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1.
Five major management goals were identified for the upper Grande Ronde River Basin on the Wallowa-Whitman National Forest in northeastern Oregon: to produce high-quality fish habitat, to maintain elk habitat, to restore and maintain forest conditions within the natural range of viability, and to contribute to community economic stability. From the broad goals, specific goals for stream temperature, habitat effectiveness index (HEI), habitat corridors, maintenance of land in late or old seral stages, and a nondeclining even flow of timber were selected. A case study was undertaken in a small watershed that is under typical societal constraints to determine whether one decisionsupport tool, SNAP II+, could evaluate the selected goals in a single planning exercise. Three riparian management strategies and two forest road scenarios were used. The exclusion of harvest and road-building from riparian zones in order to increase habitat protection decreased harvest levels and net present value but maintained preactivity stream temperatures. Other resources were generally maintained within prescribed management levels. Although the technique has limitations (e.g., it does not account for riparian zones in calculations of forage and cover for HEI, and it can use the maximum but not minimum acreage goal for some resources), it shows promise for evaluating management tradeoffs in watershed analysis.This is Paper 3069 of the Forest Research Laboratory, Oregon State University, Corvallis, Oregon.  相似文献   

2.
Dynamic zoning (systematic alteration in the spatial and temporal allocation of even-aged forest management practices) has been proposed as a means to change the spatial pattern of timber harvest across a landscape to maximize forest interior habitat while holding timber harvest levels constant. Simulation studies have established that dynamic zoning strategies produce larger tracts of interior, closed canopy forest, thus increasing the value of these landscapes for interior-dependent wildlife. We used the simulation model LANDIS to examine how the implementation of a dynamic zoning strategy would change trajectories of ecological succession in the Great Divide Ranger District of the Chequamegon–Nicolet National Forest in northern Wisconsin over 500 years. The components of dynamic zoning strategies (number of zones in a scenario and the length of the hiatus between successive entries into zones) and their interaction had highly significant impacts on patterns of forest succession. Dynamic zoning scenarios with more zones and shorter hiatus lengths increased the average amount of the forest dominated by early successional aspen (Populus sp.). Dynamic zoning scenarios with two zones produced more late successional mature northern hardwoods than scenarios with four zones. Dynamic zoning scenarios with very short (30 years) or very long (120 years) hiatus lengths resulted in more late successional mature northern hardwoods than scenarios with intermediate hiatus lengths (60 and 90 years). However, none of the dynamic scenarios produced as much late successional mature northern hardwoods as the static alternative. Furthermore, the amounts of all habitat types in all dynamic zoning scenarios fluctuated greatly in time and space relative to static alternatives, which could negatively impact wildlife species that require a stable amount of habitat above some minimum critical threshold. Indeed, implementing dynamic zoning scenarios of different designs would have both positive and negative effects on wildlife species and for other objectives of forest management.  相似文献   

3.
We assessed the probability of three major natural hazards—windthrow, drought, and forest fire—for Central and South-Eastern European forests which are major threats for the provision of forest goods and ecosystem services. In addition, we analyzed spatial distribution and implications for a future oriented management of forested landscapes. For estimating the probability of windthrow, we used rooting depth and average wind speed. Probabilities of drought and fire were calculated from climatic and total water balance during growing season. As an approximation to climate change scenarios, we used a simplified approach with a general increase of pET by 20%. Monitoring data from the pan-European forests crown condition program and observed burnt areas and hot spots from the European Forest Fire Information System were used to test the plausibility of probability maps. Regions with high probabilities of natural hazard are identified and management strategies to minimize probability of natural hazards are discussed. We suggest future research should focus on (i) estimating probabilities using process based models (including sensitivity analysis), (ii) defining probability in terms of economic loss, (iii) including biotic hazards, (iv) using more detailed data sets on natural hazards, forest inventories and climate change scenarios, and (v) developing a framework of adaptive risk management.  相似文献   

4.
A simulation model of a cattle ranch based in southern Alberta, Canada was developed to evaluate the on-ranch economics of adopting different grazing management strategies to improve riparian grazing capacity in natural grass rangeland. Under low-cost scenarios, there are positive economic incentives to adopt strategies to maintain riparian zones that already have high grazing capacity. However, riparian zones that have declined to moderate or low grazing capacity may require additional economic incentives to encourage ranches to adopt more costly management strategies to improve the grazing capacity. The economic incentives to adopt costly management strategies are highly sensitive to the size and shape of the riparian zone and rates of grazing capacity decline or improvement.  相似文献   

5.
Riparian zones are deemed significant due to their interception capability of non-point source impacts and the maintenance of ecosystem integrity region wide. To improve classification and change detection of riparian buffers, this paper developed an evolutionary computational, supervised classification method--the RIparian Classification Algorithm (RICAL)--to conduct the seasonal change detection of riparian zones in a vast semi-arid watershed, South Texas. RICAL uniquely demonstrates an integrative effort to incorporate both vegetation indices and soil moisture images derived from LANDSAT 5 TM and RADARSAT-1 satellite images, respectively. First, an estimation of soil moisture based on RADARSAT-1 Synthetic Aperture Radar (SAR) images was conducted via the first-stage genetic programming (GP) practice. Second, for the statistical analyses and image classification, eight vegetation indices were prepared based on reflectance factors that were calculated as the response of the instrument on LANDSAT. These spectral vegetation indices were then independently used for discriminate analysis along with soil moisture images to classify the riparian zones via the second-stage GP practice. The practical implementation was assessed by a case study in the Choke Canyon Reservoir Watershed (CCRW), South Texas, which is mostly agricultural and range land in a semi-arid coastal environment. To enhance the application potential, a combination of Iterative Self-Organizing Data Analysis Techniques (ISODATA) and maximum likelihood supervised classification was also performed for spectral discrimination and classification of riparian varieties comparatively. Research findings show that the RICAL algorithm may yield around 90% accuracy based on the unseen ground data. But using different vegetation indices would not significantly improve the final quality of the spectral discrimination and classification. Such practices may lead to the formulation of more effective management strategies for the handling of non-point source pollution, bird habitat monitoring, and grazing and live stock management in the future.  相似文献   

6.
A new environmental paradigm has emerged, reflecting a change in the public's understanding of resource sustainability. Forest policy makers need to be better informed about such changes to achieve economic, social, and environmental objectives in a manner that balances human needs and aspirations with ecosystem constraints. As an aid to this task, a forest resource accounting system based on the key concept of natural capital could help reshape forest policies to provide an even wider spectrum of benefits for both present and future generations by maintaining and enhancing the productive capacity of forest capital. Such a resource accounting system would provide a tool for integrating multidimensional information requirements in measuring the health of both forest ecosystems and economic systems. This paper outlines some of the features of this accounting system and proposes and framework that would integrate economic and ecological characteristics of natural resources. Forest resource accounting is urgently needed to achieve the sustainability goals of ecosystem management.  相似文献   

7.
This paper assesses the status of coastal zones in the context of expected climate change and its related impacts, as well as current and future socioeconomic pressures and impacts. It is argued that external stresses and shocks relating to sea-level rise and other changes will tend to exacerbate existing environmental pressures and damage in coastal zones. Coastal zones are under increasing stress because of an interrelated set of planning failures including information, economic market, and policy intervention failures. Moves towards integrated coastal zone management are urgently required to guide the coevolution of natural and human systems. Overtly technocentric claims that assessments of vulnerability undertaken to date are overestimates of likely future damages from global warming are premature. While it is the case that forecasts of sea-level rise have been scaled down, much uncertainty remains over, for example, combined storm, sea surge, and other events. In any case, within the socioeconomic analyses of the problem, resource valuations have been at best only partial and have failed to incorporate sensitivity analysis in terms of the discount rates utilized. This would indicate an underestimation of potential damage costs. Overall, a precautionary approach is justified based on the need to act ahead of adequate information acquisition, economically efficient resource pricing and proactive coastal planning.  相似文献   

8.
/ This study was undertaken to (1) determine the suitability of ecosystems within Mount Spil National Park (Turkey) to human activities by a systematic zoning procedure, and (2) provide the basis for developing sound management strategies based on natural-cultural resource attributes of the park. After assessing natural-cultural resources and human activity requirements, the suitability of three zones (Strict Protection Zone, SPZ; Restricted Use Zone, RUZ; and Recreation and Administration Zone, RAZ) for proposed human activities/land uses was determined in order to maintain ecological sustainability and integrity through a weighting-ranking methodology, based on a grid cell resolution of 1 km x 1 km. Results showed that out of the three management zones, the RUZ in which the recreational activities that do not require physical developments are allowed constituted 82% of the park area as the first priority management zone. The proposed zoning procedure is believed to be a key step to improve management for both the study area and other national parks with the similar landscape features.  相似文献   

9.
Federal land managers in the western United States are interested in the potential of prescribed fire as a tool to decrease fuel loads, increase vegetational heterogeneity, and increase faunal diversity in various ecosystems. I tested whether implementation of a prescribed fire program by the US Forest Service in a watershed in the central Great Basin had significant effects on butterfly species richness and composition. I monitored butterfly communities during the first two years after implementation in five to seven burn units and controls in the watershed. To estimate baseline spatial and temporal variation in butterfly communities in the greater ecosystem, I also monitored butterflies in five untreated canyons outside the project area. Butterfly species richness and butterfly species composition (measured as community similarity) did not differ significantly between burn units and controls. Geographic location had statistically significant effects on species richness. Butterfly species composition of individual locations varied over time, as did the magnitude of that variation. These results emphasize that standardized, repeatable monitoring protocols are vital for evaluating the effects of experimental management treatments and for predicting and assessing the effects of future management strategies and environmental changes.  相似文献   

10.
The objective of this study was to evaluate vegetation recovery on footpaths in woodland that have been closed for access for 6 years. A vegetation survey was conducted in four mesophile forests, in transects perpendicular to the trail. Analyses concentrated on the direction and rate of the recovery process. Vegetation on trail sides in these ecosystems recovered substantially. Non-metric multidimensional scaling based upon species composition separated the four sample locations and each cluster contained representatives of the three major trail zones: path centre, transition and undisturbed zones. Analysis of distribution of life forms, plant strategies and seedbank longevity indices showed no differences between trail zones. This indicates that vegetation on the path centre is likely to recover towards the plant composition of the undisturbed zone. Ellenberg values indicate that environmental variation is not related to former path structures, as significant variability was only observed between the forest sites. Furthermore, the analysis concentrated on characteristics of species relevant to the recovery process.  相似文献   

11.
Wildlife management is generally carried out under conditions of uncertainty. The exact population size is unknown, its future dynamics are uncertain and clear management objectives are often not formulated. In order to provide management advice in this situation, a framework is presented for combining different sources of information using a Bayesian approach for calibrating a management model. Harvesting strategies can then be explored based on predictions of future populations size and structure which incorporate parameter uncertainty. This method makes it possible to evaluate the probability of achieving certain objectives with different management strategies. The advantage of the approach presented in this paper lies in that both the model and the harvesting strategies are adaptable to any particular population of interest. The approach is illustrated for two Scottish red deer populations for which culling strategies corresponding to different management objectives are explored and their benefits evaluated. It is found that each population requires different culling rates for keeping population number stable, demonstrating the benefits of the population specific calibration of the management model.  相似文献   

12.
Forest environmental conditions are affected by climate change, but investments in forest environmental quality can be used as part of the climate change mitigation strategy. A key question involving the potential use of forests to store more carbon as part of climate change mitigation is the impact of forest investments on the timing and quantity of forest volumes that affect carbon storage. Using an economic optimization model, we project levels of U.S. forest volumes as indicators of carbon storage for a wide range of private forest investment scenarios. Results show that economic opportunities exist to further intensify timber management on some hectares and reduce the average timber rotation length such that the national volume of standing timber stocks could be reduced relative to projections reflecting historical trends. The national amount of timber volume is projected to increase over the next 50 yr, but then is projected to decline if private owners follow an economic optimization path, such as with more forest type conversions and shorter timber rotations. With perfect foresight, future forest investments can affect current timber harvest levels, with intertemporal linkages based on adjustments through markets. Forest investments that boost regenerated timber yields per hectare would act to enhance ecosystem services (e.g., forest carbon storage) if they are related to the rate of growth and extent of growing stock inventory.  相似文献   

13.
Wind-driven waves are important in structuring intertidal and shallow subtidal assemblages of macrobenthic infauna. In the sheltered waters of estuaries, boat-generated waves (wash) may play a similar role because they are typically of a similar amplitude or larger than wind-driven waves. However, few studies have attempted to determine the role of wash in structuring assemblages. Consequently, strategies for managing boating focus around minimization of bank erosion. Along the Parramatta River (Sydney, Australia), no-wash zones have been established and mangroves planted to minimize the erosion of riverbanks and collapse of seawalls purportedly caused by 35-m-long RiverCat ferries. Although intended to also reduce the ecological impacts of wash, it is unclear whether these strategies achieve this goal. Unvegetated and vegetated (among the pneumatophores of mangroves) sediments were sampled in wash and no-wash zones along the Parramatta River to assess the effectiveness of no-wash zones and vegetation of river banks in reducing the ecological impacts of wash. Specifically, it was hypothesized that (1) assemblages of intertidal macrobenthic infauna would differ between wash and no-wash zones of the Parramatta River and (2) these differences would be greater in unvegetated than in vegetated habitat. As predicted, assemblages of macrobenthic infauna differed between the wash and no-wash zones. Capitellids, nereids, and spionids were more abundant in the no-wash zone. Contrary to the hypothesis, differences were no greater in the unvegetated habitat than in the vegetated habitat. The results suggest an impact of wash on assemblages of macrobenthic infauana and a role for no-wash zones in minimizing the effects of this disturbance.  相似文献   

14.
/ As federal land management agencies such as the USDA Forest Service increasingly choose to implement collaborative methods of public participation, research is needed to evaluate the strengths and weaknesses of the technique, to identify barriers to effective implementation of collaborative processes, and to provide recommendations for increasing its effectiveness. This paper reports on the findings of two studies focused on the experiences of Forest Service employees and their external partners as they work to implement collaborative planning processes in national forest management. The studies show both similarities and differences between agency employees and their partners in terms of how they evaluate their collaborative experiences. The studies reveal that both Forest Service employees and external partners are supportive of collaborative planning and expect it to continue in the future, both see the trust and relationships built during the process as being its greatest benefit, and both see the Forest Service's organizational culture as the biggest barrier to effective collaborative efforts. The groups differed in terms of evaluating each other's motivation for participating in the process and in whether the process was a good use of time and resources, with external partners seeing it as too drawn out and expensive. The paper concludes with a discussion of the policy implications and changes necessary to increase the effectiveness of collaborative efforts within the Forest Service and other federal land management agencies.KEY WORDS: Public land management; Collaborative planning; National forests; Public participation  相似文献   

15.
U.S. Forest Service managers are required to incorporate social and biophysical science information in planning and environmental analysis. The use of science is mandated by the National Environmental Policy Act, the National Forest Management Act, and U.S. Forest Service planning rules. Despite the agency’s emphasis on ‘science-based’ decision-making, little is known about how science is actually used in recreation planning and management. This study investigated the perceptions of Forest Service interdisciplinary (ID) team leaders for 106 NEPA projects dealing with recreation and travel management between 2005 and 2008. Our survey data show how managers rate the importance of social and biophysical science compared to other potential ‘success factors’ in NEPA assessments. We also explore how team leaders value and use multi-disciplinary tools for recreation-related assessments. Results suggest that managers employ a variety of recreation planning tools in NEPA projects, but there appears to be no common understanding or approach for how or when these tools are incorporated. The Recreation Opportunity Spectrum (ROS) was the most frequently used planning tool, but the Visitor Experience and Resource Protection (VERP) framework was the most consistently valued tool by those who used it. We recommend further evaluation of the strengths and weaknesses of each planning tool and future development of procedures to select appropriate planning tools for use in recreation-related NEPA assessments.  相似文献   

16.
Political pressures exist to increase the economic efficiency of timber management and production on the national forests managed by the USDA Forest Service. There is growing belief both outside and within the Forest Service that current levels of timber production, and most particularly uneconomic timber production, should be reduced. Many argue that eliminating uneconomic timber management programs will both save money and reduce environmental degradation. This article traces the political evolution of the focus on economic efficiency in timber production and explores the political-institutional factors that are shaping the current policy debate. The below-cost issue is less about economic efficiency than it is about political advantage and alternative political visions of the societal role of the nation's national forests now and in the future.  相似文献   

17.
Acid Deposition and Integrated Zoning Control in China   总被引:3,自引:0,他引:3  
China's rapidly growing economy is coupled with the consumption of large amounts of coal. An energy mix dominated by coal and inefficient energy utilization processes have led to increasingly serious problems of acid rain and sulfur dioxide pollution. Moreover, trends in the emissions of acidifying air pollutants lead to predictions of a very serious acid deposition problem in the future. In the absence of mitigating actions, these trends foretell a future of increasingly detrimental impacts to ecosystems in China and, potentially, to ecosystems in neighboring countries. China has implemented a two control zone (TCZ) policy, resulting in the establishment of acid rain and sulfur dioxide control zones, in an attempt to implement a cost-effective approach to mitigating acid deposition problems. While some short-term successes have resulted from management actions associated with the TCZ policy, it is clear additional measures and new policy directions are needed to reverse worsening acid deposition problems in the long term. To this end the following recommendations are presented: adjusting the primary energy mix, placing a greater emphasis on abating the effects of acid deposition, concentrating pollution control on large point sources, implementing an emission permit system for coal-fired power plants, utilizing an integrated approach in designing and evaluating control measures, and developing a greater research capacity. Research strategies must be developed that will lead to: (1) an improved scientific understanding of the sources of acidifying pollutants, their associated migration patterns, and their impacts; and (2) an identification of cost-effective mitigating strategies for the entire country.  相似文献   

18.
The National Forest Management Act (1976) specifies that multiresource inventories be conducted to provide baseline data for development and, later, monitoring of national forest management plans. This mandate entails the most ambitious and complex resource planning effort ever attempted. In this paper we evaluate the structure and use of current inventory-monitoring programs and recommend a framework for gathering data to improve national forest planning. Current national guidelines are general and provide only basic directions to forest-level planners. Forest inventories have traditionally concentrated on timber. Although these inventories are often well designed, the questions we are now asking about forest resources have outgrown these methods. Forest management is impeded by general confusion over definitions of resources and the interactions among them. We outline a simple classification scheme that centers on identification of basic ecosystem elements that can be readily measured. Furthermore, spatial and temporal scales must be considered in the design of inventory-monitoring programs. The concept of ecological indicators is reviewed, and caution is advised in their use. Inventory-monitoring programs should be goal-directed and based on as rigorous a statistical design as possible. We also review fundamental issues of variable selection, validation, and sampling bias. We conclude by developing a flexible inventory-monitoring program that is designed to provide information on individual characteristics of the environment, rather than being based on fixed definitions of resources.  相似文献   

19.
ABSTRACT: For numerical modeling of ground water movement in a real aquifer system, the aquifer is usually divided into hydrogeologically defined zones, each with its own parameter values. The responses of the system, such as head or drawdown, are often available only in some of the zones. The estimated parameters of all the zones are based on the measured response in these limited zones. However, the estimates for some of the zones may be very uncertain, and these zones are therefore not justified by the data. In this paper, an approach is presented to understand which zone may produce uncertain parameter values and should be lumped with its neighbor. This approach is demonstrated using a regional numerical model for pumping test analysis in the Nottinghamshire aquifer, UK. A step-by-step process is used in identifying the aquifer zones and estimating their parameters based on the principle of using the smallest possible numbers of zones and parameters for adequate representation of the drawdown response. After the parameters of each zone are estimated, the sensitivity features of these parameters are examined. The results show that the parameters in one zone can be estimated properly by the drawdown in another zone only when there is significant sensitivity. For transmissivity, sensitivity between zones occurs when there is significant flow between them. For storativity, sufficient sensitivity can occur without large flows between the zones, provided that one zone causes significant drawdown in the other. This idea can be extended to the flow model for a large aquifer system. If the aquifer is divided in such a way that aquifer responses are not sensitive to the parameters in some of the zones, the parameters in those zones cannot be estimated properly and should be lumped into their neighboring zones. In this way, a simple but more reasonable model can be built.  相似文献   

20.
Forest Management in Northeast China: History,Problems, and Challenges   总被引:5,自引:0,他引:5  
Yu D  Zhou L  Zhou W  Ding H  Wang Q  Wang Y  Wu X  Dai L 《Environmental management》2011,48(6):1122-1135
Studies of the history and current status of forest resources in Northeast China have become important in discussions of sustainable forest management in the region. Prior to 1998, excessive logging and neglected cultivation led to a series of problems that left exploitable forest reserves in the region almost exhausted. A substantial decrease in the area of natural forests was accompanied by severe disruption of stand structure and serious degradation of overall forest quality and function. In 1998, China shifted the primary focus of forest management in the country from wood production to ecological sustainability, adopting ecological restoration and protection as key foci of management. In the process, China launched the Natural Forest Conversion Program and implemented a new system of Classification-based Forest Management. Since then, timber harvesting levels in Northeast China have decreased, and forest area and stocking levels have slowly increased. At present, the large area of low quality secondary forest lands, along with high levels of timber production, present researchers and government agencies in China with major challenges in deciding on management models and strategies that will best protect, restore and manage so large an area of secondary forest lands. This paper synthesizes information from a number of sources on forest area, stand characteristics and stocking levels, and forest policy changes in Northeastern China. Following a brief historical overview of forest harvesting and ecological research in Northeast China, the paper discusses the current state of forest resources and related problems in forest management in the region, concluding with key challenges in need of attention in order to meet the demands for multi-purpose forest sustainability and management in the future.  相似文献   

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