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561.
Effects of Forest Fragmentation and Habitat Degradation on West African Leaf-Litter Frogs 总被引:1,自引:0,他引:1
Abstract: Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We specifically asked whether the processes structuring leaf-litter anuran assemblages in fragmented forests are the same as those in continuous forests. We analyzed anuran assemblages with respect to habitat characteristics, including fragmentation and degradation parameters. In comparison with continuous forests, species richness and diversity were lower and assemblage composition was altered in forest fragments. These changes seemed to be mainly caused by habitat degradation rather than forest fragmentation. Availability of aquatic sites for breeding, vegetation structure (including those variables indicating degradation), and leaf-litter cover had the most influence on the presence of single species. The comparatively small impact of fragmentation on anurans might be due to the location of the study area; it still possessed large tracts of continuous forest. These forest blocks may stabilize the regional rainforest climate and thus weaken the effects of fragmentation . 相似文献
562.
风险评价在规划环境影响评价中的应用 总被引:1,自引:0,他引:1
规划环境影响评价(以下简称规划环评)是对规划实施后可能造成的影响进行分析、预测和评价的过程,属于战略影响评价范畴,需要解决区域内项目布局、规模等问题.规划环评中的风险评价应同规划环评的目标相对应,即从源头上对规划中涉及的风险源进行分析并提出预防或减缓风险的方案.比较了规划环评风险评价和建设项目风险评价后指出,规划环评中风险评价的目标主要在于通过对风险源的识别和分析,为整个区域内项目的布局、规模以及土地利用提供合理指导,并对原规划方案进行反馈.总结了风险评价用于规划环评中的特点及其与建设项目风险评价在步骤上的异同,并以平顶山化工城规划环境影响评价中风险评价的内容为例,对风险评价在规划环评中的应用进行了探讨.结果表明,平顶山的风险源对周围地区有一定影响,应考虑部分地区的搬迁工作. 相似文献
563.
The growth patterns of macroalgae in three-dimensional space can provide important information regarding the environments in which they live, and insights into changes that may occur when those environments change due to anthropogenic and/or natural causes. To decipher these patterns and their attendant mechanisms and influencing factors, a spatially explicit model has been developed. The model SPREAD (SPatially-explicit Reef Algae Dynamics), which incorporates the key morphogenetic characteristics of clonality and morphological plasticity, is used to investigate the influences of light, temperature, nutrients and disturbance on the growth and spatial occupancy of dominant macroalgae in the Florida Reef Tract. The model species, Halimeda and Dictyota spp., are modular organisms, with an “individual” being made up of repeating structures. These species can also propagate asexually through clonal fragmentation. These traits lead to potentially indefinite growth and plastic morphology that can respond to environmental conditions in various ways. The growth of an individual is modeled as the iteration of discrete macroalgal modules whose dynamics are affected by the light, temperature, and nutrient regimes. Fragmentation is included as a source of asexual reproduction and/or mortality. Model outputs are the same metrics that are obtained in the field, thus allowing for easy comparison. The performance of SPREAD was tested through sensitivity analysis and comparison with independent field data from four study sites in the Florida Reef Tract. Halimeda tuna was selected for initial model comparisons because the relatively untangled growth form permits detailed characterization in the field. Differences in the growth patterns of H. tuna were observed among these reefs. SPREAD was able to closely reproduce these variations, and indicate the potential importance of light and nutrient variations in producing these patterns. 相似文献
564.
565.
N'Goran PK Boesch C Mundry R N'Goran EK Herbinger I Yapi FA Kühl HS 《Conservation biology》2012,26(3):565-571
Abstract: Primates are regularly hunted for bushmeat in tropical forests, and systematic ecological monitoring can help determine the effect hunting has on these and other hunted species. Monitoring can also be used to inform law enforcement and managers of where hunting is concentrated. We evaluated the effects of law enforcement informed by monitoring data on density and spatial distribution of 8 monkey species in Taï National Park, Côte d’Ivoire. We conducted intensive surveys of monkeys and looked for signs of human activity throughout the park. We also gathered information on the activities of law‐enforcement personnel related to hunting and evaluated the relative effects of hunting, forest cover and proximity to rivers, and conservation effort on primate distribution and density. The effects of hunting on monkeys varied among species. Red colobus monkeys (Procolobus badius) were most affected and Campbell's monkeys (Cercopithecus campbelli) were least affected by hunting. Density of monkeys irrespective of species was up to 100 times higher near a research station and tourism site in the southwestern section of the park, where there is little hunting, than in the southeastern part of the park. The results of our monitoring guided law‐enforcement patrols toward zones with the most hunting activity. Such systematic coordination of ecological monitoring and law enforcement may be applicable at other sites. 相似文献
566.
567.
猫儿山自然保护区森林群落垂直格局与主导因素分析 总被引:2,自引:0,他引:2
陆地生态系统中海拔高度的变化会导致植物群落的垂直性分布,这是形成植物多样性的一个重要性原因。了解和分析不同区域植物群落的垂直性分布规律和生物多样性形成机制对保护森林生物多样性具有重要意义。本文通过对猫儿山自然保护区不同海拔高度森林植物群落和环境因子的调查,运用双向指示种分析(Two-way Indicator-Species Analysis)和典范对应分析(Canonical Correspondence Analysis),对不同海拔高度的群落进行划分,对决定植物群落分布的主导环境因子进行分析,结果表明:(1)猫儿自然保护区森林群落可以分为7个群落类型,其代表树种分别是罗浮栲Castanopsis fabri、栲树Castanopsis fargeisii、银木荷Schima argentea、铁椎栲Castanopsis lamontii、南方铁杉Tsuga chinensis、长苞铁杉Tsuga longibracterata、马尾松Pinus massoniana;(2)在中亚热带,海拔对山地植物群落形成起决定性作用;(3)土壤是仅次于海拔的重要环境因子,其中土类和土层厚度对森林群落的影响较大。在中亚热带森林生态保护和恢复过程中,按照不同海拔高度的植物群落特征选择种植合适树种,按照当地土壤条件选择适当的生态保护和恢复措施能加快生态恢复的进程,提高生态保护的效益。 相似文献
568.
健全全民所有自然资源资产管理体制,是实现自然资源资产合理使用和有效保护、发挥社会主义公有制优势、推动生态文明建设的重要举措.提炼三江源国家公园在自然资源资产管理体制改革过程中的典型实践,梳理其改革经验与启示,为探索建设以国家公园为代表的自然保护地体系内自然资源资产管理积累"青海经验"、做出"青海贡献". 相似文献
569.
The current status of the treatment and disposal of hazardous wastes in China is summarized on the basis of the results of
the Declaring and Registration Project initiated nationally in 1995. A principle framework for the sound management of hazardous
wastes is proposed, which includes three levels of technical solutions. Large-scale enterprises are encouraged to recycle,
to treat, and to dispose of wastes by means of constructing facilities, and to have their extra capacities available to the
public for a reasonable fee. Municipal governments, provincial governments, and the Central Government are to plan and construct
centralized facilities to recycle, treat, and dispose of wastes. For a solution at the manufacturing level, recycling is identified
as the main approach. Centralized facilities at the municipal level will mainly focus on special wastes that are unsuitable
to transport and store, such as hospital waste, and for the technical solution at this level, incineration and recycling are
identified as the main approaches. For the technical solution at the provincial and national levels, landfill and incineration
are identified as the main approaches. Based on this principle and the current available data on hazardous wastes, a preliminary
plan for the spatial distribution of cross-provincial centralized treatment and disposal facilities of hazardous wastes is
presented. The construction of approximately nine cross-provincial comprehensive facilities is proposed. A priority list for
the construction of these planned facilities is also presented. 相似文献
570.
The Pinelands National Reserve was created in 1978 when private interests and federal, state, and local governments allied
to protect 378,000 ha (935,000 acres) of New Jersey's Pine Barrens from encroaching development. An intergovernmental authority,
the Pinelands Commission, manages the reserve by implementing a regional plan to guide development away from environmentally
sensitive areas and into designated growth centers. Through transferable development rights, financial gains from development
in growth centers are used to compensate owners and localities in the reserve who might otherwise have developed their lands.
The national reserve strategy contrasts with other federal strategies for preserving unique environments in which the federal
government exercises exclusive control (e.g., national parks, monuments, and recreation areas). This article describes the
strategy applied in the Pinelands and discusses the conditions in which it may be more or less effective than other strategies
used to protect unique or valued landscapes. It then compares the Pinelands model with the strategies and conditions of california's
Redwood National Park and Point Reyes National Seashore to develop propositions about the circumstances in which one or another
strategy is more likely to be viable. Finally, it applies these propositions to the possibilities for future forest preservation
in New England. 相似文献