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581.
Planning for Climate Change: Identifying Minimum-Dispersal Corridors for the Cape Proteaceae 总被引:10,自引:0,他引:10
PAUL WILLIAMS§§ LEE HANNAH† SANDY ANDELMAN‡ GUY MIDGLEY§ MIGUEL ARAÚJO††† GREG HUGHES§ LISA MANNE†† ENRIQUE MARTINEZ-MEYER‡‡ RICHARD PEARSON†† 《Conservation biology》2005,19(4):1063-1074
Abstract: Climate change poses a challenge to the conventional approach to biodiversity conservation, which relies on fixed protected areas, because the changing climate is expected to shift the distribution of suitable areas for many species. Some species will persist only if they can colonize new areas, although in some cases their dispersal abilities may be very limited. To address this problem we devised a quantitative method for identifying multiple corridors of connectivity through shifting habitat suitabilities that seeks to minimize dispersal demands first and then the area of land required. We applied the method to Proteaceae mapped on a 1-minute grid for the western part of the Cape Floristic Region of South Africa, to supplement the existing protected areas, using Worldmap software. Our goal was to represent each species in at least 35 grid cells (approximately 100 km2 ) at all times between 2000 and 2050 despite climate change. Although it was possible to achieve the goal at reasonable cost, caution will be needed in applying our method to reserves or other conservation investments until there is further information to support or refine the climate-change models and the species' habitat-suitability and dispersal models. 相似文献
582.
Echelons provide an objective approach to prospecting for areas of potential concern in synoptic regional monitoring of a surface variable. Echelons can be regarded informally as stacked hill forms. The strategy is to identify regions of the surface which are elevated relative to surroundings (Relative ELEVATIONS or RELEVATIONS). These are areas which would continue to expand as islands with receding (virtual) floodwaters. Levels where islands would merge are critical elevations which delimit echelons in the vertical dimension. Families of echelons consist of surface sectors constituting separate islands for deeper waters that merge as water level declines. Pits which would hold water are disregarded in such a progression, but a complementary analysis of pits is obtained using the surface as a virtual mould to cast a counter-surface (bathymetric analysis). An echelon tree is a family tree of echelons with peaks as terminals and the lowest level as root. An echelon tree thus provides a dendrogram representation of surface topology which enables graph theoretic analysis and comparison of surface structures. Echelon top view maps show echelon cover sectors on the base plane. An echelon table summarizes characteristics of echelons as instances or cases of hill form surface structure. Determination of echelons requires only ordinal strength for the surface variable, and is thus appropriate for environmental indices as well as measurements. Since echelons are inherent in a surface rather than perceptual, they provide a basis for computer-intelligent understanding of surfaces. Echelons are given for broad-scale mammalian species richness in Pennsylvania. 相似文献
583.
Assessing Conservation Management's Evidence Base: a Survey of Management-Plan Compilers in the United Kingdom and Australia 总被引:2,自引:0,他引:2
Abstract: Conservation management is becoming increasingly resource intensive as threats to biodiversity grow through habitat destruction, habitat disturbance, and overexploitation. To achieve successful conservation and sustainable use of natural resources, we need to scientifically evaluate the effectiveness of conservation interventions and provide an efficient framework through which scientific evidence can be used to support decision making in policy and practice. We conducted the first formal assessment of the extent to which scientific evidence is used in conservation management through a questionnaire survey and follow-up interviews of compilers of protected-area management plans from major conservation organizations within the United Kingdom and Australia. Our survey results show that scientific information is not being used systematically to support decision making largely because it is not easily accessible to decision makers. This, in combination with limited monitoring and evaluation of effectiveness of management interventions, results in the majority of decisions being based on experience rather than on evidence. To address this problem we propose using an evidence-based framework adapted from that used in the health services and explain how we are currently putting an equivalent framework into practice by establishing review and dissemination units to serve the conservation sector. 相似文献
584.
Christopher A. Frissell David Bayles 《Journal of the American Water Resources Association》1996,32(2):229-240
ABSTRACT: Ecologically effective ecosystem management will require the development of a robust logic, rationale, and framework for addressing the inherent limitations of scientific understanding. It must incorporate a strategy for avoiding irreversible or large-scale environmental mistakes that arise from social and political forces that tend to promote fragmented, uncritical, short-sighted, inflexible, and overly optimistic assessments of resource status, management capabilities, and the consequences of decisions and policies. Aquatic resources are vulnerable to the effects of human activities catchment-wide, and many of the landscape changes humans routinely induce cause irreversible damage (e.g., some species introductions, extinctions of ecotypes and species) or give rise to cumulative, long-term, large-scale biological and cultural consequences (e.g., accelerated erosion and sedimentation, deforestation, toxic contamination of sediments). In aquatic ecosystems, biotic impoverishment and environmental disruption caused by past management and natural events profoundly constrain the ability of future management to maintain biodiversity and restore historical ecosystem functions and values. To provide for rational, adaptive progress in ecosystem management and to reduce the risk of irreversible and unanticipated consequences, managers and scientists must identify catchments and aquatic networks where ecological integrity has been least damaged by prior management, and jointly develop means to ensure their protection as reservoirs of natural biodiversity, keystones for regional restoration, management models, monitoring benchmarks, and resources for ecological research. 相似文献
585.
586.
区域生态系统多样性评价方法 总被引:1,自引:0,他引:1
针对不同区域尺度上同一类型的生态系统,提出了6项评价原则和一套包括多样性、特有性、代表性、稀有性、稳定性、自然性、保护价值、可接近度、人类干扰。自然灾害和保护现状等指标的分层次评价指标体系。在此基础上,采用将指标数量化的方法,建立了一种操作简单、调控性强的定量评价方法。 相似文献
587.
综述了转基因作物根系分泌物和转基因作物残茬对土壤微生物和土壤动物的影响,主要表现在3方面:(1)对某些微生物和土壤动物有毒害作用;(2)为特定的微生物和土壤生物提供营养;(3)对土壤生物可能产生长期累积影响,但对此尚无定论。 相似文献
588.
本文介绍了青藏高原青海省境内部分珍稀生物的生存状态,以及保护区的建设对保护生物多样性的作用。文章对青海省自然保护区的建设与发展提出了设想和措施。 相似文献
589.
Abstract: Our objective was to reexamine the definition and use of surrogates in biodiversity studies of disturbed ecological communities. To this end, we examined diversity and community structure in recovering (pollution damaged) and restored (via liming, fertilizing, seeding, and planting) forests in the Great Lakes-St. Lawrence zone near Sudbury, Ontario, Canada. The relationships among taxonomic groups were determined using correlations between Shannon diversity and species richness. We used correspondence analysis to quantify the contribution of taxonomic groups to diversity and community structure. We detected useful surrogates in the naturally recovering forests but not in restored forests. In the former, vascular plant diversity was significantly correlated with nonvascular plant diversity and reflected community structure in the total plant community. Our results suggest that it may be important to restore and conserve diversity relationships rather than simply diversity levels because the relationships may be better indicators of ecosystem health or function. 相似文献
590.
Enhancement of Farmland Biodiversity within Set-Aside Land 总被引:7,自引:0,他引:7
Abstract: The efficacy of agricultural set-aside policies for protecting farmland biodiversity is widely debated. Based on a meta-analysis of 127 published studies, we found that land withdrawn from conventional production unequivocally enhances biodiversity in North America and Europe. The number of species of birds, insects, spiders, and plants is 1–1.5 standard deviation units higher on set-aside land, and population densities increase by 0.5–1 standard deviation units. Set-aside land may be especially beneficial for desirable taxa because North American bird species that have exhibited population declines react most positively to set-aside agricultural land. Larger and older plots protect more species and higher densities, and set-aside land is more effective in countries with less-intensive agricultural practices and higher fractions of land removed from production. Although policies specifically designed to protect biodiversity might work even better, current incentives clearly improve the standing of plants and animals in farmland. 相似文献