, will avoid roads rather than cross them. The consequence is that roads act as barriers or filters to movement, restricting bats from accessing critical resources. Our objective was to assess specific features along the commuting route, road, or surrounding landscape (alone or in combination) that exacerbated or alleviated the likelihood of a commuting bat exhibiting an avoidance behavior in response to an approaching vehicle. At 5 frequently used commuting routes bisected by roads, we collected data on vehicles travelling along the roads (such as visibility and audibility), commuting bats (such as height), and composition of the commuting route. We revealed that commuting route structure dictated the frequency at which bats turned back along their commuting routes and avoided the road. We found that gaps (>2 m) in commuting routes, such as the road itself, caused bats to turn away just before they reached the road. Furthermore, we found that turning frequencies of bats increased with vehicle noise levels and the locations at which bats responded to vehicles corresponded with areas where noise levels were greatest, including gaps <2 m. This suggested that bats had a disturbance threshold, and only reacted to vehicles when associated noise reached a certain level. We found that threshold levels for our study species were approximately 88 dB, but this value was likely to vary among species. Thus, our findings indicate that restoring (e.g., replanting native trees and shrubs in gaps) and establishing commuting routes (such as planting tree-lines and wooded hedgerows), as well as creating road-crossing opportunities (such as interlinking canopies) will improve the permeability of a road-dominated landscape to bats. Furthermore, our study highlights the influence of the soundscape. We recommend that effective management and mitigation strategies should take into account the ecological design of the acoustic environment. © 2012 The Wildlife Society. 相似文献
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Unsanctioned travel routes through alpine ecosystems can influence water drainage patterns, cause sedimentation of streams, and erode soils. These disturbed areas can take decades to revegetate. In 2012, a volunteer‐driven project restored a 854‐m section of unsanctioned road along the Continental Divide in Colorado, United States. The restored area was seeded with three native grass species and then treated by installing erosion matting or adding supplemental rock cover. Four years later, results suggest that the seeding along with the use of erosion matting or supplemental rock can enhance revegetation. Matting appeared to accumulate litter, and this effect might have contributed to enhanced moisture retention. Treated areas contained 40% of the vegetation cover found on adjacent controls, which averaged 69% vascular plant absolute cover. Recovery on both treatments was markedly higher than published estimates of passive revegetation of disturbed areas measured elsewhere suggesting seeding with added cover or protection led to substantial vegetative cover after 4 years. Two of the 3 seeded grass species, Trisetum spicatum and Poa alpina, dominated the restored plots, composing 81.7% of relative vegetation cover on matting sites and 73.4% of relative cover on rock‐supplemented areas. Presumably due to its preference for moister sites, Deschampsia cespitosa had low establishment rates. Volunteer species, that is species that appeared on their own, contributed 6.3% to the absolute vegetation cover of matting and rock sites, and species such as Minuartia biflora, Minuartia obtusiloba, Poa glauca, and Festuca brachyphylla should be considered for use in future restorations. 相似文献
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道路绿化带可以净化空气,改善道路环境,道路中的小气候条件会改变道路污染物扩散方式和速度,进而会影响到绿化带对污染物净化效果。气象条件对道路绿地对大气污染物净化效果影响的研究将有助于了解道路绿地的净化途径,为改善城市道路环境提供依据。对太原市18个道路绿地气象因子和5种主要污染物浓度进行了观测。结果表明:夏季,太原市城市道路内各气象要素之间存在一定的相关性,气温和地温正相关显著,空气相对湿度与地温及气温呈显著和极显著负相关。大部分情况下,有绿地非机动车道污染物平均浓度低于无绿地非机动车道对照点平均浓度,即道路绿地起到了对道路污染物的净化作用。道路绿地对污染物的净化百分率与气象因子存在显著的回归关系,并可以建立达到统计显著水平的回归方程,但不同污染物受不同的主导气象因子影响。气象条件会影响道路绿地对道路污染物的净化效果,今后的城市建设和道路绿地规划中应更多地考虑气象条件对绿地净化效果的影响。 相似文献
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Urbanization is one of the most rapidly expanding forms of habitat alteration worldwide. Wildlife differs in their responses to urbanization depending upon species and site-specific factors. We used capture-mark-recapture to examine the abundance, population demographics, growth, and movements of the eastern long-necked turtle (Chelodina longicollis) in Australia over 1 year in a suburban environment and an adjacent nature reserve during drought. Contrary to expectations, sex ratios, injury incidence, and frequency of juvenile size classes did not differ between turtles in the suburbs and the nature reserve. Moreover, turtles in the suburbs were nearly 3 times more abundant, grew 5 times faster, and had populations comprised of more adults in the larger size classes than nature reserve populations. These findings, together with net movements from the nature reserves into the suburbs, suggest that suburban water bodies were the higher quality habitat, effectively buffering turtles from temporal fluctuations in environmental conditions during drought. However, reserve managers and urban planners need to recognize that suburban water bodies have the potential to attract turtles from nearby reserves during drought, and that even low levels of persistent mortality during these travels across reserve boundaries may have consequences for populations of long-lived vertebrates. © 2011 The Wildlife Society. 相似文献
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Darryl N. Jones Matthew Bakker Orphé Bichet Robert Coutts Tracy Wearing 《Ecological Management & Restoration》2011,12(1):76-79
The Compton Road overpass in southern Brisbane is known to be allowing passage by numerous birds, reptiles and amphibians; but what type of vegetation is providing habitat suitable for these movements? An evaluation of the reconstructed vegetation on the overpass shows that 45 species of plants were present after 4 years of growth. Most of these were in the original planting list but over 40% have almost certainly come from salvaged native topsoil used in the bypass construction. The resulting habitat, 4 years later, now appears similar to a typical coastal eucalypt forest secondary succession, although not yet identical to nearby forest. The current presence of a dense mid‐layer of small trees and shrubs may be an important factor in allowing even the edge‐avoiding species to cross the road. On‐going investigation of successional changes and the changing responses of the birds and other taxa will contribute to understanding the functionality of such crossing structures. 相似文献
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AbstractThe purpose of the study was to acquire the source and evaluate the risk posed by heavy metals in road dust of steel industrial city (Anshan), Liaoning, Northeast China. Potential ecological risk index (RI), pollution index (PI) and geo-accumulation index (Igeo) were applied to evaluate the heavy metal pollution level, and the carcinogenic risk (RI) and hazard index (HI) were calculated to estimate the human health risk. The geographic information system maps clearly reveal the hot spots of heavy metal spatial distribution. Principle component analysis (PCA) and cluster analysis (CA) classified heavy metals into three groups. The metal Zn and Pb originate from the traffic emission, while Cd, Cr, Fe, Mn, Ni and Sb primarily come from industrial activities. These two pathways were the major source of heavy metals pollution by positive matrix factorization (PMF). The Igeo and PI values of heavy metals were decreased in the following order: Cd?>?Sb?>?Zn?>?Fe?>?Pb?>?Cu?>?Cr?>?Sn?>?Mn?>?Ni. The RI index showed the heavy metals were moderate to very high potential ecological risk. The HI values for children and adults presented a decreasing order of Cr?>?Pb?>?Ni?>?Cu?>?Cd?>?Zn. The HI also predicted a possibility of non-carcinogenic risk for children living in urban areas in comparison with adults. 相似文献