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1.
Xie X  Wang Q  Dai L  Su D  Wang X  Qi G  Ye Y 《Environmental management》2011,48(6):1095-1106
The maintenance of a timely, reliable and accurate spatial database on current forest ecosystem conditions and changes is essential to characterize and assess forest resources and support sustainable forest management. Information for such a database can be obtained only through a continuous forest inventory. The National Forest Continuous Inventory (NFCI) is the first level of China’s three-tiered inventory system. The NFCI is administered by the State Forestry Administration; data are acquired by five inventory institutions around the country. Several important components of the database include land type, forest classification and ageclass/ age-group. The NFCI database in China is constructed based on 5-year inventory periods, resulting in some of the data not being timely when reports are issued. To address this problem, a forest growth simulation model has been developed to update the database for years between the periodic inventories. In order to aid in forest plan design and management, a three-dimensional virtual reality system of forest landscapes for selected units in the database (compartment or sub-compartment) has also been developed based on Virtual Reality Modeling Language. In addition, a transparent internet publishing system for a spatial database based on open source WebGIS (UMN Map Server) has been designed and utilized to enhance public understanding and encourage free participation of interested parties in the development, implementation, and planning of sustainable forest management.  相似文献   

2.
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   

3.
In the United States and around the world, scientists and practitioners have debated the definition and merits of ecosystem management as a new approach to natural resource management. While these debates continue, a growing number of organizations formally have adopted ecosystem management. However, adoption does not necessarily lead to successful implementation, and theories are not always put into practice. In this article, we examine how a leading natural resource agency, the United States Department of Agriculture Forest Service, has translated ecosystem management theory into concrete policy objectives and how successfully these objectives are perceived to be implemented throughout the national forest system. Through document analysis, interviews, and survey responses from 345 Forest Service managers (district rangers, forest supervisors, and regional foresters), we find that the agency has incorporated numerous ecosystem management components into its objectives. Agency managers perceive that the greatest attainment of such objectives is related to collaborative stewardship and integration of scientific information, areas in which the organization has considerable prior experience. The objectives perceived to be least attained are adaptive management and integration of social and economic information, areas requiring substantial new resources and a knowledge base not traditionally emphasized by natural resource managers. Overall, success in implementing ecosystem management objectives is linked to committed forest managers.  相似文献   

4.
Recent state of forest biodiversity at the European level was reviewed and analysed with respect to the current requirements from the environmental policies as well as with respect to scientific findings in the field. The analysis reveals the main deficits and development needs, and outlines some possible courses for future action. Specific reference is given to the boreal, Atlantic and continental regions of Europe.Especially the operational definition of biodiversity, the selection of the scale and consideration of the most appropriate indicators and data collection methods are of primary importance when defining a monitoring approach. The results of a recent assessment at national scale contribute to an improved understanding, but show some shortcomings with respect to the level of detail. The high variability of the distribution, structure and composition of forests in Europe can be comprised only partially when the monitoring follows national borders. To detect changes in time for corrective measures and to be able to apply appropriate threshold values for biodiversity indicators a more detailed approach, which takes into account different bio-geographical regions and forest ecosystem types, is needed. Technically, this could be based on aggregation national forest inventories or European-wide sampling scheme combined with remote sensing data and distinct forest types or categories.  相似文献   

5.
In last decades, numerous efforts have been carried out by the scientific community to assess the multifunctional role of forests in supporting the forest decision-making processes. Recently developed in Italy, the Forest Landscape Management Planning seems to be the most suitable tool to maintain the sustainability balance between forests and local populations. This research identifies and maps different forest ecosystem functions in a mountain Natura2000 Network site by performing a spatial estimation of forest inventory parameters, and implementing a multi-criteria and multi-level approach. Final results on mapping of forest functions show acceptable values of classification accuracy.  相似文献   

6.
This paper reports on two efforts to develop methods for quantifying and analysing greenhouse gas emissions from local places. The International Council for Local Environmental Initiatives-Cities for Climate Protection (ICLEI-CCP) campaign and the Association of American Geographers-Global Change in Local Places (AAG-GCLP) project represent independent efforts with differing origins and objectives. There is a rich and dynamic fine structure to the causal patterns that determine the level of greenhouse gas emissions in the society. This fine structure is essentially opaque to national and state-level inventories and analyses, and yet understanding it is necessary to understanding how human communities can be organised and human enterprise structured in environmentally sustainable ways. Simplified inventory methods that account for most but not all emissions, use readily available local data and, most important, inform efforts at emission reduction are currently available for cities and could be made available for larger or more diverse local regions or areas.  相似文献   

7.
National-scale inventories of soil organic carbon (SOC) and forest floor carbon (FFC) stocks have a high uncertainty. Inventories are often based on the interpolation of sampled information, often using a number of covariables to help such interpolation. The rationale for the choice of these covariables is not always documented, despite the fact that many local-scale studies have identified the factors explaining spatial variability of SOC and FFC stocks. These studies indicate, among others the importance of long-term land use history. Despite this, information on the effects of land use history has never been used to explain variability of carbon stocks in national-scale inventories. We designed an alternative method to improve national-scale inventories of SOC and FCC for the Dutch sand area that takes stock of the findings of detailed case studies. Determinants for SOC and FFC stocks derived from landscape-scale case studies were used to map national-scale spatial variability and to calculate national totals. The resulting national-scale spatial distribution was compared with the SOC stock map from the current Dutch greenhouse gas inventory. Using land use history to explain SOC variability decreased the error of the SOC stock estimate in 60 % of the area. The error in FFC stocks decreased in half of the forest area after including soil fertility, tree species, and forest age as explanatory factors. Estimates with reduced uncertainty will make land use and land management a more attractive and acceptable mitigation option to reduce emissions of greenhouse gases for the LULUCF sector.  相似文献   

8.
In addition to national inventories of emissions of greenhouse gases, there are inventories for most, but not all, states constituting the United States. This paper analyzes the state inventories to see if reported emissions of carbon dioxide, methane, and nitrous oxide are additive. Considerable reanalysis of the state inventories is required before they can be added to yield a larger-scale inventory. Some specific sources were considered by some states but not by others. Estimation techniques evolved over time as inventories were produced, and there are instances of both double-counting (two states reporting the same emission) and omission (neither state reporting the same emission), where interstate transfers of energy or materials occurred. Nevertheless, the inventories, when adjusted for obvious double-counting or omissions, are probably approximately additive, although it is difficult to quantify the extent to which this is true.  相似文献   

9.
Overview of Contemporary Issues of Forest Research and Management in China   总被引:1,自引:0,他引:1  
With 207 million ha of forest covering 22% of its land area, China ranks fifth in the world in forest area. Rapid economic growth, climate change, and forest disturbances pose new, complex challenges for forest research and management. Progress in meeting these challenges is relevant beyond China, because China’s forests represent 34% of Asia’s forests and 5% of the worlds’ forests. To provide a broader understanding of these management challenges and of research and policies that address them, we organized this special issue on contemporary forest research and management issues in China. At the national level, papers review major forest types and the evolution of sustainable forestry, the development of China’s forest-certification efforts, the establishment of a forest inventory system, and achievements and challenges in insect pest control in China. Papers focused on Northern China address historical, social, and political factors that have shaped the region’s forests; the use of forest landscape models to assess how forest management can achieve multiple objectives; and analysis and modeling of fuels and fire behavior. Papers addressing Central and South China describe the “Grain for Green” program, which converts low productivity cropland to grassland and woodland to address erosion and soil carbon sequestration; the potential effects of climate change on CO2 efflux and soil respiration; and relationships between climate and net primary productivity. China shares many forest management and research issues with other countries, but in other cases China’s capacity to respond to forest management challenges is unique and bears watching by the rest of the world.  相似文献   

10.
In this study we evaluate the accuracy of four global and regional forest cover assessments (MODIS, IGBP, GLC2000, PROARCA) as tools for baseline estimation. We conduct this research at the national scale for Costa Rica and for two tropical dry forest study sites in Costa Rica (Santa Rosa) and Mexico (Chamela-Cuixmala). We found that at the national level, the total forest cover accuracy of the four land cover maps was inflated due to an overestimation of forest in areas with an evergreen canopy. However, the four maps greatly underestimated the extent of the deciduous forest (dry forest); an ecosystem that faces high deforestation pressure and poses complications to the mapping of its extent from remotely sensed data. For the tropical dry forest sites, all maps have low forest cover accuracies (mean for Santa Rosa: 27%; mean for Chamela-Cuixmala: 56%). This has implications for policy implementation.  相似文献   

11.
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.
Tree inventories are expensive to conduct and update, so every inventory carried out must be maximized. However, increasing the number of constituent parameters increases the cost of performing and updating the inventory, illustrating the need for careful parameter selection. This article reports the results of a systematic expert rating of tree inventories aiming to quantify the relative importance of each parameter. Using the Delphi method, panels comprising city officials, arborists, and academics rated a total of 148 parameters. The total mean score, the top ranking parameters, which can serve as a guide for decision-making at practical level and for standardization of tree inventories, were: Scientific name of the tree species and genera, Vitality, Coordinates, Hazard class, and Identification number. The study also examined whether the different responsibilities and usage of urban tree databases among organizations and people engaged in urban tree inventories affected their prioritization. The results revealed noticeable dissimilarities in the ranking of parameters between the panels, underlining the need for collaboration between the research community and those commissioning, administrating, and conducting inventories. Only by applying such a transdisciplinary approach to parameter selection can urban tree inventories be strengthened and made more relevant.  相似文献   

14.
This paper investigates the effectiveness of protected areas in slowing tropical forest clearing in 64 countries in Asia/Pacific, Africa and Latin America during the period of 2001–2012 by comparing deforestation rates inside and within 10 km outside of the boundaries of protected areas. Annual time series of these deforestation rates were constructed from recently published high‐resolution data on forest clearing from Hansen et al. (2013). For 4,028 parks, panel estimation based on a variety of park characteristics was conducted to test if deforestation was lower in protected areas because of their protected status, or if other factors explained the difference. From a sample of 726 parks established since 2002, a test was also conducted to investigate the effect of park establishment on protection. Findings suggest park size, national park status and management by indigenous people all are significantly associated with effective protection across regions. For the Asia/Pacific region, the test offers compelling evidence that park establishment has a near‐immediate and powerful effect.  相似文献   

15.
人类活动排放的大量温室气体已经造成多种不利影响,为缓解这些不利影响,已有多个国家提出了碳中和目标。碳中和评估与预测预估是实现碳中和目标的科学基础,准确估算碳排放量和碳去除量是进行碳中和评估的关键,可以帮助决策者制定减排和增汇政策。本文梳理了碳排放量和碳去除量的估算方法以及预测预估方法的原理和特点,以期为准确评估碳中和现状以及预测预估未来情景下实现碳中和目标的可能性和路径提供方法论参考。碳排放量的估算方法可以分为用于支撑碳交易市场的碳排放核算方法、面向消费侧碳排放的估算方法和基于因素分解法的碳排放计量方法三大类;前两类方法主要用于历史碳排放量的盘点,第三类方法可用于碳排放量的预估。陆地生态系统碳去除量估算方法可以分为统计模型法、机理模型法和遥感模型法三大类;第一类方法应用最早但估算结果较粗糙,第二类方法模型应用最多但估算结果存在较大的不确定性,第三类方法观测范围大但缺乏预测预估能力。近年来,模型分析法在碳中和评估和预测预估上得到越来越广泛的应用。  相似文献   

16.
It is estimated that more than half the threats to national park resources originate outside park boundaries, and most threats are attributable to degradation of air and water quality. Atmospheric contaminants are the principal source of external threats to national park ecosystems. This article examines the potential impact to national park resources by anthropic atmospheric inputs and summarizes present research methods and results regarding impacts. Air quality monitoring currently receives much more emphasis and support than effects research. Present research on effects focuses on vegetation impact, biomonitoring, and acid rain. This research and that of other investigators suggest that the most likely impacts will not be direct cause-effect situations, but indirect, incremental, and possibly synergistic effects on the interactions of ecosystem components. Conceptually, such alteration of interactions can be measured through long-term observation of biogeochemical cycles, energy transfer, and community structure and function. But traditional Park Service research has not emphasized the ecosystem and especially ecosystem processes and component interactions. Most research on effects, then, must begin with baseline data acquisition. A research program to mitigate present national data base deficiencies would require a fundamental change in present research priorities, administration, and funding.  相似文献   

17.
Validation of a hybrid life-cycle inventory analysis method   总被引:2,自引:0,他引:2  
The life-cycle inventory analysis step of a life-cycle assessment (LCA) may currently suffer from several limitations, mainly concerned with the use of incomplete and unreliable data sources and methods of assessment. Many past LCA studies have used traditional inventory analysis methods, namely process analysis and input-output analysis. More recently, hybrid inventory analysis methods have been developed, combining these two traditional methods in an attempt to minimise their limitations. In light of recent improvements, these hybrid methods need to be compared and validated, as these too have been considered to have several limitations. This paper evaluates a recently developed hybrid inventory analysis method which aims to improve the limitations of previous methods. It was found that the truncation associated with process analysis can be up to 87%, reflecting the considerable shortcomings in the quantity of process data currently available. Capital inputs were found to account for up to 22% of the total inputs to a particular product. These findings suggest that current best-practice methods are sufficiently accurate for most typical applications, but this is heavily dependent upon data quality and availability. The use of input-output data assists in improving the system boundary completeness of life-cycle inventories. However, the use of input-output analysis alone does not always provide an accurate model for replacing process data. Further improvements in the quantity of process data currently available are needed to increase the reliability of life-cycle inventories.  相似文献   

18.
Three major commodity booms since the second world war are identified and analyzed. In all three, demand shocks predominated as triggers to the commodity price rises. The first boom, in 1950–51, was caused by the massive inventory buildup in response to the Korean war. The second, in 1973–74, was accentuated by widespread harvest failures and by OPEC's market management, which tripled the price of oil. The third boom started in 2004 and has not yet run its course. This time, the explosive growth of China's and India's raw materials demand has played a key role. The first two booms collapsed as the world economy went into recession and excessive inventories were sold out. The third boom may prove more durable since the world economy continues to expand briskly and commodity inventories have remained small.  相似文献   

19.
Parties to the United Nations Framework Convention on Climate Change (UNFCCC) are required to submit national greenhouse gas (GHG) inventories, together with information on methods used in estimating their emissions. Currently agricultural activities contribute a significant portion (approximately 20%) of global anthropogenic GHG emissions, and agricultural soils have been identified as one of the main GHG source categories within the agricultural sector. However, compared to many other GHG sources, inventory methods for soils are relatively more complex and have been implemented only to varying degrees among member countries. This review summarizes and evaluates the methods used by Annex 1 countries in estimating CO2 and N2O emissions in agricultural soils. While most countries utilize the Intergovernmental Panel on Climate Change (IPCC) default methodology, several Annex 1 countries are developing more advanced methods that are tailored for specific country circumstances. Based on the latest national inventory reporting, about 56% of the Annex 1 countries use IPCC Tier 1 methods, about 26% use Tier 2 methods, and about 18% do not estimate or report N2O emissions from agricultural soils. More than 65% of the countries do not report CO2 emissions from the cultivation of mineral soils, organic soils, or liming, and only a handful of countries have used country-specific, Tier 3 methods. Tier 3 methods usually involve process-based models and detailed, geographically specific activity data. Such methods can provide more robust, accurate estimates of emissions and removals but require greater diligence in documentation, transparency, and uncertainty assessment to ensure comparability between countries. Availability of detailed, spatially explicit activity data is a major constraint to implementing higher tiered methods in many countries.  相似文献   

20.
A topic of interest in the finance world is measuring systematic risk. Accurately measuring the systematic risk component—or Beta—of an asset or portfolio is important in many financial applications. In this work, we consider the efficiency of a range of Beta estimation methods commonly used in practice from a reference-day risk perspective. We show that, when using the industry standard data sample of 5 years of monthly returns, the choice of reference-day used to calculate underlying returns has a significant impact on all of the Beta estimation methods considered. Driven by this finding, we propose and test an alternative nonparametric bootstrap approach for calculating Beta estimates which is unaffected by reference-day risk. Our primary goal is to determine a point-estimate of Beta, independent of reference-day.  相似文献   

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