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1.
通过开展毒性试验和查阅国内外相关文献,获取马拉硫磷对长江三角洲流域22个代表性物种毒性数据,采用物种敏感度分布法和毒性百分数排序法推导长江三角洲流域马拉硫磷水生生物基准值。结果显示,采用物种敏感度分布法得出的急性基准值和慢性基准值分别为0.865 5和0.036 2μg·L~(-1),采用毒性百分数排序法得出的急性基准值和慢性基准值分别为0.400 0和0.033 4μg·L~(-1)。为充分保护水生生物,建议以毒性百分数排序法推导出的基准值作为长江三角洲流域马拉硫磷水生生物基准推荐值。研究结果可为我国地表水环境质量标准修订及水生生态风险评估提供科学依据。  相似文献   

2.
为减少苕溪流域农药施用量,降低该流域农药对水生生物的环境风险,通过调查苕溪流域防治卷叶螟虫(Cnaphalocrocis medinalis)、稻飞虱(Delphacidae)和水稻纹枯病的农药品种及用量,以农药暴露模拟外壳为工具,运用农药风险评价技术分析其产生的环境风险,并根据风险选择农药品种及用量。结果表明:以吡蚜酮代替噻嗪酮可减少农药用量765 g·hm~(-2),以阿维菌素代替骄子可减少农药0.75 L·hm~(-2),以爱苗替代井冈霉素可减少农药4.27 L·hm~(-2),替代后常规农药总用量降低5.79 L·hm~(-2)。同时该替代技术对试验区水稻产量和病虫害的防治效果大多优于当地农户单独分散用药。由于控制了用药次数和用药量,用药成本下降,水稻种植的经济效益则增加。该技术在减少农药总施用量的同时也降低了农药对水生生物环境毒性的影响,从源头控制了农业面源污染中的化学污染物。  相似文献   

3.
通过生态毒理试验,获得百菌清对长江三角洲流域14种代表性水生生物的毒性数据。分别采用评价因子法、物种敏感度分布法和毒性百分数排序法,推导长江三角洲流域百菌清水生生物基准值。评价因子法、物种敏感度分布法和毒性百分数排序法得出的急性基准值分别是0.066μg·L~(-1)、3.00μg·L~(-1)和0.51μg·L~(-1),慢性基准值分别是0.0089μg·L~(-1)、0.40μg·L~(-1)和0.136μg·L~(-1)。比较了3种方法得出的基准值之间的差异并分析了原因,在此基础上,提出了我国长江三角洲流域百菌清水生生物基准推荐值,并与国外基准值进行了比较。研究结果可为中国农药水质标准制修订及水生生物风险评估提供科学依据。  相似文献   

4.
搜集筛选了二甲苯对我国淡水生物的急、慢性毒性数据。物种涵盖了昆虫类、甲壳动物类、鱼类、两栖动物类、环节动物类、软体动物类、轮虫类和浮游植物类。数据分析表明,甲壳类生物对二甲苯最为敏感。采用美国水生生物基准技术对二甲苯水质基准进行推算,得出保护我国淡水生物的二甲苯急性基准域值为1.41 mg·L-1,慢性基准为0.57 mg·L-1。基于获得的二甲苯基准值对我国部分流域二甲苯的暴露生态风险进行初步评估,结果表明二甲苯并未对这些水体中的水生生物造成潜在风险。本研究将为二甲苯水质标准的制修订和流域水环境管理提供技术支持。  相似文献   

5.
红霉素是大环内酯类抗生素,环境中红霉素残留具有较高的生态风险和健康风险,而中国目前尚缺乏红霉素的淡水水生生物基准值,因而研究适合中国流域水环境的红霉素水生生物基准,对于保护中国淡水水生生物以及水质基准的研究具有重要意义。该研究搜集筛选了红霉素对中国淡水生物的急慢性毒性数据,共获得3门8科的10个急性毒性数据和2门4科的4个慢性毒性数据。利用美国环境保护局推荐的物种敏感度排序法(SSR)推导红霉素的水生生物基准,同时以log-normal SSD法和log-logisticSSD法对基准计算结果进行了比对。比较了3种方法的优缺点,以及与国内外已有研究基准值之间的差异及形成原因,分析了影响红霉素水生生物基准的关键因素。得出采用SSR法推导的保护中国水生生物的红霉素急性基准值(CMC)为0.47μg·L~(-1),慢性基准值(CCC)为0.10μg·L~(-1)相对可行。将该研究推导出的红霉素慢性基准值(CCC)与中国部分江河和湖泊中红霉素暴露浓度相比较,采用风险商值(RQ)评价了红霉素的生态风险。结果表明,风险区域主要集中在辽河、海河和珠江,部分区域点位存在一定的红霉素暴露生态风险。研究结论可为红霉素水质标准制定和流域水环境管理提供科学依据。  相似文献   

6.
以国家重点生态功能区县域——武夷山市为案例区,选取54个珍稀濒危物种为指示物种,在物种栖息地评价基础上采用系统保护规划工具MARXAN模型评估生物多样性保护的优先区域。结果表明,武夷山市生物多样性保护优先区总面积为734.7 km~2,占武夷山市国土面积的26.1%,并集中分布于东北部、西北部及东南部地区;在保护优先区内,8个一级保护物种栖息地的保护比例均超过各自栖息地总面积的50%。空缺分析发现,生物多样性保护优先区与现有自然保护地存在空间不匹配的现象,建议优先在生物多样性保护一级优先区范围内补充扩建和新建自然保护地,包括向东补充扩建武夷山国家公园、向南补充扩建武夷山黄龙岩省级自然保护区,在吴屯乡吴屯溪、东溪水库及其周边新建森林、湿地及水生野生动植物自然保护区,在上梅乡和五夫镇建设森林保护类自然公园。  相似文献   

7.
序言     
正享誉海内外的著名鱼类学家和淡水生态学家、我国淡水生态学奠基人和鱼类实验生物学主要开创者、中国科学院水生生物研究所研究员(原所长和名誉所长)、中国科学院院士刘建康先生于2017年秋天离开了我们。为深切缅怀刘建康先生对我国鱼类学和淡水生态学的卓越贡献,同时呼吁加强水生生物多样性与流域生态系统的保护,我们应《生态毒理学报》编辑委员会的邀请一起策划组织了主题为"水生生物完整  相似文献   

8.
构建了东苕溪流域水稻地表水暴露场景,对国外已广泛应用的稻田-地表水暴露评价模型(RICEWQ—EX—AMS)进行二次开发,并应用构建的场景和开发的模型对东苕溪流域稻田常用农药品种进行水生生态风险评价和健康风险评价。结果表明,在所评价的10种东苕溪流域常用农药品种中,除草剂氟乐灵对藻具有急性高风险,杀虫剂硫丹对鱼既具有急性高风险,又具有慢性风险,阿维菌素对泾具有急性高风险,氟铃脲对涵既具有急性高风险,又具有慢性风险,其余品种对鱼、溢和藻的急慢性风险均较低。运用传统评价法和风险评价模型计算法得出了相一致的结论,即所评价的10个农药品种对人体健康均无风险,该评价结果与所评价农药的实际风险表现较吻合。认为所构建的场景、模型能较好地用于东苕溪流域稻田农药品种的风险评价。  相似文献   

9.
采用毒性百分数排序法推导了马拉硫磷、乐果、甲基对硫磷、敌敌畏和对硫磷等5种有机磷农药的淡水水生生物基准,得出5种有机磷农药的基准最大浓度(CMC)分别为0.477、1.392、0.247、0.085、0.155μg·L-1;基准连续浓度(CCC)分别为0.030、0.688、0.092、0.056、0.030μg·L-1.将推导出的双值基准与我国地表水环境质量标准比较,结果表明,二者差别较大,我国目前这5种有机磷农药的水质标准可能在一定程度上存在着对水生生物"欠保护"的情况.5种有机磷农药的淡水水生生物基准可为我国淡水水生生物基准的制订提供一定的数据参考.  相似文献   

10.
构建了东苕溪流域水稻地表水暴露场景,对国外已广泛应用的稻田-地表水暴露评价模型( RICEWQ-EX-AMS)进行二次开发,并应用构建的场景和开发的模型对东苕溪流域稻田常用农药品种进行水生生态风险评价和健康风险评价.结果表明,在所评价的10种东苕溪流域常用农药品种中,除草剂氟乐灵对藻具有急性高风险,杀虫剂硫丹对鱼既具有急性高风险,又具有慢性风险,阿维菌素对溞具有急性高风险,氟铃脲对溞既具有急性高风险,又具有慢性风险,其余品种对鱼、溞和藻的急慢性风险均较低.运用传统评价法和风险评价模型计算法得出了相一致的结论,即所评价的10个农药品种对人体健康均无风险,该评价结果与所评价农药的实际风险表现较吻合.认为所构建的场景、模型能较好地用于东苕溪流域稻田农药品种的风险评价.  相似文献   

11.
The geographic distribution of the animals of Venezuela was analyzed as a basis for a series of guidelines to help develop strategies for their conservation. A total of 313 animal taxa is distributed among 24 geographic units, corresponding to the political divisions of the country. Three different criteria were considered in analyzing these data: (1) the number and density of threatened taxa were used to define a ranking system for geographic units; (2) "hotspots" were identified using the distribution of threatened endemics, and (3) a "critical faunas analysis" was used to determine the minimum number of geographic units needed to maximize the number of sampled taxa. The first two criteria emphasize the importance of protecting habitat in the northern portion of the country, where most human intervention has already taken place. But the southern portion of the country is where most of the undisturbed habitat remains. We suggest that the conservation of the animals of Venezuela must follow a mixed strategy, based on two principles: one, aimed mainly at threatened endemics, should focus on the protection of critical habitat north of the Orinoco river, the second, aimed at all threatened animals— particularly high-risk taxa—should focus on assuring the long-term persistence of the pristine habitat in the south.  相似文献   

12.
Indicator groups may be important tools with which to guide the selection of networks of areas for conservation. Nevertheless, the literature provides little guidance as to what makes some groups of species more suitable than others to guide area selection. Using distributional data on all sub-Saharan birds and mammals, we assessed factors that influence the effectiveness of indicator groups. We assessed the influence of threatened, endemic, range-restricted, widespread, and large-bodied species by systematically varying their number in indicator groups. We also assessed the influence of taxonomic diversity by systematically varying the number of distinct genera and families within the indicator groups. We selected area networks based on the indicator groups and tested their ability to represent a set of species, which, in terms of species composition, is independent of the indicator group. Increasing the proportion of threatened, endemic, and range-restricted species in the indicator groups improved effectiveness of the selected area networks; in particular it improved the effectiveness in representing other threatened and range-restricted species. In contrast increasing the proportion of widespread and large-bodied species decreased effectiveness. Changes in the number of genera and families only marginally affected the performance of indicator groups. Our results reveal that a focus on species of special conservation concern, which are legitimate conservation targets in their own right, also improves the effectiveness of indicator groups, in particular in representing other species of conservation concern.  相似文献   

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14.
Motivations for the Restoration of Ecosystems   总被引:5,自引:0,他引:5  
Abstract:  The reasons ecosystems should be restored are numerous, disparate, generally understated, and commonly underappreciated. We offer a typology in which these reasons—or motivations—are ordered among five rationales: technocratic, biotic, heuristic, idealistic, and pragmatic. The technocratic rationale encompasses restoration that is conducted by government agencies or other large organizations to satisfy specific institutional missions and mandates. The biotic rationale for restoration is to recover lost aspects of local biodiversity. The heuristic rationale attempts to elicit or demonstrate ecological principles and biotic expressions. The idealistic rationale consists of personal and cultural expressions of concern or atonement for environmental degradation, reengagement with nature, and/or spiritual fulfillment. The pragmatic rationale seeks to recover or repair ecosystems for their capacity to provide a broad array of natural services and products upon which human economies depend and to counteract extremes in climate caused by ecosystem loss. We propose that technocratic restoration, as currently conceived and practiced, is too narrow in scope and should be broadened to include the pragmatic rationale whose overarching importance is just beginning to be recognized. We suggest that technocratic restoration is too authoritarian, that idealistic restoration is overly restricted by lack of administrative strengths, and that a melding of the two approaches would benefit both. Three recent examples are given of restoration that blends the technocratic, idealistic, and pragmatic rationales and demonstrates the potential for a more unified approach. The biotic and heuristic rationales can be satisfied within the contexts of the other rationales.  相似文献   

15.
Confidence intervals for the mean of the delta-lognormal distribution   总被引:1,自引:0,他引:1  
Data that are skewed and contain a relatively high proportion of zeros can often be modelled using a delta-lognormal distribution. We consider three methods of calculating a 95% confidence interval for the mean of this distribution, and use simulation to compare the methods, across a range of realistic scenarios. The best method, in terms of coverage, is that based on the profile-likelihood. This gives error rates that are within 1% (lower limit) or 3% (upper limit) of the nominal level, unless the sample size is small and the level of skewness is moderate to high. Our results will also apply to the delta-lognormal linear model, when we wish to calculate a confidence interval for the expected value of the response variable, given the value of one or more explanatory variables. We illustrate the three methods using data on red cod densities, taken from a fisheries trawl survey in New Zealand.
David FletcherEmail:
  相似文献   

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17.
Global climatic change is likely to take place and could eventually affect Mediterranean deltas and other lowlying coastal regions. This would have serious implications for the natural resources of these deltaic areas, as well as for human settlements and related economic activities. To achieve sound decision making, to prevent damages and to avoid risky investments, it is necessary to understand the integral functioning of deltaic areas and to determine their vulnerability and response to large-scale change phenomena. Optimal use of the available knowledge will require that existing and new field measurements are combined and that integrated (physical/ecological) conceptual models of deltaic behaviour are developed with socio-economics scenarios as boundary conditions. This paper illustrates the methodological effort towards organizing a modeling framework to conduct budget computations at various scales with reference to the most significant ‘physiogrpahic units’ and to the most significant deltaic processes. The final objective is to handle the problem of evaluating possible changes under different scenarios.  相似文献   

18.
Understanding the social acceptability of biodiversity offsets is important to the design of offset policy. We used a discrete choice experiment to quantify preferences of Australians for a migratory shorebird offset in the context of an oil and gas development project. We surveyed a nationally representative sample of 1371 respondents on their preferences for current and prospective offset‐policy characteristics via an online questionnaire to inform policy design of the social dimensions related to offset acceptability. The majority of respondents accepted offsetting as a means to allow economic development; the option to reject development (and an offset) was selected in 13% of possible offset scenarios. Substituting protection of a species affected by the development with protection of a more endangered species was a desirable policy characteristic, as was having the offset implemented by a third party or the government rather than the company responsible for the development. Direct offset activities (e.g., improving degraded habitat) were preferred over indirect activities (e.g., a research program), and respondents were strongly against locating the offset at a site other than where the impact occurred. Positive and negative characteristics of offsets could be traded off by changing the number of birds protected by the offset. Our results show that Australians are likely to support increased flexibility in biodiversity‐offset policies, particularly when undesirable policy characteristics are compensated for.  相似文献   

19.
Abstract: Given their physiological requirements, limited dispersal abilities, and hydrologically sensitive habitats, amphibians are likely to be highly sensitive to future climatic changes. We used three approaches to map areas in the western hemisphere where amphibians are particularly likely to be affected by climate change. First, we used bioclimatic models to project potential climate‐driven shifts in the distribution of 413 amphibian species based on 20 climate simulations for 2071–2100. We summarized these projections to produce estimates of species turnover. Second, we mapped the distribution of 1099 species with restricted geographic ranges. Finally, using the 20 future climate‐change simulations, we mapped areas that were consistently projected to receive less seasonal precipitation in the coming century and thus were likely to have altered microclimates and local hydrologies. Species turnover was projected to be highest in the Andes Mountains and parts of Central America and Mexico, where, on average, turnover rates exceeded 60% under the lower of two emissions scenarios. Many of the restricted‐range species not included in our range‐shift analyses were concentrated in parts of the Andes and Central America and in Brazil's Atlantic Forest. Much of Central America, southwestern North America, and parts of South America were consistently projected to experience decreased precipitation by the end of the century. Combining the results of the three analyses highlighted several areas in which amphibians are likely to be significantly affected by climate change for multiple reasons. Portions of southern Central America were simultaneously projected to experience high species turnover, have many additional restricted‐range species, and were consistently projected to receive less precipitation. Together, our three analyses form one potential assessment of the geographic vulnerability of amphibians to climate change and as such provide broad‐scale guidance for directing conservation efforts.  相似文献   

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