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1.
Societal constraints often limit full process restoration in large river systems, making local rehabilitation activities valuable for regeneration of riparian vegetation. A target of much mitigation and restoration is the federally threatened Valley elderberry longhorn beetle and its sole host plant, blue elderberry, in upper riparian floodplain environments. However, blue elderberry ecology is not well understood and restoration attempts typically have low success rates. We determined broad-scale habitat characteristics of elderberry in altered systems and examined associated plant species composition in remnant habitat. We quantified vegetation community composition in 139 remnant riparian forest patches along the Sacramento River and elderberry stem diameters along this and four adjacent rivers. The greatest proportion of plots containing elderberry was located on higher and older floodplain surfaces and in riparian woodlands dominated by black walnut. Blue elderberry saplings and shrubs with stems <5.0 cm in diameter were rare, suggesting a lack of recruitment. A complex suite of vegetation was associated with blue elderberry, including several invasive species which are potentially outcompeting seedlings for light, water, or other resources. Such lack of recruitment places increased importance on horticultural restoration for the survival of an imperiled species. These findings further indicate a need to ascertain whether intervention is necessary to maintain functional and diverse riparian woodlands, and a need to monitor vegetative species composition over time, especially in relation to flow regulation.  相似文献   

2.
目前城镇体系规划在各地区相应开展,但作为城镇体系规划重要内容之一的生态与环境保护规划却没有得到普遍重视,这与城市可持续发展战略是不相适应的.从城镇体系规划角度出发,简述了生态与环境保护规划的要求、内容及作用,并以潮州市为例,对生态与环境保护规划进行了探讨,为城镇的开发与可持续发展提供决策依据.  相似文献   

3.
For the last 20 years, human–wildlife conflicts have been rapidly increasing in towns. Although people want “greener” cities, the expansion of disliked species causes problems that are difficult to manage and to reduce. The complexity of the numerous factors involved in these human–wildlife relations needs the development of a comprehensive tool for urban planners. Today, with the development of computers and geographical information systems, it is easier to analyze and combine different spatial data as methods used for the management of risks in studies of natural hazards. Here we present a method for assessing and mapping the risk in cases of human–wildlife conflict. An application to starling management in a town in western France will show the efficiency of our methods to combine information given by a network of experts and to highlight higher risk sites. The map of risk provides a spatial result useful for comprehension, communication between people and agencies, and public education.  相似文献   

4.
城市生态系统恢复研究进展   总被引:1,自引:0,他引:1  
定义了城市生态系统恢复的概念,分析了全球城市生态系统恢复状况,总结了城市生态系统恢复的研究进展,指出了城市生态系统恢复科学的研究方向.  相似文献   

5.
6.
Environmental monitoring activities are examined from a perspective which focuses on the political, economic and social factors which shape what we know and do not know about local environments. A UK urban case study is used to examine the range of influences that can operate on local level monitoring and comparisons are then made with the situation in three other European cities. Conclusions are drawn which debate the appropriate balance between local discretion and national and international direction in the collection of environmental information. It is argued that scrutiny of and revisions to the quality of current environmental monitoring in the UK and wider debate over questions of purpose, scope and resource commitment are needed.  相似文献   

7.
Analysis tools that combine large spatial and temporal scales are necessary for efficient management of wildlife species, such as the burrowing owl (Athene cunicularia). We assessed the ability of Ripley’s K-function analysis integrated into a geographic information system (GIS) to determine changes in burrowing owl nest clustering over two years at NASA Ames Research Center. Specifically, we used these tools to detect changes in spatial and temporal nest clustering before, during, and after conducting management by mowing to maintain low vegetation height at nest burrows. We found that the scale and timing of owl nest clustering matched the scale and timing of our conservation management actions over a short time frame. While this study could not determine a causal link between mowing and nest clustering, we did find that Ripley’s K and GIS were effective in detecting owl nest clustering and show promise for future conservation uses.  相似文献   

8.
当前野生动物保护公益诉讼主要呈现损害控制型司法模式的特性,该模式以刑事附带民事公益诉讼为常规渠道,救济对象是既成公益损害,救济方式是损害赔偿、修复及专项整治。诉讼方式谦抑性、因果关系推定规则以及案件线索发现机制事后性,为此模式的合理运行提供了理据。本文运用风险预防原则的理论框架,认为野生动物保护公益诉讼的救济客体不应局限于生态环境损害,公共卫生安全的风险预防等关联性客体也应纳入其中,而损害控制模式这种事后治理方法存在短板。基于此,应将公益诉讼的视角回溯至事前,大力倡导风险预防型司法模式。风险预防模式与损害控制模式属于二元协同关系,前者对后者发挥补强与优化功能。根据风险预防模式的救济观,可探索野生动物保护的预防性行政公益诉讼制度,并全方位构建程序规则,以实现公益诉讼的前瞻性价值。  相似文献   

9.
Summary This paper draws the attention to the major threats to nature conservation in Nigeria, and reviews critically the measures adopted for the protection of wildlife. The major problems include habitat degradation (through uncontrolled logging, agricultural projects, industrial plantations, highway and urban development, and exploitation for fuelwood), over-hunting and poachingSteps taken so far to protect wildlife include the creation of one national park and eighteen game reserves, enactment of wildlife laws, signing of international treaties, and manpower development. These measures have however failed to produce the desired effect owing largely to public apathy, low level of funding, inadequate game laws and weak enforcement of existing legal provisions.It is suggested that the Federal Government should intervene more positively in favour of conservation by creating more national parks and assuming joint responsibility with the states for formulating wildlife laws. Furthermore, the role of non-governmental organizations in influencing conservation policies and mobilizing public opinion will be crucial in the difficult years ahead.Dr. P. A. Anadu, although recently on secondment to the Department of Zoology, University of Oxford, UK; is currently on the staff of the Department of Forestry and Wildlife in the Faculty of Agriculture at the University of Benin.  相似文献   

10.
Within the park-deprived inner-city landscapes of Los Angeles, an unprecedented change is underway. Long considered to be the epitome of anti-nature, Los Angeles is witnessing a boom in park development and ecological restoration. Derelict, blighted and contaminated inner-city brownfield sites are being converted to greenspaces, nature parks and wildlife refuges. Indeed, Los Angeles has been the recent recipient of hitherto unimaginable political and fiscal support to ameliorate the dearth of parks in its neglected urban core. This paper situates the current round of park development within its historical context, by focusing on a very particular local site—the Kenneth Hahn State Recreation Area. Applying the theoretical lens of political ecology, the authors trace some of the political, economic, ecological and institutional factors from the late 1920s onwards, which engendered the creation of a park atop an oilfield. In so doing, the authors deepen the understanding of how local greenspace allocation, poverty, race and political power are oftentimes complexly entangled. Precursor to a much larger project currently in the planning and development stages, the creation of the Kenneth Hahn State Recreation Area reveals some of the ways that the Southern California oil industry has shaped nature spaces in Los Angeles.  相似文献   

11.
城市景观生态规划是景观生态学研完的领域之一,随着城市环境问题的出现,以及人们需求的提高,用景观生态设计理念来解决城市资源、环境和发展问题已成为当今社会的一个重要课题。本文以常州市为例,探讨以“生态基础设施建设”与“人文生态设计”为重要控制点的城市景观生态规划之路。  相似文献   

12.
13.
Hunting is a threat to wildlife within the Hkakaborazi National Park in north Myanmar. We used questionnaire surveys to obtain data on variables such as commonly targeted species, prices of traded wildlife, reasons for hunting and the relative importance of livelihood sources. We examine (a) the significance of hunting and trade for livelihoods and explore (b) the impacts of hunting on targeted species. Ninety per cent of trade records (n = 803) was constituted by seven species commonly targeted by hunters (serow, red goral, muntjac, bear, Assamese macaque, black musk deer and takin). Commercially valuable species previously targeted by hunters (tiger, otter, pangolin) appear to be completely absent from current harvest records and potentially in decline. Although farming is the predominant occupation, hunting (driven by trade) represents a significantly higher source of income than other livelihood activities. Management recommendations include increased investment in enforcement, education and outreach, small livestock development, improved crop productivity, demarcation of no-take areas for wildlife and biological monitoring of targeted species.  相似文献   

14.
Current United States National Park Service (NPS) management is challenged to balance visitor use with the environmental and social consequences of automobile use. Wildlife populations in national parks are increasingly vulnerable to road impacts. Other than isolated reports on the incidence of road-related mortality, there is little knowledge of how roads might affect wildlife populations throughout the national park system. Researchers at the Western Transportation Institute synthesized information obtained from a system-wide survey of resource managers to assess the magnitude of their concerns on the impacts of roads on park wildlife. The results characterize current conditions and help identify wildlife-transportation conflicts. A total of 196 national park management units (NPS units) were contacted and 106 responded to our questionnaire. Park resource managers responded that over half of the NPS units’ existing transportation systems were at or above capacity, with traffic volumes currently high or very high in one quarter of them and traffic expected to increase in the majority of units. Data is not generally collected systematically on road-related mortality to wildlife, yet nearly half of the respondents believed road-caused mortality significantly affected wildlife populations. Over one-half believed habitat fragmentation was affecting wildlife populations. Despite these expressed concerns, only 36% of the NPS units used some form of mitigation method to reduce road impacts on wildlife. Nearly half of the respondents expect that these impacts would only worsen in the next five years. Our results underscore the importance for a more systematic approach to address wildlife-roadway conflicts for a situation that is expected to increase in the next five to ten years.  相似文献   

15.
Deer hunter satisfaction is investigated from two perspectives, (1) satisfaction with the hunt/harvest and (2) satisfaction with the overall hunting trip experience. Regression analysis is used to determine what variables best predict satisfaction with the hunt and the hunting experience. Results indicate that animal population variables (number of deer seen, shot at, bagged) are the best determinants of a quality deer hunt, while environmental (outdoors) and social (crowding and hunter behavior) are the best predictors of a quality hunting trip experience. Wildlife managers and researchers need to realize that deer hunters view the hunt/harvest as different from the hunting trip experience and need to manage for both aspects of hunter satisfaction.  相似文献   

16.
滇中城市经济群作为云南省优先开发区,其经济发展尤其是工业经济发展与生态环境之间的矛盾日益突出。如何在工业经济发展的同时,以生态工业理论为指导,结合研究区域自身的资源优势和区位特点,建立起经济发展和生态环境保护有效整合的生态工业体系,实现经济的持续、健康和快速发展是当前滇中城市群经济发展面临的挑战。运用变异系数的距离协调度方法,定量分析滇中城市群工业经济发展与生态环境协调状况,并提出相应的对策与建议,以期为滇中城市群工业经济与生态环境的协调发展提供新的视角。  相似文献   

17.
Wildlife managers have little or no control over climate change. However, they may be able to alleviate potential adverse impacts of future climate change by adaptively managing wildlife for climate change. In particular, wildlife managers can evaluate the efficacy of compensatory management actions (CMAs) in alleviating potential adverse impacts of future climate change on wildlife species using probability-based or fuzzy decision rules. Application of probability-based decision rules requires managers to specify certain probabilities, which is not possible when they are uncertain about the relationships between observed and true ecological conditions for a species. Under such uncertainty, the efficacy of CMAs can be evaluated and the best CMA selected using fuzzy decision rules. The latter are described and demonstrated using three constructed cases that assume: (1) a single ecological indicator (e.g., population size for a species) in a single time period; (2) multiple ecological indicators for a species in a single time period; and (3) multiple ecological conditions for a species in multiple time periods.  相似文献   

18.
Irrigated Agriculture and Wildlife Conservation: Conflict on a Global Scale   总被引:10,自引:0,他引:10  
/ The demand for water to support irrigated agriculture has led to the demise of wetlands and their associated wildlife for decades. This thirst for water is so pervasive that many wetlands considered to be hemispheric reserves for waterbirds have been heavily affected; for example, the California and Nevada wetlands in North America, the Macquarie Marshes in Australia, and the Aral Sea in central Asia. These and other major wetlands have lost most of their historic supplies of water and some have also experienced serious impacts from contaminated subsurface irrigation drainage. Now mere shadows of what they once were in terms of biodiversity and wildlife production, many of the so-called "wetlands of international importance" are no longer the key conservation strongholds they were in the past. The conflict between irrigated agriculture and wildlife conservation has reached a critical point on a global scale. Not only has local wildlife suffered, including the extinction of highly insular species, but a ripple effect has impacted migratory birds worldwide. Human societies reliant on wetlands for their livelihoods are also bearing the cost. Ironically, most of the degradation of these key wetlands occurred during a period of time when public environmental awareness and scientific assertion of the need for wildlife conservation was at an all-time high. However, designation of certain wetlands as "reserves for wildlife" by international review boards has not slowed their continued degradation. To reverse this trend, land and water managers and policy makers must assess the true economic costs of wetland loss and, depending on the outcome of the assessment, use the information as a basis for establishing legally enforceable water rights that protect wetlands from agricultural development.  相似文献   

19.
To facilitate forest planning and management on National Wildlife Refuges, we synthesized multiple data sources to describe land ownership patterns, land cover, landscape pattern, and changes in forest composition for four ecoregions and their associated refuges of the Upper Midwest. We related observed patterns to ecological processes important for forest conservation and restoration, with specific attention to refuge patterns of importance for forest landbirds of conservation priority. The large amount of public land within the ecoregions (31–80%) suggests that opportunities exist for coarse and meso-scale approaches to conserving and restoring ecological processes affecting the refuges, particularly historical fire regimes. Forests dominate both ecoregions and refuges, but refuge forest patches are generally larger and more aggregated than in associated ecoregions. Broadleaf taxa have increased in dominance in the ecoregions and displaced fire-dependent taxa such as pine (Pinus spp.) and other coniferous species; these changes in forest composition have likely also affected refuge forests. Despite compositional changes, larger forest patches on refuges suggests that they may provide better habitat for area-sensitive forest landbirds of mature, compositionally diverse forests than surrounding lands if management continues to promote increased patch size. We reason that although fine-scale research and monitoring for species of conservation priority is important, broad scale (ecoregional) assessments provide crucial context for effective forest and wildlife management in protected areas.  相似文献   

20.
Some believe that provision of private property rights in wildlife on private land provides a powerful economic incentive for nature conservation because it enables property owners to market such wildlife or its attributes. If such marketing is profitable, private landholders will conserve the wildlife concerned and its required habitat. But land is not always most profitably used for exploitation of wildlife, and many economic values of wildlife (such as non-use economic values) cannot be marketed. The mobility of some wildlife adds to the limitations of the private-property approach. While some species may be conserved by this approach, it is suboptimal as a single policy approach to nature conservation. Nevertheless, it is being experimented with, in the Northern Territory of Australia where landholders had a possibility of harvesting on their properties a quota of eggs and chicks of red-tailed black cockatoos for commercial sale. This scheme was expected to provide an incentive to private landholders to retain hollow trees essential for the nesting of these birds but failed. This case and others are analysed. Despite private-property failures, the long-term survival of some wildlife species depends on their ability to use private lands without severe harassment, either for their migration or to supplement their available resources, for example, the Asian elephant. Nature conservation on private land is often a useful, if not essential, supplement to conservation on public lands. Community and public incentives for such conservation are outlined.  相似文献   

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