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1.
In this study, the overall utility of forest management alternatives at the forest management unit level is evaluated with regard to multi-purpose and multi-user settings by a multi-criteria analysis (MCA) method. The MCA is based on an additive utility model. The relative importance of partial objectives of forest management (carbon sequestration, ground water recharge, biodiversity, and timber production) is defined in cooperation with stakeholders. The forest growth model 4C (Forest Ecosystems in a Changing Environment) is used to simulate the impact of six forest management strategies and climate on forest functions. Two climate change scenarios represent uncertainties with regard to future climatic conditions. The study is based on actual forest conditions in the Kleinsee management unit in east Germany, which is dominated by Scots pine (Pinus sylvestris L.) and oak (Quercus robur L. and Quercus petraea Liebl.) stands. First, there is an analysis of the impact of climate and forest management on forest functions. Climate change increases carbon sequestration and income from timber production due to increased stand productivity. Secondly, the overall utility of the management strategies is compared under the priority settings of different stakeholder groups. From an ecological perspective, a conservation strategy would be preferable under all climate scenarios, but the business as usual management would also fit the expectations under the current climate due to high biodiversity and carbon sequestration in the forest ecosystem. In contrast, a forest manager in public-owned forests or a private forest owner would prefer a management strategy with an intermediate thinning intensity and a high share of pine stands to enhance income from timber production while maintaining the other forest functions.  相似文献   

2.
针对东北林区贮木场的特点,应用层次分析法对其贮木场火灾危险等级的评定进行了研究。结果表明:贮木场的企业状况、气象条件和人为影响是贮木场火灾发生发展的主要影响因素。其中贮木场的单位木材储存量、单位木材生产人数、设备使用时长以及防火检查力度等因素对其火灾发生发展的影响最大。用层次分析法得出了东北林区贮木场火灾危险等级评定指数模型,并制定出贮木场火灾危险等级的评定表。东北林区各贮木场可依据评定表,并结合自身实情,对火灾危险等级进行测报。  相似文献   

3.
森林生态系统在全球碳循环与平衡中具有极为重要和不可替代的作用。黑龙江省森工林区是我国最大的国有林区和森林工业基地,森林面积806.37万hm2,森林覆盖率80.20%。丰富的碳汇既具有重要的生态功能,也蓄藏着巨大的经济利益。以森工林区天然用材林的碳汇价值作为研究对象,运用森林蓄积换算因子法,推算森工林区天然用材林碳汇价值:1986年碳汇价值10.110 3亿美元,1990年碳汇价值10.630 1亿美元,1995年碳汇价值10.266 3亿美元,2000年碳汇价值8.980 1亿美元。研究还表明,阔叶林和针叶林是黑龙江省森工林区天然用材林重要碳库树种,为发展森工林区林业碳汇将起到重要作用。在开采利用天然林资源的过程中,必须统筹兼顾森林的生态、社会、经济三大效益,保持和发挥现有天然林的生态效益,才能达到森林资源的永续利用。  相似文献   

4.
Carbon sinks constitute an important element within the complex phenomenon of global climate change,and forest ecosystems are important global carbon sinks.The Natural Forest Protection Program(NFPP) is an ecological program in China that was established after catastrophic flooding in the country in 1998.The goals of the NFPP are to curb the deterioration of the ecological environment,strengthen the protection and restoration of habitat to increase biodiversity,and rehabilitate natural forests to support sustainable development in forest regions.This study looked at changes in carbon sequestration in a forested area of northeast China after the inception of the NFPP.The program divides China's natural forests into three classes—commercial and two types of noneconomic forests—that are subject to management regimes prescribing varying levels of timber harvest,afforestation,and reforestation.During the 18-year period from 1998 to 2015,the total amount of carbon sequestration increased at an average annual rate of 0.04 MT C.This trend reflects a transformation of forest management practices after implementation of the NFPP that resulted in prohibited and/or restricted logging and tighter regulation of allowable harvest levels for specific areas.In documenting this trend,guidelines for more effective implementation of forestry programs such as the NFPP in other countries in the future are also suggested.  相似文献   

5.
Determining the optimal rotation period was a crucial component of forest sustainable management strategies, especially under climate change. This paper had two objectives: (1) to determine the economic benefits and optimal rotation periods for timber production when coupled to carbon sequestration, as predicted by time series prediction models for Pinus tabulaeformis plantations in China; and (2) to evaluate how different carbon prices and interest rates affected optimal rotation periods using the forest land expectation value. The results suggested that time series prediction models were valuable for estimating timber volumes and carbon sequestrations based on surveys of different-aged stands. Importantly, since integrating carbon sequestrations into timber production benefits did not increase optimal rotation periods, this should promote P. tabulaeformis plantation management. In the sensitivity analysis, a higher carbon price increased the profitability of carbon sequestration and timber production, but not optimal rotation periods, though they were reduced under higher interest rates. In conclusion, incorporating both timber production and carbon sequestration benefits would sharply increase forest-based revenues, while realizing the carbon sequestration potential of P. tabulaeformis plantations. This approach was clearly useful to the development of reforestation/afforestation projects trying to mitigate climate change and also provided a theoretical basis for sustainable forest management.  相似文献   

6.
全球人工林环境管理策略研究   总被引:1,自引:0,他引:1  
全球人工林为木材生产和缓解贫困做出了重要贡献, 在减缓和适应气候变化中起到了非常重要的作用。文中在介绍全球人工林资源的基础上, 分析了人工林对生物多样性、水分循环、养分循环和碳循环的影响和相互作用机制, 提出了人工林环境管理策略, 即建立人工林多功能经营制度、通过森林认证助推人工林可持续经营、充分利用REDD+机制提高人工林固碳效应的政策推动策略, 加强生物多样性保护、降低人工林对水循环负面影响、提高人工林的养分循环、促进人工林生态系统碳循环的生态系统完整性策略, 以及保育高保护价值区域策略和鼓励利益相关者参与人工林规划与管理策略。  相似文献   

7.
Abstract

Changing forest policies in both riparian and upland areas to help protect threatened and endangered species have contributed to the reduction of timber harvests in western Washington. The economic, biodiversity, and environmental impacts of these policy actions have been substantial. Policy simulations across 9.4 million acres of timber-land show that relative to proactive management strategies, current habitat conservation and environmental programs (largely based on a reservation strategy) result in net present value reductions to forestland owners of $9.9 billion. Accompanying these asset value reductions are employment losses (sustained) of 30% and tax receipt losses of 26%. The policy simulations further demonstrate that proactive management will not decrease the long-term percentage of the upland landscape occupied by functionally old forests relative to the reservation strategy. In the riparian area, adoption of a reservation strategy actually decreases (by 29%) the percent of the landscape occupied by functionally old forests relative to a proactive management approach. These results illustrate the importance of proactively managing western Washington forests to provide maximum functionally old forest habitat for endangered upland animals (such as the northern spotted owl and the marbled murrelet) as well as riparian species.  相似文献   

8.
We studied how the use of certain tree species in forest regeneration affected the volume growth, timber yield, and carbon stock of boreal forests in Finland under the current climate (1981–2010) and recent-generation global climate model (GCM) predictions (i.e., multi-model means and individual GCMs of CMIP5), using the representative concentration pathways RCP4.5 and RCP8.5 over the period 2010–2099. Forest ecosystem model simulations were conducted on upland national forest inventory plots throughout Finland. In a baseline management regime, forest regeneration was performed by planting the same tree species that was dominant before the final cut. In alternative management regimes, either Scots pine, Norway spruce, or silver birch were planted on medium-fertility sites. Other management actions over rotation were done as in a baseline management. Compared to baseline management, an increased planting of birch resulted in relative sense highest increase in the volume growth, timber yield, and carbon stock in forests in the south, especially under severe climate projections (e.g., multi-model mean RCP8.5, and GCMs such as HadGEM2-ES RCP8.5 and GFDL-CM3 RCP8.5). This situation was opposite for Norway spruce. In the north, the volume growth, timber yield, and carbon stock of forests increased the most under severe climate projections (e.g., multi-model mean RCP8.5 and CNRM-CM5 RCP8.5), regardless of tree species preference. The magnitude of the climate change impacts depended largely on the geographical region and the severity of the climate projection. Increasing the cultivation of birch and Scots pine, as opposed to Norway spruce, could be recommended for the south. In the north, all three species could be cultivated, regardless of the severity of climate change.  相似文献   

9.
万雷  薛伟 《森林工程》2013,(6):28-32
应用模糊综合分析法结合贮木场实地调查和询问专家意见,对东北林区贮木场的火险等级做出评估.东北林区的贮木场火险隐患主要来自于气象因素、人为因素和场地条件,这3个主要因素又包含相应的子因素.通过建立模糊评价模型,分析不同因素对火险等级的影响,做出综合评价,为林区防火决策的制定提供依据.  相似文献   

10.
Most tropical forests outside protected areas have been or will be selectively logged because the timber industry is a main income-generating resource for many developing countries. Therefore, understanding the composition of commercial timber species and logging types is key for sustainable forest management in countries like Vietnam as they move toward fulfilling Reducing Emissions from Deforestation and Forest Degradation (REDD+) agreements. Seven 1-ha plots were surveyed in the Central Highland of Vietnam, and 18 commercial tree species from these plots, whose timber is widely used by local people for housing and furniture making and timber is easily sold at local markets for high prices, were analyzed. In total, 151 tree species with a diameter at breast height (DBH) of ≥?10 cm were recorded. The 18 commercially valuable species assessed in this study accounted for 33.2% of all stems (total of 524 stems ha?1 for all species), 47.1% of basal area (total of 34.35 m2 ha?1 for all species), and 50.8% of aboveground biomass/AGB (total of 262.68 Mg ha?1 for all species). Practicing diameter-limit harvesting of all commercially valuable species with DBH of ≥?40 cm, which is widely performed in Vietnam, will reduce the number of stems by 7%, basal area by 31.6%, and AGB by 38.2%. Because such harvesting practices cause severe ecological impacts on the remaining forest, logged forests may require >?40 years to recover the structure status of a pre-logged forest. In addition, the recovery of the 18 commercially valuable species may require a much longer time because they comprised 33.2% of stems. Permission for logging natural forests should be given in Vietnam to sustain lives of local communities, where logging has been prohibited. However, alternative harvesting systems, such as reduced-impact logging systems, should be considered. The systems selected must simultaneously generate economic returns for local people and respect the REDD+ agreements with regard to protecting biodiversity and reducing carbon emissions.  相似文献   

11.
Abstract

This paper comparatively examines two forest management planning approaches: multipurpose forest management and traditional timber management, with carbon, timber and oxygen production objectives in mind. The effects of both approaches on carbon and oxygen values were estimated with an oxygen and carbon flow matrix, while timber production was modelled through a growth and yield model. The estimated values were simultaneously integrated into a linear programming model developed for this study. The objective was to maximize the net present value (NPV) of the profits of timber, oxygen and carbon under the constraints of an even flow of timber production and ending forest inventory for each planning approach. The results showed that the ecological and environmental regulations in multipurpose management substantially decreased the NPV of timber production even though they increased the NPV of carbon and oxygen flow. The results also indicated that over a 100 year planning horizon the total NPV of all forest ecosystem values including carbon, timber and oxygen is almost the same (only 1.9% reduction in multipurpose management approach) in both management approaches. Although multipurpose management creates more NPV of carbon and oxygen than timber management does, the latter provides better results in terms of timber production. It is therefore important to take into account the NPV of all apparent and quantifiable forest values in preparing forest management plans, particularly in developing new management planning approaches.  相似文献   

12.
Defining the spatial arrangement and length of the cutting cycle in a logged area is crucial for reconciling potential conflicts between timber yields and maintenance of ecosystem services in natural forests. In this study, we investigated long-term impacts of clear-fell logging on timber production and tree species diversity in a subtropical forest on the Ryukyu Islands, using an individual-based simulation model. We assumed six logging scenarios defined by combinations of forest type and regeneration processes, which acted as surrogates for spatial scales of clear-fell logging. These scenarios were simulated under cutting cycles ranging from 20 to 150 years. Short-cutting cycles resulted in dominance by the sprouting species Castanopsis sieboldii. The compositional shift was accelerated by the lack of seed dispersal from surrounding forest areas. The simulations demonstrated that a sustainable logging regime maintaining both yield and tree species diversity requires a cutting cycle longer than 50 years. The simulation results also suggest that the trade-off between the recovery of tree species diversity and timber production is favored more in stands surrounded by mature forest than in isolated stands or stands surrounded by immature forest. Ecological risk assessments based on model simulations provide an alternative to current forest management practices that rely on empirical knowledge.  相似文献   

13.
The likely environmental changes throughout the next century have the potential to strongly alter forest disturbance regimes which may heavily affect forest functions as well as forest management. Forest stands already poorly adapted to current environmental conditions, such as secondary Norway spruce (Picea abies (L.) Karst.) forests outside their natural range, are expected to be particularly prone to such risks. By means of a simulation study, a secondary Norway spruce forest management unit in Austria was studied under conditions of climatic change with regard to effects of bark beetle disturbance on timber production and carbon sequestration over a time period of 100 years. The modified patch model PICUS v1.41, including a submodule of bark beetle-induced tree mortality, was employed to assess four alternative management strategies: (a) Norway spruce age-class forestry, (b) Norway spruce continuous cover forestry, (c) conversion to mixed species stands, and (d) no management. Two sets of simulations were investigated, one without the consideration of biotic disturbances, the other including possible bark beetle damages. Simulations were conducted for a de-trended baseline climate (1961–1990) as well as for two transient climate change scenarios featuring a distinct increase in temperature. The main objectives were to: (i) estimate the effects of bark beetle damage on timber production and carbon (C) sequestration under climate change; (ii) assess the effects of disregarding bark beetle disturbance in the analysis.Results indicated a strong increase in bark beetle damage under climate change scenarios (up to +219% in terms of timber volume losses) compared to the baseline climate scenario. Furthermore, distinct differences were revealed between the studied management strategies, pointing at considerably lower amounts of salvage in the conversion strategy. In terms of C storage, increased biotic disturbances under climate change reduced C storage in the actively managed strategies (up to −41.0 tC ha−1) over the 100-year simulation period, whereas in the unmanaged control variant some scenarios even resulted in increased C sequestration due to a stand density effect.Comparing the simulation series with and without bark beetle disturbances the main findings were: (i) forest C storage was higher in all actively managed strategies under climate change, when biotic disturbances were disregarded (up to +31.6 tC ha−1 over 100 years); and (ii) in the undisturbed, unmanaged variant C sequestration was lower compared to the simulations with bark beetle disturbance (up to −69.9 tC ha−1 over 100 years). The study highlights the importance of including the full range of ecosystem-specific disturbances by isolating the effect of one important agent on timber production and C sequestration.  相似文献   

14.
Incorporating an ecosystem management perspective into forest planning requires consideration of the impacts of timber management on a suite of landscape characteristics at broad spatial and long temporal scales. We used the LANDIS forest landscape simulation model to predict forest composition and landscape pattern under seven alternative forest management plans drafted for the Chequamegon-Nicolet National Forest in Wisconsin. We analyzed 20 response variables representing changes in landscape characteristics that relate to eight timber and wildlife management objectives. A MANOVA showed significant variation in the response variables among the alternative management plans. For most (16 out of 20) response variables, plans ranked either directly or inversely to the extent of even-aged management. The amount of hemlock on the landscape had a surprising positive relationship with even-aged management because hemlock is never cut, even in a clear cut. Our results also show that multiple management objectives can create conflicts related to the amount and arrangement of management activities. For example, American marten and ruffed grouse habitat are maintained by mutually exclusive activities. Our approach demonstrates a way to evaluate alternative management plans and assess if they are likely to meet their stated, multiple objectives.  相似文献   

15.
Decline of cavity-using wildlife species is a major forest management issue. One of the causes of this problem is the loss in cavity tree abundance, resulting from short rotation silviculture, stand-replacing disturbance events and timber harvesting in disturbed stands. Cavity tree availability cannot be guaranteed due to the stochastic nature of disturbance events. We developed a Markov model to predict future cavity tree availability under alternative tree felling and fire protection strategies using information on cavity tree dynamics and fire history. Stochastic dynamic programming was used to find a strategy that maximizes timber revenues less forest management costs, including the cost of an artificial nest-box program that must be implemented whenever cavity trees become critically scarce. The requirement to implement a nest-box program in such circumstances strongly influenced the optimal tree felling strategy and resulted in a higher probability of having cavity trees in the future. This reflected an increase in the retention of old growth forest and stands with fire-killed cavity trees as well as stands of younger trees to provide a future source of cavities. These results demonstrate the need to consider the costs of artificial habitat enhancement and the risk of future cavity tree scarcity in multiple-use forest management planning.  相似文献   

16.
This paper addresses the economics of forest fuel thinning programs on federal lands in the U.S. West, and presents a model of regional timber and product market impacts. The issue of economics is vital to the debate about fire management, and this paper presents market implications of two alternative silvicultural strategies, even-aged and uneven-aged thinning. Projections are based on a regional market model called FTM—West (Fuel Treatment Market model—West), which uses the method of price-endogenous linear programming to project annual market equilibria for softwood timber and wood products in the western United States from 1997 to 2020. The model takes into account variability in tree and log size, as well as economic effects of variable size class on harvest costs, log value, product recovery and mill capacity. Results show large potential market impacts from expanded thinning on federal lands, but impacts vary by silvicultural regime due to differences in size–class distributions of trees available under different thinning regimes. A hypothetical even-aged thinning program (“thin-from-below” strategy) results in net negative market welfare over the projection period (2005–2020), while a hypothetical uneven-aged thinning program (thinning based on stand density index) results in positive net market welfare. Net welfare results are the same over a range of different subsidy and administrative fee assumptions. An implication is that even-aged thinning regimes on federal lands in the U.S. West are less economical and therefore will be less effective.  相似文献   

17.
Large-scale scenario models have been developed to combine forest inventory data and forest growth models to explore impacts of changes in environmental conditions and consequences of changes in forest management, and to support decision-making and policy development. This article reviews some of the scenario studies done by EFI researchers in the past, and attempts to identify current limitations as well as future challenges in this field of research. Main emphasis so far has been on science-driven, technical scenario studies focussing on timber supply and carbon budget studies. While the need remains to improve the science-driven part of large-scale scenario analysis, there is an urgent need to extend the analysis to include value-driven aspects of forest management strategies, to arrive at consistent and comprehensive scenarios for possible future developments in European forestry that can be used in policy-making processes.  相似文献   

18.
Russian forests are of high importance for the Russian economy, the European wood market, for nature conservation, and for carbon sequestration. However, the ongoing changes in forest management and administration in Russia led to uncertainty about forest ownership, wood harvesting levels, and long-term impacts of alternative management plans. Therefore, better insight in their current and future state is highly desirable. We present a study for the Leningrad region forests in which alternative management regimes for wood production and nature conservation values are balanced in varying ways. The total forest land area in the Leningrad region forest fund is 4.8 million ha. Coniferous species dominate and due to the natural succession occurring, the forests are divers in vertical structurally.

A timber assessment model was used to project the forest until 2040. Five forest management scenarios were run. Special attention was paid to a scenario that simulates recovery of the Russian forest sector in combination with the incorporation of a ‘set-aside for nature conservation’ policy. All scenarios showed that recovery of the forest sector in the Leningrad region is biologically feasible. A sustainable continuous annual production of 10.6 million m3 per year (2.8 m3 ha−1 per year) by 2040 was found. The ‘Recovery with Nature Conservation’ scenario showed that recovery of the forest sector in combination with the establishment of set-aside areas is very well feasible. It was possible to set aside 28% of the forest area for nature conservation while still developing a forest sector to a production level higher than that achieved in the late eighties.

The timber assessment model applied was not specifically designed to incorporate nature-oriented forest management. We, therefore, discuss ways of improving the required methodology to analyse long-term effects of nature-oriented forest management in Europe.  相似文献   


19.
Forest management has been criticised in the last 20 years for its negative impact on the native species, structures and functions of the forest. Of many possible alternatives proposed to minimize these effects, the functional zoning (or TRIAD) approach is gaining popularity in North America. The goal of this approach is to minimize the negative environmental impacts of forestry while maintain timber supply by dividing the forest into three broad land-use zones: (1) conservation, (2) ecosystem management, and (3) wood production. In this study, we used a spatially explicit landscape model to simulate the effects of fire and six different forest management scenarios on a boreal mixedwood forest management unit in central Quebec. The management scenarios examined included the current practices scenario, a scenario proposed by the provincial government, and four TRIAD scenarios varying in the amount of forest allocated to each of the three zones. For each scenario, we examined the harvest volume, percentage old-growth forest or old forest managed to favour old-growth attributes, and effective mesh size of forest patches by 20-year age classes. With more area set aside for conservation and high-retention partial cut harvesting techniques designed to maintain the attributes of old-growth stands, all TRIAD scenarios resulted in higher percentages of stands with old-growth attributes than the current practices scenario and the government proposed scenario, and two of the four TRIAD scenarios also resulted in higher harvest volume over the long term. All forest management scenarios resulted in significantly lower effective mesh size than the fire-only scenario, but this difference was not as pronounced for the four TRIAD scenarios as for the current practice and government proposed scenarios. We conclude that the TRIAD approach has the potential to minimize some of the negative impacts of forestry on the landscape, while maintaining timber supply over the long term.  相似文献   

20.
We assessed the effectiveness of alternative forest management strategies for maintaining American martens (Martes americana) in a sub-boreal landscape subject to an extensive mountain pine beetle (Dendroctonus ponderosae) outbreak, associated salvage logging, and climate change in north-central British Columbia, Canada. We structured the analysis in a Bayesian network (BN) meta-model that incorporated the results of spatially explicit modelling of landscape conditions (natural and logging disturbance, habitat quality, number of potential territories, and connectedness of territories) with analytical population modelling. The BN meta-model was then used to examine habitat and population size responses (adult females only are presented) to management scenarios, in the context of uncertainty of model parameters, management objectives, and climate change. Status quo management is dominantly clear-cutting with 3–20% of each harvest unit retained as mature patches, with reforestation by planting in the remainder. Management options we examined were: (1) the status quo, (2) varying the total annual timber harvest on the landscape (100%, 80% or 50% of current long-term sustained yield estimates), (3) the protection of understory trees during logging, and (4) 30–70% retention of overstory (partial cutting in distinct patches <1 ha in size) in each harvest unit, for 33% or 50% of the annual timber harvest. We found that marten habitat and population size declined substantively with the beetle outbreak and associated salvage cutting. The choice of management strategy then had a long-term effect on the potential for marten recovery after the beetle outbreak. Partial cutting scenarios had the greatest average long-term marten population levels, followed in order by reduced harvest rates, understory protection, and the status quo. Management scenarios with the best chance of meeting conservation goals without over-protecting habitat (and thus unnecessarily constraining timber management) varied with the population objective chosen. The choice of management strategy will depend on the weighting of marten outcomes against the economic desirability of timber harvest strategies, willingness to gamble on climate change, and the time-frame of interest.  相似文献   

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