首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   91篇
  免费   32篇
安全科学   2篇
废物处理   1篇
环保管理   1篇
基础理论   119篇
  2023年   9篇
  2022年   5篇
  2021年   10篇
  2020年   14篇
  2019年   12篇
  2018年   10篇
  2017年   8篇
  2016年   6篇
  2015年   8篇
  2014年   6篇
  2013年   12篇
  2012年   6篇
  2011年   3篇
  2010年   9篇
  2009年   2篇
  2008年   3篇
排序方式: 共有123条查询结果,搜索用时 46 毫秒
71.
72.
At the global scale, biodiversity indicators are typically used to monitor general trends, but are rarely implemented with specific purpose or linked directly to decision making. Some indicators are better suited to predicting future change, others are more appropriate for evaluating past actions, but this is seldom made explicit. We developed a conceptual model for assigning biodiversity indicators to appropriate functions based on a common approach used in economics. Using the model, indicators can be classified as leading (indicators that change before the subject of interest, informing preventative actions), coincident (indicators that measure the subject of interest), or lagging (indicators that change after the subject of interest has changed and thus can be used to evaluate past actions). We classified indicators based on ecological theory on biodiversity response times and management objectives in 2 case studies: global species extinction and marine ecosystem collapse. For global species extinctions, indicators of abundance (e.g., the Living Planet Index or biodiversity intactness index) were most likely to respond first, as leading indicators that inform preventative action, while extinction indicators were expected to respond slowly, acting as lagging indicators flagging the need for evaluation. For marine ecosystem collapse, indicators of direct responses to fishing were expected to be leading, while those measuring ecosystem collapse could be lagging. Classification defines an active role for indicators within the policy cycle, creates an explicit link to preventative decision-making, and supports preventative action.  相似文献   
73.
Rewilding has been an increasingly popular tool to restore plant–animal interactions and ecological processes impaired by defaunation. However, the reestablishment of such processes has seldom been assessed. We investigated the restoration of ecological interactions following the reintroduction of the brown howler monkey (Alouatta guariba) to a defaunated Atlantic forest site. We expected the reintroduction to restore plant–animal interactions and interactions between howlers and dung beetles, which promote secondary seed dispersal. We estimated the number of interactions expected to be restored by the reintroduction to provide the baseline interaction richness that could be restored. We followed the reintroduced howler monkeys twice a week for 24 months (337 hours total) to assess their diet. We used howler monkey dung in secondary seed dispersal experiments with 2484 seed mimics to estimate the removal rates by dung beetles and collected the beetles to assess community attributes. We compared the potential future contribution of howler monkeys and other frugivores to seed dispersal based on the seed sizes they disperse in other areas where they occur. In 2 years, howler monkeys consumed 60 animal-dispersed plant species out of the 330 estimated. Twenty-one dung beetle species were attracted to experimentally provided dung; most of them were tunnelers, nocturnal, and large-sized (>10 mm). On average 30% (range 0–100%) of the large seed mimics (14 mm) were moved by dung beetles. About 91% of the species consumed by howlers (size range 0.3–34.3 mm) overlapped in seed size with those removed by dung beetles. In our study area, howler monkeys may consume more large-seeded fruit species than most other frugivores, highlighting their potential to affect forest regeneration. Our results show reintroductions may effectively restore ecological links and enhance ecological processes.  相似文献   
74.
Conservation efforts to protect forested landscapes are challenged by climate projections that suggest substantial restructuring of vegetation and disturbance regimes in the future. In this regard, paleoecological records that describe ecosystem responses to past variations in climate, fire, and human activity offer critical information for assessing present landscape conditions and future landscape vulnerability. We illustrate this point drawing on 8 sites in the northwestern United States, New Zealand, Patagonia, and central and southern Europe that have undergone different levels of climate and land‐use change. These sites fall along a gradient of landscape conditions that range from nearly pristine (i.e., vegetation and disturbance shaped primarily by past climate and biophysical constraints) to highly altered (i.e., landscapes that have been intensely modified by past human activity). Position on this gradient has implications for understanding the role of natural and anthropogenic disturbance in shaping ecosystem dynamics and assessments of present biodiversity, including recognizing missing or overrepresented species. Dramatic vegetation reorganization occurred at all study sites as a result of postglacial climate variations. In nearly pristine landscapes, such as those in Yellowstone National Park, climate has remained the primary driver of ecosystem change up to the present day. In Europe, natural vegetation–climate–fire linkages were broken 6000–8000 years ago with the onset of Neolithic farming, and in New Zealand, natural linkages were first lost about 700 years ago with arrival of the Maori people. In the U.S. Northwest and Patagonia, the greatest landscape alteration occurred in the last 150 years with Euro‐American settlement. Paleoecology is sometimes the best and only tool for evaluating the degree of landscape alteration and the extent to which landscapes retain natural components. Information on landscape‐level history thus helps assess current ecological change, clarify management objectives, and define conservation strategies that seek to protect both natural and cultural elements.  相似文献   
75.
A significant limitation in biodiversity conservation has been the effective implementation of laws and regulations that protect species’ habitats from degradation. Flexible, efficient, and effective monitoring and enforcement methods are needed to help conservation policies realize their full benefit. As remote sensing data become more numerous and accessible, they can be used to identify and quantify land-cover changes and habitat loss. However, these data remain underused for systematic conservation monitoring in part because of a lack of simple tools. We adapted 2 algorithms that automatically identify differences between pairs of images. We used free, publicly available satellite data to evaluate their ability to rapidly detect land-cover changes in a variety of land-cover types. We compared algorithm predictions with ground-truthed results at 100 sites of known change in the United States. We also compared algorithm predictions to manually created polygons delineating anthropogenic change in 4 case studies involving imperiled species’ habitat: oil and gas development in the range of the Greater Sage Grouse (Centrocercus urophasianus); sand mining operations in the range of the dunes sagebrush lizard (Sceloporus arenicolus); loss of Piping Plover (Charadrius melodus) coastal habitat after Hurricane Michael (2018); and residential development in St. Andrew beach mouse (Peromyscus polionotus peninsularis) habitat. Both algorithms effectively discriminated between pixels corresponding to land-cover change and unchanged pixels as indicated by area under a receiver operating characteristic curve >0.90. The algorithm that was most effective differed among the case-study habitat types, and both effectively delineated habitat loss as indicated by low omission (min. = 0.0) and commission (min. = 0.0) rates, and moderate polygon overlap (max. = 47%). Our results showed how these algorithms can be used to help close the implementation gap of monitoring and enforcement in biodiversity conservation. We provide a free online tool that can be used to run these analyses ( https://conservationist.io/habitatpatrol ).  相似文献   
76.
To help stem the continuing decline of biodiversity, effective transfer of technology from resource‐rich to biodiversity‐rich countries is required. Biodiversity technology as defined by the Convention on Biological Diversity (CBD) is a complex term, encompassing a wide variety of activities and interest groups. As yet, there is no robust framework by which to monitor the extent to which technology transfer might benefit biodiversity. We devised a definition of biodiversity technology and a framework for the monitoring of technology transfer between CBD signatories. Biodiversity technology within the scope of the CBD encompasses hard and soft technologies that are relevant to the conservation and sustainable use of biodiversity, or make use of genetic resources, and that relate to all aspects of the CBD, with a particular focus on technology transfer from resource‐rich to biodiversity‐rich countries. Our proposed framework introduces technology transfer as a response indicator: technology transfer is increased to stem pressures on biodiversity. We suggest an initial approach of tracking technology flow between countries; charting this flow is likely to be a one‐to‐many relationship (i.e., the flow of a specific technology from one country to multiple countries). Future developments should then focus on integrating biodiversity technology transfer into the current pressure‐state‐response indicator framework favored by the CBD (i.e., measuring the influence of technology transfer on changes in state and pressure variables). Structured national reporting is important to obtaining metrics relevant to technology and knowledge transfer. Interim measures, that can be used to assess biodiversity technology or knowledge status while more in‐depth indicators are being developed, include the number of species inventories, threatened species lists, or national red lists; databases on publications and project funding may provide measures of international cooperation. Such a pragmatic approach, followed by rigorous testing of specific technology transfer metrics submitted by CBD signatories in a standardized manner may in turn improve the focus of future targets on technology transfer for biodiversity conservation.  相似文献   
77.
78.
Substantial declines in farmland biodiversity have been reported in Europe for several decades. Agricultural changes have been identified as a main driver of these declines. Although different agrienvironmental schemes have been implemented, their positive effect on biodiversity is relatively unknown. This raises the question as to how to reconcile farming production and biodiversity conservation to operationalize a sustainable and multifunctional agriculture. We devised a bioeconomic model and conducted an analysis based on coviability of farmland biodiversity and agriculture. The coviability approach extended population viability analyses by including bioeconomic risk. Our model coupled stochastic dynamics of both biodiversity and farming land‐uses selected at the microlevel with public policies at the macrolevel on the basis of financial incentives (taxes or subsidies) for land uses. The coviability approach made it possible for us to evaluate bioeconomic risks of these public incentives through the probability of satisfying a mix of biodiversity and economic constraints over time. We calibrated the model and applied it to a community of 34 common birds in metropolitan France at the small agricultural regions scale. We identified different public policies and scenarios with tolerable (0–0%) agroecological risk and modeled their outcomes up to 2050. Budgetary, economic, and ecological (based on Farmland Bird Index) constraints were essential to understanding the set of viable public policies. Our results suggest that some combinations of taxes on cereals and subsidies on grasslands could be relevant to develop a multifunctional agriculture. Moreover, the flexibility and multicriteria viewpoint underlying the coviability approach may help in the implementation of adaptive management. Del Análisis de Viabilidad Poblacional a la Co‐Viabilidad de la Agricultura y la Biodiversidad de las Tierras de Cultivo  相似文献   
79.
We present a framework of resource characteristics critical to the design and assessment of citizen science programs that monitor natural resources. To develop the framework we reviewed 52 citizen science programs that monitored a wide range of resources and provided insights into what resource characteristics are most conducive to developing citizen science programs and how resource characteristics may constrain the use or growth of these programs. We focused on 4 types of resource characteristics: biophysical and geographical, management and monitoring, public awareness and knowledge, and social and cultural characteristics. We applied the framework to 2 programs, the Tucson (U.S.A.) Bird Count and the Maui (U.S.A.) Great Whale Count. We found that resource characteristics such as accessibility, diverse institutional involvement in resource management, and social or cultural importance of the resource affected program endurance and success. However, the relative influence of each characteristic was in turn affected by goals of the citizen science programs. Although the goals of public engagement and education sometimes complimented the goal of collecting reliable data, in many cases trade‐offs must be made between these 2 goals. Program goals and priorities ultimately dictate the design of citizen science programs, but for a program to endure and successfully meet its goals, program managers must consider the diverse ways that the nature of the resource being monitored influences public participation in monitoring.  相似文献   
80.
Fluvial fishes face increased imperilment from anthropogenic activities, but the specific factors contributing most to range declines are often poorly understood. For example, the range of the fluvial‐specialist shoal bass (Micropterus cataractae) continues to decrease, yet how perceived threats have contributed to range loss is largely unknown. We used species distribution models to determine which factors contributed most to shoal bass range loss. We estimated a potential distribution based on natural abiotic factors and a series of currently occupied distributions that incorporated variables characterizing land cover, non‐native species, and river fragmentation intensity (no fragmentation, dams only, and dams and large impoundments). We allowed interspecific relationships between non‐native congeners and shoal bass to vary across fragmentation intensities. Results from the potential distribution model estimated shoal bass presence throughout much of their native basin, whereas models of currently occupied distribution showed that range loss increased as fragmentation intensified. Response curves from models of currently occupied distribution indicated a potential interaction between fragmentation intensity and the relationship between shoal bass and non‐native congeners, wherein non‐natives may be favored at the highest fragmentation intensity. Response curves also suggested that >100 km of interconnected, free‐flowing stream fragments were necessary to support shoal bass presence. Model evaluation, including an independent validation, suggested that models had favorable predictive and discriminative abilities. Similar approaches that use readily available, diverse, geospatial data sets may deliver insights into the biology and conservation needs of other fluvial species facing similar threats.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号