The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Hugh P. Possingham - One of the best experts on this subject based on the ideXlab platform.
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the effect of applying alternate ipcc climate scenarios to marine Reserve Design for range changing species
Conservation Letters, 2015Co-Authors: Azusa Makino, Carissa J Klein, Hugh P. Possingham, Hiroya Yamano, Yumiko Yara, Toshinori Ariga, Keisuke Matsuhasi, Maria BegerAbstract:Effectively protecting of biodiversity in the future relies on Reserves that accommodate potential climate change impacts. Climate predictions are based on plausible ranges of greenhouse gas concentration scenarios from the IPCC, called Representative Concentration Pathways (RCPs). It is unknown how different scenarios influence spatial prioritization, particularly for species that change their range due to climate change. Using corals in Japan, we explore differences in priorities under three RCPs (RCP8.5, 4.5, and 2.6), comparing three time frames (current conditions, near future, and distant future). We targeted three temperature zones representing different coral community types, determined from predictions of sea-surface temperature for three RCPs. Results showed that using one RCP prediction to Design a Reserve system does a poor job at meeting conservation targets for other RCPs, missing up to 100% of the targets. We emphasize the importance of focusing conservation investment in “no regrets” areas that are important under every RCP.
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using multivariate statistics to explore trade offs among spatial planning scenarios
Journal of Applied Ecology, 2014Co-Authors: Linda R Harris, Hugh P. Possingham, Matthew E Watts, Ronel Nel, David S SchoemanAbstract:Scenario planning can be useful to guide decision-making under uncertainty. While systematic conservation planning can create protected-area networks for multiple and complex Reserve-Design scenarios, planners rarely compare different Reserve networks explicitly, or quantify trade-offs among scenarios. We demonstrate the use of multivariate statistics traditionally applied in community ecology to compare Reserves Designed under different scenarios, using conservation planning for beaches in South Africa as an example. Twelve Reserve-Design scenarios were run in Marxan in a hierarchical experimental Design with three levels: including/excluding the probability of site destruction; two different cost types; and three different configurations of existing terrestrial and marine Reserves. Multivariate statistics proved to be useful tools in the conservation planning context. In our case study, they showed that the trade-off associated with including the probability of site destruction during coastal Reserve Design depended on the cost type: if the cost is related to the site-destruction probability then Reserves are significantly larger; if not, then Reserves are significantly more costly. In both cases, the configuration of existing Reserves locked a priori into the solutions was more important and resulted in significantly larger and more costly Reserves.Synthesis and applications. This study demonstrates a novel application of multivariate statistical tools to robustly quantify potential trade-offs among diverse sets of Reserve-Design scenarios. These statistics can be applied: to support negotiations with stakeholders and decision-makers regarding Reserve configurations in the face of uncertainty; in Reserve-Design sensitivity analyses; and in priority setting for future research and data collection to improve conservation plans.
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tradeoffs in marine Reserve Design habitat condition representation and socioeconomic costs
Conservation Letters, 2013Co-Authors: Carissa J Klein, Charles Steinback, Astrid Scholz, Vivitskaia J D Tulloch, Benjamin S Halpern, Matthew E Watts, Kimberly A Selkoe, Hugh P. PossinghamAbstract:We present a novel method for Designing marine Reserves that trades off three important attributes of a conservation plan: habitat condition, habitat representation, and socioeconomic costs. We calculated habitat condition in four ways, using different human impacts as a proxy for condition: all impacts; impacts that cannot be managed with a Reserve; land-based impacts; and climate change impacts. We demonstrate our approach in California, where three important tradeoffs emerged. First, Reserve systems that have a high chance of protecting good condition habitats cost fishers less than 3.1% of their income. Second, cost to fishers can be reduced by 1/2-2/3 by triaging less than 1/3 of habitats. Finally, increasing the probability of protecting good condition habitats from 50% to 99% costs fishers an additional 1.7% of their income, with roughly 0.3% added costs for each additional 10% confidence. Knowing exactly what the cost of these tradeoffs are informs discussion and potential compromise among stakeholders involved in protected area planning worldwide.
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incorporating uncertainty associated with habitat data in marine Reserve Design
Biological Conservation, 2013Co-Authors: Vivitskaia J D Tulloch, Ayesha I T Tulloch, Chris Roelfsema, Hugh P. Possingham, Stacy D Jupiter, Carissa J KleinAbstract:Abstract One of the most pervasive forms of uncertainty in data used to make conservation decisions is error associated with mapping of conservation features. Whilst conservation planners should consider uncertainty associated with ecological data to make informed decisions, mapping error is rarely, if ever, accommodated in the planning process. Here, we develop a spatial conservation prioritization approach that accounts for the uncertainty inherent in coral reef habitat maps and apply it in the Kubulau District fisheries management area, Fiji. We use accuracy information describing the probability of occurrence of each habitat type, derived from remote sensing data validated by field surveys, to Design a marine Reserve network that has a high probability of protecting a fixed percentage (10–90%) of every habitat type. We compare the outcomes of our approach to those of standard Reserve Design approaches, where habitat-mapping errors are not known or ignored. We show that the locations of priority areas change between the standard and probabilistic approaches, with errors of omission and commission likely to occur if Reserve Design does not accommodate mapping accuracy. Although consideration of habitat mapping accuracy leads to bigger Reserve networks, they are unlikely to miss habitat conservation targets. We explore the trade-off between conservation feature representation and Reserve network area, with smaller Reserve networks possible if we give up on trying to meet targets for habitats mapped with a low accuracy. The approach can be used with any habitat type at any scale to inform more robust and defensible conservation decisions in marine or terrestrial environments.
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planning for Reserve adequacy in dynamic landscapes maximizing future representation of vegetation communities under flood disturbance in the pantanal wetland
Diversity and Distributions, 2011Co-Authors: Reinaldo Lourival, Matthew E Watts, Martin Drechsler, Edward T Game, Hugh P. PossinghamAbstract:Aim Using a probabilistic modelling framework, we aimed to incorporate landscape spatiotemporal dynamics into Reserve Design. We employed a spatially explicit stochastic model, which integrates both hydrological and biological processes, to simulate the wetland’s biological succession. Location Pantanal wetland (with 140,000 km2) between Brazil, Bolivia and Paraguay. Methods We used the Reserve Design software Marxan to optimize the current and future representation (up to 50 years) of 20% of five plant communities with maximum reliability (i.e. smallest uncertainty). The Kappa statistic was used to compare selection frequencies of individual sites through a set of planning timeframes (5, 17, 25 and 50 years) and the likely pattern of biological succession over these periods. Results Solutions based on static vegetation distributions were significantly dissimilar from solutions based on the expected modelled changes resulting from the flood disturbance and succession dynamics. Increasing the required reliability of biodiversity outcomes resulted in more expensive Reserve solutions. We demonstrated the flexibility of probabilistic decision-making methods to illuminate the trade-offs between reliability and efficiency of site selection. Main conclusions Considering the importance of habitat heterogeneity to the principles and practice of systematic conservation planning, it is notable that landscape dynamics have not been a central theme in conservation planning. In the case of the Pantanal hydrosere, acknowledging and planning for temporal dynamics required an ability to model succession and define acceptable levels of outcome reliability, but ultimately improved the long-term Adequacy of resulting Reserve networks.
Alan L Shanks - One of the best experts on this subject based on the ideXlab platform.
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evidence for limited larval dispersal in black rockfish sebastes melanops implications for population structure and marine Reserve Design
Canadian Journal of Fisheries and Aquatic Sciences, 2004Co-Authors: Jessica A Miller, Alan L ShanksAbstract:Although dispersal distances of marine larvae influence gene flow and the establishment of population struc- ture, few data on realized dispersal distances exist for marine species. We combined otolith microstructure and micro- chemistry of black rockfish (Sebastes melanops) to assess their potential to provide relative estimates of larval dispersal distance. In 2001 and 2002 we measured trace elements at discrete otolith regions, representing the (i) egg/early-larval, (ii) pelagic larval, and (iii) late-larval/early-juvenile periods of fish collected at three locations 120-460 km apart. Discriminant-function analyses based on geochemical signatures at each otolith region accurately grouped an average of 85% (jackknife = 67%) and 87% (jackknife = 81%) of the fish to collection location in 2001 and 2002, respectively. Age at collection ranged from 83 to 174 days and parturition dates within each site were spread over a 22- to 66-day period. Therefore, individuals within sites were not released at similar times. A probable explanation of these data is that larvae from different geographic locations did not mix during ontogeny and possibly did not disperse long dis- tances alongshore. Larval dispersal distances may be appreciably shorter, <120 km, than previously assumed based on models of passive dispersal.
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evidence for limited larval dispersal in black rockfish sebastes melanops implications for population structure and marine Reserve Design
Canadian Journal of Fisheries and Aquatic Sciences, 2004Co-Authors: Jessica A Miller, Alan L ShanksAbstract:Although dispersal distances of marine larvae influence gene flow and the establishment of population structure, few data on realized dispersal distances exist for marine species. We combined otoli...
Steven D. Gaines - One of the best experts on this subject based on the ideXlab platform.
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accounting for tourism benefits in marine Reserve Design
PLOS ONE, 2017Co-Authors: Daniel F Viana, Benjamin S Halpern, Steven D. GainesAbstract:Marine Reserve Design often considers potential benefits to conservation and/or fisheries but typically ignores potential revenues generated through tourism. Since tourism can be the main source of economic benefits for many marine Reserves worldwide, ignoring tourism objectives in the Design process might lead to sub-optimal outcomes. To incorporate tourism benefits into marine Reserve Design, we develop a bioeconomic model that tracks tourism and fisheries revenues through time for different management options and location characteristics. Results from the model show that accounting for tourism benefits will ultimately motivate greater ocean protection. Our findings demonstrate that marine Reserves are part of the optimal economic solution even in situations with optimal fisheries management and low tourism value relative to fisheries. The extent of optimal protection depends on specific location characteristics, such as tourism potential and other local amenities, and the species recreational divers care about. Additionally, as tourism value increases, optimal Reserve area also increases. Finally, we demonstrate how tradeoffs between the two services depend on location attributes and management of the fishery outside marine Reserve borders. Understanding when unavoidable tradeoffs will arise helps identify those situations where communities must choose between competing interests.
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marine Reserve Design and the evolution of size at maturation in harvested fish
Ecological Applications, 2005Co-Authors: Marissa Leanne Baskett, Steven D. Gaines, Simon A Levin, Jonathan DushoffAbstract:By significantly changing size-dependent mortality, fisheries can cause rapid evolution toward earlier maturation in harvested species. Because earlier maturation neg- atively affects biomass yield and sustainability, ignoring evolutionary changes could sig- nificantly reduce the success of fisheries management policy. With a quantitative genetic model of size at maturation that incorporates phenotype plasticity, we examine the impact of different management strategies including traditional effort control and Marine Protected Areas (MPAs). After verifying the model's accuracy, using historical trajectories for size at maturation in cod (Gadus morhua), we test model predictions under different management schemes with life history parameters for red snapper (Lutjanus campechanus) and two rockfish species (Sebastes paucispinis and S. ruberrimus). The model results show that no- take MPAs can protect against strong fisheries-based selection for earlier maturation. The potential to protect against anthropogenic selection declines with increasing fragmentation of Reserves to networks of small Reserves. Accounting for the evolution of size at maturation increases the predicted biomass contribution from MPA populations to harvested popula- tions. Traditional management approaches, such as adjustments to harvest rate and maxi- mum size limits, can lead to equivalent protection against anthropogenic selection and equivalent or greater long-term biomass yield than establishing MPAs; however, the pro- tection and yield from establishing no-take MPAs appears more robust to uncertainty.
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ensuring persistence of marine Reserves catastrophes require adopting an insurance factor
Ecological Applications, 2003Co-Authors: Gary W Allison, Jane Lubchenco, Steven D. Gaines, Hugh P. PossinghamAbstract:When viewed across long temporal and large spatial scales, severe disturbances in marine ecosystems are not uncommon. Events such as hurricanes, oil spills, disease outbreaks, hypoxic events, harmful algal blooms, and coral bleaching can cause massive mortality and dramatic habitat effects on local or even regional scales. Although Designers of marine Reserves might assume low risk from such events over the short term, catastrophes are quite probable over the long term and must be considered for successful implementation of Reserves. A simple way to increase performance of a Reserve network is to incorporate into the Reserve Design a mechanism for calculating how much additional area would be required to buffer the Reserve against effects of catastrophes. In this paper, we develop a method to determine this "insurance factor": a multiplier to calculate the additional Reserve area necessary to ensure that functional goals of Reserves will be met within a given ‘‘catastrophe regime.’’ We document and analyze the characteristics of two relatively well-studied types of disturbances: oil spills and hurricanes. We examine historical data to characterize catastrophe regimes within which Reserves must function and use these regimes to illustrate the application of the insurance factor. This tool can be applied to any Reserve Design for which goals are defined by a quantifiable measure, such as a fraction of shoreline, that is necessary to accomplish a particular function. In the absence of such quantitative measures, the concept of additional area as insurance against catastrophes may still be useful.
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avoiding current oversights in marine Reserve Design
Ecological Applications, 2003Co-Authors: Steven D. Gaines, Brian Gaylord, John L LargierAbstract:The pun in the above title reflects two points. First, marine life cycles com- monly include a dispersive juvenile stage that is moved about by ocean currents. This stage often is the predominant, or only, means of dispersal that connects spatially disjunct pop- ulations. As a consequence, details of dispersal likely play a critical role in determining the effectiveness of marine Reserves as a management and conservation tool. Curiously, however (and this is the second point of the title), although dozens of models for marine Reserves now exist, few actually account explicitly for larval dispersal. Moreover, those that do include dispersal, do so almost exclusively by considering it to be a nondirectional spreading process (diffusion), ignoring the effects of directional transport by currents (ad- vection). Here we develop a population dynamical model for marine organisms with rel- atively sedentary adults whose larvae are transported in a simple flow field with both diffusive spreading and directional characteristics. We find that advection can play a dom- inant role in determining the effectiveness of different Reserve configurations. Two of the most important consequences are: (1) with strong currents, multiple Reserves can be mark- edly more effective than single Reserves of equivalent total size; and (2) in the presence of strong currents, Reserves can significantly outperform traditional, effort-based manage- ment strategies in terms of fisheries yield, and do so with less risk. These results suggest that successful Reserve Design may require considerable new efforts to examine explicitly the role of dispersal of young.
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population models for marine Reserve Design a retrospective and prospective synthesis
Ecological Applications, 2003Co-Authors: Leah Gerber, Steven D. Gaines, Hugh P. Possingham, Alan Hastings, Louis W Botsford, Stephen R Palumbi, Sandy J AndelmanAbstract:We synthesize results from existing models of marine Reserves to identify key theoretical issues that appear to be well understood, as well as issues in need of further exploration. Models of marine Reserves are relatively new in the scientific literature; 32 of the 34 theoretical papers we reviewed were published after 1990. These models have focused primarily on questions concerning fishery management at the expense of other objectives such as conservation, scientific understanding, recreation, education, and tourism. Roughly one-third of the models analyze effects on cohorts while the remaining models have some form of complete population dynamics. Few models explicitly include larval dispersal. In a fisheries context, the primary conclusion drawn by many of the complete population models is that Reserves increase yield when populations would otherwise be overfished. A second conclusion, resulting primarily from single-cohort models, is that Reserves will provide fewer benefits for species with greater adult rates of movement. Although some models are beginning to yield information on the spatial configurations of Reserves required for populations with specific dispersal distances to persist, it remains an aspect of Reserve Design in need of further analysis. Other outstanding issues include the effects of (1) particular forms of density dependence, (2) multispecies interactions, (3) fisher behavior, and (4) effects of concentrated fishing on habitat. Model results indicate that marine Reserves could play a beneficial role in the protection of marine systems against overfishing. Additional modeling and analysis will greatly improve prospects for a better understanding of the potential of marine Reserves for conserving biodiversity.
Carissa J Klein - One of the best experts on this subject based on the ideXlab platform.
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the effect of applying alternate ipcc climate scenarios to marine Reserve Design for range changing species
Conservation Letters, 2015Co-Authors: Azusa Makino, Carissa J Klein, Hugh P. Possingham, Hiroya Yamano, Yumiko Yara, Toshinori Ariga, Keisuke Matsuhasi, Maria BegerAbstract:Effectively protecting of biodiversity in the future relies on Reserves that accommodate potential climate change impacts. Climate predictions are based on plausible ranges of greenhouse gas concentration scenarios from the IPCC, called Representative Concentration Pathways (RCPs). It is unknown how different scenarios influence spatial prioritization, particularly for species that change their range due to climate change. Using corals in Japan, we explore differences in priorities under three RCPs (RCP8.5, 4.5, and 2.6), comparing three time frames (current conditions, near future, and distant future). We targeted three temperature zones representing different coral community types, determined from predictions of sea-surface temperature for three RCPs. Results showed that using one RCP prediction to Design a Reserve system does a poor job at meeting conservation targets for other RCPs, missing up to 100% of the targets. We emphasize the importance of focusing conservation investment in “no regrets” areas that are important under every RCP.
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tradeoffs in marine Reserve Design habitat condition representation and socioeconomic costs
Conservation Letters, 2013Co-Authors: Carissa J Klein, Charles Steinback, Astrid Scholz, Vivitskaia J D Tulloch, Benjamin S Halpern, Matthew E Watts, Kimberly A Selkoe, Hugh P. PossinghamAbstract:We present a novel method for Designing marine Reserves that trades off three important attributes of a conservation plan: habitat condition, habitat representation, and socioeconomic costs. We calculated habitat condition in four ways, using different human impacts as a proxy for condition: all impacts; impacts that cannot be managed with a Reserve; land-based impacts; and climate change impacts. We demonstrate our approach in California, where three important tradeoffs emerged. First, Reserve systems that have a high chance of protecting good condition habitats cost fishers less than 3.1% of their income. Second, cost to fishers can be reduced by 1/2-2/3 by triaging less than 1/3 of habitats. Finally, increasing the probability of protecting good condition habitats from 50% to 99% costs fishers an additional 1.7% of their income, with roughly 0.3% added costs for each additional 10% confidence. Knowing exactly what the cost of these tradeoffs are informs discussion and potential compromise among stakeholders involved in protected area planning worldwide.
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incorporating uncertainty associated with habitat data in marine Reserve Design
Biological Conservation, 2013Co-Authors: Vivitskaia J D Tulloch, Ayesha I T Tulloch, Chris Roelfsema, Hugh P. Possingham, Stacy D Jupiter, Carissa J KleinAbstract:Abstract One of the most pervasive forms of uncertainty in data used to make conservation decisions is error associated with mapping of conservation features. Whilst conservation planners should consider uncertainty associated with ecological data to make informed decisions, mapping error is rarely, if ever, accommodated in the planning process. Here, we develop a spatial conservation prioritization approach that accounts for the uncertainty inherent in coral reef habitat maps and apply it in the Kubulau District fisheries management area, Fiji. We use accuracy information describing the probability of occurrence of each habitat type, derived from remote sensing data validated by field surveys, to Design a marine Reserve network that has a high probability of protecting a fixed percentage (10–90%) of every habitat type. We compare the outcomes of our approach to those of standard Reserve Design approaches, where habitat-mapping errors are not known or ignored. We show that the locations of priority areas change between the standard and probabilistic approaches, with errors of omission and commission likely to occur if Reserve Design does not accommodate mapping accuracy. Although consideration of habitat mapping accuracy leads to bigger Reserve networks, they are unlikely to miss habitat conservation targets. We explore the trade-off between conservation feature representation and Reserve network area, with smaller Reserve networks possible if we give up on trying to meet targets for habitats mapped with a low accuracy. The approach can be used with any habitat type at any scale to inform more robust and defensible conservation decisions in marine or terrestrial environments.
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effectiveness of marine Reserve networks in representing biodiversity and minimizing impact to fishermen a comparison of two approaches used in california
Conservation Letters, 2008Co-Authors: Carissa J Klein, Charles Steinback, Astrid Scholz, Hugh P. PossinghamAbstract:We compared the effectiveness of marine Reserve networks Designed using a numerical optimization tool with networks Designed by stakeholders during the course of California's Marine Life Protection Act Initiative at representing biodiversity and minimizing estimated negative impacts to fishermen. We used the same spatial data representing biodiversity and recreational fishing effort that were used by the stakeholders to Design marine Reserves. In addition, we used commercial fishing data not explicitly available to the stakeholders. Networks of marine Reserves Designed with numerical optimization tools represented the same amount of each habitat, or more, and had less of an estimated impact on commercial and recreational fisheries than networks Designed by the stakeholders. The networks Designed by the stakeholders could have represented 2.0–9.5% more of each habitat with no additional impact on the fisheries. Of four different marine Reserve proposals considered in the initiative, the proposal Designed by fishermen was more efficient than the proposals Designed by other stakeholder groups at representing biodiversity and minimizing impact to the fishing industry. These results highlight the necessity of using comprehensive information on fishing effort to Design a Reserve network that efficiently minimizes negative socioeconomic impacts. We recommend that numerical optimization tools support, not replace, the stakeholder-driven Reserve Design process along California's northern and southern coasts to help accomplish two of the initiative's core objectives: (1) Protect representative and unique marine habitats, and (2) Minimize negative socioeconomic impacts. The involvement of stakeholders is necessary as additional factors important to Reserve Design can not be considered using a numerical optimization tool.
Barry R Noon - One of the best experts on this subject based on the ideXlab platform.
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Reserve Design for territorial species the effects of patch size and spacing on the viability of the northern spotted owl
Conservation Biology, 1994Co-Authors: Roland H Lamberson, Barry R Noon, Curtis Voss, Kevin S MckelveyAbstract:Designing a Reserve system for a threatened territorial species such as the Northern Spotted Owl requires the balancing of biological necessity against economic reality. The Spotted Owl conservation plan and the Pacific Northwest timber industry are in conflict because both demand large areas of mature and old-growth coniferous forests. The primary focus of this paper is the efficient Design of a Reserve system for territorial species with obligate juvenile dispersal. We examine the relationship between the degree of aggregation of suitable owl habitat, the level of occupancy of that habitat by pairs of Spotted Owls, and the likelihood of owl persistence given different amounts and spatial arrangements of suitable habitat across the landscape. We develop a population model for Spotted Owls that includes an abstracted forest landscape where suitable owl habitat is arrayed in clusters embedded in a matrix not suitable for owl habitation. We conclude from our study of this model that, for any given fraction of the landscape set aside in Reserves, the level of occupancy (efficiency of use) of that area will increase as the aggregation of suitable habitat increases. After the Reserves reach a size that includes territories for 20 to 25 owl pairs, however, there are diminishing returns from further increases. Preserving connectivity and increasing the geographical extent of the Reserve begin to outweigh increased size in importance in insuring the long-term viability of the species.
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integrating scientific methods with habitat conservation planning Reserve Design for northern spotted owls
Ecological Applications, 1992Co-Authors: Dennis D Murphy, Barry R NoonAbstract:To meet the requirements of Congressional legislation mandating the pro- duction of a "scientifically credible" conservation strategy for the threatened Northern Spotted Owl (Strix occidentalis caurina), the Interagency Spotted Owl Scientific Committee employed scientific methods to Design a habitat Reserve system. Information on the current and historical distributions of the owl and its habitats was reviewed in light of economic, political, and legal constraints; results were used to develop a preliminary Reserve system of habitat "polygons." A map representing these polygons and their attendant properties served as a set of hypotheses that were tested. Statistical analyses of empirical data, pre- dictions from ecological theory, predictions from population dynamics models, and infer- ences drawn from studies of related species were used to test properties of the preliminary map, including the number and sizes of habitat conservation areas (HCAs), their distri- bution, configuration, and spacing, and the nature of the landscape matrix between HCAs. Conclusions that failed to confirm specific map properties were used to refine the Reserve system, a process that continued iteratively until all relevant data had been examined and all map properties had been tested. This conservation planning process has proven to be credible, repeatable, and scientifically defendable, and should serve as a model for wildlife management, endangered species recovery, and national forest planning.
