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 46 毫秒
1.
在借鉴国内外森林生态系统服务功能基本分析方法的基础上,对庐山自然保护区的森林生态系统的价值进行了评估,得出庐山森林生态系统的服务总价值约为114221.26万元/a.其中,直接经济价值70855万元/a,占总价值的62.03%;生态价值为43357.26万元/a,占总价值的37.97%.此外,庐山的景观游憩价值63600万元/a,占总价值的55.68%,在庐山森林生态系统服务价值中占主要地位.因此,庐山森林生态系统服务功能的保护开发,一方面体现在森林生态功能的保护开发,另一方面要促进生态系统保护和旅游资源开发的有机结合.  相似文献   

2.
根据林业调查统计数据和有关文献资料,利用市场价格法、影子价值法、机会成本法和费用支出法等对乐山市森林生态系统2004~2012年的实物产品价值、水源涵养功能价值、土壤保持功能价值、生物多样性保护功能价值、积累营养物质价值及森林休憩价值进行了分别评估和综合评估。按照各类生态服务功能2004~2012年总价值比例从高到低排序为土壤保持价值(56.6%)生物多样性保护价值(22.05%)水源涵养价值(14.22%)实物产品价值(4.34%)森林游憩价值(2.41%)积累营养物质价值(0.39%);2012年乐山市森林生态系统服务功能总价值达163.61亿元,比2004年增长了6.21%。  相似文献   

3.
基于单位面积价值当量因子法计算2015年京津冀地区生态系统服务功能价值,并对生态系统服务价值和生态压力的空间特征进行深入分析。结果表明,2015年,京津冀地区各生态系统服务功能的总价值量为8539.4亿元。不同生态系统类型提供生态服务的价值依次为森林生态系统>草地生态系统>水域生态系统>农田生态系统>荒漠生态系统,不同生态功能类型的价值量依次为调节服务价值>支持服务>供给服务>文化服务。京津冀三地各生态系统的总价值分别为788.3亿元、812.9亿元和6938.2亿元京津冀地区单位面积的生态服务价值与2010年全国平均水平持平,为395.3万元/km^2。京津冀地区人均生态功能价值分别为3727.5,8072.0,9521.4元/人,生态压力北京>天津>河北,但都远远低于全国平均的27941.2元/人。京津冀地区生态资源少,人口数量多,生态压力较大,迫切需要三地通过多渠道保护和共建生态环境,不断提高生态系统服务功能,促进区域可持续发展。  相似文献   

4.
以青海省大通县2015年Landsat-8TM遥感影像数据、社会经济统计数据和野外勘查数据为基本数据源,探讨大通县土地利用和生态系统服务功能在不同空间尺度上的表现特征和分布规律,研究大通县不同空间尺度上生态补偿的时空配置。结果表明:大通县生态功能总价值约为133.32亿元,其中水域生态系统的贡献率达到65.56%,其次为林地,占14.81%。大通县生态补偿的最终价值为111.77亿元。初步完成了大通县"生态立县"的目标,推动了县域生态系统良性循环发展。  相似文献   

5.
为全面认识新安江水资源价值,本文对河流生态系统的各项服务功能开展了定量评价。本文按照联合国千年评估对生态系统的划分方法(供给、调节、文化与支持4项服务),结合新安江流域水生态系统的特征和结构,建立了15项评估指标体系。以2013年为基准年,对新安江水生态系统服务功能及其生态经济价值进行评价。结果显示:新安江水生态系统服务总价值为73.72亿元,其中,提供产品功能价值9.58亿元、调节功能价值11.77亿元、支持功能价值24.13亿元、文化服务功能价值28.24亿元,分别占总价值的13.0%、16.0%、32.7%、38.3%。新安江单位面积提供的生态系统服务价值为0.41亿元/km~2,高于黄山市单位面积GDP产值0.28亿元/km~2。研究认为,新安江流域水生态系统对支持和保护当地经济发展具有重要作用,研究结果以期为新安江水资源有效管理和区域生态环境保护及水环境补偿提供生态学依据。  相似文献   

6.
以祖山林场为研究对象,采用《森林生态系统服务功能评估规范》中的方法,结合本区域的特点,从涵养水源、固碳释氧、保育土壤、释放负氧离子、保护生物多样性和森林游憩六个方面评价其生态服务功能与价值。结果表明:2017年,祖山林场现有林地涵养水源量为1 106.19万t,涵养水源总价值为10 077.4万元;固土量13.53万t,保育土壤总价值为1 605.65万元;吸收CO_2量3.31万t,释放O_2量为8.88万t,固碳释氧价值为12 847.87万元;释放负氧离子个数为11 521.62×10~(19)个,释放负氧离子价值为109.01万元;保护物种多样性价值为5 284.03万元;门票收入为762万元。  相似文献   

7.
植被生态系统在整个生态环境体系中的作用至关重要。综合运用机会成本和生态服务价值当量等方法评估新疆阿克苏地区五类植被的生态服务功能价值,测算得2013年总价值为6222.58亿元。结果表明,草地植被是构成研究区生态服务功能的核心价值,之后依次为湿地植被、林地植被、农田植被和荒漠植被,这与面积及功能发挥的物质量和价值当量有重要联系;土壤保育、气候调节和涵养水源功能对当地环境改善作用明显;特定服务功能在各植被类型中占比存在差异。环境资源货币化、充分保护和发挥植被生态系统的服务功能将是南疆社会经济可持续发展的关键。  相似文献   

8.
生态资产是以货币的形式来度量生态系统为人类社会提供物资和生态服务的价值,核算一个区域的生态资产实际上就是评估一个区域的可持续发展能力。生态绿当量依据"服务功能相当、服务价值相当"的理论,以森林生态系统生态资产为参考标准,能简单、高效、可计量地核算出区域的生态资产价值。通过生态绿当量模式,核算了云南省抚仙湖流域1992—2014年间的生态资产价值。结果表明:1抚仙湖流域1992年、1996年、2001年、2006年、2010年、2014年生态资产价值分别为161.44亿元、162.02亿元、160.56亿元、160.49亿元、160.52亿元、160.45亿元,总体呈逐年下降趋势;2抚仙湖提供的生态价值占总资产价值的90%,湖泊在维持生态稳定方面起着非常重要的作用。  相似文献   

9.
生态资产是以货币的形式来度量生态系统为人类社会提供物资和生态服务的价值,核算一个区域的生态资产实际上就是评估一个区域的可持续发展能力。生态绿当量依据"服务功能相当、服务价值相当"的理论,以森林生态系统生态资产为参考标准,能简单、高效、可计量地核算出区域的生态资产价值。通过生态绿当量模式,核算了云南省抚仙湖流域1992—2014年间的生态资产价值。结果表明:1抚仙湖流域1992年、1996年、2001年、2006年、2010年、2014年生态资产价值分别为161.44亿元、162.02亿元、160.56亿元、160.49亿元、160.52亿元、160.45亿元,总体呈逐年下降趋势;2抚仙湖提供的生态价值占总资产价值的90%,湖泊在维持生态稳定方面起着非常重要的作用。  相似文献   

10.
周兴民 《青海环境》2009,19(4):167-171,178
文章比较详细的阐述了生态系统服务的项目,中国不同草地类型的服务价值、不同区域草地生态系统单位面积服务价值和不同区域草地生态系统年服务总价值。  相似文献   

11.
Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.  相似文献   

12.
In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.  相似文献   

13.
Urban ecological systems: scientific foundations and a decade of progress   总被引:9,自引:0,他引:9  
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.  相似文献   

14.
Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.  相似文献   

15.
Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.  相似文献   

16.
ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.  相似文献   

17.
All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by outside sources. However, much of the previous research on agricultural information has concentrated on what information various media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy. Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work, and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel study.  相似文献   

18.
Mapped environmental classifications are defined using various procedures, but there has been little evaluation of the differences in their ability to discriminate variation in independent ecological characteristics. We tested the performance of environmental classifications of the streams and rivers of France that had been defined from the same environmental data using geographic regionalization and numerical classification of individual river valley segments. Test data comprised invertebrate assemblages, water chemistry, and hydrological indexes obtained from sites throughout France. Classification performance was measured by analysis of similarity (ANOSIM). Geometric regions defined by a regular grid and without regard to environmental variables and a posteriori classifications based on clustering the test datasets defined lower and upper bounds of performance for a given number of classes. Differences in classification performances were generally small. The ANOSIM statistics for the a posteriori classifications were around twice that of all environmental classifications, including geometrically defined regions. The hydro-ecoregions performed slightly better for the invertebrate data and the network classification performed slightly better for the chemistry and hydrological data. Our results indicate that environmental classifications that are defined using different procedures can be comparable in terms of their ability to discriminate variation of ecological characteristics and that alleged differences in performance arising from different classification procedures can be small relative to unexplained variation. We conclude that definition procedures might have little effect on the performance of large-scale environmental classifications and decisions over which procedures to use should be based primarily on pragmatic considerations.  相似文献   

19.
Manganese entering impounded water will undergo a cyclic transformation. Oxidation precipitates manganese from top waters. At the bottom of the lake, biological activity will render manganese soluble by both intracellular as well as extracellular activity. The study was made to demonstrate that biological reduction and transformation, organometallic complexation, together with the presence of carbon dioxide and the lowering of pH all have some effect on the solubility of manganese. Dissolved manganese may be brought back to top waters during the lake overturn and therefore deteriorates the water quality.  相似文献   

20.
Zimbabwean provincial plans were instituted to help in the achievement of the national goal of the creation of an egalitarian, socialist and integrated society. The national goal itself was adopted as an antithesis to the dualist society characterised by spatial, economic, social, politican and technological inequalities that Zimbabwe inherited from colonialism. This meant that provincial plans had to play both a functional (or growth allocating/distribution) and a territorial (or redistribution) role.

This paper reviews their role in achieving the national goal by examining their functions, content, structure and methodology. The paper concludes that because of their nature, provincial plans are not suitable tools for the achievement of the national goal.  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