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1.
In this paper, we apply the approach of conditional nonlinear optimal perturbation related to the parameter (CNOP-P) to study parameter uncertainties that lead to the stability (maintenance or degradation) of a grassland ecosystem. The maintenance of the grassland ecosystem refers to the unchanged or increased quantity of living biomass and wilted biomass in the ecosystem, and the degradation of the grassland ecosystem refers to the reduction in the quantity of living biomass and wilted biomass or its transformation into a desert ecosystem. Based on a theoretical five-variable grassland ecosystem model, 32 physical model parameters are selected for numerical experiments. Two types of parameter uncertainties could be obtained. The first type of parameter uncertainty is the linear combination of each parameter uncertainty that is computed using the CNOP-P method. The second type is the parameter uncertainty from multi-parameter optimization using the CNOP-P method. The results show that for the 32 model parameters, at a given optimization time and with greater parameter uncertainty, the patterns of the two types of parameter uncertainties are different. The different patterns represent physical processes of soil wetness. This implies that the variations in soil wetness (surface layer and root zone) are the primary reasons for uncertainty in the maintenance or degradation of grassland ecosystems, especially for the soil moisture of the surface layer. The above results show that the CNOP-P method is a useful tool for discussing the abovementioned problems. 相似文献
2.
Measurement of ecological capital of Chinese terrestrial ecosystem based on remote sensing 总被引：5，自引：0，他引：5
PAN Yaozhong SHI Peijun ZHU Wenquan GU Xiaohe FAN Yida & LI Jing Key Laboratory of Environmental Change Natural Disaster of the Ministry of Education of China Beijing Normal University Beijing China Correspondence should be addressed to Fan Yida 《中国科学D辑(英文版)》2005,48(6):786-796
The biosphere of the Earth is the material founda-tion of human survival and development.With the increasing problems of the resources,the environment and population,most countries in the world have paid special attention to the measurement and evaluation of ecological capital,which refers to the sum of the direct natural resources value and the indirect ecosystem services value.Ecological capital depends on not only the quality of the national ecological environment,butalso the social recogni… 相似文献
3.
The physical conditions at which a model ecosystem in an artificial aquatic ecosystem is still similar to the parent ecosystem are considered. A similarity criterion for the parent and model ecosystems is created based on optical data. An experimental proof is given for the fact that the optical characteristics of a model ecosystem that has not been subjected to anthropogenic load remain similar to those of the parent ecosystem for several weeks. It is shown that the optical characteristics of polluted artificial ecosystems can be assessed from the spectra of the brightness coefficients of the upward irradiance from water. 相似文献
4.
生态功能区划是我国正在开展的一项关于资源与环境管理的重大基础性工作.生态功能区划的理论和方法是当前生态学、环境科学、地理学等学科面临的一项新的热点课题.本文首先讨论了生态功能区划的概念,从认识区划看,生态功能区划属于生态系统区域划分的范畴,从实践的角度,则强调人文活动对生态系统可持续能力产生的影响,指出自然生态区不是生态功能区,生态功能区须反映人类的利用和价值判断.生态功能区划,不单是以自然要素或自然系统的"地带性分异"为基础,更是以生态系统的等级结构和尺度原则为基础,用生态系统完整性的评价测量人类活动对生态系统的影响,将生态功能区划的科学基础落在"基于生态系统的管理"平台上.文章提出了基于流域的我国生态功能区划的初步思想,讨论了区划的原则和方法,建立了生态系统完整性评价和功能区划分的指标体系.其基本内容是,认识并按照生态系统的自然边界划分生态系统单元;进行生态系统完整性评价;在此基础上划分不同的生态功能区,确定主导生态功能. 相似文献
5.
水生态系统是人类赖以生存的基础,近年来气候变化和水资源开发、水体污染、过度捕捞等人类活动导致水生态系统严重受损,水生态系统的保护和修复已成为全球面临的重大挑战。科学合理的水生态评价方法是实现水生态系统稳定、健康和可持续管理的基本保障,也是目前我国各相关管理部门高度重视的关键问题,多个部门围绕水生态评价展开了积极探索与实践。本文系统回顾了水生态评价方法的发展历程并阐释了水生态评价的内涵,梳理了常用的水生态评价方法,明晰了各方法的基本理念和应用场景,分析了各方法的优点和不足,提出了基于生态完整性的水生态健康评价方法,最后对目前我国水生态评价需进一步完善的工作进行了展望。本文以期与相关领域研究者和管理者在水生态评价理论和方法方面进行探讨,为我国水生态考核工作提供理论支持。 相似文献
6.
Shiliang Su Dan Li Xiang Yu Zhonghao Zhang Qi Zhang Rui Xiao Junjun Zhi Jiaping Wu 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(6):737-746
Given the important role of land ecosystem in social-economic progress at regional, national, and international scale and
concurrent degradation of land ecosystems under rapid urbanization, a systematic diagnosis of land ecological security (eco-security)
for sustainable development is needed. A catastrophe model for land ecological security assessment was developed in order
to overcome the disadvantages in subjectivity and complexity of the currently used assessment methods. The catastrophe assessment
index system was divided into hierarchical sub-systems under the pressure-state-response framework. The catastrophe model
integrated multiple assessment indices of land eco-security according to the inherent contradictions and relative importance
of indices without calculating weights. Specifically, membership degree of higher level index was calculated based on the
membership degrees of lower level indices that were subjective to suitable model, such as cusp, fold, swallowtail and butterfly
model. This model was applied to evaluate the state of land eco-security in Shanghai. Mann–Kendall’s test was utilized to
characterize its temporal trend between 1999 and 2008. Significant downward trend was identified for land eco-security, in
terms of pressure sub-index, state sub-index, response sub-index and synthetic index. All these implied that land ecosystem
conditions were not optimistic for Shanghai and such situation should draw the attention of policy makers. The calculation
procedure presented in this paper does not require a high level of technical expertise to determine the membership degree,
making it simple and operational. Being applicable to similar land ecosystems, the catastrophe model is thus believed to provide
an alternative approach to land eco-security assessment. 相似文献
7.
湖沼学是研究内陆水体的多学科整合科学——兼论我国湖沼学发展面临的挑战与机遇 总被引：1，自引：0，他引：1
湖沼学是研究内陆水体的多学科交叉综合性科学,自从Forel F.A.于1892年首次对湖沼学做出定义以来已有近130年历史.湖沼学的主要分支学科包括地质湖沼学(包括古湖沼学)、物理湖沼学、化学(生物地球化学)湖沼学和生物湖沼学.湖沼学的关键自然属性是通过跨学科的整合,从水生态系统水平综合分析相关过程与机理,并对生态系统变化进行预测.因此,湖泊学也是支撑水资源与生态系统保护、管理与修复的核心科学.然而,目前我国湖沼学发展面临分支学科发展不平衡、研究碎片化等问题,而人类活动加剧和气候变化对内陆水体生态系统的影响及管理对策是湖沼学研究面临的挑战与机遇.我国湖沼学研究亟需围绕人类活动、气候变化的影响,重点开展以下几个方面的工作:1)水动力与水文地貌特征变化及其环境生态效应; 2)营养盐和有机质生物地球化学循环及其环境生态效应; 3)食物网结构与功能; 4)外来入侵物种的影响与控制对策; 5)与水环境有关的传染病防治; 6)地表水生态评价; 7)生态系统演变机理与退化生态系统修复等. 相似文献
8.
Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively serious degradation. Furthermore, from the angles of grassland coverage and biological production the variation characteristics of high-cold eco- systems in different representative regions and different geomorphologic units under different climatic conditions were quantitatively assessed. In the future, adopting effective measures to protect permafrost is of vital importance to maintaining the stability of permafrost engineering and alpine cold eco- systems in the plateau. 相似文献
9.
C. D. Field 《Marine pollution bulletin》1999,37(8-12):383-392
The concept and goals of mangrove ecosystem rehabilitation are considered and contrasted with ideas of ecosystem restoration. Three reasons for mangrove rehabilitation: conservation and landscaping; multiple use systems for high sustainable yield and protection of coastal areas, are then examined in detail. In each case, the underlying philosophy and limitations are presented. The practical problems of site selection for mangrove planting and techniques for regenerating mangroves are then considered. Some comments and data are then offered on mangrove ecosystem rehabilitation that is being carried out world-wide. Comment is made on the paucity of information. The practice and importance of monitoring and maintaining rehabilitated mangrove ecosystems is then presented. Finally, there is a discussion on the future management and research needs of mangrove ecosystem rehabilitation. 相似文献
10.
Reservoirs impose many negative impacts on riverine ecosystems. To balance human and ecosystem needs, we propose a reservoir operation method that combines reservoir operating rule curves with the regulated minimum water release policy to meet the environmental flow requirements of riverine ecosystems. Based on the relative positions of the reservoir and the water intakes, we consider three scenarios: water used for human needs (including industrial, domestic and agricultural) is directly withdrawn from (1) the reservoir; (2) both reservoirs and downstream river channels and (3) downstream river. The proposed method offers two advantages over traditional methods: First, it can be applied to finding the optimal reservoir operating rule curves with the consideration of environmental flow requirement, which is beneficial to the sustainable water uses. Second, it avoids a problem with traditional approaches, which prescribe the minimum environmental flow requirements as the regulated minimum environmental flow releases from reservoirs, implicitly giving lower priority to the riverine ecosystem. Our method instead determines the optimal regulated minimum releases of water to sustain environmental flows while more effectively balancing human and ecosystem needs. To demonstrate practical use of the model, we present a case study for operation of the Tanghe reservoir in China's Tang river basin for the three above‐mentioned scenarios. The results demonstrate that this approach will help the reservoir's managers satisfy both human and environmental requirements. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
11.
This paper presents an ecological–economic model for a lake and its watershed systems. We describe the linkage between the watershed system and the lake aquatic ecosystem and the modeling process. The lake–watershed system was divided into six subsystems: social system, economic system, terrestrial ecosystem, lake water system, pollutant system, and lake aquatic ecosystem. The model equations were constructed based on five main assumptions. The Lake Qionghai watershed in southwestern China, which is undergoing rapid eutrophication, was used as a case study. The targeted goals for total phosphorus (TP) and chlorophyll a (Chl a) concentrations in the lake in 2015 are 0.025 and 10.0 mg m−3, respectively. We present two scenarios from 2004 to 2015 based on the ecological–economic model. In both scenarios, the TP and Chl a concentrations in the lake are predicted to increase under the effects of watershed pressures and the targeted goals cannot be met. The application of techniques to reduce pollutants loading and the corresponding pollutants reductions are reflected again in the constructed model. The model predicts that TP and Chl a concentrations will decrease to 0.024 and 7.71 mg m−3, respectively, which meet the targeted thresholds. The model results provide directions for local government management of watersheds and lake aquatic ecosystem restoration. 相似文献
12.
Banking carbon: a review of organic carbon storage and physical factors influencing retention in floodplains and riparian ecosystems 
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下载免费PDF全文 Rivers are dynamic components of the terrestrial carbon cycle and provide important functions in ecosystem processes. Although rivers act as conveyers of carbon to the oceans, rivers also retain carbon within riparian ecosystems along floodplains, with potential for long‐term (> 102 years) storage. Research in ecosystem processing emphasizes the importance of organic carbon (OC) in river systems, and estimates of OC fluxes in terrestrial freshwater systems indicate that a significant portion of terrestrial carbon is stored within river networks. Studies have examined soil OC on floodplains, but research that examines the potential mechanistic controls on OC storage in riparian ecosystems and floodplains is more limited. We emphasize three primary OC reservoirs within fluvial systems: (1) standing riparian biomass; (2) dead biomass as large wood (LW) in the stream and on the floodplain; (3) OC on and beneath the floodplain surface, including litter, humus, and soil organic carbon (SOC). This review focuses on studies that have framed research questions and results in the context of OC retention, accumulation and storage within the three primary pools along riparian ecosystems. In this paper, we (i) discuss the various reservoirs for OC storage in riparian ecosystems, (ii) discuss physical conditions that facilitate carbon retention and storage in riparian ecosystems, (iii) provide a synthesis of published OC storage in riparian ecosystems, (iv) present a conceptual model of the conditions that favor OC storage in riparian ecosystems, (v) briefly discuss human impacts on OC storage in riparian ecosystems, and (vi) highlight current knowledge gaps. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
13.
A simulation model of the phosphorus system is used to study the ecosystems functioning in the Dautkul'skoe Reservoir and Shegekul Lake (Mezhdurech'e). Dependence of the internal flows (turnover) and normal annual concentrations of P forms in the water body on its external load onto the ecosystem is established. The budgets of P and its production–destruction flows (1993–1999), calculated using the model, are presented and analyzed. Comparison estimates are made for the anthropogenic impact on the water bodies of the southern Aral Sea region. 相似文献
14.
MACIEJ ZALEWSKI 《水文科学杂志》2013,58(5):823-832
Abstract The increasing human population and degradation of biological integrity of ecosystems has been expressed, to a great extent, as a decline in water resources, the most critical factor to achieve sustainable development. This is because overexploitation and degradation of the biotic structure alters ecosystem processes to the point at which the ecosystem ability to provide desired resources is seriously diminished. The progress in ecology during recent years has created a background for integration of ecology and hydrology. UNESCO, under the International Hydrological Programme IHP-V, has initiated and provided a framework for such an interdisciplinary effort. During the programme, the conceptual background and principles of the surficial processes of ecohydrology were defined: first, by integration and quantification of biological and hydrological processes at the basin scale; second, by the enhancement of basin ecosystem absorbing capacity against human impact; and third, by using ecosystem properties as a management tool. Those principles are targeted, not only to eliminate threats, but also to amplify the opportunities for sustainable development as far as the control and regulation of nutrients and water cycling at the basin scale become possible. According to Popper's philosophy, the predictive planning of the future cannot be generated by extrapolating from recently used solutions. The integration of environmental sciences should create not only new scientific disciplines, but also a new solution which can face new challenges-sustainable management of the biogeosphere. 相似文献
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快速有效的生物监测指标对于评估、保护、管理和恢复淡水生态系统至关重要.传统评估方法主要利用指示生物或类群的出现率和多度信息,但是忽略了水体环境中“生物”与“生物”,以及“生物”与“环境”间相互作用的复杂关系,而这些相互作用对淡水生态系统的生物多样性、生态系统服务功能以及生态系统对环境变化的响应有着深刻影响.生物共现网络是群落水平物种互作的结构模型,通过物种在群落出现及丰度数据,描述了物种间潜在的相互作用、群落的基本结构,反映群落在生态系统的功能和结构特性.生物共现网络展示了淡水生态系统中所有生物体之间潜在的相互作用关系,其拓扑结构特性可与特定的生态系统状态相关联,能够揭示生态系统的组织规律及其功能,可作为早期的、灵敏的生物指标,是一种很有应用前景的评估淡水生态系统状态和稳定性的工具. 相似文献
17.
Biological invasions represent a relevant ecological and economic problem of our globalized world. While a few species have been classified as invasive due to their ecological and economic impacts on the invaded ecosystems (e.g., zebra mussel), others show contrasting invasive potential, depending on the invaded ecosystem and/or the traits of the exotic species. This paper reviews the worldwide distribution, ecological impacts and the reasons that explain the invasive success of the aquatic mud snail Potamopyrgus antipodarum Gray (Hydrobiidae, Mollusca), which is native to New Zealand. This review shows that most studies on P. antipodarum distribution have been conducted in Europe, North America and Australia, and few studies in Asia. The distribution of this snail is still unknown in other parts of the world (e.g., Africa, South and Central America). The range of invaded aquatic ecosystems varies from fresh to salt water and from lentic to lotic ecosystems. The ecological impact of this species is due to the fast population growth rate and to the extremely high densities that it can reach, leading to altered C and N cycles in invaded ecosystems. However, at low densities mud snails have been shown to enhance secondary production. Additionally, P. antipodarum has been found to overcome the negative effects of predators and parasites (e.g., it survives the pass through the digestive tracts of fish). This review contributes to assess the magnitude and ecological risk of P. antipodarum invasion throughout the world. 相似文献
18.
Jae-Hyung Ji Ni-Bin Chang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2005,19(2):111-124
Coastal zones are the primary interface for the exchange of natural and man-made materials between terrestrial and coastal ecosystems. While continuous industrial development and population growth in the coastal region promote unprecedented economic prosperity, water resource management in bay and estuary areas turns out to be a crucial challenge. Therefore, local, state, and federal water planning groups are attempting to manage the supply of freshwater inflow based on sustainability goals, especially for semi-arid coastal regions like South Texas. Surface and ground water management practices in this semi-arid coastal region are implemented to ensure an ever-lasting water supply on one hand and to maintain ecosystem integrity in the bay and estuary system on the other hand. The aim of this study is to apply a stochastic compromise programming model to identify a compromise solution under uncertainty in terms of two competing objectives: minimizing freshwater release from a coastal reservoir and maximizing fishery harvest in its associated bay—Corpus Christi Bay, South Texas. The global criterion method used in the solution procedure seeks to select a compromise solution that possesses the shortest distance from a positive ideal solution (PIS) and the farthest distance from a negative ideal solution (NIS). Solutions were found using three distance-based functions in conjunction with stochastic constraints reflecting the risk levels involved in decision-making. Results indicate that current flows in the mouth of the Nueces River are not sufficient to maintain the salinity level and to satisfy harvest requirements in the Corpus Christi Bay if water supply goal in the city has higher priority. Therefore, a sustainable management plan of exploring the structure of demand and supply is highly desirable in this fast growing urban region. 相似文献
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