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121.
植物不同器官水、碳、氮、磷等元素含量及其生态化学计量特征能够反映植物的生态策略及其环境适应性。本研究以黄土高原两种乡土树种油松(Pinus tabulaeformis)和柴松(Pinus tabulaefirmis f.shekanensis)为研究对象,分析了研究区两种树种水、碳、氮和磷在不同器官的含量及其生态化学计量特征,探讨了两种树种基于水、碳、氮和磷分配格局的生态适应策略。结果表明:(1)油松和柴松对水分和碳素的分配格局总体表现为根和叶最大,其次为枝和干,树皮最小;对氮、磷的分配格局则表现为叶片显著高于其他器官。(2)油松将更多的水和氮分配给叶、根等生产性器官,而柴松将更多的水和碳分配给枝、干等防御性器官,反映了柴松较油松具有更加保守的生长策略,能够更好适应逆境条件。(3)植物器官不同元素间通过相互耦合后可以表现出较好的相关性,反映了植物元素之间具有高度复杂的协同关系,这种协同关系的体现形式可能与植物类型及其对外界环境变化的生长适应策略密切相关。  相似文献   
122.
赤潮藻类的适应与竞争策略   总被引:10,自引:0,他引:10  
赤潮藻类的生活策略与赤潮发生的机理紧密相关。在漫长的自然进化过程中,赤潮藻类发展出一系列独特的生活策略以适应环境的变化。赤潮藻类可以在不良环境下形成孢囊以度过寒冷的冬季或者营养缺乏时期并在条件合适时萌发。甲藻可以通过主动迁移或者产生粘液的行为来适应水流和光照,甚至有时能够改变藻细胞周围的微环境。赤潮藻类采用多种营养方式如自养、异养或混养进行生长和繁殖,这对我们就赤潮与富营养化的关系的研究带来了全新的理解。赤潮藻类与其他生物存在复杂的相互关系,某些蓝绿藻可以与细菌或病毒共生,而有毒藻类也许可以通过抑制捕食或者植化相克为自身获利。最后,我们提出了赤潮藻类的形态结构上的不同也许可以解释某些生态策略的差异。  相似文献   
123.
旧城区绿地作为关键的社会—生态系统载体,是城市高质量发展与转型治理亟需关注的问题。构建广州旧城区绿地服务基本单元,引入适应性循环理论的潜力—连通度—恢复力三维框架,构建表征生态、社会与经济服务的绿地景观指标体系,综合评估2000—2018年广州旧城区绿地的空间恢复力水平及适应性转化特征。研究结果显示:旧城区绿地的恢复力演化具有明显的核心区与外围区的时空分异,在拆除重建阶段呈现快速开发—快速释放—重组的转化,在微更新阶段主要呈现开发—保护的提升,并具有提升型、稳定型和更替型的社会—生态系统服务适应性。由此说明,城市更新具有调节社会—生态系统服务治理的效果。其中,绿地形状指数、5 min可达绿地率以及土地利用混合度对核心区绿地恢复力具有显著的促进作用,为外围区治理提供参考。同时,进一步探讨了更新政策与城市绿地空间恢复力演化的关系,为促进旧城区绿地空间更新治理提供社会—生态系统适应性的理论与实证案例研究。  相似文献   
124.
Conflict is an important factor in ongoing climate change debates and its role in management is under increasing scrutiny. In this paper, I present the results of an advanced discourse analysis that analyses trends in the relationship between conflict and climate change. I present two primary discourses dominate discussion: (i) climate as a security risk and (ii) climate as one of many factors affecting power relations that may lead to conflict. Both narratives implicitly or explicitly discuss climate conflict as a cause–outcome relationship, and further primarily construct conflict and climate change within normative frames. Yet, conflict has transformative potential and can be incorporated into management in ways that harness its capacity to drive innovation and lead to more robust and just adaptive governance. I argue for a shift in the discursive frame from a cause– outcome-oriented approach to a process-driven approach, one that treats conflict as an integral part of adaptive governance processes, thus being more just and equitable. Such a shift in focus can lead to positive on ground climate adaptation outcomes, in ways that respect rather than are counter-intuitive to dominant political and societal imbalances and institutional structures.  相似文献   
125.
There is increasing recognition among conservation scientists that long‐term conservation outcomes could be improved through better integration of evolutionary theory into management practices. Despite concerns that the importance of key concepts emerging from evolutionary theory (i.e., evolutionary principles and processes) are not being recognized by managers, there has been little effort to determine the level of integration of evolutionary theory into conservation policy and practice. We assessed conservation policy at 3 scales (international, national, and provincial) on 3 continents to quantify the degree to which key evolutionary concepts, such as genetic diversity and gene flow, are being incorporated into conservation practice. We also evaluated the availability of clear guidance within the applied evolutionary biology literature as to how managers can change their management practices to achieve better conservation outcomes. Despite widespread recognition of the importance of maintaining genetic diversity, conservation policies provide little guidance about how this can be achieved in practice and other relevant evolutionary concepts, such as inbreeding depression, are mentioned rarely. In some cases the poor integration of evolutionary concepts into management reflects a lack of decision‐support tools in the literature. Where these tools are available, such as risk‐assessment frameworks, they are not being adopted by conservation policy makers, suggesting that the availability of a strong evidence base is not the only barrier to evolutionarily enlightened management. We believe there is a clear need for more engagement by evolutionary biologists with policy makers to develop practical guidelines that will help managers make changes to conservation practice. There is also an urgent need for more research to better understand the barriers to and opportunities for incorporating evolutionary theory into conservation practice.  相似文献   
126.
Adaptive management implies a continuous knowledge‐based decision‐making process in conservation. Yet, the coupling of scientific monitoring and management frameworks remains rare in practice because formal and informal communication pathways are lacking. We examined 4 cases in Micronesia where conservation practitioners are using new knowledge in the form of monitoring data to advance marine conservation. These cases were drawn from projects in Micronesia Challenge jurisdictions that received funding for coupled monitoring‐to‐management frameworks and encompassed all segments of adaptive management. Monitoring in Helen Reef, Republic of Palau, was catalyzed by coral bleaching and revealed evidence of overfishing that led to increased enforcement and outreach. In Nimpal Channel, Yap, Federated States of Micronesia (FSM), monitoring the recovery of marine food resources after customary restrictions were put in place led to new, more effective enforcement approaches. Monitoring in Laolao Bay, Saipan, Commonwealth of the Northern Mariana Islands, was catalyzed by observable sediment loads from poor land‐use practices and resulted in actions that reduced land‐based threats, particularly littering and illegal burning, and revealed additional threats from overfishing. Pohnpei (FSM) began monitoring after observed declines in grouper spawning aggregations. This data led to adjusting marine conservation area boundaries and implementing market‐based size class restrictions. Two themes emerged from these cases. First, in each case monitoring was conducted in a manner relevant to the social and ecological systems and integrated into the decision‐making process. Second, conservation practitioners and scientists in these cases integrated culturally appropriate stakeholder engagement throughout all phases of the adaptive management cycle. More broadly, our study suggests, when describing adaptive management, providing more details on how monitoring and management activities are linked at similar spatial scales and across similar time frames can enhance the application of knowledge.  相似文献   
127.
The ecosystem approach—as endorsed by the Convention on Biological Diversity (CDB) in 2000—is a strategy for holistic, sustainable, and equitable natural resource management, to be implemented via the 12 Malawi Principles. These principles describe the need to manage nature in terms of dynamic ecosystems, while fully engaging with local peoples. It is an ambitious concept. Today, the term is common throughout the research and policy literature on environmental management. However, multiple meanings have been attached to the term, resulting in confusion. We reviewed references to the ecosystem approach from 1957 to 2012 and identified 3 primary uses: as an alternative to ecosystem management or ecosystem‐based management; in reference to an integrated and equitable approach to resource management as per the CBD; and as a term signifying a focus on understanding and valuing ecosystem services. Although uses of this term and its variants may overlap in meaning, typically, they do not entirely reflect the ethos of the ecosystem approach as defined by the CBD. For example, there is presently an increasing emphasis on ecosystem services, but focusing on these alone does not promote decentralization of management or use of all forms of knowledge, both of which are integral to the CBD's concept. We highlight that the Malawi Principles are at risk of being forgotten. To better understand these principles, more effort to implement them is required. Such efforts should be evaluated, ideally with comparative approaches, before allowing the CBD's concept of holistic and socially engaged management to be abandoned or superseded. It is possible that attempts to implement all 12 principles together will face many challenges, but they may also offer a unique way to promote holistic and equitable governance of natural resources. Therefore, we believe that the CBD's concept of the ecosystem approach demands more attention. La Necesidad de Desenredar Conceptos Clave del Argot Ambiente‐Estrategia  相似文献   
128.
Globally, marine protected areas (MPAs) have been relatively unsuccessful in meeting biodiversity objectives. To be effective, they require some alteration of people's use and access to marine resources, which they will resist if they do not perceive associated benefits. Stakeholders’ support is crucial to ecological success of MPAs, and their support is likely to depend on their capacity to adapt to and benefit from MPAs. We examined the influence of social adaptive capacity (SAC) on perceived benefits of MPAs in Siquijor, Philippines, in the Coral Triangle. This region has substantial biodiversity and a population of over 120 million people, many of them dependent on marine resources for food and income. The region has many MPAs, most of which are managed under decentralized governance systems. We collected survey data from 540 households in 19 villages with associated MPAs. We evaluated the influence of multiple SAC variables (e.g., occupational multiplicity and social capital) on perceived benefits with decision trees (CHAID) and qualitatively analyzed this relationship with respect to types and recipients of benefits. Our models revealed the key role of social capital, particularly trust in leadership, in influencing perceptions of benefits (χ2 = 14.762, p = 0.000). A path analysis revealed that perceptions of distributional equity were a key mechanism through which social capital affected perceived MPA benefits (root mean‐square error of approximation = 0.050). Building social capital and equity within communities could lead to more effective management of MPAs and thus to expenditure of fewer resources relative to, for example, regulation enforcement.  相似文献   
129.
In the recent years, global environmental change research has seen increased attention to the concept of vulnerability. There have been a growing number of vulnerability assessments, but relatively little discussion on appropriate and common methods. Here we propose a method to guide vulnerability assessments of coupled human–environment systems toward a common objective: informing the decision-making of specific stakeholders about options for adapting to the effects of global change. We suggest five criteria vulnerability assessments must at least possess to achieve this objective. They should have a knowledge base from various disciplines and stakeholder participation, be place based, consider multiple interacting stresses, examine differential adaptive capacity, and be prospective as well as historical. On the basis of these criteria, we present a general methodological guideline of eight steps. To examine whether these eight steps, if attentively coordinated, do in fact achieve the criteria, and in turn satisfy the objective of the assessment, we discuss two case studies. We expect most readers to identify some of the steps as part of their well-established disciplinary practices. However, they should also identify one or more steps as uncommon to their research traditions. Thus taken together the eight steps constitute a novel methodological framework. We hypothesize that if researchers employ this framework, then the products of the research will (1) achieve the objective of preparing stakeholders for the effects of global change on a site-specific basis, and (2) further the “public good” of additional insights through cross-study comparisons of research projects designed according to common principles.  相似文献   
130.
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