硝酸盐对淡水水生生物毒性及水质基准推导

为推导保护淡水水生生物的NO3-水质基准,收集了NO3-的水生生物毒性数据,然后分析了不同水生生物类群的毒性敏感性,并分别采用评价因子法、毒性百分数排序法和物种敏感度分布法进行基准值推导.结果表明,不同生物类群的水生生物对NO3-毒性的敏感性存在明显差异,其敏感性排序为节肢动物门>软体动物门>脊索动物门;甲壳纲>昆虫纲>腹足纲>双壳>两栖纲>辐鳍纲.3种基准计算方法得到的基准值存在一定差异,最终推荐采用毒性百分数排序法得出的87.97mg·L-1和5.17 mg·L-1为现阶段NO3-(以N计)的水质急性毒性和慢性毒性基准值.     

A binational, supply-side evaluation for managing water quality and invasive fouling species on California's coastal boats

Integrated solutions are needed for sustainable management of risks posed by recreational boats to coastal water quality and ecosystems. Fouling organisms roughen vessel hull surfaces, creating friction that slows sailboats and increases fuel consumption by powerboats. Hull fouling control strategies for recreational boats that are stored in the water may include antifouling hull paints, newer alternative hull coatings, periodic in-water hull cleaning, and excluding propagules by surrounding the boat with a slip liner or raising it above water on a lift. Copper discharged to harbor waters from antifouling paints via passive leaching and in-water hull cleaning may elevate dissolved copper levels above government standards. Invasive species carried among boat-hull fouling organisms may be introduced as boats move among coastal areas. Some of these species tolerate copper in antifouling paints and copper-polluted harbor waters. Policy development must consider supply-side capacity, as well as economic and environmental sustainability, in managing these issues. This paper presents a supply-side evaluation useful in developing policies to co-manage water quality and invasive species risks for recreational boats navigating along the coasts of California, the Baja California peninsula and California's Sacramento-San Joaquin Delta. Supply-side perspectives on services, materials, costs, and boat owner behaviors, such as residence and travel patterns, awareness of hull-coating choices and selection of hull coatings, are determined. Analyses include evaluation of risks, risk management capacity and costs, and role of education in risk management. The issues raised are broadly applicable, as they are appearing on research and policy agendas in diverse coastal areas.     

Compliance of Australian threatened species recovery plans with legislative requirements

Recovery plans are the main documents supporting management decision-making for threatened species. We evaluated Australian recovery plans to assess their appropriateness as conservation and management planning instruments. Six legislative requirements (species information and general requirements, species distribution and location, known and potential threats, objectives, performance criteria and actions, duration of the plan, and estimated costs of plan implementation) were used to assess the degree of compliance of recovery plans with the relevant legislation. We assessed all 236 official recovery plans which had been adopted as at January 2006. The results showed that plans were most compliant regarding the setting of objectives, performance criteria, recovery actions, and duration of plan. Most plans included a single performance criterion that was generally related to the population status of target species. Improvement is required in relation to identification of current threats and critical habitats, and the establishment of basic elements of monitoring and evaluation for measuring recovery progress. Gaps in ecological information are the main factors affecting adequate compliance with legislative requirements as opposed to managerial information (e.g. clarity in establishing the implementation schedule, costs and resource allocation). Planning deficiencies could be addressed by improving the recovery planning guidelines and more carefully reviewing the drafting and adoption of new plans.     

Predicting the economic costs and property value losses attributed to sudden oak death damage in California (2010-2020)

Phytophthora ramorum, cause of sudden oak death, is a quarantined, non-native, invasive forest pathogen resulting in substantial mortality in coastal live oak (Quercus agrifolia) and several other related tree species on the Pacific Coast of the United States. We estimate the discounted cost of oak treatment, removal, and replacement on developed land in California communities using simulations of P. ramorum spread and infection risk over the next decade (2010-2020). An estimated 734 thousand oak trees occur on developed land in communities in the analysis area. The simulations predict an expanding sudden oak death (SOD) infestation that will likely encompass most of northwestern California and warrant treatment, removal, and replacement of more than 10 thousand oak trees with discounted cost of $7.5 million. In addition, we estimate the discounted property losses to single family homes of $135 million. Expanding the land base to include developed land outside as well as inside communities doubles the estimates of the number of oak trees killed and the associated costs and losses. The predicted costs and property value losses are substantial, but many of the damages in urban areas (e.g. potential losses from increased fire and safety risks of the dead trees and the loss of ecosystem service values) are not included.     

对羟基苯甲酸酯雌激素活性物种差异的理论研究

受体功能区结构的分化是导致部分环境污染物内分泌干扰效应种间选择性的主要原因之一.本研究采用同源模建的方法构建了青鳉的雌激素受体α亚型(medERα)配体结合区的三维结构,并与人的hERα结构进行比对.在此基础上,经过分子对接分析了对羟基苯甲酸酯类化合物及其含氯衍生物与两个物种ERα作用模式的差异及其分子基础,并基于此提...     

白水江国家自然保护区野生中药材资源现状研究——基于保护区白马河保护站管辖区的实地调查

通过实地考察、问卷调查和半结构式访谈,对白水江国家自然保护区白马河保护站管辖区的野生中药材资源现状进行了研究.结果表明,项目区共有野生中药材88种,隶属于39科82属,主要采集种有14种,其中社区居民经常采集的有10种.这10种中药材的蕴藏量在2006-2010年间呈下降趋势,但下降幅度在减小;采集量和交易量逐年下降,而收购价格则逐年攀升.     

Using classification trees to analyze the impact of exotic species on the ecological assessment of polder lakes in Flanders, Belgium

Polder lakes in Flanders are stagnant waters that were flooded by the sea in the past. Several of these systems are colonized by exotic species, but have hardly been studied until present. The aim of the present study was: (1) to assess the influence of exotic macrobenthic species on the outcome of the Multimetric Macroinvertebrate Index Flanders (MMIF) and (2) to use classification trees for evaluating to what extent physical-chemical characteristics affect the presence of exotic species.In total, 27 mollusc and 10 macro-crustacean species were present in the monitored lakes of which respectively five and four were exotic. The exclusion of the exotic species from the MMIF resulted in a significant decline of this ecological index (−0.03 ± 0.04; p = 0.00). This elimination often resulted into a lower ecological water quality class and more samples were classified into the bad and poor ecological water quality classes.Single-target classification trees for Gammarus tigrinus and Potamopyrgus antipodarum were constructed, relating environmental parameters and ecological status (MMIF) to the occurrence of both exotic invasive species. The major advantages of using single-target classification trees are the transparency of the rule sets and the possibility to use relatively small datasets. However, this classification technique only predicts a single-target attribute and the trees of the different species are often hard to integrate and use for water managers. As a solution, a multi-target approach was used in the present study. Exotic molluscs and crustaceans communities were modelled based on environmental parameters and the ecological status (MMIF) using multi-target classification trees. Multi-target classification trees can be used in management planning and investment decisions as they can lead to integrated decisions for the whole set of exotic species and avoid the construction of many models for each individual species. These trees provide general insights concerning the occurrence patterns of individual crustaceans and molluscs in an integrated way.     

An island biogeography approach for understanding changes in compositional similarity at present scenario of biotic homogenization

Local extinction of native species and colonization of non-native species are commonly invoked as responsible for changes in species similarity among biotas of different regions. In this study we used a model of species similarity between islands to assess the emergent, and unexplored, effects of changes in colonization by native species, extinction of non-native species, and propagule pressure on species similarity among insular communities. The model predicts that extinction probability of endemic species has a positive but asymptotic effect on species similarity, which is exacerbated by increasing colonization and reducing extinction of non-native species. Species similarity tends to increase with increasing colonization probability by non-native species, however this effect may be reduced, or even reverted, when the islands are exposed to an elevated number of non-native species that are prone to extinction, high levels of endemic species loss, and an initially large number of native species shared between islands. Species similarity was positively affected by the propagule pressure rate of non-native species only when their colonization and extinction probabilities were large and small enough, respectively. A negative effect of propagule pressure rate can be caused by an increase in the pool size of non-native species, which involves the introduction of different species into different islands, promoting biotic differentiation between islands. Our results indicate that the interactions between colonization, extinction and species pool lead to nonlinear responses and unexpected scenarios of biotic change. In order to validate model predictions, future research programs should focus on understanding the dynamics on such complex meta-communities where coexist native, non-native and endemic species.     

Translating effects of inbreeding depression on component vital rates to overall population growth in endangered bighorn sheep

Evidence of inbreeding depression is commonly detected from the fitness traits of animals, yet its effects on population growth rates of endangered species are rarely assessed. We examined whether inbreeding depression was affecting Sierra Nevada bighorn sheep (Ovis canadensis sierrae), a subspecies listed as endangered under the U.S. Endangered Species Act. Our objectives were to characterize genetic variation in this subspecies; test whether inbreeding depression affects bighorn sheep vital rates (adult survival and female fecundity); evaluate whether inbreeding depression may limit subspecies recovery; and examine the potential for genetic management to increase population growth rates. Genetic variation in 4 populations of Sierra Nevada bighorn sheep was among the lowest reported for any wild bighorn sheep population, and our results suggest that inbreeding depression has reduced adult female fecundity. Despite this population sizes and growth rates predicted from matrix-based projection models demonstrated that inbreeding depression would not substantially inhibit the recovery of Sierra Nevada bighorn sheep populations in the next approximately 8 bighorn sheep generations (48 years). Furthermore, simulations of genetic rescue within the subspecies did not suggest that such activities would appreciably increase population sizes or growth rates during the period we modeled (10 bighorn sheep generations, 60 years). Only simulations that augmented the Mono Basin population with genetic variation from other subspecies, which is not currently a management option, predicted significant increases in population size. Although we recommend that recovery activities should minimize future losses of genetic variation, genetic effects within these endangered populations-either negative (inbreeding depression) or positive (within subspecies genetic rescue)-appear unlikely to dramatically compromise or stimulate short-term conservation efforts. The distinction between detecting the effects of inbreeding depression on a component vital rate (e.g., fecundity) and the effects of inbreeding depression on population growth underscores the importance of quantifying inbreeding costs relative to population dynamics to effectively manage endangered populations.     

一座南亚热带中富营养水库夏季浮游植物群落的稳态平衡分析

于2009年7月23日~9月12日(共8周)研究了广东省大沙河水库湖泊区表层5 m水柱浮游植物群落结构和演替过程及其环境影响因子.降雨明显分为二个阶段,前4周降雨丰富,后4周降雨稀少;水体的透明度与水温也相应地分为二个阶段,但营养盐水平没有明显的变化.平均N/P为33,而可溶解磷浓度很低,说明浮游植物的生长受磷的限制较为强烈.浮游植物种类分析中共检到藻类64种,生物量变化为0.95~2.03 mg L-1,主要由绿藻、甲藻和蓝藻组成.1~5周浮游植物的总生物量变化较大,后3周总生物量变化相对较小.在整个采样期间,光角角星鼓藻(Staurastrum muticum)为第一优势种,弯曲角星鼓藻藻(Staurastrum inflexum)为第二优势种(二者约占总生物量的70%);在1~5周第三个优势种的种类和生物量有较大的变化,6~8周第三优势种为飞燕角甲藻(Ceratium hirundinella)且前3个优势种的组成和生物量较稳定(共占到总生物量的80%以上),群落结构处于稳态平衡状态.降雨带来的干扰是影响浮游植物群落稳态平衡的主要因子.当降雨的干扰结束后,浮游植物之间通过1周左右的竞争,浮游植物群落达到稳态平衡.