Validity of Performance Criteria and a Tentative Model for Regulatory Use in Compensatory Wetland Mitigation Permitting

The purpose of this paper is to develop the principles for a manageable and practical set of performance criteria that will reasonably assure no net loss in a situation in which it cannot be absolutely assured. To this end, the performance criteria proposed for 116 compensatory wetland projects on file with the Army Corps of Engineers in San Francisco, between 1988 and 1995, were examined. The trends discerned in the project proposals were analyzed and evaluated in light of the current state of wetland science. Specific suggestions for the development of uniform criteria in each of four major wetland types—riparian, perennial tidal, perennial nontidal, and seasonal—are discussed, and a system of regulation tying qualitative assessment with quantitative requirements is outlined as a reasonable solution to the enforcement of the no-net-loss policy.     

Determination of types of interactions exhibited by binary mixtures of heavy metals tested against the hermit crab,Clibanarius africanus

Single and joint action toxicity of heavy metal compounds (ZnCO₃, CuSO₄ and CdSO₄) were carried out against the hermit crab, Clibanarius africanus in laboratory bioassays. On the basis of 96?h LC₅₀ values, CuSO₄ (96?h LC₅₀?=?0.03?mM) was found to be the most toxic followed by CdSO₄ and ZnCO₃ (96?h LC₅₀?=?0.24?mM) in decreasing order of toxicity. The evaluation of the metal compounds in mixtures of ZnCO₃–CuSO₄, ZnCO₃–CdSO₄ and CdSO₄–CuSO₄ in pre-defined molar ratios revealed that interactions between Zn–Cu and Zn–Cd test mixtures were in conformity with the models of antagonism (reduction in toxicity of constituent metals). The synergistic ratios (S.R.s) and relationship between observed/predicted 96?h LC₅₀ values (relative toxic unit, RTU) were consistently below 1, indicating antagonistic interactions. Analysis using isobolograms also indicated the interactions between the mixture components to be antagonistic. However, with regards to CdSO₄–CuSO₄ test mixtures, the interactions between these metals were mainly in conformity with the model of synergism. The S.R. and RTU values were largely above 1, indicating synergistic interactions. The importance of the joint action evaluations for the management and protection of aquatic ecosystems, particularly in the setting up of water quality criteria was discussed.     

Applicability of Montreal Process Criterion 4 — soil and water conservation — to rangeland sustainability

SUMMARY

Criterion 4 of the Montreal Process addresses the conservation of soil and water resources as a way to assess the sustainability of a nation's forests. For the most part, the indicators under this criterion are relevant to rangelands. The area and percent of rangeland with significant soil erosion apply equally well to both biomes. Percent of streams with flow rates and timing outside its range of historical variation is also equally important, although a measure of proper functioning and condition may provide a better measure of the indicator. The area and percent of rangeland with diminished soil productive capability because of a loss of reduced organic matter or changed physical characteristics can be useful indicators locally and regionally.     

Development of a risk measure as a sustainable project selection criterion

SUMMARY

Sustainable decision-making requires consideration of technology, ecology, and the social and political infrastructure of society. While it may never be possible to identify with certainty what is sustainable and what is not, an attempt has been made in this paper to formulate a measure that permits one to compare the performances of project alternatives with respect to risk. An algorithm is presented for the evaluation of a risk criterion that can be used with other criteria in the process of selecting project alternatives. The intent of the risk criterion is to involve project stakeholders in the process of quantifying the risks associated with different project alternatives.     

水体沉积物质量基准研究现状

沉积物质量基准是对水质基准的补充,对水质管理具有重要意义。目前国际上沉积物质量基准计算方法有十几种。对各种方法的理论基础、数据需求、适用范围等方面进行了概述之后,综合分析了各种方法的理论基础。研究结果认为,应将建立沉积物质量基准的方法分为以生物效应数据为基础的生物效应数据库法和以相平衡分配原理为依据的相平衡分配法。而根据统计方法不同,生物效应数据库法又分为单值基准、双值基准和三轴图法。同时还对美国、加拿大、荷兰、英国、澳大利亚和新西兰的沉积物质量基准研究发展和应用概况进行了分析。结合我国实际情况认为,依赖于大量生物效应数据的生物效应数据库法,目前在我国的适用范围有限,只能用于推导少数几种污染物的基准值。相平衡分配法具有可靠的理论基础而且不需要大量的生物效应数据,具有很大的发展潜力。因此,对于目前沉积物质量基准研究处于初级阶段的我国,更适合使用相平衡分配法计算污染物沉积物质量基准。     

我国水生生物水质基准推导的物种选择

水生生物水质基准旨在保护水生生物不受水体中化学物质的有害影响,是水质基准体系的重要组成部分.不同区域水生态系统的生物区系不同,导致基准值也会存在差异.在综合研究美国、欧盟、加拿大、荷兰、澳大利亚和新西兰等国家和地区在推导水生生物水质基准的物种选择及其考虑因素的基础上,初步研究我国水生生物水质基准推导的物种选择原则.结果表明:推导我国水生生物水质基准需要选择来自8科的水生生物,分别为鲤科鱼类、硬骨鱼纲中的另一科、两栖动物纲的一科、浮游动物中节肢动物门和轮虫动物门各一科、底栖动物中节肢动物门和环节动物门各一科及一种最敏感的大型水生植物(或浮游植物),可全面代表我国水生态系统不同的营养级和生命形式.      

基于浮游生物群落变化的生态学基准值计算方法初探

基于浮游生物群落对环境压力变化的响应,参照美国国家环境保护局(US EPA)颁布的生物学基准计算方法,结合理化因子,采用综合指数法计算了我国太湖流域和辽河流域的生态学基准值.计算框架为:①确定流域水环境生态学基准参照点和生态学基准指标;②作出参照点各基准指标box分布图并进行评分;③将各生态学基准指标得分等权重相加,并把90分位数值作为该流域的基准值.结果表明:我国太湖流域夏、冬季的生态学基准值分别为94.7和86.7,辽河流域夏、冬季的生态学基准值分别为100.0和96.4.通过该基准值可较好地区分2009年辽河流域和太湖流域夏、冬季采样点位的生境优劣,这说明基于浮游生物群落变化来计算生态学基准值的方法是可行的.      

我国典型流域镉水质基准研究

对《我国淡水水生生物镉基准研究》一文推算的国家镉基准进行了修正,采用“重新计算法”推算了我国典型流域的镉生物基准,并以辽河上游的大伙房水库为试点,利用“水效应比值法”推算了区域镉基准. 结果表明:我国国家镉急性和慢性基准分别修正为1.81和0.21 μg/L;珠江流域、长江流域、太湖流域和辽河流域的镉急性基准分别为3.60,3.61,3.19和2.95 μg/L;镉慢性基准分别为1.39,0.06,0.04和0.04 μg/L;大伙房水库镉急性和慢性基准分别为2.72和0.05 μg/L. 流域及区域的镉急性基准值全部大于国家急性基准值,但大部分镉慢性基准都严于国家慢性基准.      

Establishing IUCN Red List Criteria for Threatened Ecosystems

Abstract: The potential for conservation of individual species has been greatly advanced by the International Union for Conservation of Nature's (IUCN) development of objective, repeatable, and transparent criteria for assessing extinction risk that explicitly separate risk assessment from priority setting. At the IV World Conservation Congress in 2008, the process began to develop and implement comparable global standards for ecosystems. A working group established by the IUCN has begun formulating a system of quantitative categories and criteria, analogous to those used for species, for assigning levels of threat to ecosystems at local, regional, and global levels. A final system will require definitions of ecosystems; quantification of ecosystem status; identification of the stages of degradation and loss of ecosystems; proxy measures of risk (criteria); classification thresholds for these criteria; and standardized methods for performing assessments. The system will need to reflect the degree and rate of change in an ecosystem's extent, composition, structure, and function, and have its conceptual roots in ecological theory and empirical research. On the basis of these requirements and the hypothesis that ecosystem risk is a function of the risk of its component species, we propose a set of four criteria: recent declines in distribution or ecological function, historical total loss in distribution or ecological function, small distribution combined with decline, or very small distribution. Most work has focused on terrestrial ecosystems, but comparable thresholds and criteria for freshwater and marine ecosystems are also needed. These are the first steps in an international consultation process that will lead to a unified proposal to be presented at the next World Conservation Congress in 2012.     

定量风险评价技术在管道城市穿越段的应用

介绍了管道高后果区定量风险评价的方法和风险可接收标准.将定量风险评价技术在我国某长输原油管道城市穿越段的应用表明,定量风险评价方法适用于人口密集的管道高后果区,能对管道高后果区的风险管理、决策提供重要的参考.