首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 203 毫秒
1.
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   

2.
Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) components around the world. Currently, information regarding the prevalence, status, and methods of DW inventories occurring in the world’s forested landscapes is scattered. The goal of this study is to describe the status, DW components measured, sample methods employed, and DW component thresholds used by national forest inventories that currently inventory DW around the world. Study results indicate that most countries do not inventory forest DW. Globally, we estimate that about 13% of countries inventory DW using a diversity of sample methods and DW component definitions. A common feature among DW inventories was that most countries had only just begun DW inventories and employ very low sample intensities. There are major hurdles to harmonizing national forest inventories of DW: differences in population definitions, lack of clarity on sample protocols/estimation procedures, and sparse availability of inventory data/reports. Increasing database/estimation flexibility, developing common dimensional thresholds of DW components, publishing inventory procedures/protocols, releasing inventory data/reports to international peer review, and increasing communication (e.g., workshops) among countries inventorying DW are suggestions forwarded by this study to increase DW inventory harmonization.  相似文献   

3.
The personal assessments of the current and expected future state of the environment by 3232 community respondents in 18 nations were investigated at the local, national, and global spatial levels. These assessments were compared to a ranking of each country's environmental quality by an expert panel. Temporal pessimism (“things will get worse”) was found in the assessments at all three spatial levels. Spatial optimism bias (“things are better here than there”) was found in the assessments of current environmental conditions in 15 of 18 countries, but not in the assessments of the future. All countries except one exhibited temporal pessimism, but significant differences between them were common. Evaluations of current environmental conditions also differed by country. Citizens' assessments of current conditions, and the degree of comparative optimism, were strongly correlated with the expert panel's assessments of national environmental quality. Aside from the value of understanding global trends in environmental assessments, the results have important implications for environmental policy and risk management strategies.  相似文献   

4.
A comparison of different transportation route types and their combined effects on landscape diversity was conducted within Tiaoxi watershed (China) between 1994 and 2005. Buffer analysis and Mann–Kendall’s test were used to quantify the relationships between distance from transportation routes (railway, highway, national, and provincial road) and a family of landscape diversity parameters (Simpson’s diversity index, Simpson’s evenness index, Shannon’s diversity index, and Shannon’s evenness index). One-way ANOVA was further applied to compare influences from different route types and their combined effects. Five other landscape metrics (patch density, edge density, area-weighted mean shape index, connectance index, and Euclidean nearest neighbor distance) were also calculated to analyze the associations between landscape diversity and landscape pattern characteristics. Results showed that transportation routes exerted significant impacts on landscape diversity. Impact from railway was comparable to that from highway and national road but was more significant than that from provincial road. The spatial influential range of railway and national road was wider than that of highway and provincial road. Combined effects of routes were nonlinear, and impacts from different route types were more complex than those from the same type. The four landscape diversity metrics were comparably effective at the buffer zone scale. In addition, landscape diversity can be alternatively used to indicate fragmentation, connectivity, and isolation at route buffer scale. This study demonstrates an applicable approach to quantitatively characterize the impacts from transportation routes on landscape patterns and has potential to facilitate route network planning.  相似文献   

5.
Environmental auditing: Theory and applications   总被引:3,自引:0,他引:3  
The environmental audit has become a regular part of corporate environmental management in Canada and is also gaining recognition in the public sector. A 1991 survey of 75 private sector companies across Canada revealed that 76% (57/75) had established environmental auditing programs. A similar survey of 19 federal, provincial, and municipal government departments revealed that 11% (2/19) had established such programs. The information gained from environmental audits can be used to facilitate and enhance environmental management from the single facility level to the national and international levels. This paper is divided into two sections: section one examines environmental audits at the facility/company level and discusses environmental audit characteristics, trends, and driving forces not commonly found in the available literature. Important conclusions are: that wherever possible, an action plan to correct the identified problems should be an integral part of an audit, and therefore there should be a close working relationship between auditors, managers, and employees, and that the first audits will generally be more difficult, time consuming, and expensive than subsequent audits. Section two looks at environmental audits in the broader context and discusses the relationship between environmental audits and three other environmental information gathering/analysis tools: environmental impact assessments, state of the environment reports, and new systems of national accounts. The argument is made that the information collected by environmental audits and environmental impact assessments at the facility/company level can be used as the bases for regional and national state of the environment reports and new systems of national accounts.  相似文献   

6.
National parks have mandates both to preserve and protect natural settings and to assist visitors in viewing and interacting with those settings. Considerable scholarship has examined the trade-offs between preservation and recreation goals, such as protection of a natural setting when some visitors want to experience it from noisy aircraft or ground vehicles. The current project expands on previous noise research that showed the presence of aircraft noise to be detrimental to aesthetic and affective environmental assessments. Participants rated 25 scenes under quiet conditions or while hearing 45 dB(A) or 60 dB(A) of either natural sounds (bird calls, breeze through foliage), natural sounds with aircraft sounds, natural sounds with ground traffic sounds, or natural sounds with human voices. Results indicated that the presence of any anthropogenic noise–air traffic, ground traffic, or voices–negatively impacted environmental assessments, and more so at louder levels, while the natural soundscape had little to no effect on assessments. Additionally, the presence of air traffic, ground traffic, and human voices significantly decreased participant ratings of serenity while also increasing ratings of hostility. These effects were strongest for scenes that were high in scenic beauty. Results are discussed in the context of sound quality management in national parks and other settings.  相似文献   

7.
The concept of ecological footprint (EF) assessment embeds into the broader concept of sustainable development, relating directly to quality of life and maintaining the natural constraints of the global ecosystem. EFs relate to the balance between the Earth's biocapacity and consumption, measured as land equivalence in global hectares per capita. The majority of studies relating to EF assessments have adopted a top-down methodology in order to assess national and regional EFs. Furthermore, these studies are mainly based upon national accounts of input, output and trade; information which is readily available for most countries, and the EFs usually require an assessment of equivalent land area per capita to maintain the current levels of consumption. Since its inception in the mid-1990s, the EF methodology has been refined and has been widely adopted by many countries and governments as a tool to measure biocapacity, or, the consumption of resources. In this paper, we present a bottom-up methodology to measure the EF of a rural region (near Chennai) in southern India. Advantages and limitations of this approach are then discussed through comparisons with regional and national assessments.  相似文献   

8.
Policymakers, program managers, and landowners need information about net terrestrial carbon sequestration in forests, croplands, grasslands, and shrublands to understand the cumulative effects of carbon trading programs, expanding biofuels production, and changing environmental conditions in addition to agricultural and forestry uses. Objective information systems that establish credible baselines and track changes in carbon storage can provide the accountability needed for carbon trading programs to achieve durable carbon sequestration and for biofuels initiatives to reduce net greenhouse gas emissions. A multi-sector stakeholder design process was used to produce a new indicator for the 2008 State of the Nation's Ecosystems report that presents metrics of carbon storage for major ecosystem types, specifically change in the amount of carbon gained or lost over time and the amount of carbon stored per unit area (carbon density). These metrics have been developed for national scale use, but are suitable for adaptation to multiple scales such as individual farm and forest parcels, carbon offset markets and integrated national and international assessments. To acquire the data necessary for a complete understanding of how much, and where, carbon is gained or lost by U.S. ecosystems, expansion and integration of monitoring programs will be required.  相似文献   

9.
Since 1994 UNIDO and UNEP cooperate in a Programme to establish National Cleaner Production Centres (NCPCs) as a mechanism for delivery of Cleaner Production (CP) services to businesses, governments and other organisations. In 2007, 38 NCPCs were operational in 37 developing and transition countries. While initially set up in near-identical ways in each country, over time NCPCs evolved in response to both programme-internal and country-level factors. The resulting diversity among NCPCs is described and analysed here. Differentiation and specialisation had occurred in service areas or topics both within and between NCPCs, however without a clear strategy for integration and synergy. NCPCs were becoming part of expanding networks of business services providers nationally forcing some to focus on audit and training services (tier 1), and others on specialist services in CP technology and/or policy (tier 2) and/or networking services (tier 3). All NCPCs were on a trajectory from a project management organisation to a nationally-owned entity. The different management requirements were not proactively managed and technical aspects of CP service delivery overshadowed institutional and governance aspects of establishing and operating the NCPC institution. Differences in service delivery methods between NCPCs are most evident in three service areas: CP assessments; policy advice; and transfer of Environmentally Sound Technologies. It is argued here that understanding root causes and benefits of this presently-observed differentiation, could lay the foundation for capturing and advancing best practice CP concepts, methods and policies. This in turn would enable strategic planning for customised interventions and support at the national level.  相似文献   

10.
This paper discusses climate, land, energy and water (CLEW) interactions in Burkina Faso. It shows that integrated assessments of resource use at the national level can provide important insights and benefits, especially for a resource constrained least developed country. Agricultural policy is shown to have strong implications for energy use, whereas energy policies are found to be strongly interrelated with water constraints. Without an integrated and coordinated approach, strategy and policy formulation efforts to increase energy, food and water security could become both incoherent and counter‐productive.  相似文献   

11.
ABSTRACT: A national trend over the last 25 years has been to require increasing amounts of biological information on industrial waste discharges. Acquisition of this essential information frequently involves complex assessments. In order to optimize the value of information gathered and to minimize the cost of this information, it is essential that analyses of redundancy be accompanied by the determination of which groups of organisms give the most information relative to a particular problem. Studies of the effect of temperature on the fishes of the New River, Glen Lyn, Virginia, provide us with the opportunity to evaluate the redundancy of information relative to the influence of temperature on fish distribution. Information of this type will be useful in selecting groups of organisms for laboratory temperature preference and avoidance tests. It was shown that the distribution of three genera (Notropis, Micropterus, and Etheostoma) had the highest correlation with the distribution of the total fish fauna and, therefore, provided the most information relative to temperature selection of the New River ichthyofauna. The final temperature preferences of the most abundant species of Notropis and Micropterus were representative of the response of the entire fish community based on the distribution of diversity indices relative to temperature.  相似文献   

12.
Efficient use of phosphorus (P) for producing food, preventing water pollution, and managing a dwindling rock P reserve are major challenges for China. We analyzed P stocks and flows in the Chinese food chain to identify where P use efficiency can be improved, where P leaks to the environment, and the research, technologies, and policies needed to improve P use. We found a high degree of inefficiency; of 6652 Gg P entering the food chain, only 1102 Gg P (18%) exit as food for humans. The greatest inefficiencies were a large build-up of soil P (3670 Gg P yr; 52% of P inputs) and high P losses to the environment from animal production (1582 Gg P yr; 60% of excreted P). Improving P use in China must focus on national-scale nutrient management strategies, better animal nutrition, and adoption of technologies and policies to reduce P discharges from the animal sector and recycle P as manures in agriculture.  相似文献   

13.
Abstract: Estimates of mean annual streamflow are needed for a variety of hydrologic assessments. Away from gage locations, regional regression equations that are a function of upstream area, precipitation, and temperature are commonly used. Geographic information systems technology has facilitated their use for projects, but traditional approaches using the polygon overlay operator have been too inefficient for national scale applications. As an alternative, the Elevation Derivatives for National Applications (EDNA) database was used as a framework for a fully distributed implementation of mean annual streamflow regional regression equations. The raster “flow accumulation” operator was used to efficiently achieve spatially continuous parameterization of the equations for every 30 m grid cell of the conterminous United States (U.S.). Results were confirmed by comparing with measured flows at stations of the Hydro‐Climatic Data Network, and their applications value demonstrated in the development of a national geospatial hydropower assessment. Interactive tools at the EDNA website make possible the fast and efficient query of mean annual streamflow for any location in the conterminous U.S., providing a valuable complement to other national initiatives (StreamStats and the National Hydrography Dataset Plus).  相似文献   

14.
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   

15.
A warmer climate leads to rising sea levels. Despite uncertainties about how rapid and substantial future sea-level rise (SLR) will be, society needs to prepare and adapt. This study examines the state of planning for future SLR in Sweden by surveying 33 coastal municipalities in southern Sweden and interviewing local, regional and national authorities with relevant accountability. The results reveal that there are considerable gaps in current planning for SLR. Almost one-third of municipalities lack guiding planning documents for SLR, and more than two-thirds do not discuss SLR beyond 2100. We argue that the prevailing uncertainty and ambiguity in assessments of future SLR is problematic within a traditional “predict-then-act” paradigm, and that robust approaches, such as scenario planning, can reduce many of these problems.  相似文献   

16.
A new framework for environmental assessment is needed because no existing framework explicitly includes all types of environmental assessments. We propose a framework that focuses on resolving environmental problems by integrating different types of assessments. Four general types of assessments are included: (1) condition assessments to detect chemical, physical, and biological impairments; (2) causal pathway assessments to determine causes and identify their sources; (3) predictive assessments to estimate environmental, economic, and societal risks, and benefits associated with different possible management actions; and (4) outcome assessments to evaluate the results of the decisions of an integrative assessment. The four types of assessments can be neatly arrayed in a two-by-two matrix based on the direction of analysis of causal relationships (rows) and whether the assessment identifies problems or solves them (columns). We suggest that all assessments have a common structure of planning, analysis, and synthesis, thus simplifying terminology and facilitating communication between types of assessments and environmental programs. The linkage between assessments is based on intermediate decisions that initiate another assessment or a final decision signaling the resolution of the problem. The framework is applied to three cases: management of a biologically impaired river, remediation of a contaminated site, and reregistration of a pesticide. We believe that this framework clarifies the relationships among the various types of assessment processes and their links to specific decisions.  相似文献   

17.
The overall objective of the Ramsar Convention, signed in 1971, is the conservation and wise use of wetlands by national action and international cooperation as a means to achieving sustainable development. This complex and challenging task requires national, local and international bodies involved in the implementation of the convention to rely on suitable geo-information to better understand wetland areas, complete national inventories, perform monitoring activities, carry out assessments and put in practice suitable management plans based on updated and reliable information. In the last years, Earth Observation (EO) technology has been revealed as a key tool and unique information source to support the environmental community in different application domains, including wetlands' conservation and management. In this context, the European Space Agency (ESA) in collaboration with the Ramsar Secretariat launched in 2003 the "GlobWetland" project in order to demonstrate the current capabilities of Earth Observation technology to support inventorying, monitoring, and assessment of wetland ecosystems. This paper collects the main results and findings of the "GlobWetland" project, providing an overview of the current capabilities and limits of EO technology as a tool to support the implementation of the Ramsar Convention. The project was carried out in collaboration with several regional, national and local conservation authorities and wetland managers, involving 50 different wetlands across 21 countries on four continents. This large range of users provided an excellent test bed to assess the potential of this technology to be applied in different technical, economic and social conditions.  相似文献   

18.
A regional framework for establishing recovery criteria   总被引:6,自引:0,他引:6  
Effective assessments of aquatic ecosystem recovery require ecologically sound endpoints against which progress can be measured. Site-by-site assessments of end points and potential recovery trajectories are impractical for water resource agencies. Because of the natural variation among ecosystems, applying a single set of criteria nationwide is not appropriate either. This article demonstrates the use of a regional framework for stratifying natural variation and for determining realistic biological criteria. A map of ecoregions, drawn from landscape characteristics, formed the framework for three statewide case studies and three separate studies at the river basin scale. Statewide studies of Arkansas, Ohio, and Oregon, USA, streams demonstrated patterns in fish assemblages corresponding to ecoregions. The river basin study in Oregon revealed a distinct change at the ecoregion boundary; those in Ohio and Montana demonstrated the value of regional reference sites for assessing recovery. Ecoregions can be used to facilitate the application of ecological theory and to set recovery criteria for various regions of states or of the country. Such a framework provides an important alternative between site-specific and national approaches for assessing recovery rates and conditions.  相似文献   

19.
Annual expenditures by the federal government in the United States for agricultural conservation programs increased about 80 percent with passage of the 2002 Farm Bill. However, environmental benefits of these programs have not been quantified. A national project is under way to estimate the effect of conservation practices on environmental resources. The watershed models intended for use in that project are focused on water quantity and quality and have minimal habitat assessment capability. Major impairments to aquatic ecosystems in many watersheds consist of physical habitat degradation, not water quality, suggesting that current models for this national initiative do not address one of the most significant aspects of aquatic ecosystem degradation. Currently used models contain some components relevant to aquatic habitat, and this paper describes specific components that should be added to allow rudimentary stream habitat quality assessments. At least six types of variables could be examined for ecological impact: land use, streamflow, water temperature, streambed material type, large woody debris, and hydraulic conditions at base flow. All of these variables are influenced by the presence, location, and quality of buffers. Generation of stream corridor ecological or habitat quality indices might contribute to assessments of the success or failure of conservation programs. Additional research is needed to refine procedures for combining specific measures of stream habitat into ecologically meaningful indices.  相似文献   

20.
Sequential sampling is a method for monitoring benthic macroinvertebrates that can significantly reduce the number of samples required to reach a decision, and consequently, decrease the cost of benthic sampling in environmental impact assessments.Rather than depending on a fixed number of samples, this analysis cumulatively compares measured parameter values (for example, density, community diversity) from individual samples, with thresholds that are based on specified degrees of precision.In addition to reducing sample size, a monitoring program based on sequential sampling can provide clear-cut decisions as to whethera priori-defined changes in the measured parameter(s) have or have not occurred. As examples, sequential sampling programs have been developed to evaluate the impact of geothermal energy development on benthic macroinvertebrate diversity at The Geysers, California, and for monitoring the impact of crude oil contamination on chironomid midge [Cricotopus bicinctus (Meigen) andC. mackenziensis Oliver] population densities in the Trail River, Northwest Territories, Canada.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号