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991.
近年来,全球及区域生态系统服务均呈现出快速变化趋势,分析研究生态系统服务变化的驱动机制有助于精准模拟未来生态系统服务情景,进而服务于生态系统管理决策的科学制定。虽然已有部分研究探讨了土地利用或气候变化对生态系统服务的影响,但生态系统服务变化的驱动机理与应对策略亟待全面揭示。为此,该文回顾总结了国内外关于生态系统服务变化驱动机制的研究成果,并分析归纳了生态系统服务变化的主要驱动因子与未来模拟技术,结果发现:(1)土地利用与气候变化是造成生态系统服务变化的主要因素,且相互作用共同驱动生态系统服务的变化;(2)生态系统服务变化的单影响因子识别取得较大进展,但多种影响因子的交互作用及其在生态服务变化中贡献亟需清晰分解;(3)基于遥感与气候模型的多情景模拟是预测未来生态系统服务变化的主要手段,但需要科学模拟多因素交互作用下的综合影响及其应对途径;(4)未来研究应加强人类活动对生态系统服务影响的分解与模拟,研发区域生态系统服务对重大生态工程的时空响应与探测技术,以科学指导区域生态保护建设与规划布局。  相似文献   
992.
Climate change is decreasing glacier cover and increasing the frequency and magnitude of precipitation-driven high flows and floods in many regions of the world. Precipitation may become the dominant water source for river systems in recently deglaciated catchments, with major rainfall events driving significant changes in river channel morphology. Few studies, however, have examined river channel response to repeated precipitation-driven high flows. In this study, we measured the geomorphological condition of four low-order rivers in recently deglaciated catchments (70–210 years ice free) before and after a series of repeated precipitation-driven high flows during summer 2014. High flows drove substantial initial morphological change, with up to 75% change in baseflow channel planform position and active channel form change from pre- to post-high flow. Post-high flow years were associated with increased instream wood and geomorphological complexity at all but the youngest river. Channel changes were part of an active relaxation stage at all rivers, where channels continued to migrate, and complexity varied through time. Overall, these measurements permit us to propose a conceptual model of the role of geomorphologically effective high flows in the context of paraglacial adjustment theory. Specifically, we suggest that older rivers in recently deglaciated catchments can undergo a short-term (<10 years) increase in the rate of geomorphological development as a result of the recruitment of instream wood and channel migration during and following repeated precipitation-driven high flows. Enhancing our knowledge of these geomorphological and paraglacial processes in response to high flows is important for the effective management of riverine water and ecosystem resources in rapidly changing environments.  相似文献   
993.
Accurate and detailed accounting of energy-induced carbon dioxide(CO2) emissions is crucial to the evaluation of pressures on natural resources and the environment, as well as to the assignment of responsibility for emission reductions. However, previous emission inventories were usually production- or consumption-based accounting, and few studies have comprehensively documented the linkages among socio-economic activities and external transaction in urban areas. Therefore, we address this gap in proposing an analytical framework and accounting system with three dimensions of boundaries to comprehensively assess urban energy use and related CO2 emissions. The analytical framework depicted the input, transformation, transfer and discharge process of the carbon-based(fossil) energy flows through the complex urban ecosystems, and defined the accounting scopes and boundaries on the strength of ‘carbon footprint' and ‘urban metabolism'. The accounting system highlighted the assessment for the transfer and discharge of socio-economic subsystems with different spatial boundaries. Three kinds methods applied to Beijing City explicitly exhibited the accounting characteristics. Our research firstly suggests that urban carbon-based energy metabolism can be used to analyze the process and structure of urban energy consumption and CO2 emissions. Secondly, three kinds of accounting methods use different benchmarks to estimate urban energy use and CO2 emissions with their distinct strength and weakness. Thirdly, the empirical analysis in Beijing City demonstrate that the three kinds of methods are complementary and give different insights to discuss urban energy-induced CO2 emissions reduction. We deduce a conclusion that carbon reductions responsibility can be assigned in the light of production, consumption and shared responsibility based principles. Overall, from perspective of the industrial and energy restructuring and the residential lifestyle changes, our results shed new light on the analysis on the evolutionary mechanism and pattern of urban energy-induced CO2 emissions with the combination of three kinds of methods. And the spatial structure adjustment and technical progress provides further elements for consideration about the scenarios of change in urban energy use and CO2 emissions.  相似文献   
994.
南四湖湖区内造田圩田、挖池养鱼等破坏湿地行为比较突出,导致该湖滨带出现水位变化幅度大、生境恶化、水体富营养化等问题。为改善湖滨带生态环境,在客观评估湖滨带生态环境本底和现状诊断的基础上,应用生态塘-人工生态岛技术在南四湖湖西湖滨带开展湿地修复,取得了显著的生态修复效果。  相似文献   
995.
大气污染物向海洋的输入及其生态环境效应   总被引:7,自引:3,他引:7  
纵观20年来,特别是近几年来逐渐成为生物地球化学循环研究热点之一的大气对海洋物质输入的研究,从大气物质入海通量,大气物质入海对海洋生态系统和环境的影响,大气物质入海的科学研究计划和项目等方面分析了这一领域的研究现状和未来趋势。给出了不同海区各种主要大气入海物质的通量或在同类物质入海总量中的比例,讨论了氮、磷、铁等营养物质和持续性有毒污染物,如PAH、PCBs、杀虫剂和重金属对海洋生态系统和环境的不同影响。  相似文献   
996.
In recent decades, China has undergone an impressive development, which has produced increasing human pressures including coastal degradation. Bohai Bay, located in the west of the Bohai Sea (north of China), has been affected by various human pressures, including waste water discharges, land reclamation and oil exploitation. To monitor the effects of these pressures on this ecosystem, benthic macroinvertebrates and environmental variables (dissolved oxygen, nutrients, metals, etc.) were sampled in 2009 and 2011. To assess the ecological status of the benthic communities, the AZTI Marine Biotic Index (AMBI) and multivariate‐AMBI (M‐AMBI) were used, including both density and biomass in the calculation. This is the first research in which M‐AMBI based on biomass (M‐bAMBI) is applied. Both methods showed that the nearshore areas, especially close to the Haihe and Jiyun estuaries, were affected by human pressures, with a clear gradient of decreasing impacts offshore. The ecological status as assessed using density and biomass was quite similar. Significant relationships were also found between both methods and environmental variables. The use of AMBI and M‐AMBI, based upon density and biomass, in assessing the ecological status of water bodies in China seems to be promising.  相似文献   
997.
首次报道了闽东海域分布的3种石珊瑚,分别为造礁石珊瑚陀螺珊瑚(Turbinaria sp.)、非造礁石珊瑚猩红筒星珊瑚(Tubastrea coccinea Lesson)和1个珊瑚待定种,其中陀螺珊瑚和1个珊瑚待定种为中国新记录.珊瑚分布面积约3.24km2,主要呈零星斑块状分布在岛礁周围水深2—25m近岸岩礁区.2012年5~8月对闽东台山列岛和星仔列岛4km2范围内的55个岛礁近岸海域进行4个航次的调查表明,珊瑚的分布总体上南部的台山列岛海域分布数量多于北部的星仔列岛,海岛东部海域略多于西部.研究认为,闽东海域发现陀螺珊瑚说明其分布主要受台湾暖流的影响,揭示我国大陆沿岸造礁石珊瑚分布北缘可能扩展到台山列岛和星仔列岛.  相似文献   
998.
In Antarctica, the marine ecosystem is dynamically interrelated with the terrestrial ecosystem. An example of the link between these two ecosystems is the biogeochemical cycle of phosphorus. Biovectors, such as penguins, transport phosphorus from sea to land, play a key role in this cycle. In this paper, we selected three colonies of penguins, the most important seabirds in Antarctica, and computed the annual quantity of phosphorus transferred from sea to land by these birds. Our results show that adult penguins from colonies at Ardley Island, the Vestfold Hills, and Ross Island could transfer phosphorus in the form of guano at up to 12 349, 167 036, and 97 841 kg/a, respectively, over their breeding period. These quantities are equivalent to an annual input of 3.96×109–1.63×1010 kg of seawater to the land of Antarctica. Finally, we discuss the impact of phosphorus on the ice-free areas of the Antarctica.  相似文献   
999.
Poverty reduction and environmental protection are two global tasks for sustainable development.The study perspective has changed over time,from narrowly focusing on poverty reduction to comprehensively strengthening human-welfare.We reviewed key references targeting the theoretical content and practical approach relying on poverty,environment protection and ecosystem services.We discussed the contradicting views on the relationship of poverty and environmental degradation,and then illustrated the study progress of a cutting-age topic-ecosystem services which pave a way to address poverty reduction and environmental protection together.At last,we investigated essential factors that affect the development and environmental protection.Considering the evolution of the concept of poverty,we found that the environment has occupied an increasing proportion in the cognizance of poverty.The relationship between poverty and environmental degradation is regional uniqueness.In practical aspect,projects based on the management and valuation assessment of ecosystem services draw researchers′attention all over the world.The appropriate scale,essential economic incentives,morality,law and social equality are key factors affecting individuals′decisions which directly relate to the sustainable development.  相似文献   
1000.
This introduction to the special section on “Governing Agriculture-Forest Landscapes to Achieve Climate Change Mitigation” reviews external interventions to improve forest conditions and reduce deforestation, and by extension, influence carbon storage in agriculture-forest landscapes. The review is based on a careful survey of 123 cases of project-based and policy interventions to influence land use and forest cover outcomes. We propose that outcomes of interventions can be explained in terms of rights, incentives, and technologies related to land use and apply this framework to examine 12 types of interventions in agriculture-forest landscapes. The analysis of the identified 123 cases raises concerns about consistency of data and comparability of cases. Our preliminary evidence suggests limited association between the stated objective of an intervention and its success. This evidence also suggests that smaller scale and effective enforcement may be positively associated with improved forest outcomes. But the effectiveness of interventions across different agriculture-forest landscapes varies and available evidence does not permit easy generalizations. The variable effects of interventions across different agriculture-forest landscapes point to the need to better understand the forms and functions of interventions and to problems associated with assessing their relative efficacy.  相似文献   
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