共查询到20条相似文献,搜索用时 31 毫秒
1.
AKÇAKAYA HR 《Environmental management》2000,26(Z1):S75-S83
Multiple-species reserves aim at supporting viable populations of selected species. Population viability analysis (PVA) is a group of methods for predicting such measures as extinction risk based on species-specific data. These methods include models that simulate the dynamics of a population or a metapopulation. A PVA model for the California gnatcatcher in Orange County was developed with landscape (GIS) data on the habitat characteristics and requirements and demographic data on population dynamics of the species. The potential applications of this model include sensitivity analysis that provides guidance for planning fieldwork, designing reserves, evaluating management options, and assessing human impact. The method can be extended to multiple species by combining habitat suitability maps for selected species with weights based on the threat faced by each species, and the contribution of habitat patches to the persistence of each species. These applications and extensions, together with the ability of the model to combine habitat and demographic data, make PVA a powerful tool for the design, conservation, and management of multiple species reserves. 相似文献
2.
Many species of conservation concern are spatially structured and require dispersal to be persistent. For such species, altering the distribution of suitable habitats on the landscape can affect population dynamics in ways that are difficult to predict from simple models. We argue that for such species, individual-based and spatially explicit population models (SEPMs) should be used to determine appropriate levels of off-site restoration to compensate for on-site loss of ecologic resources. Such approaches are necessary when interactions between biologic processes occur at different spatial scales (i.e., local [recruitment] and landscape [migration]). The sites of restoration and habitat loss may be linked to each other, but, more importantly, they may be linked to other resources in the landscape by regional biologic processes, primarily migration. The common management approach for determining appropriate levels of off-site restoration is to derive mitigation ratios based on best professional judgment or pre-existing data. Mitigation ratios assume that the ecologic benefits at the site of restoration are independent of the ecologic costs at the site of habitat loss. Using an SEPM for endangered red-cockaded woodpeckers, we show that the spatial configuration of habitat restoration can simultaneously influence both the rate of recruitment within breeding groups and the rate of migration among groups, implying that simple mitigation ratios may be inadequate. 相似文献
3.
Watanabe M Adams RM Wu J Bolte JP Cox MM Johnson SL Liss WJ Boggess WG Ebersole JL 《Journal of environmental management》2005,75(2):93-104
This paper integrates economic, biological, and physical models to explore the efficient combination and spatial allocation of conservation efforts to protect water quality and increase salmonid populations in the Grande Ronde basin, Oregon. We focus on the effects of shade on water temperatures and the subsequent impacts on endangered juvenile salmonid populations. The integrated modeling system consists of a physical model that links riparian conditions and hydrological characteristics to water temperature; a biological model that links water temperature and riparian conditions to salmonid abundance, and an economic model that incorporates both physical and biological models to estimate minimum cost allocations of conservation efforts. Our findings indicate that conservation alternatives such as passive and active riparian restoration, the width of riparian restoration zones, and the types of vegetation used in restoration activities should be selected based on the spatial distribution of riparian characteristics in the basin. The relative effectiveness of passive and active restoration plays an important role in determining the efficient allocations of conservation efforts. The time frame considered in the restoration efforts and the magnitude of desired temperature reductions also affect the efficient combinations of restoration activities. If the objective of conservation efforts is to maximize fish populations, then fishery benefits should be directly targeted. Targeting other criterion such as water temperatures would result in different allocations of conservation efforts, and therefore are not generally efficient. 相似文献
4.
Jason Bried Tim Tear Rebecca Shirer Chris Zimmerman Neil Gifford Steve Campbell Kathy O’Brien 《Environmental management》2014,54(6):1385-1398
Monitoring is essential to track the long-term recovery of endangered species. Greater emphasis on habitat monitoring is especially important for taxa whose populations may be difficult to quantify (e.g., insects) or when true recovery (delisting) requires continuous species-specific habitat management. In this paper, we outline and implement a standardized framework to facilitate the integration of habitat monitoring with species recovery efforts. The framework has five parts: (1) identify appropriate sample units, (2) select measurable indicators of habitat requirements, (3) determine rating categories for these indicators, (4) design and implement appropriate data collection protocols, and (5) synthesize the ratings into an overall measure of habitat potential. Following these steps, we developed a set of recovery criteria to estimate habitat potential and initially assess restoration activities in the context of recovering an endangered insect, the Karner blue butterfly (Lycaeides melissa samuelis). We recommend basing the habitat potential grading scheme on recovery plan criteria, the latest information on species biology, and working hypotheses as needed. The habitat-based assessment framework helps to identify which recovery areas and habitat patches are worth investing in and what type of site-specific restoration work is needed. We propose that the transparency and decision-making process in endangered insect recovery efforts could be improved through adaptive management that explicitly identifies and tracks progress toward habitat objectives and ultimate population recovery. 相似文献
5.
Biodiversity policies in the European Union (EU) are mainly implemented through the Birds and Habitats Directives as well
as the establishment of Natura 2000, a network of protected areas throughout the EU. Considerable resources must be allocated
for fulfilling the Directives and the question of optimal allocation is as important as it is difficult. In general, economic
evaluations of conservation targets at most consider the costs and seldom the welfare economic benefits. In the present study,
we use welfare economic benefit estimates concerning the willingness-to-pay for preserving endangered species and for the
aggregate area of heathland preserved in Denmark. Similarly, we obtain estimates of the welfare economic cost of habitat restoration
and maintenance. Combining these welfare economic measures with expected species coverage, we are able to estimate the potential
welfare economic contribution of a conservation network. We compare three simple nonprobabilistic strategies likely to be
used in day-to-day policy implementation: i) a maximum selected area strategy, ii) a hotspot selection strategy, and iii)
a minimizing cost strategy, and two more advanced and informed probabilistic strategies: i) a maximum expected coverage strategy
and ii) a strategy for maximum expected welfare economic gain. We show that the welfare economic performance of the strategies
differ considerably. The comparison between the expected coverage and expected welfare shows that for the case considered,
one may identify an optimal protection level above which additional coverage only comes at increasing welfare economic loss. 相似文献
6.
Increasing oil transportation and severe oil accidents in the past have led to the development of various sensitivity maps
in different countries all over the world. Often, however, the areas presented on the maps are far too large to be safeguarded
with the available oil combating equipment and prioritization is required to decide which areas must be safeguarded. While
oil booms can be applied to safeguard populations from a drifting oil slick, decision making on the spatial allocation of
oil combating capacity is extremely difficult due to the lack of time, resources and knowledge. Since the operational decision
makers usually are not ecologists, a useful decision support tool including ecological knowledge must be readily comprehensible
and easy to use. We present an index-based method that can be used to make decisions concerning which populations of natural
organisms should primarily be safeguarded from a floating oil slick with oil booms. The indices take into account the relative
exposure, mortality and recovery potential of populations, the conservation value of species and populations, and the effectiveness
of oil booms to safeguard different species. The method has been implemented in a mapping software that can be used in the
Gulf of Finland (Baltic Sea) for operational oil combating. It could also be utilized in other similar conservation decisions
where species with varying vulnerability, conservational value, and benefits received from the management actions need to
be prioritized. 相似文献
7.
Francis R. Thibodeau 《Environmental management》1983,7(2):101-107
Many species face extinction because preservation organizations do not have the resources to mount all of the interventions that are needed. Decision analysis provides techniques that can help managers of these organizations to make judgments about which species they will attempt to rescue. A formal analysis of the choices available to the US Fish and Wildlife Services' endangered species program with regard toIsotria medeoloides illustrates how the difficulties of making preservation decisions can be lessened.I. medeoloides is perhaps the rarest orchid in the United States. Little is known of the species' biology and less about effective management. Yet unless a preservation effort is mounted, the species will continue to be threatened by habitat destruction and botanical collecting. The analysis employs formal probabalistic techniques to weigh the utility of possible intervention strategies, that is, their likelihood of achieving different amounts of increase in the longevity of the species, and to balance these gains against their costs. If similar decision analyses are performed on other endangered species, the technique can be used to choose among them, as well as among strategies for individual species. 相似文献
8.
Frank A. Ward James F. Booker 《Journal of the American Water Resources Association》2003,39(2):427-440
ABSTRACT: The U.S. Endangered Species Act (ESA) restricts federal agencies from carrying out actions that jeopardize the continued existence of any endangered species. The U.S. Supreme Court has emphasized that the language of the ESA and its amendments permits few exceptions to the requirement to give endangered species the highest priority. This paper estimates economic costs associated with one measure for increasing instream flows to meet critical habitat requirements of the endangered Rio Grande silvery minnow. Impacts are derived from an integrated regional model of the hydrology, economics, and institutions of the upper Rio Grande Basin in Colorado, New Mexico, Texas, and Mexico. One proposal for providing minimum streamflows to protect the silvery minnow from extinction would provide guaranteed year round streamflows of at least 50 cubic feet per second in the San Acacia reach of the upper Rio Grande. These added flows can be accomplished through reduced surface diversions by New Mexico water users in dry years when flows would otherwise be reduced below the critical level required by the minnow. Based on a 44‐year simulation of future inflows to the basin, we find that some agricultural users suffer damages, but New Mexico water users as a whole do not incur damages from a policy that reduces stream depletions sufficiently to provide habitat for the minnow. The same policy actually benefits downstream users, producing average annual benefits of over $200,000 per year for west Texas agriculture, and over $1 million for El Paso municipal and industrial water users, respectively. Economic impacts of instream flow deliveries for the minnow are highest in drought years. 相似文献
9.
Peñas J Benito B Lorite J Ballesteros M Cañadas EM Martinez-Ortega M 《Environmental management》2011,48(1):168-176
Habitat fragmentation due to human activities is one of the most important causes of biodiversity loss. In Mediterranean areas
the species have co-evolved with traditional farming, which has recently been replaced for more severe and aggressive practices.
We use a methodological approach that enables the evaluation of the impact that agriculture and land use changes have for
the conservation of sensitive species. As model species, we selected Linaria nigricans, a critically endangered plant from arid and semiarid ecosystems in south-eastern Spain. A chronosequence of the evolution
of the suitable habitat for the species over more than 50 years has been reconstructed and several geometrical fragmentation
indices have been calculated. A new index called fragmentation cadence (FC) is proposed to quantify the historical evolution
of habitat fragmentation regardless of the habitat size. The application of this index has provided objective forecasting
of the changes of each remnant population of L. nigricans. The results indicate that greenhouses and construction activities (mainly for tourist purposes) exert a strong impact on
the populations of this endangered species. The habitat depletion showed peaks that constitute the destruction of 85% of the
initial area in only 20 years for some populations of L. nigricans. According to the forecast established by the model, a rapid extinction could take place and some populations may disappear
as early as the year 2030. Fragmentation-cadence analysis can help identify population units of primary concern for its conservation,
by means of the adoption of improved management and regulatory measures. 相似文献
10.
Saproxylic (dead-wood-associated) and old-growth species are among the most threatened species in European forest ecosystems,
as they are susceptible to intensive forest management. Identifying areas with particular relevant features of biodiversity
is of prime concern when developing species conservation and habitat restoration strategies and in optimizing resource investments.
We present an approach to identify regional conservation and restoration priorities even if knowledge on species distribution
is weak, such as for saproxylic and old-growth species in Switzerland. Habitat suitability maps were modeled for an expert-based
selection of 55 focal species, using an ecological niche factor analyses (ENFA). All the maps were then overlaid, in order
to identify potential species’ hotspots for different species groups of the 55 focal species (e.g., birds, fungi, red-listed
species). We found that hotspots for various species groups did not correspond. Our results indicate that an approach based
on “richness hotspots” may fail to conserve specific species groups. We hence recommend defining a biodiversity conservation
strategy prior to implementing conservation/restoration efforts in specific regions. The conservation priority setting of
the five biogeographical regions in Switzerland, however, did not differ when different hotspot definitions were applied.
This observation emphasizes that the chosen method is robust. Since the ENFA needs only presence data, this species prediction
method seems to be useful for any situation where the species distribution is poorly known and/or absence data are lacking.
In order to identify priorities for either conservation or restoration efforts, we recommend a method based on presence data
only, because absence data may reflect factors unrelated to species presence. 相似文献
11.
Prévot-Julliard AC Clavel J Teillac-Deschamps P Julliard R 《Environmental management》2011,47(3):315-321
To garner support for biodiversity from the World’s human population, conservation biologists need an open-minded, integrated
conservation strategy. We suggest that this strategy should include efforts to (1) preserve existing high quality, diverse
ecosystems, (2) remediate impaired systems, (3) balance the needs of people and ecological resources, and (4) engender appreciation
of nature and its services. We refer to these four key tenets as reservation, restoration, reconciliation, and reconnection.
We illustrate these concepts by presenting the debate surrounding the management of exotic species from an unusual perspective,
the benefits of exotic species. By this example we hope to encourage an integrated approach to conservation in which management
strategies can be flexible, adjusting to society’s needs and the overall goals of conservation. 相似文献
12.
13.
Brian Miller Richard Reading Courtney Conway Jerome A. Jackson Michael Hutchins Noel Snyder Steve Forrest Jack Frazier Scott Derrickson 《Environmental management》1994,18(5):637-645
This paper discusses common organizational problems that cause inadequate planning and implementation processes of endangered
species recovery across biologically dissimilar species. If these problems occur, even proven biological conservation techniques
are jeopardized. We propose a solution that requires accountability in all phases of the restoration process and is based
on cooperative input among government agencies, nongovernmental conservation organizations, and the academic community. The
first step is formation of a task-oriented recovery team that integrates the best expertise into the planning process. This
interdisciplinary team should be composed of people whose skills directly address issues critical for recovery. Once goals
and procedures are established, the responsible agency (for example, in the United States, the US Fish and Wildlife Service)
could divest some or all of its obligation for implementing the plan, yet still maintain oversight by holding implementing
entities contractually accountable. Regular, periodic outside review and public documentation of the recovery team, lead agency,
and the accomplishments of implementing bodies would permit evaluation necessary to improve performance. Increased cooperation
among agency and nongovernmental organizations provided by this model promises a more efficient use of limited resources toward
the conservation of biodiversity. 相似文献
14.
Managing an Endangered Asian Bovid in an Australian National Park: The Role and Limitations of Ecological-Economic Models in Decision-Making 总被引:1,自引:0,他引:1
Brook BW Bowman DM Bradshaw CJ Campbell BM Whitehead PJ 《Environmental management》2006,38(3):463-469
Should north Australia’s extensive populations of feral animals be eradicated for conservation, or exploited as a rare opportunity for Indigenous enterprise in remote regions? We examine options for a herd of banteng, a cattle species endangered in its native Asian range but abundant in Garig Gunak Barlu National Park, an Aboriginal land managed jointly by traditional owners and a conservation agency in the Northern Territory of Australia. We reflect on the paradoxes that arise when trying to deal effectively with such complex and contested issues in natural resource management using decision-support tools (ecological-economic models), by identifying the trade-offs inherent in protecting values whilst also providing incomes for Indigenous landowners. 相似文献
15.
Smith CB 《Journal of environmental management》2011,92(5):1414-1419
Active adaptive management is the centerpiece of a major species recovery program now underway on the central Platte River in Nebraska. The Platte River Recovery Implementation Program initiated on January 1, 2007 and is a joint effort between the states of Colorado, Wyoming, and Nebraska; the U.S. Department of the Interior; waters users; and conservation groups. This program is intended to address issues related to endangered species and loss of habitat along the Platte River in central Nebraska by managing land and water resources and using adaptive management as its science framework. The adaptive management plan provides a systematic process to test hypotheses and apply the information learned to improve management on the ground, and is centered on conceptual models and priority hypotheses that reflect different interpretations of how river processes work and the best approach to meeting key objectives. This framework reveals a shared attempt to use the best available science to implement experiments, learn, and revise management actions accordingly on the Platte River. This paper focuses on the status of adaptive management implementation on the Platte, experimental and habitat design issues, and the use of decision analysis tools to help set objectives and guide decisions. 相似文献
16.
本文根据我国珍稀濒危植物的保护现状和管理工作中存在的问题,系统地探讨了加强我国珍稀濒危植物和野生植物资源保护的政策措施。文中提出一系列具体、有效的政策构思,以及建立政府有关主管部门对珍稀濒危植物协调管理的体制等。 相似文献
17.
Conor P. McGowan 《Environmental management》2013,51(1):241-250
Decision making related to incidental take of endangered species under U.S. law lends itself well to a structured decision making approach. Incidental take is the permitted killing, harming, or harassing of a protected species under the law as long as that harm is incidental to an otherwise lawful activity and does not “reduce appreciably the probability of survival and recovery in the wild.” There has been inconsistency in the process used for determining incidental take allowances across species and across time for the same species, and structured decision making has been proposed to improve decision making. I use an example decision analysis to demonstrate the process and its applicability to incidental take decisions, even under significant demographic uncertainty and multiple, competing objectives. I define the example problem, present an objectives statement and a value function, use a simulation model to assess the consequences of a set of management actions, and evaluate the tradeoffs among the different actions. The approach results in transparent and repeatable decisions. 相似文献
18.
A commonly overlooked aspect of conservation planning assessments is that wildlife managers are increasingly focused on habitats that contain non-native species. We examine this management challenge in the Gila River basin (150,730 km2), and present a new planning strategy for fish conservation. By applying a hierarchical prioritization algorithm to >850,000 fish records in 27,181 sub-watersheds we first identified high priority areas (PAs) termed “preservation PAs” with high native fish richness and low non-native richness; these represent traditional conservation targets. Second, we identified “restoration PAs” with high native fish richness that also contained high numbers of non-native species; these represent less traditional conservation targets. The top 10 % of preservation and restoration PAs contained common native species (e.g., Catostomus clarkii, desert sucker; Catostomus insignis, Sonora sucker) in addition to native species with limited distributions (i.e., Xyrauchen texanus, razorback sucker; Oncorhynchus gilae apache, Apache trout). The top preservation and restoration PAs overlapped by 42 %, indicating areas with high native fish richness range from minimally to highly invaded. Areas exclusively identified as restoration PAs also encompassed a greater percentage of native species ranges than would be expected by the random addition of an equivalent basin area. Restoration PAs identified an additional 19.0 and 26.6 % of the total ranges of two federally endangered species—Meda fulgida (spikedace) and Gila intermedia (Gila chub), respectively, compared to top preservation PAs alone—despite adding only 5.8 % of basin area. We contend that in addition to preservation PAs, restoration PAs are well suited for complementary management activities benefiting native fishes. 相似文献
19.
Human-induced global climate change presents a unique and difficult challenge to the conservation of biodiversity. Despite
increasing attention on global climate change, few studies have assessed the projected impacts of sea-level rise to threatened
and endangered species. Therefore, we estimated the impacts of rising sea levels on the endangered Lower Keys marsh rabbit
(Sylvilagus palustris hefneri) across its geographic distribution under scenarios of current conditions, low (0.3-m), medium (0.6-m), and high (0.9-m)
sea-level rise. We also investigated the impacts of allowing vegetation to migrate upslope and not allowing migration and
of two land-use planning decisions (protection and abandonment of human-dominated areas). Not surprisingly, under all simulations
we found a general trend of decreasing total potential LKMR habitat with increasing sea-level rise. Not allowing migration
and protecting human-dominated areas both tended to decrease potential LKMR habitat compared with allowing migration and abandoning
human-dominated areas. In conclusion, conservation strategies at multiple scales need to be implemented in order to reduce
the impact of global climate change on biodiversity and endangered species. At the regional level, managers must consider
land-use planning needs that take into account the needs of both humans and biodiversity. Finally, at the local scale those
agencies that are in charge of endangered species conservation and ecosystem management need to rethink static approaches
to conservation or else stand by and watch ecosystems degrade and species go extinct. This can be accomplished by bioclimatic
reserve systems where climatically underrepresented areas are included in conservation planning along with the standard concerns
of threat, opportunity, connectivity, and viability. 相似文献
20.
Economic growth,biodiversity loss and conservation effort 总被引:6,自引:0,他引:6
This paper investigates the relationship between economic growth, biodiversity loss and efforts to conserve biodiversity using a combination of panel and cross section data. If economic growth is a cause of biodiversity loss through habitat transformation and other means, then we would expect an inverse relationship. But if higher levels of income are associated with increasing real demand for biodiversity conservation, then investment to protect remaining diversity should grow and the rate of biodiversity loss should slow with growth. Initially, economic growth and biodiversity loss are examined within the framework of the environmental Kuznets hypothesis. Biodiversity is represented by predicted species richness, generated for tropical terrestrial biodiversity using a species-area relationship. The environmental Kuznets hypothesis is investigated with reference to comparison of fixed and random effects models to allow the relationship to vary for each country. It is concluded that an environmental Kuznets curve between income and rates of loss of habitat and species does not exist in this case. The role of conservation effort in addressing environmental problems is examined through state protection of land and the regulation of trade in endangered species, two important means of biodiversity conservation. This analysis shows that the extent of government environmental policy increases with economic development. We argue that, although the data are problematic, the implications of these models is that conservation effort can only ever result in a partial deceleration of biodiversity decline partly because protected areas serve multiple functions and are not necessarily designated to protect biodiversity. Nevertheless institutional and policy response components of the income biodiversity relationship are important but are not well captured through cross-country regression analysis. 相似文献