首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Beginning with an outline of uncertainties about the number of species on Earth today, this paper addresses likely causes and consequences of the manifest acceleration in extinction rates over the past few centuries. The ultimate causes are habitat destruction, alien introductions, overexploitation and climate change. Increases in human numbers and per capita impacts underlie all of these. Against a background review of these factors, I conclude with a discussion of the policy implications for equitably proportionate actions—and of the difficulties in achieving them.  相似文献   

2.
Visitor management in parks, wilderness and other protected areas requires information about visitor-environment interactions and, particularly, the distribution and flow of visitors in space and time. Such information is usually sketchy and based largely on the verbal reports of visitors. A review of recent psychological and neurological research and theory suggests that traditional verbal survey methods cannot in principle provide an adequate basis for models of human landscape navigation. We argue for more use of direct observation of visitor movements and the utility of travel simulation models. Simulation modelling of visitor flow can be helpful in making monitoring programs more efficient, in fine-tuning existing management programs, and in assessing the likely consequences of alternative future scenarios We review early efforts to simulate the flow of recreation use, describe several current modelling efforts and conclude with suggestions for a research and development effort.  相似文献   

3.
The financial returns to Kenyan tourism demonstrate the importance of the country's tourist potential to its economic development. Protected areas and their inhabitants are the principal focus of the tourist industry, the nations's main foreign exchange earner, and a source of wonder and value for a global population of non-users. It might be expected that such assets would be accorded some degree of security with sufficient funding to safeguard current and potential economic benefits. Yet park use is haphazard, and there is frequently little coincidence between those that benefit and those that pay for the continued existence of such areas. Growing economic and demographic pressures which threaten to swamp protected areas only emphasize the implicit subsidy currently paid by Kenyans to support conservation for the benefit of the world at large. In this climate the case for conservation depends on the measurement and capture of economic benefits. Using a contingent valuation survey of expressed preference this study estimates the consumer surplus attached to current non-consumptive use of protected areas by foreign visitors at some $450 million per annum. This sum alone is more than double the best available estimate of opportunity cost and appears to justify current resource use. The estimate is additional to current financial returns from tourism and makes no allowance for other direct and indirect benefits and potential returns from consumptive uses. Measured consumer surplus contains some margin of willingness to pay that could be captured through the current fee structure. Moreover, park fees represent the most accessible market mechanism to finance revenue sharing and additional park investment before potential recourse to emerging global market institutions.  相似文献   

4.
Protected areas are key to conservation of biodiversity, and Australia is one of the world’s megadiverse regions. Monitoring programs provide the information to assess the state of conservation resources, the severity of threats and the success of management responses. Here we compare the management priorities, monitoring priorities and actual monitoring practices of protected area management agencies in Australia, using four sets of data at continental scale and five at a more restricted regional scale. We track changes over a period of several years and focus at successively finer levels of detail. At both continental and regional scales, most management plans emphasise fire, invasive species and visitor management; and most monitoring programmes refer to visitor numbers and impacts as well as species and ecosystems. There is only a weak match, however, between reported management priorities and actual monitoring programmes; and the effectiveness of management responses is rarely monitored. The level of detail in visitor monitor programmes varies considerably: most parks count visitors, but few know what those visitors do. Threats from fire and invasive species receive more attention that those from recreation. At regional scale, the proportion of parks with defined monitoring programmes and priorities increased significantly from 2003/2004 to 2006/2007. Whilst only a proportion of protected areas monitor endangered species populations, for those that do this is the parameter reported in most detail, with many parks reporting single records of single individuals. Some parks also maintain anecdotal records of rare species outside routine monitoring programs.  相似文献   

5.
6.
Protected areas (PAs) play an important role in biodiversity conservation and the implementation of ambitious multilateral environmental agreements, like the 2010 targets of the Convention on Biological Diversity (CBD). In the CBD's Programme of Work on Protected Areas, it is requested that each country conduct management effectiveness evaluations of at least thirty percent of its PAs by 2010. This article compares the most common methodologies of PA management effectiveness evaluations, such as the Rapid Assessment and Prioritization of Protected Area Management (RAPPAM) Methodology, the Management Effectiveness Tracking Tool (METT) and UNESCO's Enhancing our Heritage (EoH) Toolkit. These and other methodologies can help to (1) examine overall effectiveness of PAs, (2) identify factors influencing the effectiveness and (3) determine common threats and their seriousness.However, the outcomes of major studies concerning overall effectiveness as well as success and failure factors for PA management are partially contradictory. Different results can be due to the approach (e.g. number and type of indicators or assessors included in the evaluation process) or to the individual context of the PA (e.g. age, region, IUCN category) and therefore these factors need to be considered when comparing results of management effectiveness studies.Research indicates that increased attention should be paid to regular monitoring of conservation activities in PAs including systematic social science studies with a socio-economic and socio-cultural focus. Unfortunately, the outcomes of the management effectiveness studies are not easily accessible and have not yet been widely shared or distributed among the conservation community.
  相似文献   

7.
A method is described for rapid multidisciplinary environmental assessment of coastal areas within the conceptual framework of comprehensive management of Marine Protected Areas (MPAs). The aim is to provide tools for the selection, design and management of coastal MPAs when time, budget or potential human pressures, either alone or in combination, create an urgent need for prioritisation. Maximising results and minimising cost and time is the goal, using a methodology that re evaluates existing information on the area, allows use of physical, environmental and socio-economic indicators, and finally integrates information in a Geographic Information System capable of generating outputs in the form of thematic maps to support managers.The final products obtained inform planners and managers about the study areas, across multiple aspects that all need to be considered in integrated coastal management. Although originally proposed for widespread use in the Mediterranean, this methodology can be flexibly adapted, with minor modifications in the selection of indicators, for its use in other regions. The results show its potential for merging and synthesising information not only as a tool in Rapid Assessment Programs but also as a tool for facing management of wide coastal areas as social-ecological ecosystems.  相似文献   

8.
Marine protected areas (MPAs) have been widely adopted as the leading tool for coral-reef conservation, but resource users seldom accept them , and many have failed to produce tangible conservation benefits [3]. Few studies have objectively and simultaneously examined the types of MPAs that are most effective in conserving reef resources and the socioeconomic factors responsible for effective conservation [4-6]. We simultaneously explored measures of reef and socioeconomic conservation success at four national parks, four comanaged reserves, and three traditionally managed areas in Indonesia and Papua New Guinea. Underwater visual censuses of key ecological indicators [7, 8] revealed that the average size and biomass of fishes were higher in all areas under traditional management and at one comanaged reserve when compared to nearby unmanaged areas. Socioeconomic assessments [6, 9, 10] revealed that this effective conservation was positively related to compliance, visibility of the reserve, and length of time the management had been in place but negatively related to market integration, wealth, and village population size. We suggest that in cases where the resources for enforcement are lacking, management regimes that are designed to meet community goals can achieve greater compliance and subsequent conservation success than regimes designed primarily for biodiversity conservation.  相似文献   

9.
Biodiversity and Conservation - Biodiversity keeps declining in the European Union despite the large conservation effort done over the last decades. The Biodiversity Strategy for 2030 aims to...  相似文献   

10.
11.
12.
13.
Abstract. 1. Corythucha marmorata (Hemiptera: Tingidae) was more abundant in clusters of small experimental patches of its host plant, goldenrod (Solidago altissima) , than in large patches covering the same area.
2. Adults and egg masses were more abundant on stems on the edges of the patches than on those in the interior.
3. Female Cmarmorata caged on edge plants laid more eggs than females caged on interior plants, and eggs on exposed plants developed faster than those in the middle of a pacth.
4. A preference for edges results in negative 'response' to patch size because large patches invariably have a lower proportion of edge than small patches.  相似文献   

14.
A substantial shift toward use of marine protected areas (MPAs) for conservation and fisheries management is currently underway. This shift to explicit spatial management presents new challenges and uncertainties for ecologists and resource managers. In particular, the potential for MPAs to change population sustainability, fishery yield, and ecosystem properties depends on the poorly understood consequences of three critical forms of connectivity over space: larval dispersal, juvenile and adult swimming, and movement of fishermen. Conventional fishery management describes the dynamics and current status of fish populations, with increasing recent emphasis on sustainability, often through reference points that reflect individual replacement. These compare lifetime egg production (LEP) to a critical replacement threshold (CRT) whose value is uncertain. Sustainability of spatially distributed populations also depends on individual replacement, but through all possible paths created by larval dispersal and LEP at each location. Model calculations of spatial replacement considering larval connectivity alone indicate sustainability and yield depend on species dispersal distance and the distribution of LEP created by species habitat distribution and fishing mortality. Adding MPAs creates areas with high LEP, increasing sustainability, but not necessarily yield. Generally, short distance dispersers will persist in almost all MPAs, while sustainability of long distance dispersers requires a specific density of MPAs along the coast. The value of that density also depends on the uncertain CRT, as well as fishing rate. MPAs can increase yield in areas with previously low LEP but for short distance dispersers, high yields will require many small MPAs. The paucity of information on larval dispersal distances, especially in cases with strong advection, renders these projections uncertain. Adding juvenile and adult movement to these calculations reduces LEP near the edges in MPAs, if movement is within a home-range, but more broadly over space if movement is diffusive. Adding movement of fishermen shifts effort on the basis of anticipated revenues and fishing costs, leading to lower LEP near ports, for example. Our evolving understanding of connectivity in spatial management could form the basis for a new, spatially oriented replacement reference point for sustainability, with associated new uncertainties.  相似文献   

15.
16.
论保护区的管理体制   总被引:11,自引:4,他引:11  
一个国家保护区管理体制是否合理和完善与该国保护区发展的速度和管理的有效程度有密切关系。世界各国保护区的管理体制很不相同,各有长处和不足。本文对保护区的主管部门和管理系统、管理现况、存在问题和发展趋势以及我国保护区管理体制的改革等作一些粗略的评论,期待引起有关方面的关注并进一步开展研究。  相似文献   

17.
Habitat fragmentation is one of the major threats to species diversity. In this review, we discuss how the genetic and demographic structure of fragmented populations of herbaceous forest plant species is affected by increased genetic drift and inbreeding, reduced mate availability, altered interactions with pollinators, and changed environmental conditions through edge effects. Reported changes in population genetic and demographic structure of fragmented plant populations have, however, not resulted in large-scale extinction of forest plants. The main reason for this is very likely the long-term persistence of small and isolated forest plant populations due to prolonged clonal growth and long generation times. Consequently, the persistence of small forest plant populations in a changing landscape may have resulted in an extinction debt, that is, in a distribution of forest plant species reflecting the historical landscape configuration rather than the present one. In some cases, fragmentation appears to affect ecosystem integrity rather than short-term population viability due to the opposition of different fragmentation-induced ecological effects. We finally discuss extinction and colonization dynamics of forest plant species at the regional scale and suggest that the use of the metapopulation concept, both because of its heuristic power and conservation applications, may be fruitful.  相似文献   

18.
Climate change is posing new challenges to conservation because management policies on protected coral reefs are less effective than they were before the current ecosystem degradation. Coral reefs, the most diverse and complex marine ecosystem provide economic services for millions, but are seriously threatened worldwide because reef-building corals are experiencing bleaching phenomena and a steady decline in abundance. The resources of a Marine Protected Area (MPA) in Cartagena, Colombia, are in constant decline, despite a current management plan and on-site staff, urging new conservation actions. A multidisciplinary team gathered to evaluate management effectiveness including biophysical, socioeconomic and governance indicators. Coral cover and fish diversity and abundance were low both inside and outside the MPA, which suggests a limited efficiency of management. Currently, the MPA is a reef with low coral cover and high algae cover as well as large dead coral areas, which are generally signs of highly degraded reef habitats. Live coral cover in the MPA was represented by pioneer coral species such as Agaricia tenuifolia and Porites astreoides. Nonetheless, 35% of the scleractinian species sampled in the area harbored more than one zooxanthellae symbiont, which suggests potential resistance and resilience against coral bleaching. Maintenance of trophic structure and functional diversity is an important endeavor that should be a priority for management in order to allow ecosystem resilience. Social and governance indicators showed low-income levels and few opportunities for communities living in and around the park, low governability, weak communication among stakeholders and with authorities at different levels. As a result, problems related to over exploitation of resources were commonplace in the MPA. These results reflect low adaptive capacity of communities to comply with restrictive conservation rules, showing that establishment of a protected area is a necessary but insufficient condition to guarantee conservation goals. Ignoring the role of local communities only will exacerbate the problems associated with natural resources. Involvement of communities in strategic ecosystems management appears to be a requisite to improve effectiveness of protected areas, and participatory strategies, such as co-management, offer opportunities to improve governability while letting communities adapt to MPA needs.  相似文献   

19.
Recent reviews of the conservation literature indicate that significant biases exist in the published literature regarding the regions, ecosystems and species that have been examined by researchers. Despite the global threat of climatic change, similar biases may be occurring within the sub-discipline of climate-change ecology. Here we hope to foster critical thought and discussion by considering the directions taken by conservation researchers when addressing climate change. To form a quantitative basis for our perspective, we assessed 248 papers from the climate change literature that considered the conservation management of biodiversity and ecosystems. We found that roughly half of the studies considered climate change in isolation from other threatening processes. We also found that the majority of surveyed scientific publications were conducted in the temperate forests of Europe and North America. Regions such as Latin America that are rich in biodiversity but may have low adaptive capacity to climate change were not well represented. We caution that such biases in research effort may be distracting our attention away from vulnerable regions, ecosystems and species. Specifically we suggest that the under-representation of research from regions low in adaptive capacity and rich in biodiversity requires international collaboration by those experienced in climate-change research, with researchers from less wealthy nations who are familiar with local issues, ecosystems and species. Furthermore, we caution that the propensity of ecologists to work in essentially unmodified ecosystems may fundamentally hamper our ability to make useful recommendations in a world that is experiencing significant global change.  相似文献   

20.
中国保护区分类的研究   总被引:36,自引:1,他引:36  
保护区是一个泛称,由于其建立的目的、要求和本身所具备的条件不同,所以具有多种多样的类型,不同类型管理的侧重点也有所区别.以保护区管理的目标为原则划分第一级分类单位,共有5个类型,即:严格的保护区、国家公园、保护景观、栖息地/物种管理区、资源管理保护区.再以保护对象原则划分第二、三级分类单位,共同构成一个完整的分类系统,以适应保护区事业日益发展的要求.  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