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311.
The Boundary-Quality Penalty: a Quantitative Method for Approximating Species Responses to Fragmentation in Reserve Selection 总被引:3,自引:0,他引:3
Abstract: Aggregation of reserve networks is generally considered desirable for biological and economic reasons: aggregation reduces negative edge effects and facilitates metapopulation dynamics, which plausibly leads to improved persistence of species. Economically, aggregated networks are less expensive to manage than fragmented ones. Therefore, many reserve-design methods use qualitative heuristics, such as distance-based criteria or boundary-length penalties to induce reserve aggregation. We devised a quantitative method that introduces aggregation into reserve networks. We call the method the boundary-quality penalty (BQP) because the biological value of a land unit (grid cell) is penalized when the unit occurs close enough to the edge of a reserve such that a fragmentation or edge effect would reduce population densities in the reserved cell. The BQP can be estimated for any habitat model that includes neighborhood (connectivity) effects, and it can be introduced into reserve selection software in a standardized manner. We used the BQP in a reserve-design case study of the Hunter Valley of southeastern Australia. The BQP resulted in a more highly aggregated reserve network structure. The degree of aggregation required was specified by observed (albeit modeled) biological responses to fragmentation. Estimating the effects of fragmentation on individual species and incorporating estimated effects in the objective function of reserve-selection algorithms is a coherent and defensible way to select aggregated reserves. We implemented the BQP in the context of the Zonation method, but it could as well be implemented into any other spatially explicit reserve-planning framework . 相似文献
312.
Objectives for Multiple-Species Conservation Planning 总被引:2,自引:0,他引:2
Abstract: The first step in conservation planning is to identify objectives. Most stated objectives for conservation, such as to maximize biodiversity outcomes, are too vague to be useful within a decision-making framework. One way to clarify the issue is to define objectives in terms of the risk of extinction for multiple species. Although the assessment of extinction risk for single species is common, few researchers have formulated an objective function that combines the extinction risks of multiple species. We sought to translate the broad goal of maximizing the viability of species into explicit objectives for use in a decision-theoretic approach to conservation planning. We formulated several objective functions based on extinction risk across many species and illustrated the differences between these objectives with simple examples. Each objective function was the mathematical representation of an approach to conservation and emphasized different levels of threat. Our objectives included minimizing the joint probability of one or more extinctions, minimizing the expected number of extinctions, and minimizing the increase in risk of extinction from the best-case scenario. With objective functions based on joint probabilities of extinction across species, any correlations in extinction probabilities had to be known or the resultant decisions were potentially misleading. Additive objectives, such as the expected number of extinctions, did not produce the same anomalies. We demonstrated that the choice of objective function is central to the decision-making process because alternative objective functions can lead to a different ranking of management options. Therefore, decision makers need to think carefully in selecting and defining their conservation goals. 相似文献
313.
Habitat Suitability Models and the Shortfall in Conservation Planning for African Vertebrates 总被引:4,自引:0,他引:4
Abstract: Ongoing loss of biodiversity requires identifying large-scale conservation priorities, but the detailed information on the distribution of species required for this purpose is often missing. We present a systematic reserve selection for 1223 African mammals and amphibians in which habitat suitability models are used as estimates of the area occupied by species. In the framework of the World Conservation Union (IUCN) Global Amphibian Assessment and IUCN Global Mammal Assessment, we collected the geographic range (extent of occurrence) and habitat preferences for each species. We used the latter to build species-specific habitat suitability models inside geographic ranges, and for 181 species we verified the models by comparing suitability levels to presence-absence data collected in the field. We then used the suitable areas as estimators of the area of occupancy and compared the results of systematic reserve selection based on geographic ranges to those based on estimated areas of occupancy. Our results showed that the reserve system would need a 30-100% expansion to achieve minimal conservation targets, concentrated in the tropics, where species richness reaches a maximum. Comparative analyses revealed that using geographic ranges, which overestimate the area occupied by species, underestimates the total amount of area that needs to be conserved. The area selected for conservation doubled when we used the estimated area of occupancy in place of the geographic ranges. This happened because the suitable areas potentially occupied by each species overlapped less than their geographic ranges. As a result, any given protected area contained fewer species than predicted by the analysis of ranges. Because species are more specialized than our estimates of distribution based on extent of occurrence suggest, we propose that this is a general effect in systematic conservation planning. 相似文献
314.
论述了山东省生物多样性现状及受危原因,讨论了自然保护区的建设对生物多样性保护的作用和存在的不足,对山东省自然保护区的发展及生物多样性保护对策进行了初步探讨。 相似文献
315.
自然保护区经济价值评价探讨 总被引:1,自引:0,他引:1
概括论述自然保护区社会经济价值的表现形式、类型及作用等,对资源直接、间接和潜在用途的社会经济价值估算方式、方法及评价进行了探讨。 相似文献
316.
The SITES reserve selection system: A critical review 总被引:1,自引:0,他引:1
Douglas?T.?FischerEmail author Richard?L.?Church 《Environmental Modeling and Assessment》2005,10(3):215-228
Numerous models have been put forth to help with the growing demand for the establishment of biodiversity reserves. One site
selection model that has been used in several recent studies is SITES [S.J. Andelman, I. Ball, F.W. Davis and D.M. Stoms,
SITES V 1.0: an analytical toolbox for designing ecoregional conservation portfolios, Unpublished manual prepared for the
nature conservancy, 1999, 1–43. (available at )]. SITES includes two heuristic solvers: based on Greedy and Simulated Annealing. We discuss the formulation of the SITES
model, present a new formulation for that problem, and solve a number of test problems optimally using off-the-shelf software.
We compared our optimal results with the SITES Simulated Annealing heuristic and found that SITES frequently returns significantly
suboptimal solutions. Our results add further support to the argument, started by Underhill [L.G. Underhill, Optimal and suboptimal
reserve selection algorithms, Biol. Conserv. 70 (1994) 85–87], continuing through Rodrigues and Gaston [A.S.L. Rodrigues and
K.J. Gaston, Optimization in reserve selection procedures – why not?, Biol. Conserv. 107 (2002) 123–129], for greater integration
of optimal methods in the reserve design/selection literature. 相似文献
317.
Charles S. ReVelle Justin C. Williams John J. Boland 《Environmental Modeling and Assessment》2002,7(2):71-80
Five classes of zero–one programming models for discrete facility location problems are compared to counterpart models for the selection of conservation reserves. The basic problem of siting facilities to cover demand for services is analogous to the problem of selecting reserves to support species diversity. The classes of models include the set covering and maximal covering models, as well as models for backup and redundant coverage. Issues of reliability and uncertainty are addressed by chance constrained covering models and maximal expected covering models. Exact and heuristic solution approaches are discussed. Multi-objective and economic issues are considered. 相似文献
318.
基于遥感影像、无人机航摄与移动核查技术,构建了集自然保护区"一张图"、图斑任务管理、移动核查为一体的天地一体化自然保护区人类活动监管系统,并以防城金花茶国家级自然保护区为例,进行试点监测监管研究。结果表明,利用监管系统可提高自然保护区监管时效性,有效解决监管盲区。对防城金花茶国家级自然保护区的人类活动进行监测评价,该保护区有工矿用地、农田、居民点、道路、其他人工设施等5类,以农田、居民点、普通道路为主,人类活动影响一般。 相似文献
319.
Darek?J.?NalleEmail author Jeffrey?L.?Arthur 《Environmental Modeling and Assessment》2005,10(3):229-238
The efficacy of simultaneously advancing two distinct conceptual designs (referred to here as fixed-site and non-fixed-site)
for species conservation and protection is addressed. In the literature, numerous models can be found that typically stem
from a particular design, but rarely are comparisons made between approaches. This paper presents a more integrated optimization
framework that models landowner behavior and species viabilities at a landscape scale. Regional demand for resource extraction
is used as the economic driver, a variant of simulated annealing is used to solve the model under different species protection
approaches, and a detailed species population simulator is utilized to measure biological responses. When directly comparing
the outcomes of different species protection strategies from a case study in Oregon (USA), it was found that neither approach
was universally superior in terms of financial value or degree of protection for two late seral forest dependent species. 相似文献
320.
Efficiency,costs and trade-offs in marine reserve system design 总被引:1,自引:0,他引:1
Romola?R.?StewartEmail author Hugh?P.?Possingham 《Environmental Modeling and Assessment》2005,10(3):203-213
With marine biodiversity conservation the primary goal for reserve planning initiatives, a site's conservation potential is
typically evaluated on the basis of the biological and physical features it contains. By comparison, socio-economic information
is seldom a formal consideration of the reserve system design problem and generally limited to an assessment of threats, vulnerability
or compatibility with surrounding uses. This is perhaps surprising given broad recognition that the success of reserve establishment
is highly dependent on widespread stakeholder and community support. Using information on the spatial distribution and intensity
of commercial rock lobster catch in South Australia, we demonstrate the capacity of mathematical reserve selection procedures
to integrate socio-economic and biophysical information for marine reserve system design. Analyses of trade-offs highlight
the opportunities to design representative, efficient and practical marine reserve systems that minimise potential loss to
commercial users. We found that the objective of minimising the areal extent of the reserve system was barely compromised
by incorporating economic design constraints. With a small increase in area (<3%) and boundary length (<10%), the economic
impact of marine reserves on the commercial rock lobster fishery was reduced by more than a third. We considered also how
a reserve planner might prioritise conservation areas using information on a planning units selection frequency. We found
that selection frequencies alone were not a reliable guide for the selection of marine reserve systems, but could be used
with approaches such as summed irreplaceability to direct conservation effort for efficient marine reserve design. 相似文献