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1.
Abstract:  I evaluated the Northwest Forest Plan as a model for ecosystem management to achieve social and economic goals in communities located around federal forests in the U.S. Pacific Northwest. My assessment is based on the results of socioeconomic monitoring conducted to evaluate progress in achieving the plan's goals during its first 10 years. The assessment criteria I used related to economic development and social justice. The Northwest Forest Plan incorporated economic development and social justice goals in its design. Socioeconomic monitoring results indicate that plan implementation to achieve those goals met with mixed success, however. I hypothesize there are two important reasons the plan's socioeconomic goals were not fully met: some of the key assumptions underlying the implementation strategies were flawed and agency institutional capacity to achieve the goals was limited. To improve broad-scale ecosystem management in the future, decision makers should ensure that natural-resource management policies are socially acceptable; land-management agencies have the institutional capacity to achieve their management goals; and social and economic management goals (and the strategies for implementing them) are based on accurate assumptions about the relations between the resources being managed and well-being in local communities. One of the difficulties of incorporating economic development and social justice goals in conservation initiatives is finding ways to link conservation behavior and development activities. From a social perspective, the Northwest Forest Plan as a model for ecosystem management is perhaps most valuable in its attempt to link the biophysical and socioeconomic goals of forest management by creating high-quality jobs for residents of forest communities in forest stewardship and ecosystem management work, thereby contributing to conservation.  相似文献   

2.
Abstract:  The Northwest Forest Plan in the Pacific Northwest sought to stabilize local economies, including local employment and income, by stabilizing the flow of wood fiber from public forests. This is also a common forest management objective in other regions and countries. Because this economic strategy ignores basic market adjustments, it is likely to fail and to unnecessarily damage forest ecosystems. Application of basic economic principles on how markets operate significantly changes the apparent efficacy of efforts to manage local economies by managing timber supply. The emphasis on timber supply tends to ignore the dominant role that the demand for wood fiber and wood products, rather than wood-fiber supply, plays in determining levels of harvest and production. Contemporary economics indicates that markets tend to operate to offset reductions in wood-fiber supply. This significantly moderates the economic cost of reducing commercial timber harvest in the pursuit of environmental objectives. In addition, contemporary economic analysis indicates that the economic links between natural forests and local communities are much broader than simply the flow of commercially valuable logs to manufacturing facilities. At least in the United States, the flow of environmental services from natural forests has increasingly become an amenity that has drawn people and economic activity to forested areas. Attractive site-specific qualities, including those supported by natural forests, can potentially support local economic development even in the face of reduced timber harvests. These market-related adjustments partially explain the Northwest Forest Plan's overestimation of the expected regional impacts associated with reduced federal timber supply and the ineffectiveness of the plan's efforts to protect communities by stabilizing federal timber supply.  相似文献   

3.
Abstract: The Northwest Forest Plan was implemented in 1994 to protect habitat for species associated with old‐growth forests, including Northern Spotted Owls (Strix occidentailis caurina) in Washington, Oregon, and northern California (U.S.A.). Nevertheless, 10‐year monitoring data indicate mixed success in meeting the ecological goals of the plan. We used the ecosystem management decision‐support model to evaluate terrestrial and aquatic habitats across the landscape on the basis of ecological objectives of the Northwest Forest Plan, which included maintenance of late‐successional and old‐growth forest, recovery, and maintenance of Pacific salmon (Oncorhynchus spp.), and viability of Northern Spotted Owls. Areas of the landscape that contained habitat characteristics that supported these objectives were considered of high conservation value. We used the model to evaluate ecological condition of each of the 36, 180 township and range sections of the study area. Eighteen percent of the study area was identified as habitat of high conservation value. These areas were mostly on public lands. Many of the sections that contained habitat of exceptional conservation value were on Bureau of Land Management land that has been considered for management‐plan revisions to increase timber harvests. The results of our model can be used to guide future land management in the Northwest Forest Plan area, and illustrate how decision‐support models can help land managers develop strategies to better meet their goals.  相似文献   

4.
Conservation of the Northern Spotted Owl under the Northwest Forest Plan   总被引:2,自引:0,他引:2  
Abstract:  Development of the Northwest Forest Plan (NWFP) was motivated by concerns about the overharvest of late-seral forests and the effects of intensive forest management on the long-term viability of the Northern Spotted Owl ( Strix occidentalis caurina ). Following several years of intense political and legal debates, the final NWFP was approved in 1994. Even though the plan evolved with a broad ecosystem perspective, it remained anchored in the Spotted Owl reserve design proposed in 1990. Based on a criterion of stable or increasing populations, a decade later it remains unclear whether the enactment of the NWFP has improved the conservation status of Spotted Owls. The results of intensive monitoring of several Spotted Owl populations for over a decade suggest a continuing range-wide decline even though rates of timber harvest have declined dramatically on federal lands. The cause of the decline is difficult to determine because the research needed to establish cause and effect relations has not been done. One plausible hypothesis is that the owl's life history greatly constrains its rate of population growth even when habitat is no longer limiting. Since enactment of the NWFP, new threats have arisen, including the movement of Barred Owls ( S. varia ) into the range of the Spotted Owl, political pressure to increase levels of timber harvest, and recent changes to forest laws that eliminate the requirement to assess the viability of wildlife populations on U.S. Department of Agriculture Forest Service lands. At this time is appears that Spotted Owl conservation rests critically on continued implementation of the protections afforded by the NWFP and the U.S. Endangered Species Act.  相似文献   

5.
《Ecological modelling》2003,164(1):33-47
This study investigated the impacts of landuse history and forest age structure on regional carbon fluxes for the forests in the Pacific Northwest of the United States based on a two-stage modeling strategy. In the first stage, an individual-based forest ecosystem carbon flux model (IntCarb) at stand scale is developed. IntCarb combines components from the ZELIG and CENTURY models to simulate forest development and heterotrophic respiration, respectively. Stand scale carbon fluxes simulated by IntCarb strongly depend on stand age. A forest stand can be a carbon sink for up to 200 years old with a peak at 30–40 years old. Old-growth stands are carbon neutral to the atmosphere in the long term. For any particular year, an old-growth stand can be either a carbon sink or source. The interannual variation of Net Ecosystem Productivity (NEP) for an old-growth stand is primarily determined by heterotrophic respiration. Due to the high spatial variability of stand ages, forest age structure needs to be taken into account to improve estimation of carbon budgets of forest ecosystems over large areas. In the stand stage, a regional carbon budget model (RegCarb) is developed to estimate regional carbon fluxes over large areas based on forest age structure, adjusting for the nonrespiratory carbon losses (timber harvesting). Our initial estimate with RegCarb for the Pacific Northwest of the United States indicates that this region was a tremendous carbon source to the atmosphere from 1890 to 1990 due to extensive logging of old-growth forest. Projection for the role of forests in this region in global carbon cycle in the future strongly depend on the amount of timber to be harvested, i.e. how the age structure of forests in this region is to be altered.  相似文献   

6.
Conservation of the Marbled Murrelet under the Northwest Forest Plan   总被引:1,自引:0,他引:1  
Abstract:  The Marbled Murrelet ( Brachyramphus marmoratus ) was listed as threatened in 1992, primarily because of loss of its old-forest nesting habitat. Monitoring conducted over the first 10 years following implementation of the Northwest Forest Plan shows at-sea murrelet populations appear to be stationary, but recruitment is very low and demographic models project a 4–6% annual rate of decline. Monitoring of nesting habitat indicated there were about 1.6 million ha of higher-suitability nesting habitat on all lands at the start of the plan, about half of which occurred on federal lands. Most (88%) of higher-suitability habitat on federal lands was protected within reserves. Over the past 10 years, losses of habitat due primarily to fire have totaled about 2% on federal lands. Losses have been much greater (12%) on nonfederal lands, due primarily to timber harvest. Habitat is expected to accrue within reserves as younger forest matures and attains sufficient diameter to support nesting sites. At-sea estimates of population size are strongly and positively correlated with amounts of adjacent nesting habitat at a broad scale, supporting the idea that amounts of nesting habitat are a primary driver in wide-scale murrelet population distribution. Conditions at sea, however, such as temperature regimes, prey availability, and pollutants, continue to affect murrelet populations. The system of large reserves seems to have achieved the short-term objective of conserving much of the remaining nesting habitat on federal lands. These reserves are also likely to contribute to the long-term objective of creating large, contiguous blocks of nesting habitat. The plan has a primary role in conserving and restoring nesting habitat on federal land but will succeed in this role only if land allocations calling for such protection are in place for many decades.  相似文献   

7.
Old-Growth Mangrove Forests in the United States   总被引:7,自引:0,他引:7  
Criteria used to identify old-growth forests in the Pacific Northwest have not been proven applicable in other ecological life zones. For example, Pacific Northwest criteria are not suitable for the identification of old-growth mangrove forests. To identify old-growth mangroves one has to take into account differences in stand structure and function due to geomorphology, within-site environmental gradients, and regional disturbance regimes. A flexible and holistic approach is needed. Stand age, defined in terms of Pacific Northwest forests, is not necessarily the best criterion for identifying for conservation mangrove forests or any forest outside the Pacific Northwest. No single stand will have all old-growth characteristics, and even if they are present in a stand, these characteristics do not necessarily assure that the stand is old growth. Whether a mangrove stand reaches old-growth stage depends on the dynamics of coastal conditions under which it grows. Moreover, it is necessary to differentiate between the age of trees in a stand and the age of the mangrove system, which includes the substrate. Old-growth mangrove stands are improbable states for this ecosystem type, and they can revert to younger stages. Mangroves offer a challenge to the concept of the old-growth forest, and through our analysis of this system we show that when ecosystem functions and states are evaluated it is necessary to avoid geographic biases based on particular ecological conditions.  相似文献   

8.
Protecting biodiversity has become a major goal in managing coastal forests in the Pacific Northwest--an area in which human activities have had a significant influence on landscape change. A complex pattern of public and private forest ownership, combined with new regulations for each owner group, raises questions about how well and how efficiently these policies achieve their biodiversity goals. To develop a deeper understanding of the aggregate effect of forest policies, we simulated forest structures, timber production, and socioeconomic conditions over time for the mixture of private and public lands in the 2.3-million-ha Coast Range Physiographic Province of Oregon. To make these projections, we recognized both vegetative complexity at the stand level and spatial complexity at the landscape level. We focused on the two major factors influencing landscape change in the forests of the Coast Range: (1) land use, especially development for houses and cities, and (2) forest management, especially clearcutting. Our simulations of current policy suggest major changes in land use on the margins of the Coast Range, a divergence in forest structure among the different owners, an increase in old-growth forests, and a continuing loss of the structural elements associated with diverse young forests. Our simulations also suggest that current harvest levels can be approximately maintained, with the harvest coming almost entirely from private lands. A policy alternative that retained live trees for wildlife would increase remnant structures but at a cost to landowners (5-7% reduction in timber production). Another alternative that precluded thinning of plantations on federal land would significantly reduce the area of very large diameter (>75 cm dbh) conifer forests 100 years into the future  相似文献   

9.
Stand structure develops with stand age. Old-growth forests with well-developed stand structure support many species. However, development rates of stand structure likely vary with climate and topography. We modeled structural development of 4 key stand variables and a composite old-growth index as functions of climatic and topographic covariates. We used a hierarchical Bayesian method for analysis of extensive snap-shot National Forest Inventory (NFI) data in Japan (n = 9244) to account for differences in stand age. Development rates of structural variables and the old-growth index exhibited curvilinear responses to environmental covariates. Flat sites were characterized by high rates of structural development. Approximately 150 years were generally required to attain high values (approximately 0.8) of the old-growth index. However, the predicted age to achieve specific values varied depending on environmental conditions. Spatial predictions highlighted regional variation in potential structural development rates. For example, sometimes there were differences of >100 years among sites, even in the same catchment, in attainment of a medium index value (0.5) after timber harvesting. The NFI data suggested that natural forests, especially old natural forests (>150 years), remain generally on unproductive ridges, steep slopes, or areas with low temperature and deep snow, where many structural variables show slow development rates. We suggest that maintenance and restoration of old natural forests on flat sites should be prioritized for conservation due to the likely rapid development of stand structure, although remaining natural forests on low-productivity sites are still important and should be protected.  相似文献   

10.
Abstract: We assessed quantitatively the woody species used for timber, medicine, and other products in 10 tropical wet-forest stands with different land-use histories in the Atlantic lowlands of northeastern Costa Rica. Species were classified into 20 use categories based on regional ethnobotanical studies. Three size classes of woody vegetation were sampled in nested, contiguous plots along transects: trees (≥5 cm diameter at breast height [dbh]), saplings (>1 m high, <5 cm dbh), and seedlings (>20 cm high, <1 m high). Our study included five second-growth stands, three old-growth stands, and two selectively logged stands. Of the 459 woody species surveyed, 70% of the species and 86% of the total number of individuals had at least one use. Overall, species richness was highest for medicinal species (167 species). Absolute and relative abundance of medicinal and timber trees was significantly higher in second-growth stands than in old-growth and selectively logged stands. For 8 of the 15 use categories examined statistically, stem density showed no significant differences across forest types for any stem size class. Young, tropical, second-growth forests and selectively logged forests have high utilitarian as well as conservation value and will likely become important sources of forest products. The success of secondary forest regeneration, however, depends critically upon conservation of genetically diverse source populations in forest fragments and protected old-growth stands.  相似文献   

11.
The Aquatic Conservation Strategy of the Northwest Forest Plan   总被引:5,自引:0,他引:5  
Abstract:  Implemented in 1994, the Aquatic Conservation Strategy of the Northwest Forest Plan was designed to restore and maintain ecological processes for aquatic and riparian area conservation on federal lands in the western portion of the Pacific Northwest. We used decision support models to quantitatively evaluate changes in the condition of selected watersheds. In the approximately 10 years since strategy implementation, watershed condition scores changed modestly, but conditions improved in 64% of 250 sampled watersheds, declined in 28%, and remained relatively the same in 7%. Watersheds that had the largest declines included some where wildfires burned 30–60% of their area. The overall statistical distribution of the condition scores did not change significantly, however. Much of the increase in watershed condition was related to improved riparian conditions. The number of large trees (>51 cm diameter at breast height) increased 2–4%, and there were substantial reductions in tree harvest and other disturbances along streams. Whether such changes will translate into longer-term improvements in aquatic ecosystems across broader landscapes remains to be seen.  相似文献   

12.
Riparian forests regulate linkages between terrestrial and aquatic ecosystems, yet relationships among riparian forest development, stand structure, and stream habitats are poorly understood in many temperate deciduous forest systems. Our research has (1) described structural attributes associated with old-growth riparian forests and (2) assessed linkages between these characteristics and in-stream habitat structure. The 19 study sites were located along predominantly first- and second-order streams in northern hardwood-conifer forests in the Adirondack Mountains of New York (U.S.A.). Sites were classified as mature forest (6 sites), mature with remnant old-growth trees (3 sites), and old-growth (10 sites). Forest-structure attributes were measured over stream channels and at varying distances from each bank. In-stream habitat features such as large woody debris (LWD), pools, and boulders were measured in each stream reach. Forest structure was examined in relation to stand age using multivariate techniques, ANOVA, and linear regression. We investigated linkages between forest structure and stream characteristics using similar methods, preceded by information-theoretic modeling (AIC). Old-growth riparian forest structure is more complex than that found in mature forests and exhibits significantly greater accumulations of aboveground tree biomass, both living and dead. In-stream LWD volumes were significantly (alpha = 0.05) greater at old-growth sites (200 m3/ha) compared to mature sites (34 m3/ha) and were strongly related to the basal area of adjacent forests. In-stream large-log densities correlated strongly with debris-dam densities. AIC models that included large-log density, debris-dam density, boulder density, and bankfull width had the most support for predicting pool density. There were higher proportions of LWD-formed pools relative to boulder-formed pools at old-growth sites as compared to mature sites. Old-growth riparian forests provide in-stream habitat features that have not been widely recognized in eastern North America, representing a potential benefit from late-successional riparian forest management and conservation. Riparian management practices (including buffer delineation and restorative silvicultural approaches) that emphasize development and maintenance of late-successional characteristics are recommended where the associated in-stream effects are desired.  相似文献   

13.
Forest biodiversity policies in multi-ownership landscapes are typically developed in an uncoordinated fashion with little consideration of their interactions or possible unintended cumulative effects. We conducted an assessment of some of the ecological and socioeconomic effects of recently enacted forest management policies in the 2.3-million-ha Coast Range Physiographic Province of Oregon. This mountainous area of conifer and hardwood forests includes a mosaic of landowners with a wide range of goals, from wilderness protection to high-yield timber production. We projected forest changes over 100 years in response to logging and development using models that integrate land use change and forest stand and landscape processes. We then assessed responses to those management activities using GIS models of stand structure and composition, landscape structure, habitat models for focal terrestrial and aquatic species, timber production, employment, and willingness to pay for biodiversity protection. Many of the potential outcomes of recently enacted policies are consistent with intended goals. For example, we project the area of structurally diverse older conifer forest and habitat for late successional wildlife species to strongly increase. 'Other outcomes might not be consistent with current policies: for example, hardwoods and vegetation diversity strongly decline within and across owners. Some elements of biodiversity, including streams with high potential habitat for coho salmon (Oncorhynchus kisutch) and sites of potential oak woodland, occur predominately outside federal lands and thus were not affected by the strongest biodiversity policies. Except for federal lands, biodiversity policies were not generally characterized in sufficient detail to provide clear benchmarks against which to measure the progress or success. We conclude that land management institutions and policies are not well configured to deal effectively with ecological issues that span broad spatial and temporal scales and that alternative policies could be constructed that more effectively provide for a mix of forest values from this region.  相似文献   

14.
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   

15.
SUMMARY

The contention is examined that forests can contribute to biodiversity conservation either as protected areas or as production forests, especially where the latter are managed for timber extraction. This notion is explored for the Peninsular Malaysian forests, and it is shown that biodiversity conservation would be optimized if the system of protected areas is located within a broader matrix of carefully managed production forests. A model is developed to illustrate how the biodiversity value of protected areas would be enhanced through interaction with production forests. In no way is the suggestion being made here that production forests could serve as critical centres for the conservation of biotic diversity, but then neither should they be dismissed as areas completely devoid of any contribution to the biodiversity cause. These findings are especially significant in Peninsular Malaysia where two-thirds of the forests legally set aside as Permanent Forest Estate is to be managed as production forests. If the incremental biodiversity value of these forests can be captured through improved management practices, then the overall biodiversity status of the country, and the globe, could be greatly increased. The extent to which any country is willing to set aside forests as protected areas, strictly for biodiversity conservation, is limited, hence the integrated approach to the management of protected and production forests advocated here could prove an attractive and feasible strategy. Where funding is limited, as in the case of the Global Environment Facility, it may be worthwhile to provide incentives for improved management of production forests as a means of conserving biodiversity.  相似文献   

16.
Development and maintenance of structurally complex forests in landscapes formerly managed for timber production is an increasingly common management objective. It has been postulated that the rate of forest structural development increases with site productivity. We tested this hypothesis for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests using a network of permanent study plots established following complete timber harvest of the original old-growth forests. Forest structural development was assessed by comparing empirical measures of live tree structure to published values for Douglas-fir forests spanning a range of ages and structural conditions. The rate of forest structural development--resilience--exhibited a positive relationship with site index, a measure of potential site productivity. Density of shade-intolerant conifers declined in all study stands from an initial range of 336-4068 trees/ha to a range of 168-642 trees/ha at the most recent measurement. Angiosperm tree species declined from an initial range of 40-371 trees/ha to zero in seven of the nine plots in which they were present. Trends in shade-tolerant tree density were complex: density ranged from 0 to 575 trees/ha at the first measurement and was still highly variable (25-389 trees/ha) at the most recent measurement. Multivariate analysis identified the abundance of hardwood tree species as the strongest compositional trend apparent over the study period. However, structural variables showed a strong positive association with increasing shade-tolerant basal area and little or no association with abundance of hardwood species. Thus, while tree species succession and forest structural development occur contemporaneously, they are not equivalent processes, and their respective rates are not necessarily linearly related. The results of this study support the idea that silvicultural treatments to accelerate forest structural development should be concentrated on lower productivity sites when the management objective is reserve-wide coverage of structurally complex forests. Alternatively, high-productivity sites should be prioritized for restoration treatments when the management objective is to develop structurally complex forests on a portion of the landscape.  相似文献   

17.
Old-growth forests are valuable sources of ecological, conservation, and management information, yet these ecosystems have received little study in New England, due in large part to their regional scarcity. To increase our understanding of the structures and processes common in these rare forests, we studied the abundance of downed coarse woody debris (CWD) and snags and live-tree size-class distributions in 16 old-growth hemlock forests in western Massachusetts. Old-growth stands were compared with eight adjacent second-growth hemlock forests to gain a better understanding of the structural differences between these two classes of forests resulting from contrasting histories. In addition, we used stand-level dendroecological reconstructions to investigate the linkages between disturbance history and old-growth forest structure using an information-theoretic model selection framework. Old-growth stands exhibit a much higher degree of structural complexity than second-growth forests. In particular, old-growth stands had larger overstory trees and greater volumes of downed coarse woody debris (135.2 vs. 33.2 m3/ha) and snags (21.2 vs. 10.7 m3/ha). Second-growth stands were characterized by either skewed unimodal or reverse-J shaped diameter distributions, while old-growth forests contained bell-shaped, skewed unimodal, rotated sigmoid, and reverse J-shaped distributions. The variation in structural attributes among old-growth stands, particularly the abundance of downed CWD, was closely related to disturbance history. In particular, old-growth stands experiencing moderate levels of canopy disturbance during the last century (1930s and 1980s) had greater accumulations of CWD, highlighting the importance of gap-scale disturbances in shaping the long-term development and structural characteristics of old-growth forests. These findings are important for the development of natural disturbance-based silvicultural systems that may be used to restore important forest characteristics lacking in New England second-growth stands by integrating structural legacies of disturbance (e.g., downed CWD) and resultant tree-size distribution patterns. This silvicultural approach would emulate the often episodic nature of CWD recruitment within old-growth forests.  相似文献   

18.
Information about how vegetation composition and structure vary quantitatively and spatially with physical environment, disturbance history, and land ownership is fundamental to regional conservation planning. However, current knowledge about patterns of vegetation variability across large regions that is spatially explicit (i.e., mapped) tends to be general and qualitative. We used spatial predictions from gradient models to examine the influence of environment, disturbance, and ownership on patterns of forest vegetation biodiversity across a large forested region, the 3-million-ha Oregon Coast Range (USA). Gradients in tree species composition were strongly associated with environment, especially climate, and insensitive to disturbance, probably because many dominant tree species are long-lived and persist throughout forest succession. In contrast, forest structure was strongly correlated with disturbance and only weakly with environmental gradients. Although forest structure differed among ownerships, differences were blurred by the presence of legacy trees that originated prior to current forest management regimes. Our multi-ownership perspective revealed biodiversity concerns and benefits not readily visible in single-ownership analyses, and all ownerships contributed to regional biodiversity values. Federal lands provided most of the late-successional and old-growth forest. State lands contained a range of forest ages and structures, including diverse young forest, abundant legacy dead wood, and much of the high-elevation true fir forest. Nonindustrial private lands provided diverse young forest and the greatest abundance of hardwood trees, including almost all of the foothill oak woodlands. Forest industry lands encompassed much early-successional forest, most of the mixed hardwood-conifer forest, and large amounts of legacy down wood. The detailed tree- and species-level data in the maps revealed regional trends that would be masked in traditional coarse-filter assessment. Although abundant, most early-successional forests originated after timber harvest and lacked legacy live and dead trees important as habitat and for other ecological functions. Many large-conifer forests that might be classified as old growth using a generalized forest cover map lacked structural features of old growth such as multilayered canopies or dead wood. Our findings suggest that regional conservation planning include all ownerships and land allocations, as well as fine-scale elements of vegetation composition and structure.  相似文献   

19.
The national legislative and policy context for integrated ocean management in Canada is provided by the Oceans Act (1996) and the supporting policy statement, Canada’s Oceans Strategy. Under the Oceans Act, Fisheries and Oceans Canada (DFO) is the lead federal authority for ocean affairs and is charged with leading and facilitating the development and implementation of integrated management plans for all marine waters. Integrated management efforts in Canada are being undertaken through an area-based approach that enables marine planning, management and decision making to occur at appropriate spatial scales, from regional to site-specific. This article focuses on the Eastern Scotian Shelf Integrated Management (ESSIM) process, an offshore-focused effort to develop an integrated ocean management plan for a large portion of the Scotian Shelf, off Nova Scotia. The resulting Eastern Scotian Shelf Integrated Ocean Management Plan (the ESSIM plan) has been developed through a collaborative process involving all interested and affected government departments and ocean stakeholders, and provides an objectives-based approach to ocean management. The ESSIM plan contains a set of long-term, overarching goals for collaborative governance and integrated management, sustainable human use, and healthy ecosystems. These goals are supported by more specific objectives that express desired outcomes and conditions for the marine region. The objectives-based approach seeks to ensure that interrelationships among ecosystem and human use objectives are recognized and reflected in the identification of management strategies and supporting actions. This article considers the role of marine spatial planning within the context of the integrated ocean management process underway for the Scotian Shelf. The policy and management context for integrated ocean management in Canada is briefly described and a summary of the ESSIM plan is provided. The current and potential role for marine spatial planning in implementing the objectives and strategies of the ESSIM plan is highlighted using examples related to multiple ocean use and marine conservation and protected area planning. The article concludes by drawing out key lessons learned to date through the ESSIM process for marine spatial planning and looks to the future in terms of the development of tools and approaches for this integral aspect of integrated ocean management.  相似文献   

20.
Abstract:  Questions persist regarding whether the science of conservation biology can successfully affect environmental decision making. One of the most prominent fields of intersection between conservation science and environmental policy is public-lands debates in the United States. I reviewed the role of conservation science in the roadless-area policies of the U.S. Forest Service. Since 1971, the Forest Service has systematically evaluated roadless areas on national forests three times, most recently during the Clinton administration's Roadless Area Conservation Review (1998–2000) ( U.S. Department of Agriculture Forest Service 2000b ). Drawing on the agency's environmental impact statements and supporting documents and the internal records of conservation organizations, I examined the changing goals, methodology, and outcome of roadless-area advocacy and policy. Since the 1970s, conservation science has successfully informed public and administrative concern for roadless-area protection. Conservation science has transformed public discourse regarding roadless areas and has changed the scope and rationale of national conservation organizations' goals for roadless-area policy from protecting some to protecting all remaining national forest roadless areas. The Forest Service has increasingly drawn on the lessons of conservation biology to justify its methodology and its administrative recommendations to protect roadless areas. The 2000 Roadless Area Conservation Review resulted in a recommendation to protect all remaining national forest roadless areas, up from 22% of roadless areas in the first roadless review. Despite the scientific merits of recent roadless-area advocacy and policy, however, such initiatives have faced political difficulties. The emphasis on large-scale, top-down, national approaches to conservation policy has rendered such policies politically problematic.  相似文献   

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