广州南沙滨海湿地公园水质状况及模拟酸雨影响效应

通过野外实地调查、理化分析和生物毒性试验对广州南沙滨海湿地公园的水质状况进行了评价，同时用模拟酸雨作用于南沙水样，研究酸雨对南沙水体的污染效应。结果表明，所检测的水质指标目前尚处于国家标准范围之内，试验生物隆线溢可以正常地生长、发育和繁殖；然而，在模拟酸雨的影响下，水样可对隆线涵产生毒害致死作用，说明广州市目前频繁出现的酸雨现象，可能对未来该次生湿地生态系统的健康发育产生抑制作用，因而需要引起重视。     

土地利用变化对生态系统碳汇-碳源的影响研究——以河北武安市为例

土地利用变化引起的生态系统类型转变对于区域碳循环有着极其重要的作用。运用1997～2008年土地利用变更数据,煤、石油、天然气燃烧的碳排放量,对河北省武安市碳汇-碳源进行了估算,结果表明1997～2008年武安市碳汇处于不稳定状态,碳源呈明显增加趋势。武安市碳增汇由1997年的绿灯区转变为2008年的红灯区。各乡（镇）碳汇-碳源变化的区域差异显著,其中12个乡（镇）处于红灯区,10个乡（镇）处于绿灯区。笔者根据结果提出增加碳汇,减少碳排放的建议,旨在为区域的减排目标和可持续发展提供借鉴。     

黄淮海平原农田防护林生态服务价值研究

在国内外森林生态系统服务价值研究的基础上,运用市场价值法,机会成本法和影子价格法等对黄淮海平原2001和2005年农田防护林生态服务的价值进行研究.主要内容包括农田防护林的活立木蓄积的价值、农田防护林的防护功能、净化空气、固碳供氧、保育土壤以及生物多样性保护功能的价值.结果表明:2001～2005年农田防护林生态服务的...     

环境污染对城镇生态服务价值的影响

从生态服务价值概念出发,介绍了近年来国内外有关生态服务价值的分类,包括直接利用价值和间接利用价值,与价值评价方法包括替代市场技术和模拟市场技术,以及在不同生态功能体系中的运用。大量研究显示,酸雨、重金属等环境污染及气候异常对城镇生态系统功能产生明显的负面影响,如酸雨造成农作物减产、森林退化、土壤和水体酸化,重金属在生物体内积累富集,造成生物体的慢性中毒等,由此降低了城镇生态系统的服务价值。城镇生态服务价值评估和城镇规划建设,应考虑生态恢复的经济消耗以及生态服务本身所具有的协同作用。     

Biological control of fruit flies in Hawaii: Factors affecting non-target risk analysis

The potential negative impacts of biological pest control on non-target species have become the focus of a contentious debate. In this article, we use examples from both classical and augmentative biological control of fruit fly pests in Hawaii to address several important factors in assessing non-target risks of fruit fly parasitoids. Several fruit fly parasitoids have been introduced to Hawaii and contribute substantially to the reduction of pest populations in the state's farms and forests. However, an historical lack of host-specificity testing of these parasitoids with non-target species has raised concerns about their impact on non-pest fruit flies, including some flies deliberately introduced for biological control of weeds and others that are endemic Hawaiian species. When developing protocols to assess risks of introduced fruit fly parasitoids, we need first to define an appropriate range of species against which host specificity should be tested. For assessing susceptibility of a non-target species to parasitoids, behavioral tests are as important as suitability tests. Experimental factors, such as host-exposure substrate, absence or presence of preferred hosts, and laboratory vs. natural conditions, are shown to affect the results of host-specificity tests and risk analysis. Still, assessing long-term, indirect ecological impacts of parasitoids and weighing potential risks and benefits in multiple dimensions (besides dollar values) remains a challenge to environmentalists, conservationists, applied ecologists, and biocontrol practitioners.     

蔬菜地农药施用的土壤生态风险评估

通过对浙江萧山围垦区农场蔬菜种植区农药施用记录的调查分析,建立了土壤生态风险水平评价预测方法,结合GIS技术构建以种植区块为农药施用的土壤生态风险评价基本单元,定量分析蔬菜地土壤中农药施用后的生态风险水平。20种不同农药施用后对各蔬菜地土壤产生的生态风险结果表明,4月份使用多菌灵后产生的生态风险值最高,短期和长期风险值分别达到104.6和106.1,毒死蜱、啶虫脒、吡虫啉和嘧菌酯的施用也具有较高的生态风险(均超过85),而甲维盐等7种农药基本无风险(60)。同时,针对不同的蔬菜种植区块,完成了不同时空条件下多种农药累加施用后对土壤产生的综合生态风险值(Integrated Ecological Risk Values,IERV)的计算,实现了风险值的空间可视化。以4月份为例,多个芦笋地块综合风险达到了高风险等级,萝卜地块则为低风险。     

Cascading effects of the loss of apex predatory sharks from a coastal ocean

Impacts of chronic overfishing are evident in population depletions worldwide, yet indirect ecosystem effects induced by predator removal from oceanic food webs remain unpredictable. As abundances of all 11 great sharks that consume other elasmobranchs (rays, skates, and small sharks) fell over the past 35 years, 12 of 14 of these prey species increased in coastal northwest Atlantic ecosystems. Effects of this community restructuring have cascaded downward from the cownose ray, whose enhanced predation on its bay scallop prey was sufficient to terminate a century-long scallop fishery. Analogous top-down effects may be a predictable consequence of eliminating entire functional groups of predators.     

外来杂草刺萼龙葵及其风险评估

外来入侵生物已对世界各国的自然生态系统、农业生产及公众健康造成了严重危害。刺萼龙葵(Solanum rostratum)起源于北美洲,其繁殖和适应能力很强,是具有潜在危险的外来有害杂草。对刺萼龙葵的分布、生物生态学特性、经济和生态影响及其控制和管理措施等进行了系统综述。根据生物生态学特性、潜在危险及管理控制的难度等特点,对刺萼龙葵进行了风险评估,得出其风险值为86,属高度危险的检疫性有害生物。应当高度重视刺萼龙葵的入侵,积极采取措施控制其危害蔓延。     

水培蕹菜使用吡唑醚菌酯的水生生态系统风险评估

为研究水培蕹菜使用吡唑醚菌酯对水生生物的潜在影响，在水培蕹菜白锈病发病初期，喷施25%吡唑醚菌酯悬浮剂和9%吡唑醚菌酯微囊悬浮剂，测定水培蕹菜和水体中的吡唑醚菌酯残留量，并结合毒理学数据评估其对水生生态系统的暴露风险。结果表明：吡唑醚菌酯在水培蕹菜和水中降解较快。悬浮剂和微囊悬浮剂在植株中的消解半衰期分别为2.9 d和3.9 d，微囊悬浮剂较悬浮剂在植株上的持效期更长。两种剂型在水中的消散半衰期都小于2 d，微囊悬浮剂在水中的有效浓度小于悬浮剂。基于暴露浓度峰值和时间加权平均浓度进行风险评估，悬浮剂对水生脊椎动物和无脊椎动物的急性和慢性风险商值，及其对初级生产者的慢性风险商值均大于1；微囊悬浮剂对每一类水生生物的风险商值都小于悬浮剂，但其对水生生物的急性暴露风险同样不可接受（风险商值仍大于1），慢性风险商值仅在基于时间加权平均浓度计算时小于1。研究表明，吡唑醚菌酯在水培蕹菜上使用对水生生态系统的风险不容忽视，应重点关注鱼和无脊椎动物的暴露风险。建议在水生蔬菜生产中谨慎使用吡唑醚菌酯，同时修订吡唑醚菌酯在水生蔬菜上的限量标准。     

城市化流域生态系统服务价值时空分异特征及其对土地利用程度的响应

以南京市九乡河流域为研究区域,以2003与2009年2景QuickBird影像数据为基本信息源,应用空间自相关模型,结合GIS空间分析技术,定量探讨了城市化流域生态系统服务价值时空分异特征,以及土地利用程度对生态服务价值空间分异的影响.结果表明:2003-2009年,九乡河流域生态系统服务总价值减少了2.59％,而流域生态系统服务价值的空间聚集性增强;生态服务价值的高-高区域主要集中在流域上游,低-低区域主要集中在流域下游的仙林大学城一带;九乡河流域生态系统服务价值空间分异发生了明显变化,下游仙林大学城一带低-低分布区快速扩张,而高-高分布区仅在九乡河源头及下游的局部区域有所增加;流域生态服务价值空间自相关表现出明显的尺度效应,随着研究尺度增大,生态服务价值的空间自相关性逐渐增强;九乡河流域生态服务价值的空间分异及其变化主要是由土地开发利用引起,流域土地利用程度对生态服务价值存在明显的负效应.     

气候变化对青藏高原陆地生态系统的影响研究进展

气候变化对陆地生态系统的影响及其反馈是当前全球变化研究的重要内容,青藏高原是全球气候变化的敏感区和启动区,气候变化对青藏高原陆地生态系统的影响是当前全球气候变化的重要研究领域。系统总结了目前关于气候变化对青藏高原陆地生态系统的影响与反馈的相关研究,最后根据当前研究中存在的问题,讨论了未来的研究方向。     

生物入侵对农田生态系统影响间接经济损失评价

生物入侵对农田生态系统影响间接经济损失主要是肥沃土壤的维持、营养物质循环、废弃物同化功能、CO2吸收功能等农田生态系统公益性服务功能降低所造成的经济损失，间接经济损失的大小与农作物产量的下降成正比。以典型案例报道和相关政府部门统计资料为主要信息源，计算了2000年度生物入侵对农田生态系统影响间接经济损失。计算结果表明：生物入侵对农田生态系统造成的间接损失为153.5871亿元/a。其中，外来病虫害对农田生态系统造成的损失为55.0066亿元/a，占总损失的35.81％.外来杂草对农田生态系统造成的损失为45.2742亿元/a，占总损失的29.48％；外来鼠害对农田生态系统造成的损失为48.8814亿元/a，占总损失的31.83％；外来病虫害对果园生态系统造成的损失为4.4249亿元/a，占总损失的2.88％。     

Utilizing a social ethic toward the environment in assessing genetically engineered insect-resistance in trees

Social policies are used to regulate how members of a society interact and share resources. If we expand our sense of community to include the ecosystem of which we are a part, we begin to develop an ethical obligation to this broader community. This ethic recognizes that the environment has intrinsic value, and each of us, as members of society, are ethically bound to preserve its sustainability. In assessing the environmental risks of new agricultural methods and technologies, society should not freely trade economic gains for ecological damage, but rather seek practices that are compatible with ecosystem health. This approach is used to evaluate the environmental risks associated with genetically engineered insect-resistant trees. The use of insect-resistant trees is a biologically based pest control strategy that has several advantages over pesticide use. However, the use of genetically engineered trees presents particular ecological concerns because the trees are long lived and often are not highly domesticated. The main environmental concerns reviewed include: (1) adaptation of pests to the trees, leading to a non-sustainable agricultural practice, (2) transgenic trees producing environmental toxins, (3) insect resistance enhancing the invasiveness of the tree, causing it to become weedy or invade wild habitats, and (4) transfer of the transgene to wild or feral relatives of the tree, possibly increasing the invasiveness of weeds or wild plants. Some methods are available to offset these risks; however, the environmental risks associated with this technology have been poorly researched and need to be more clearly identified so that when we evaluate the risks, it is based on the best information obtainable. To fulfil an ethical obligation to the environment, public policies and government regulations are needed to preserve the sustainability of both the environment and the future of our production systems. A better understanding of both the ecological issues and of genetic engineering in general are needed on the part of citizens and policy makers alike to ensure that sound environmental decisions are made. Otherwise, the environmental benefits of this technology, mainly decreasing the use of more toxic pesticides in tree crops and forests, will either be lost or traded for other environmental hazards.     

Biomass, size, and trophic status of top predators in the Pacific Ocean

Fisheries have removed at least 50 million tons of tuna and other top-level predators from the Pacific Ocean pelagic ecosystem since 1950, leading to concerns about a catastrophic reduction in population biomass and the collapse of oceanic food chains. We analyzed all available data from Pacific tuna fisheries for 1950-2004 to provide comprehensive estimates of fishery impacts on population biomass and size structure. Current biomass ranges among species from 36 to 91% of the biomass predicted in the absence of fishing, a level consistent with or higher than standard fisheries management targets. Fish larger than 175 centimeters fork length have decreased from 5% to approximately 1% of the total population. The trophic level of the catch has decreased slightly, but there is no detectable decrease in the trophic level of the population. These results indicate substantial, though not catastrophic, impacts of fisheries on these top-level predators and minor impacts on the ecosystem in the Pacific Ocean.     

Cumulative impacts of oil fields on northern alaskan landscapes

Proposed further developments on Alaska's Arctic Coastal Plain raise questions about cumulative effects on arctic tundra ecosystems of development of multiple large oil fields. Maps of historical changes to the Prudhoe Bay Oil Field show indirect impacts can lag behind planned developments by many years and the total area eventually disturbed can greatly exceed the planned area of construction. For example, in the wettest parts of the oil field (flat thaw-lake plains), flooding and thermokarst covered more than twice the area directly affected by roads and other construction activities. Protecting critical wildlife habitat is the central issue for cumulative impact analysis in northern Alaska. Comprehensive landscape planning with the use of geographic information system technology and detailed geobotanical maps can help identify and protect areas of high wildlife use.     

酸雨对土壤质量影响的研究进展

酸雨对土壤生态系统的功能特性与土壤质量产生很大的影响,主要表现在酸性物质改变土壤的物理、化学和生物生理作用过程等方面。同时,就酸雨对土壤质量与生态系统造成的影响进行了系统总结。     

北京市永定河生态系统服务价值评价与研究

客观评价与分析河流生态系统服务价值对于水环境和生态系统的保护、修复和管理都具有重要意义。本文提出适用于北京市永定河生态系统服务价值的评价指标,采用相关方法从供给、调节、文化和支持4方面对2007至2012年的北京市永定河生态系统服务做出货币化价值评估。在此基础上,运用因子分析法从15个指标中筛选出影响生态系统服务的4个主成分,并通过复合权重法对4个主成分的得分赋权重,综合评价出2007—2012年北京市永定河的生态系统服务情况。结果表明:传统的货币化价值评估方法中,永定河的生态系统服务价值在不断提高,这与永定河实施的修复工程有关;而在生态系统服务得分上,2007—2012年整体呈上升趋势,但存在波动性,说明虽然经济价值在不断提升,但河流水资源存贮和调节功能下降实质上还是对生态系统服务功能产生了影响。经分析永定河的旅游功能是其核心服务功能,生态功能又是旅游功能得以实现的保障,因此在河流管理中要做到经济效益与生态效益和谐发展。      

环鄱阳湖地区土地利用与生态系统服务价值分析

生态系统服务价值是生态经济研究的热点问题.通过对环鄱阳湖地区1996年、2000年、2005年土地利用变化的分析,探讨了该区域内生态系统的服务功能价值的变化.结果表明:该地区生态系统服务价值呈增加趋势,2000～2005年的增加量为1996～2000年问增加量的6.6倍;间接服务价值大于直接服务价值:其单位面积生态系统服务价值2005年为11359元/hm2,高于全国平均水平.     

气候变化对西南大西洋渔业生态系统的影响研究进展

西南大西洋是世界重要的渔区之一，捕捞国家包括阿根廷等西南大西洋沿海国以及中国、日本等众多非沿海国家，其中阿根廷滑柔鱼（Illex argentinus）、阿根廷无须鳕（Merluccius hubbsi）、巴西小沙丁鱼（Sardinella brasiliensis）与弗氏绒须石首鱼（Micropogonias furnieri）是西南大西洋年均产量最高的4种主要经济渔获物。探究气候变化对西南大西洋生态系统的影响有利于建立基于生态系统的渔业资源保护与利用格局。本文从渔业资源与生态系统两个角度出发，分别归纳了生态系统的生物因子（主要经济渔获物）、非生物因子（环境因素）与营养结构（食物链和食物网）对气候变化的响应情况。分析认为，在今后探究西南大西洋生态系统对气候变化的响应的研究中，选取代表物种表征生态系统的变化并结合人类活动与气候变化的影响可以丰富生态系统的相关结论，为西南大西洋海域提供基于生态系统的科学管理策略。     

Biodiversity effects on soil processes explained by interspecific functional dissimilarity

The loss of biodiversity can have significant impacts on ecosystem functioning, but the mechanisms involved lack empirical confirmation. Using soil microcosms, we show experimentally that functional dissimilarity among detritivorous species, not species number, drives community compositional effects on leaf litter mass loss and soil respiration, two key soil ecosystem processes. These experiments confirm theoretical predictions that biodiversity effects on ecosystem functioning can be predicted by the degree of functional differences among species.