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 31 毫秒
1.
Ecologically sustainable management of temperate forests is a complex task that involves balancing potentially conflicting land uses such as wood production and nature conservation. We argue that a variety of strategies implemented at different spatial scales is required for biodiversity conservation in temperate forests where wood production is permitted. This is a form of "risk-spreading;" if one option is ineffective for a given species, it may still be conserved as a result of the implementation of other approaches. At the largest scale, there is a clear need for reserves to protect representative samples of forest ecosystems. Within landscapes broadly designated for timber harvesting, intermediate-scale strategies such as the implementation of networks of streamside reserves and wildlife corridors are important for biodiversity conservation. At smaller spatial scales within harvested areas, critical habitat components for forest-dependent organisms like large old trees and logs must be provided. We focus on the importance of these fine-scale attributes for the conservation of biodiversity within logged forests using the mountain ash (  Eucalyptus regnans) forests of the Central Highlands of Victoria as a case study. Forest managers must develop silvicultural practices that maintain and perpetuate critical stand attributes essential for the conservation of forest-dependent organisms. To this end, a shift is required from the extensive use of clearfelling to the adoption of new silvicultural techniques that maintain more structurally complex multi-aged stands. The maintenance of key structural features should be used as a template to guide harvesting methods to ensure that production forests contribute to biodiversity conservation, not only in mountain ash forests, but also temperate wood production elsewhere around the world.  相似文献   

2.
Abstract:  Ecological research and biodiversity management often raise ethical questions in areas that include responsibilities and duties to the scientific community, public welfare, research animals, species, and ecosystems. Answering these questions is challenging because ecologists and biodiversity managers do not have the equivalent of bioethics, an established field with a support network focused mainly on biomedicine, to guide them in making decisions. Environmental ethics provides some insight into environmental values and the duties these may impose on humans. But for the most part those in the field have not considered many of the common responsibilities and obligations that ecologists and managers have to the scientific profession or to public welfare. There is a need to bring ethicists, scientists, and biodiversity managers together in a collaborative effort to study and inform the methods of ethical analysis and problem solving in ecological research and biodiversity management. We present a series of cases that illustrate the kinds of ethical questions faced by researchers and biodiversity managers in practice. We argue for the creation of an extensive case database and a pluralistic and integrated ethical framework, one that draws from the theoretical (normative), research, animal, and environmental ethics traditions. These tools form the foundations of a new area of inquiry and practical ethical problem solving, that we call "ecological ethics."  相似文献   

3.
Abstract:  Caughley (1994) argued that researchers working on threatened populations tended to follow the "small population paradigm" or the "declining population paradigm," and that greater integration of these paradigms was needed. Here I suggest that two related paradigms exist at the broader spatial scale, namely the metapopulation paradigm and habitat paradigm, and that these two paradigms also need to be integrated if we are to provide sound management advice. This integration is not trivial, and I outline five problems that need to be addressed: (1) habitat variables may not measure habitat quality, so site-specific data on vital rates are needed to resolve the effects of habitat quality and metapopulation dynamics; (2) measurements of vital rates may be confounded by movements; (3) vital rates may be density dependent; (4) vital rates may be affected by genotype; and (5) vital rates cannot be measured in unoccupied patches. I reviewed papers published in Conservation Biology from 1994 to 2003 and found 41 studies that analyzed data from 10 or more sites to understand the factors limiting species' distributions. Five of the analyses presented were purely within the metapopulation paradigm, 14 were purely within the habitat paradigm, 17 involved elements of both paradigms, and 7 were theoretically ambiguous (2 papers presented 2 distinct analyses and were counted twice). This suggests that many researchers appreciate the need to integrate the paradigms. Only one study, however, used data on vital rates to resolve the effects of habitat quality and metapopulation dynamics (problem 1), and this study did not address problems 2–5. I conclude that more intensive research incorporating site-specific data on vital rates and movement is needed to complement the numerous analyses of distributional data being produced.  相似文献   

4.
Abstract:  The difficult task of managing species of conservation concern is likely to become even more challenging due to the interaction of climate change and invasive species. In addition to direct effects on habitat quality, climate change will foster the expansion of invasive species into new areas and magnify the effects of invasive species already present by altering competitive dominance, increasing predation rates, and enhancing the virulence of diseases. In some cases parapatric species may expand into new habitats and have detrimental effects that are similar to those of invading non-native species. The traditional strategy of isolating imperiled species in reserves may not be adequate if habitat conditions change beyond historic ranges or in ways that favor invasive species. The consequences of climate change will require a more active management paradigm that includes implementing habitat improvements that reduce the effects of climate change and creating migration barriers that prevent an influx of invasive species. Other management actions that should be considered include providing dispersal corridors that allow species to track environmental changes, translocating species to newly suitable habitats where migration is not possible, and developing action plans for the early detection and eradication of new invasive species.  相似文献   

5.
Abstract:  Leadership is a critical tool for expanding the influence of conservation science, but recent advances in leadership concepts and practice remain underutilized by conservation scientists. Furthermore, an explicit conceptual foundation and definition of leadership in conservation science are not available in the literature. Here we drew on our diverse leadership experiences, our reading of leadership literature, and discussions with selected conservation science leaders to define conservation-science leadership, summarize an exploratory set of leadership principles that are applicable to conservation science, and recommend actions to expand leadership capacity among conservation scientists and practitioners. We define 2 types of conservation-science leadership: shaping conservation science through path-breaking research, and advancing the integration of conservation science into policy, management, and society at large. We focused on the second, integrative type of leadership because we believe it presents the greatest opportunity for improving conservation effectiveness. We identified 8 leadership principles derived mainly from the "adaptive leadership" literature: recognize the social dimension of the problem; cycle frequently through action and reflection; get and maintain attention; combine strengths of multiple leaders; extend your reach through networks of relationships; strategically time your effort; nurture productive conflict; and cultivate diversity. Conservation scientists and practitioners should strive to develop themselves as leaders, and the Society for Conservation Biology, conservation organizations, and academia should support this effort through professional development, mentoring, teaching, and research.  相似文献   

6.
Mitigation of Habitat "Take": Application to Habitat Conservation Planning   总被引:2,自引:0,他引:2  
One of the most important provisions of the U.S. Endangered Species Act precludes the "taking" of listed species on both public and private land. In past Endangered Species Act litigation, take has been broadly interpreted to include the destruction or modification of habitats as well as the direct killing of animals. This requirement created an extensive burden on private landowners to provide habitats for listed species. This burden was substantially lessened when the ESA was modified in 1982 to allow incidental takings conditioned on preparation of a satisfactory "habitat conservation plan." Because the majority of listed species are imperiled due to habitat modification, most habitat conservation plans must demonstrate defensible methods to mitigate against incidental habitat loss. A review of HCPs for the Northern Spotted Owl ( Strix occidentalis), and other species, indicates that mitigation solutions are often arbitrary, lacking an empirical foundation in the species' life history requirements. Based on data from the Spotted Owl, we illustrate a biologically based method for estimating the areal requirements necessary to mitigate against the take of essential habitats. Toward this goal we adopt the concept of "core area," that portion of an animal's home range that receives disproportionate use. We estimated core areas by means of the adaptive kernel density function and tested against a null distribution of animal use that assumes a bivariate, uniform distribution of locations within the home range. The method we illustrate, which is defensible, repeatable, and empirical, is a clear improvement over the ad hoc methods used in many habitat conservation plans. Further, the methods we propose should be applicable to a large number of terrestrial species for which home range is a meaningful concept.  相似文献   

7.
Abstract:  Threatened species often exist in a small number of isolated subpopulations. Given limitations on conservation spending, managers must choose from strategies that range from managing just one subpopulation and risking all other subpopulations to managing all subpopulations equally and poorly, thereby risking the loss of all subpopulations. We took an economic approach to this problem in an effort to discover a simple rule of thumb for optimally allocating conservation effort among subpopulations. This rule was derived by maximizing the expected number of extant subpopulations remaining given n subpopulations are actually managed. We also derived a spatiotemporally optimized strategy through stochastic dynamic programming. The rule of thumb suggested that more subpopulations should be managed if the budget increases or if the cost of reducing local extinction probabilities decreases. The rule performed well against the exact optimal strategy that was the result of the stochastic dynamic program and much better than other simple strategies (e.g., always manage one extant subpopulation or half of the remaining subpopulation). We applied our approach to the allocation of funds in 2 contrasting case studies: reduction of poaching of Sumatran tigers ( Panthera tigris sumatrae ) and habitat acquisition for San Joaquin kit foxes ( Vulpes macrotis mutica ). For our estimated annual budget for Sumatran tiger management, the mean time to extinction was about 32 years. For our estimated annual management budget for kit foxes in the San Joaquin Valley, the mean time to extinction was approximately 24 years. Our framework allows managers to deal with the important question of how to allocate scarce conservation resources among subpopulations of any threatened species.  相似文献   

8.
Abstract:  Collection-based institutions—zoos, aquariums, museums, and botanical gardens—exhibit wildlife and thus have a special connection with nature. Many of these institutions emphasize a mission of conservation, and, undeniably, they do contribute directly to conservation education and conservation science. They present an exceptional opportunity for many urban residents to see the wonders of life, and they can contribute to education and habitat preservation. Because many collection-based institutions now hold a stated mission of conservation, we suggest eight potential questions to evaluate actions toward that mission: (1) Does conservation thought define policy decisions? (2) Is there sufficient organizational funding for conservation activities? (3) Is there a functional conservation department? (4) Does the institution advocate for conservation? (5) Do conservation education programs effectively target children and adults? (6) Does the institution contribute directly to habitat protection locally and internationally? (7) Do exhibits explain and promote conservation efforts? and (8) Do internal policies and activities protect the environment? These questions are offered as a place to begin discussion. We hope they will help employees and administrators of a collection-based institution (and citizens of the surrounding community) think about and support their institution's conservation activities. Public support and praise for institutions that are striving toward solutions for conservation problems and pressure on organizations that are moving more slowly toward a conservation orientation can help shift more resources toward saving nature.  相似文献   

9.
Raptors and Red Grouse: Conservation Conflicts and Management Solutions   总被引:7,自引:0,他引:7  
Abstract: Recovering predator populations may present problems for conservationists if their prey are of economic or conservation value. We address this issue by examining the conflict between raptor conservation and management of Red Grouse (   Lagopus l. scoticus ) in Britain. Heather moorland is a distinctive habitat that supports an important assemblage of breeding birds. Large areas of moorland are managed by private landowners for shooting grouse. Although grouse shooting benefits conservation by retaining heather moorland, it is currently unclear whether grouse management directly benefits other upland birds. Human persecution has greatly restricted the range and abundance of most raptor species in Britain. Following the introduction of bird protection laws, the decline in gamekeeping, and the restriction of organochlorine pesticides, raptor populations have started to recover. Persecution of raptors on grouse moors is widespread and limits the range and abundance of Hen Harriers (  Circus cyaneus ), Peregrine Falcons (   Falco peregrinus ), and Golden Eagles ( Aquila chrysaetos ). In some circumstances, raptor predation can reduce both the breeding density and productivity of Red Grouse. Limitation of grouse populations through raptor predation is most likely to occur where raptors are at high density because of the abundance of alternative prey, and grouse are at low density either because of poor management or the cyclic nature of some grouse populations. In the long term, habitat management may reduce densities of alternative prey, leading to reductions in raptor densities and their predation on grouse. More active intervention may be required, however, if grouse moors are to remain viable in the short-term. Current research is focused on manipulating harrier diet through diversionary feeding. Complementary research is needed to investigate methods to reduce raptor numbers locally while ensuring their national status.  相似文献   

10.
Abstract:  To be successful, conservation practitioners and resource managers must fully integrate the effects of climate change into all planning projects. Some conservation practitioners are beginning to develop, test, and implement new approaches that are designed to deal with climate change. We devised four basic tenets that are essential in climate-change adaptation for conservation: protect adequate and appropriate space, reduce nonclimate stresses, use adaptive management to implement and test climate-change adaptation strategies, and work to reduce the rate and extent of climate change to reduce overall risk. To illustrate how this approach applies in the real world, we explored case studies of coral reefs in the Florida Keys; mangrove forests in Fiji, Tanzania, and Cameroon; sea-level rise and sea turtles in the Caribbean; tigers in the Sundarbans of India; and national planning in Madagascar. Through implementation of these tenets conservation efforts in each of these regions can be made more robust in the face of climate change. Although these approaches require reconsidering some traditional approaches to conservation, this new paradigm is technologically, economically, and intellectually feasible.  相似文献   

11.
Abstract: Applied conservation biology must provide solutions for the conservation of species in modern landscapes, where prime habitats are being continuously fragmented and altered and animals are restricted to small, nonviable populations. We studied habitat selection in a fragmented population of endangered Iberian lynx (   Lynx pardinus ) by examining 14 years of radiotracking data obtained from lynx trapped in two different source areas. Habitat selection was studied independently for predispersal lynx in the source areas, for dispersing individuals through the region, and for postdispersing animals, most of which settled far from their point of origin. A multivariate analysis of variance showed that habitat use differed significantly among these phases and between area of origin, but not between sexes. The habitat type most used, and best represented within home ranges, was the mediterranean scrubland. Pine plantations were also important during and after dispersal. The rest of the habitats were either avoided (open habitats) or used according to availability ( pine and eucalyptus plantations) by dispersing lynx. Differences due to lynx origin were detected only during predispersal and dispersal and were observed because animals from each area had different habitat availability. Lynx with established territories did not use areas at random. They occupied patches of mediterranean scrubland more often than would be expected from scrubland availability during predispersal; the rest of the habitats were included within home ranges less than would be expected from their availability in the landscape. Results indicate that dispersing animals may use habitats of lower quality than habitats used by resident individuals, which suggests that conservation strategies applied across regions might be a viable objective.  相似文献   

12.
The protection and sustainable management of habitat trees is an integral part of modern forest nature conservation concepts such as retention forestry. Bats, cavity-nesting birds, arboreal marsupials, and many different saproxylic species depend on habitat trees and their great variety of microhabitats and old-growth characteristics. With a focus on insights from temperate forests, we traced the development of habitat-tree protection over 200 years. The idea was first conceptualized by foresters and natural scientists in the early 19th century. At that time, utilitarian conservation aimed to protect cavity trees that provided roosts and nesting holes for insectivorous bats and birds. By the second half of the 19th century, habitat-tree protection was well known to foresters and was occasionally implemented. Knowledge of the protection of large old trees, a special kind of habitat tree, for sociocultural and aesthetic reasons developed similarly. But, many foresters of that time and in the following decades fundamentally rejected protection of habitat trees for economic reasons. Beginning in the 1970s, forest conservation and integrative forest management became increasingly important issues worldwide. Since then, the protection of habitat trees has been implemented on a large scale. Long-term views on the development of conservation concepts are important to inform the implementation of conservation today. In particular, historical analyses of conservation concepts allow the testing of long-term conservation outcomes and make it possible to study the resilience of conservation approaches to changing social or ecological conditions. We encourage all conservation ecologists to assess the practical and conceptual impact of the initial ideas that led to modern conservation concepts in terms of long-term biodiversity conservation.  相似文献   

13.
Abstract:  The Global Strategy of Plant Conservation states that at least 60% of threatened plant species should be within protected areas. This goal has been met in some regions with long traditions of plant protection. We used gap analysis to explore how particular groups of species of conservation interest, representing different types of natural or anthropogenic rarity, have been covered by protected areas on a national scale in Estonia during the last 100 years. Species-accumulation curves indicated that plant species that are naturally rare (restricted global or local distribution, always small populations, or very rare habitat requirements) needed almost twice as many protected areas to reach the 60% target as plant species that are rare owing to lack of suitable management (species depending on grassland management, moderate forest disturbances, extensive traditional agriculture, or species potentially threatened by collecting). Temporal analysis of the establishment of protected areas suggested that grouping plant species according to the predominant cause of rarity accurately reflected the history of conservation decision making. Species found in very rare habitats have previously received special conservation attention; species dependent on traditional extensive agriculture have been largely ignored until recently. Legislative initiative and new nature-protection schemes (e.g., Natura 2000, network of protected areas in the European Union) have had a positive influence on all species groups. Consequently, the species groups needing similar action for their conservation are sensitive indicators of the effectiveness of protected-area networks. Different species groups, however, may not be uniformly conserved within protected areas, and all species groups should fulfill the target of 60% coverage within protected areas.  相似文献   

14.
Abstract:  Conservation management is becoming increasingly resource intensive as threats to biodiversity grow through habitat destruction, habitat disturbance, and overexploitation. To achieve successful conservation and sustainable use of natural resources, we need to scientifically evaluate the effectiveness of conservation interventions and provide an efficient framework through which scientific evidence can be used to support decision making in policy and practice. We conducted the first formal assessment of the extent to which scientific evidence is used in conservation management through a questionnaire survey and follow-up interviews of compilers of protected-area management plans from major conservation organizations within the United Kingdom and Australia. Our survey results show that scientific information is not being used systematically to support decision making largely because it is not easily accessible to decision makers. This, in combination with limited monitoring and evaluation of effectiveness of management interventions, results in the majority of decisions being based on experience rather than on evidence. To address this problem we propose using an evidence-based framework adapted from that used in the health services and explain how we are currently putting an equivalent framework into practice by establishing review and dissemination units to serve the conservation sector.  相似文献   

15.
When Agendas Collide: Human Welfare and Biological Conservation   总被引:3,自引:0,他引:3  
Abstract:  Conservation should benefit ecosystems, nonhuman organisms, and current and future human beings. Nevertheless, tension among these goals engenders potential ethical conflicts: conservationists' true motivations may differ from the justifications they offer for their activities, and conservation projects have the potential to disempower and oppress people. We reviewed the promise and deficiencies of integrating social, economic, and biological concerns into conservation, focusing on research in ecosystem services and efforts in community-based conservation. Despite much progress, neither paradigm provides a silver bullet for conservation's most pressing problems, and both require additional thought and modification to become maximally effective. We conclude that the following strategies are needed to make conservation more effective in our human-dominated world. (1) Conservation research needs to integrate with social scholarship in a more sophisticated manner. (2) Conservation must be informed by a detailed understanding of the spatial, temporal, and social distributions of costs and benefits of conservation efforts. Strategies should reflect this understanding, particularly by equitably distributing conservation's costs. (3) We must better acknowledge the social concerns that accompany biodiversity conservation; accordingly, sometimes we must argue for conservation for biodiversity's sake, not for its direct human benefits.  相似文献   

16.
Climate change is a key threat to biodiversity. To conserve species under climate change, ecologists and conservation scientists suggest 2 main conservation strategies regarding land use: supporting species’ range shifts to enable it to follow its climatic requirements by creating migration pathways, such as corridors and stepping stones, and conserving climate refugia (i.e., existing habitat areas that are somewhat buffered from climate change). The policy instruments that could be used to implement these conservation strategies have yet to be evaluated comprehensively from an economic perspective. The economic analyses of environmental policy instruments are often based on ecological effectiveness and cost-effectiveness criteria. We adapted these general criteria to evaluate policy instruments for species’ conservation under climate change and applied them to a conceptual analysis of land purchases, offsets, and conservation payments. Depending on whether the strategy supporting species’ range shifts or conserving climate refugia is selected, the evaluation of the policy instruments differed substantially. For example, to ensure ecological effectiveness, habitat persistence over time was especially important for climate refugia and was best achieved by a land-purchase policy instrument. In contrast, for the strategy supporting range shifts to be ecologically effective, a high degree of flexibility in the location of conserved sites was required to ensure that new habitat sites can be created in the species’ new range. Offset programs were best suited for that because the location of conservation sites can be chosen comparatively freely and may also be adapted over time.  相似文献   

17.
Abstract: Mountain sheep (Ovis canadensis) are closely associated with steep, mountainous, open terrain. Their habitat consequently occurs in a naturally fragmented pattern, often with substantial expanses of unsuitable habitat between suitable patches; the sheep have been noted to be slow colonizers of vacant suitable habitat. As a result, resource managers have focused on (1) conserving "traditional" mountainous habitats, and (2) forced colonization through reintroduction. Telemetry studies in desert habitats have recorded more intermountain movement by desert sheep than was previously thought to OCCUT. Given the heretofore unrecognized vagility of mountain sheep, we argue that existing corridors of "nontraditional" habitat connecting mountain ranges be given adequate conservation consideration. Additionally, small areas of mountainous habitat that an? not permanently occupied but that may serve as "stepping stones" within such corridors must be recognized for their potential importance to relatively isolated populations of mountain sheep. We discuss the potential importance of such corridors to other large, vagile species.  相似文献   

18.
Abstract: Designing reserves that preserve the habitat of many coexisting and threatened species often involves use of conservation surrogates, such as umbrella species. Typically, animals with legal protection are used as umbrella species, and these selections are overwhelmingly vertebrates. The tacit assumption that vertebrates automatically serve as conservation umbrellas for invertebrates rarely has been justified. The California Gnatcatcher (   Polioptila californica, Muscicapidae ), is a federally listed and endangered species in the United States and has been used as an umbrella species for the conservation of coastal sage scrub in southern California. Conservation planning efforts for this community follow a general paradigm of using vertebrate-based reserve designs as de facto protection for invertebrate cohabitants. To test the effectiveness of this strategy, I surveyed 50 patches of coastal sage scrub in San Diego County for three species of Lepidoptera: Mormon metalmark ( Apodemia mormo, Riodinidae ), Bernardino blue, (   Euphilotes bernardino, Lycaenidae ), and Electra buckmoth (    Hemileuca electra, Saturniidae ). The presence of the gnatcatcher was a poor indicator of the presence of these insects. Only the largest or most recently separated habitat patches supported all three species of Lepidoptera, but the gnatcatcher was present on nearly every site, regardless of size. Results indicate that vertebrates do not automatically function as umbrella species for invertebrate cohabitants. Reserve designs based on vertebrate umbrella species, which assume invertebrates will be protected, may result in the loss of a large portion of invertebrate diversity.  相似文献   

19.
{en} Over the past decades, much research has focused on understanding the critical factors for marine extinctions with the aim of preventing further species losses in the oceans. Although conservation and management strategies are enabling several species and populations to recover, others remain at low abundance levels or continue to decline. To understand these discrepancies, we used a published database on abundance trends of 137 populations of marine mammals worldwide and compiled data on 28 potentially critical factors for recovery. We then applied random forests and additive mixed models to determine which intrinsic and extrinsic factors are critical for the recovery of marine mammals. A mix of life‐history characteristics, ecological traits, phylogenetic relatedness, population size, geographic range, human impacts, and management efforts explained why populations recovered or not. Consistently, species with lower age at maturity and intermediate habitat area were more likely to recover, which is consistent with life‐history and ecological theory. Body size, trophic level, social interactions, dominant habitat, ocean basin, and habitat disturbance also explained some differences in recovery patterns. Overall, a variety of intrinsic and extrinsic factors were important for species’ recovery, pointing to cumulative effects. Our results provide insight for improving conservation and management strategies to enhance recoveries in the future.  相似文献   

20.
The geographic distribution of the animals of Venezuela was analyzed as a basis for a series of guidelines to help develop strategies for their conservation. A total of 313 animal taxa is distributed among 24 geographic units, corresponding to the political divisions of the country. Three different criteria were considered in analyzing these data: (1) the number and density of threatened taxa were used to define a ranking system for geographic units; (2) "hotspots" were identified using the distribution of threatened endemics, and (3) a "critical faunas analysis" was used to determine the minimum number of geographic units needed to maximize the number of sampled taxa. The first two criteria emphasize the importance of protecting habitat in the northern portion of the country, where most human intervention has already taken place. But the southern portion of the country is where most of the undisturbed habitat remains. We suggest that the conservation of the animals of Venezuela must follow a mixed strategy, based on two principles: one, aimed mainly at threatened endemics, should focus on the protection of critical habitat north of the Orinoco river, the second, aimed at all threatened animals— particularly high-risk taxa—should focus on assuring the long-term persistence of the pristine habitat in the south.  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