太湖不同湖区生态系统健康评价方法研究

基于长期的监测资料,计算了表征湖泊生态系统健康的系统能(Ex)、系统能结构(Exst)和生态缓冲容量(|β|)指标,以及湖泊营养状态指数(Its)。结果表明,太湖不同湖区生态系统健康状况差异明显,1998—2001年太湖典型湖区健康状况由好到差的相对顺序为:东太湖、贡湖和湖心区、梅梁湾、五里湖。在此基础上,提出了富营养化浅水湖泊生态系统健康指标阈值和湖泊系统能量健康指数(IEx)及其健康状况分级。经2002、2003年太湖不同湖区实测检验表明,所提出的湖泊系统能量健康指数及其健康状况分级适用于评价太湖不同湖区生态系统健康的区域分异状况。     

青海湖生态系统健康评价

生态系统健康是一个新概念。对湖泊生态系统来说，目前尚没有统一的评价指标和评价方法。利用Xu等(1999)提出的指标体系对青海湖1988—1989年的生态系统健康状况进行评价。结果表明：青海湖生态系统健康在秋季最好，其次为夏季和春季，冬季最差。该结果客观地反映了青海湖的实际情况。     

微囊藻毒素在太湖白鲢体内的累积规律及其影响因素

太湖蓝藻水华及其次级代谢产物微囊藻毒素(MCs)的生物累积对生态系统和人体健康造成严重威胁,已成为最近环境科学研究的热点。本研究从太湖的不同区域(梅梁湖、西部沿岸区、南部沿岸区和湖心区)采集不同体重和体长的白鲢,利用固相萃取方法提取、高效液相色谱-质谱联用仪测定了白鲢不同器官中MCs的3种异构体MC-RR、MC-YR及MC-LR的含量,结合不同湖区的相关水质指标分析了MCs在白鲢体内的累积规律及其影响因素。研究结果表明:白鲢不同器官MCs的含量由高到低为:肠壁肾脏肝脏肌肉心脏,且肠壁累积的MCs显著高于肾脏、肝脏、肌肉和心脏。MC-RR含量是白鲢各器官累积MCs的异构体的主体,约占MCs的60%。梅梁湖鲢鱼的肌肉、肾脏和心脏中MCs均高于西部沿岸区、南部沿岸区和湖心区。生物指标(体重和体长)是影响白鲢肾脏内MCs和MC-RR含量以及肠壁内MCs含量重要因素。太湖水质指标总磷(TP)、藻细胞数量、湖泊营养指数及环节动物数量尤其是TP对白鲢肝脏累积MCs产生明显影响,TP、总氮(TN)、铵态氮(NH4-N)、内梅罗指数和环节动物数量尤其是NH4-N对肠壁累积MCs产生明显影响。     

太湖站湖泊生态系统动态监测数据库的建立与管理

太湖站是研究湖泊生态系统的一个生太研究网络站，它观测 和记录了长期大量的第一手资料。由于缺乏数据的有效管理，数据长期以来没得到充分整理和应用。根据中国生态研究网络（CERN）关于建立统一的动态监测数据库的要求，太湖站建立了湖泊生态系统动态监数据库，以便有效地管理数据。本文主要就动态监测数据库的建立和数据的管理做一介绍。     

不同外源氮素对西湖湖区藻类生长的影响

正自Science上报道了太湖由于营养盐超负荷引起的蓝藻水华对水生生态系统的破坏和人类健康的威胁后[1],中国淡水湖泊的富营养化问题成为水环境领域的研究热点之一.西湖作为杭州地标之一,其生态系统平衡的维护关乎区域的可持续发展.本文针对西湖富营养化问题,通过对杭州西湖4个湖区(西湖、岳湖、北里湖和西里湖)氮、磷化学形态和叶绿素分布的分析,结合人工气候室的模拟研究,探索外源氮素输入对西湖优势藻类生长的影响,揭示不同外源氮素(NH+4和NO-3)对西湖各湖区藻类生物量的调控.     

海门市蛎岈山牡蛎礁海洋特别保护区生态系统健康评价

在分析海门市蛎岈山牡蛎礁海洋特别保护区海域生态系统现状及特点基础上,构建了包含环境、结构、稳定性3个方面24个指标的海洋特别保护区生态系统健康评价指标体系,并采用熵权综合指数模型和模糊综合评价模型对保护区的生态系统健康状况进行评价及对比分析。熵权综合指数法评价结果表明,保护区生态系统处于健康趋向亚健康的状态;熵权模糊综合模型评价结果表明,保护区生态系统处于健康状态。由于模糊综合评价模型能反映保护区各生态要素的健康状况,其评价结论更趋近于保护区客观现状,更适用于海洋保护区健康评价。     

湖北省湖泊大型底栖动物群落结构及水质生物学评价

大型底栖动物是湖泊生态系统的重要生物类群,在生态系统物质循环和能量流动中起着重要作用。底栖动物具有生命周期长、迁移能力较弱、对环境变化反应敏感等特点,可有效指示湖泊生态系统的健康状况。湖北省是我国淡水湖泊分布最密集的区域之一,湖泊总面积为3025 km2。近年来,伴随着工农业、养殖业及城市化的快速发展,富营养化已成为本地区湖泊面临的一个主要环境问题,并可能直接影响大型底栖动物的群落结构。目前关于本地区湖泊大型底栖动物群落的研究还较少,为此本研究对湖北省27个浅水湖泊底栖动物进行了调查,并对水质状况进行生物学评价。共采集到底栖动物40种,隶属于4门7纲18科,其中寡毛类5种,摇蚊幼虫16种,软体动物双壳类4种、腹足类8种。霍甫水丝蚓（Limnodrilus hoffmeisteri）、苏氏尾鳃蚓（Branchiura sowerbyi）、花翅前突摇蚊（Procladius choreus）、中国长足摇蚊（Tanypus chinensis）、多巴小摇蚊（Microchironomus tabarui）及铜锈环棱螺（Bellamya aeruginosa）是本地区湖泊最常见的种类。所调查湖泊底栖动物平均密度为32~1243 ind·m-2,其中12个湖泊密度低于200 ind·m-2,摇蚊幼虫和寡毛类对密度的贡献较大,以摇蚊幼虫占优势的湖泊有19个。底栖动物平均生物量为0.034~460.7 g·m-2,生物量低于50 g·m-2的湖泊数量最多（19个）,软体动物占优势的湖泊有16个,摇蚊幼虫和寡毛类占优势的湖泊数量共11个。各湖泊底栖动物物种数为3~14种,Margalef指数为0.71~2.33,Simpson指数为0.69~0.85,Shannon-Wiener为0.78~2.13,Spearman相关性分析结果显示物种丰富度和三种多样性指数与湖泊面积呈显著正相关。BI（Hilsenhoff生物指数）评价结果显示共11个湖泊为一般和轻度污染（6.01~7.44）,中度污染湖泊数量为13个（7.57~8.47）,长湖（8.52）、上津湖（8.65）和玉湖（8.50）处于重污染状态。     

太湖不同湖区无机氮转化潜力

采集太湖梅梁湾和东太湖的水样和积物,在实验室内模拟研究不同湖区水体中溶解性无机氮(DIN)短期内的转化潜力.研究结果表明,太湖藻型湖区(梅梁湾)和草型湖区(东太湖)水体中存在着强烈的硝化作用,NH 4-N和NO3-N含量之间表现出显著的负相关关系(P＜0.05或P＜0.01),NH 4-N质量浓度下降速率为0.08～0.19 mg·L-1·d-1.在同样的试验条件下,藻型湖区硝化速率高于草型湖区.NH 4-N初始浓度越高则硝化速率也越高,不添加外源氮时硝化速率随着时间的推移而逐渐降低.藻型湖区的反硝化作用强于草型湖区.室内模拟试验20 d后,沉积物中TN含量平均下降了3.7%,东太湖水样中平均下降26.7%,梅梁湾平均下降42.2%.湖泊沉积物是进行反硝化作用的重要场所.短期内DIN的转化潜力反映了不同湖区氮素转化速率,也反映了不同生态类型水体对湖泊氮素转化的影响.     

北京西山地区不同林分健康状况比较研究

以不同树种林分健康状况比较研究为切入点,以北京西山地区同一时期的油松×侧柏混交林、油松（Pinus tabulaeformis）林、侧柏（Platycladus orientalis）林和栓皮栎（Quercus variabis）林为研究对象。通过构建林分健康评价指标体系,计算林分综合健康指数,分别对不同林分的健康状况进行了分析和比较,探讨不同林分开展森林健康经营的关键环节,同时也从森林健康的角度说明造林树种选择的重要性。研究结果表明：各林分综合健康指数都为正值但数值都不高,这表明目前各林分都处于健康状态,但对外界扰动反应较为敏感,按健康状况排序：油松×侧柏林0．234〉栓皮栎林0．186〉油松林0．145〉侧柏林0．128;从单个指标看,各林分中都有负值指标出现,由此揭示,对负值指标的调整和增加正向指标的指标值是森林健康经营的关键。     

不同水质对沉水植物马来眼子菜主要生理指标的影响研究

沉水植物生理指标能反映其生长的环境条件变化,建立二者的关系对认识沉水植物衰退机理以及湖泊生态系统修复具有重要的意义。采用原位试验,分析了太湖不同营养状态条件下马来眼子菜(Potamogeton wrightii Morong)叶片内叶绿素含量、过氧化物酶(POD)活性以及游离脯氨酸(PRO)含量的差异,初步探讨了马来眼子菜叶片内主要生理指标对水质的响应机理。结果表明:(1)马来眼子菜分布的不同湖区间水质理化因子、综合营养状态指数(TLI)存在显著的空间差异,马来眼子菜主要生长于中营养水质或富营养状态下;(2)太湖马来眼子菜叶片内主要生理指标存在显著空间差异,其叶绿素、POD与TLI呈显著二次多项式回归关系,中营养水平下,除游离脯氨酸外,其他生理指标均与TLI呈显著相关;(3)中营养水平下,马来眼子菜叶片内各生理指标与水质理化因子之间表现为显著相关性,且与TN、TP及COD_Mn关系最为密切。本试验表明,马来眼子菜比较适合中营养水质条件,水体氮磷浓度、高锰酸盐指数对马来眼子菜的生理影响较大。     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.     

Effects of Coffee Management on Deforestation Rates and Forest Integrity

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km² around Bonga and 3000 km² in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.