共查询到20条相似文献，搜索用时 437 毫秒
1.
以典型断陷盆地——小江流域为研究对象,以1982年的TM影像、2003年的Landsat ETM+影像和2016年的Landsat OLI影像为数据源,结合云南省测绘局所提供的150 000的土地利用状况图,采用 Costanza 公式对生态系统服务价值进行评估,精细刻画出云南小江流域“盆—山”共存的地质分异结构下生态系统服务价值的时空变化特征。结果表明:（1）小江流域以农田生态系统为主,研究期内生态系统格局总体稳定,耕地、建设用地、林地和园地都有不同程度的增加,而未利用地面积减少,水域面积基本不变;（2）1982-2016年,研究区生态系统服务总价值呈上升趋势,1982、2003和2016年生态系统服务总价值分别为90.11×108元、105.65×108元和136.81×108元,耕地、林地、园地和水域的生态系统服务价值整体上升,而未利用地的生态系统服务价值减少;（3）整体上,小江流域南部和东部生态系统服务价值增加明显,而中部和西部地区生态系统服务价值呈阶段性变化或持续下降趋势,小江岩溶河谷区的生态系统服务价值最高,而沉积平坝区的生态系统服务价值密度最低,且为唯一一个衰退型生态系统服务功能区;（4）研究期内小江流域各项生态系统服务价值均呈上升趋势,调节服务居主导地位,且以气候调节服务价值最高。小江流域生态系统服务价值缺乏弹性,水域生态系统面积变化对研究区生态系统价值的变化具有放大作用。实施封山育林、退耕还林、小流域治理工程等石漠化综合治理工程可增加生态系统服务价值。 相似文献
2.
Joel C. Hoffman John R. Kelly Greg S. Peterson Anne M. Cotter Matthew A. Starry Michael E. Sierszen 《Estuaries and Coasts》2012,35(6):1453-1467
There is growing interest in applying ??15N in biota as an indicator of anthropogenic nutrient inputs to coastal environments because changes in ??15N correlate to inputs of land-based nutrients. In complex coastal receiving waters, however, land-use effects on biota ??15N may be masked by local hydrologic processes, especially exchange with coastal waters of different geochemical character. We examined ??15N differences among larval fish, a novel biotic indicator, in coastal receiving waters at both among and within watershed scales. Our goal was to characterize how hydrologic processes within coastal river mouths and embayments mediate the effect of land-based N sources on larval fish ??15N. We sampled three Lake Superior river-embayment systems from watersheds that span a large population density gradient. Over all stations, mean fish ??15N ranged from 2.7??? to 10.8???. Within each system, we found a different pattern in ??15N across the river?Clake transition zone. Correlations between fish ??15N and water quality, particularly NH 4 + and total nitrogen, were highly significant and corresponded to known differences in sewage waste water inputs. A multivariate model that included both watershed-based population density and NH 4 + was found to provide the best fit to the ??15N data among a series of multi- and univariate candidate models. These results demonstrate that: (1) fish larvae ??15N responded at within watershed scales, and (2) within coastal receiving waters, fish larvae ??15N was related to waste water inputs at the watershed scale; however, expression at specific locations within a coastal system was strongly influenced by local hydrologic processes. 相似文献
3.
喀斯特生态系统服务研究进展与展望 总被引：1，自引：1，他引：0
喀斯特生态系统是全球典型的脆弱生态系统之一,它为人类提供了重要的服务功能和价值。回顾国内外喀斯特生态系统服务研究的文献可发现,当前研究多遵循“土地利用变化—生态系统服务价值响应”的研究范式,仅重视中小尺度喀斯特生态系统服务价值的空间异质性,强调土地利用变化和生态工程对生态系统服务价值的影响。而今后应加强基于“生态系统结构、过程—功能—服务”级联框架的喀斯特生态系统服务研究,构建喀斯特生态系统服务分类体系,突出大尺度喀斯特生态系统服务评估,拓展喀斯特生态系统服务之间权衡与协同及喀斯特生态系统服务对人类福祉的影响,定量分析自然和人为因素对喀斯特生态系统服务的影响。 相似文献
4.
Diann J. Prosser Thomas E. Jordan Jessica L. Nagel Rochelle D. Seitz Donald E. Weller Dennis F. Whigham 《Estuaries and Coasts》2018,41(1):2-18
The nearshore land-water interface is an important ecological zone that faces anthropogenic pressure from development in coastal regions throughout the world. Coastal waters and estuaries like Chesapeake Bay receive and process land discharges loaded with anthropogenic nutrients and other pollutants that cause eutrophication, hypoxia, and other damage to shallow-water ecosystems. In addition, shorelines are increasingly armored with bulkhead (seawall), riprap, and other structures to protect human infrastructure against the threats of sea-level rise, storm surge, and erosion. Armoring can further influence estuarine and nearshore marine ecosystem functions by degrading water quality, spreading invasive species, and destroying ecologically valuable habitat. These detrimental effects on ecosystem function have ramifications for ecologically and economically important flora and fauna. This special issue of Estuaries and Coasts explores the interacting effects of coastal land use and shoreline armoring on estuarine and coastal marine ecosystems. The majority of papers focus on the Chesapeake Bay region, USA, where 50 major tributaries and an extensive watershed (~ 167,000 km2), provide an ideal model to examine the impacts of human activities at scales ranging from the local shoreline to the entire watershed. The papers consider the influence of watershed land use and natural versus armored shorelines on ecosystem properties and processes as well as on key natural resources. 相似文献
5.
River ecosystems are closely linked to human economic and social development, which are the most ecosystems at risk on earth. The research of ecosystem services can provide important scientific references for the ecosystems utilization,protection and management. On basis of summarizing the basic theories,assessment frameworks,technical methods and application practices related with research findings of river ecosystem services both at home and abroad,the existing shortcomings such as weak research foundation,lack of scientific and reasonable methods in ecosystem service evaluation,narrow application scope of the research results were pointed out. In consideration of the needs of society and the research tendency,the future developing directions of river ecosystems service were described: the solid research foundation should be established by multi-disciplinary and multi-scale integrations, the standardized,normalized and scientific evaluation system for ecosystem services shall be built by innovating assessment framework and technical methodology systems comprehensively, the new research areas including trade-offs and commercialization of ecosystem services will be carried out widely to expand our research perspectives and enhance the application values of the results. 相似文献
6.
Global patterns of dissolved inorganic and particulate nitrogen inputs to coastal systems: Recent conditions and future projections 总被引：1，自引：0，他引：1
We examine the global distribution of dissolved inorganic nitrogen (DIN) and particulate nitrogen (PN) export to coastal systems and the effect of human activities and natural processes on that export. The analysis is based on DIN and PN models that were combined with spatially explicit global databases. The model results indicate the widely uneven geographic distribution of human activities and rates of nitrogen input to coastal systems at the watershed, latitudinal, and regional-continental scales. Future projections in a business-as-usual scenario indicate that DIN export rates increase from approximately 21 Tg N yr−1 in 1990 to 47 Tg N yr−1 by 2050. Increased DIN inputs to coastal systems in most world regions are predicted by 2050. The largest increases are predicted for Southern and Eastern Asia, associated with predicted large increases in population, increased fertilizer use to grow food to meet the dietary demands of that population, and increased industrialization. Results of an alternative scenario for North America and Europe in 2050 indicate that reductions in the human consumption of animal protein could reduce fertilizer use and result in substantial decreases in DIN export rates by rivers. In another scenario for 2050, future air pollution control in Europe that would reduce atmospheric deposition of nitrogen oxides in watersheds is predicted to decrease DIN export by rivers, particularly from Baltic and North Atlantic watersheds. Results of a newly developed global PN river export model indicate that total global PN and DIN export by rivers in 1990 are similar, even though the global distribution of the two differ considerably. 相似文献
7.
As the largest ecosystems of the earth, marine ecosystem provides many types of ecosystem service to human. More than 60% of the global population lives the coastal area. A healthy ocean is critical to our economy, health and way of life. However, with rapid population growth and densely inhabited coastal areas, our dependence on marine resources is greater than ever. The overuse and mismanagement of ecosystem services have placed great pressure on marine systems, thereby threatening the future of marine ecosystems, and the services they provide. With anthropogenic pressures increasing in coastal cities, adopting ecosystem-based management frameworks that minimize impacts on marine environments while allowing for sustainable development is critical. Marine Ecosystem-Based Management seeks to manage marine resources in ways that protect ecosystem health while providing the ecosystem services needed by people. Rather than focusing solely on a single species or resource, MEBM incorporates science and balances the demands of user groups in a manner that produces management strategies that are more likely to be sustainable than traditional approaches. The definition, principles and framework were discussed in this paper based on the summary of literature, and two examples were introduced. Last, some suggestions were put forward to marine ecosystem management for ocean ecosystem and for healthy coastal resources sustainable utilization. 相似文献
8.
The continued urbanization of coastal watersheds can influence the quality of water that enters rivers and estuaries. Intelligent
management of aquatic resources will require the capability to quantitatively assess and evaluate the impacts of alterations
in surface waters that result from changes in patterns of land use. An aquatic ecosystem model was developed and linked to
an empirical landscape model to estimate ecological risks posed by nutrients and potentially toxic trace elements (copper
[Cu], cadmium [Cd], arsenic [As]) in the Patuxent River, Maryland. The empirical landscape model translated reductions in
croplands within the Patuxent River watershed into corresponding changes in nitrate estimated to enter the river. Trace element
concentrations were increased in relation to urbanization associated with the loss of agricultural lands in the watershed.
The aquatic ecosystem model used the altered inputs of nutrients and trace elements to estimate changes in the annual production
dynamics of selected producer and consumer populations within the Patuxent River. The models were implemented for four mainstem
locations that defined a transect from the upper freshwater portion of the river to downstream estuarine locations. Ecological
impacts were estimated for 4 hypothetical changes in land use that consisted of 10%, 7.5%, 5%, and 2.5% watershed coverage
by cropland. Impacts were estimated as the probability (risk) of different magnitudes of increases or decreases in total annual
production of populations representative of freshwater and estuarine food webs in the Patuxent River. 相似文献
9.
The global coastal zone is characterized by high biological productivity and serves as an important channel through which materials are transferred from land to the open ocean, yet little is known how it will be affected by climate change. Here, we use Kaneohe Bay, Hawaii, a semi-enclosed subtropical embayment partially surrounded by a mountainous watershed and fed by river runoff as an example to explore the potential impact of climate change on the pelagic and benthic cycling of nitrogen. We employ a nine-compartment nitrogen cycle biogeochemical box model and perturb it with a set of four idealized climate scenarios. We find that hydrological changes play a dominant role in determining the ecosystem structure, while temperature changes are more important for the trophic state and stability of the ecosystem. The ecosystem stability against storm events does not significantly change under any scenario. The system remains autotrophic in the future; however, it becomes significantly less autotrophic under drier climate, while it turns slightly more autotrophic under wetter climate. These findings may have implications for other high island watershed and coastal ecosystems in the tropics and subtropics. 相似文献
10.
Modeling hydrological ecosystem services and tradeoffs: a case study in Baiyangdian watershed, China 总被引：2，自引：1，他引：1
Yang Bai Hua Zheng Zhiyun Ouyang Changwei Zhuang Bo Jiang 《Environmental Earth Sciences》2013,70(2):709-718
Policy makers and scientists consider that land use strategies are designed to provide direct benefits to people by protecting vital ecosystem services. However, due to lack of information and evaluation methods, there is no effective and systematic tool for assessing tradeoffs between direct human benefits and ecosystem services. Land use changes influence ecosystem properties, processes and components, which are the basis for providing services. Five alternative land use scenarios (no conversion of agricultural lands, no urban expansion, agricultural expansion, forestry expansion, and riparian reforestation) were modeled for the Baiyangdian watershed, China, a densely populated, highly modified watershed with serious water shortage and pollution problems. The model InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) is designed to inform decisions about natural resource management, with an aim to align economic forces with conservation. Three ecosystem services (agricultural production, hydropower production, and water quality) were modeled to balance direct benefits and hydrological ecosystem services using InVEST. The results showed that: hydropower production was the greatest in the forestry expansion, but the lowest in agricultural expansion; agricultural production was reduced the most in forestry expansion, while retained the most in riparian reforestation. Riparian reforestation also provided the highest N and P retention and lowest N and P exportation. Riparian reforestation was the optimal land use strategy, since it protected and enhanced the vital ecosystem services without undermining direct human benefits. This research presents an initial analytical framework for integrating direct human benefits and ecosystem services in policy planning and illustrates its application. Although there are important potential tradeoffs between ecosystem services, this systematic planning framework offers a means for identifying valuable synergies between conservation and development. 相似文献
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13.
Couplings of watersheds and coastal waters: Sources and consequences of nutrient enrichment in Waquoit Bay,Massachusetts 总被引：1，自引：0，他引：1
Ivan Valiela Kenneth Foreman Michael LaMontagne Douglas Hersh Joseph Costa Paulette Peckol Barbara DeMeo-Andreson Charlene D’Avanzo Michele Babione Chi-Ho Sham John Brawley Kate Lajtha 《Estuaries and Coasts》1992,15(4):443-457
Human activities on coastal watersheds provide the major sources of nutrients entering shallow coastal ecosystems. Nutrient loadings from watersheds are the most widespread factor that alters structure and function of receiving aquatic ecosystems. To investigate this coupling of land to marine systems, we are studying a series of subwatersheds of Waquoit Bay that differ in degree of urbanization and hence are exposed to widely different nutrient loading rates. The subwatersheds differ in the number of septic tanks and the relative acreage of forests. In the area of our study, groundwater is the major mechanism that transports nutrients to coastal waters. Although there is some attenuation of nutrient concentrations within the aquifer or at the sediment-water interface, in urbanized areas there are significant increases in the nutrient content of groundwater arriving at the shore’s edge. The groundwater seeps or flows through the sediment-water boundary, and sufficient groundwater-borne nutrients (nitrogen in particular) traverse the sediment-water boundary to cause significant changes in the aquatic ecosystem. These loading-dependent alterations include increased nutrients in water, greater primary production by phytoplankton, and increased macroaglal biomass and growth (mediated by a suite of physiological responses to abundance of nutrients). The increased macroalgal biomass dominates the bay ecosystem through second- or third-order effects such as alterations of nutrient status of water columns and increasing frequency of anoxic events. The increases in seaweeds have decreased the areas covered by eelgrass habitats. The change in habitat type, plus the increased frequency of anoxic events, change the composition of the benthic fauna. The data make evident the importance of bottom-up control in shallow coastal food webs. The coupling of land to sea by groundwater-borne nutrient transport is mediated by a complex series of steps; the cascade of processes make it unlikely to find a one-to-one relation between land use and conditions in the aquatic ecosystem. Study of the process and synthesis by appropriate models may provide a way to deal with the complexities of the coupling. 相似文献
14.
基于生态工程的海岸带全球变化适应性防护策略 总被引：2，自引：0，他引：2
在全球变化导致的海平面上升和灾害性气候等压力下,我国海岸带风暴潮、海岸侵蚀、地面沉降等灾害发生频率和强度正在增加,对海岸防护体系的需求日益提高。传统海岸防护工程维护成本高,更新困难,而且可能造成地面沉降、水质恶化、生态退化、渔业资源衰退等后果。基于生态工程的海岸防护提供了抵御海岸带灾害的新理念。修复和重建沙滩、红树林、沼泽湿地、珊瑚礁等海岸带生态系统,可以起到消浪、蓄积泥沙、抬升地面的作用,有效应对全球变化引发的灾害风险,形成更可持续的海岸防护体系。通过分析不同海岸防护技术的优势和限制,认为以生态工程为核心理念构建和管理我国海岸防护体系,才能起到保障社会经济发展和维持生态健康的最佳效果。 相似文献
15.
D. Sanger A. Blair G. DiDonato T. Washburn S. Jones G. Riekerk E. Wirth J. Stewart D. White L. Vandiver A. F. Holland 《Estuaries and Coasts》2015,38(1):49-66
Upland areas of southeastern United States tidal creek watersheds are popular locations for development, and they form part of the estuarine ecosystem characterized by high economic and ecological value. The primary objective of this work was to define the relationships between coastal development, with its concomitant land use changes and associated increases in nonpoint source pollution loading, and the ecological condition of tidal creek ecosystems including related consequences to human populations and coastal communities. Nineteen tidal creek systems, located along the southeastern US coast from southern North Carolina to southern Georgia, were sampled in the summer, 2005 and 2006. Within each system, creeks were divided into two primary segments based upon tidal zoning—intertidal (i.e., shallow, narrow headwater sections) and subtidal (i.e., deeper and wider sections)—and then watersheds were delineated for each segment. Relationships between coastal development, concomitant land use changes, nonpoint source pollution loading, the ecological condition of tidal creek ecosystems, and the potential impacts to human populations and coastal communities were evaluated. In particular, relationships were identified between the amount of impervious cover (indicator of coastal development) and a range of exposure and response measures including increased chemical contamination of the sediments, increased pathogens in the water, increased nitrate/nitrite levels, increased salinity range, decreased biological productivity of the macrobenthos, alterations to the food web, increased flooding potential, and increased human risk of exposure to pathogens and harmful chemicals. The integrity of tidal creeks, particularly the headwaters or intertidally dominated sections, was impaired by increases in nonpoint source pollution associated with sprawling urbanization (i.e., increases in impervious cover). This finding suggests that these habitats are valuable early warning sentinels of ensuing ecological impacts and potential public health and flooding risk from sprawling coastal development. The results also validate the use of a conceptual model with impervious cover thresholds for tidal creek systems in the southeast region. 相似文献
16.
Some chemical and biological parameters were analysed at sixteen stations in the mangrove ecosystem, of the neighbouring Gautami-Godavari
(GG) river estuary and Kakinada (KKD) bay to understand the present status of water quality and the impact of external terrigenous
inputs during southwest (SW) monsoon in the study areas. High concentrations of nutrients in the mangrove ecosystem compared
to the bay and estuarine ecosystems reveal the importance of this zone as a source of nutrients to the adjacent coastal ecosystems.
Low Si:N:P (29:4:1) ratios in these ecosystems are due to the enrichment of these nutrients through external anthropogenic
inputs even after the utilization by phytoplankton in the biological cycle. The mean Chl b/Chla and Chl c/Chla ratios and high phaeopigments (Pp) concentrations compared to Chlb and high ratios of Chl a/Pp suggests the possibility of the potential growth of phytoplankton populations in lower light
intensity and low turbulent areas of these mangrove ecosystems. 相似文献
17.
全球生态系统服务的状况与趋势 总被引：4，自引：0，他引：4
简要介绍了千年生态系统评估（MA）状况与趋势工作组的报告《生态系统与人类福祉：现状与趋势》中的第2部分，即“对生态系统服务的评估”。该部分主要对全球生态系统服务在20世纪末的总体状况，以及它们在20世纪后半叶的主要变化趋势进行了评估。评估结果表明，在MA明确评估的24项服务中，15项处于下降趋势，约占60%；4项处于上升趋势，约占18%；其余5项（约占22%）存在显著的空间或时间差异，即在有些地区（时段）处于上升趋势，而在另外一些地区（时段）处于下降趋势。这些变化主要表现在：①全球谷类作物和牲畜等方面的生态系统服务已经取得了显著的提高，但同时却对淡水资源和调控害虫等方面的服务造成了巨大的损害；② 按照当前的捕捞速度，野生鱼类资源已经无法承受人类的持续捕捞；③ 许多地区的淡水资源已经不能满足人类和生态系统的需求，如果延续当前的水资源利用模式，供需之间的差距将会继续扩大；④ 在对污染物质进行无害化处理、保持养分平衡、调控自然灾害，以及控制害虫、疾病与入侵生物的爆发等方面，许多生态系统的调节服务已经呈现出明显的下降趋势；⑤作为生态系统提供供给服务、调节服务和文化服务的基础条件，全球生态系统的支持服务出现了复杂的变化趋势。 相似文献
18.
我国海洋生态系统服务功能及其价值评估研究计划 总被引：24，自引：0，他引：24
国家海洋局于2005年启动了为期5年“海洋生态系统服务功能及其价值评估”研究计划。该计划的目标是建立具有我国海洋生态特征,适应我国社会经济发展水平的海洋生态系统服务功能定量模型和服务价值计算方法,并基于GIS技术开发生态系统服务价值评估系统,应用于评估渤海、黄海、东海和南海四大生态系统的服务价值和11个沿海省市区的近海服务价值,同时评估赤潮、病原生物和外来种导致的海洋生态系统服务价值损失,为实现人海和谐的海洋开发产业布局和用海活动提供定量评估技术支持,为基于生态系统的海洋管理提供理论支撑。目前,该计划已经建立了我国海洋生态系统服务功能分类体系、服务功能量化指标和服务价值计算指标体系,完成评估软件系统的设计。 相似文献
19.
湿地具有去除水中营养物质或污染物质的特殊结构和功能属性,在维护流域生态平衡和水环境稳定方面发挥巨大作用。提出了流域湿地是将流域中湿地看作一个整体,研究其水质净化功能。对国内外湿地净水功能的特殊属性、湿地系统各组分对污染物质的去除作用及湿地对污染物质的去除过程研究作了不同程度的探讨。在流域的尺度上,进行了流域湿地水质净化功能的环境因子、影响流域湿地水质净化功能的重要湿地类型和流域湿地整体水质净化功能的研究,总结了流域湿地水质净化功能。对流域湿地水质净化功能未来的研究进行了讨论与展望。 相似文献
20.
我国近海生态系统食物产出的关键过程及其可持续机理 总被引：1，自引：0，他引：1
围绕国家重点基础研究发展计划（973计划）项目“我国近海生态系统食物产出的关键过程及其可持续机理”,介绍了海洋可持续生态系统研究对我国社会与科技发展的意义、研究现状和发展趋势、拟解决的关键科学问题和预期目标,以及研究实施计划。该项研究的最终目标是从人类活动和自然变化两个方面认识我国近海海洋生态系统服务与产出功能,量化其生态容纳量及动态变化,预测生态系统的承载能力和易损性,寻求我国近海海洋可持续开发利用与资源环境相协调发展的途径。 相似文献