生态模型在环境化学中的应用

本文通过总结生态模型在环境化学各个研究领域的应用实例,阐明了生态建模这一研究方法在环境化学理论的发展中所起的促进作用.此外,本文还着重就各种富营养化生态模型进行了比较.详细地追述了它们的建立、应用及改进过程.同时系统地介绍了生态建模的理论及步骤.     

活性污泥动力学模型的建立及在完全混合式污泥系统中的应用

首先建立了微生物衰减系数和污泥浓度、底物浓度的函数关系式,带入Lawrence-McCarty第一方程式得到了Logistic方程形式的微生物生长方程式.在分析污泥泥龄和污泥停留时间关系基础上,引入Monod方程建立了活性污泥动力学模型,推导证明了Lawrence-McCarty方程式是模型静态条件下的表达形式.用建立的活性污泥动力学模型对完全混合式污泥系统进行了模拟,并分析了水力停留时间Hydraulic retention time(HRT)和污泥停留时间Sludge retention time(SRT)对完全混合式污泥系统的影响,表明模型能很好地对活性污泥系统的动态过程进行模拟.根据模型编程画出了污泥系统相关变量关于HRT和SRT变化的三维曲面图,通过编程将复杂模型看作一定输入输出的函数,使得模型更易于应用和推广.     

化学品环境归趋模型及应用

环境归趋模型是化学品管控的重要工具.环境中化学品归趋模型的开发和应用逐渐增多,然而有关应用化学品归趋模拟的模型综述报道较少.本文汇总了目前已用于模拟化学品归趋的模型清单,结合模型结构特点,将化学品归趋模型分为四类:以源排放估算为基础的化学品归趋模型、以环境多介质模型为基础的化学品归趋模型、以水文水质模型为基础的化学品归趋模型及化学品综合管理模型.介绍了模型的基本原理和发展历程,概述了各种模型特点和不同环境条件下模型的应用情况,并进一步探讨化学品归趋模型的应用前景和发展趋势.文章以期为目前化学品归趋模拟研究提供更清晰的现状分析,为化学品归趋模型的选择提供参考.     

生态工业园区生态效率评估方法研究及应用

生态效率兼顾经济效益和环境效益,是定量描述环境和经济系统相互关系的核心指标,是评价生态工业园发展水平的热点.借鉴生态足迹和生态效率的理论,依据生态足迹核算方法,建立了生态工业园生态效率评价模型,并应用该模型对昆山高新区生态效率进行分析.结果显示,昆山高新区生态效率呈逐年上升趋势,限制其提高的主要因素是区内从业人员的生物资源需求以及电子信息行业和除三大主导行业以外的其他行业较低的生态效率.     

河流中的BOD模型及其应用

本文将入流点源或主要支流作为一条新河段 并将分布水源的影响范围视为整条河流,既可避免S—P方程无法反映沿河污染排放态的缺陷.又可解决BOD修正模型计算繁杂的缺陷.建立在此基础上的各种BOD分布模型,具有较好的回归性和可操作性,反映了有机物随时间和空间的迁移转化.这些模式的提出,可为评价和选择污染物控制方案,制订排放标准,提供一个定量的科学依展     

环境中金属生物有效性的预测模型——生物配体模型研究进展

生物配体模型(BLM)是一种用于预测环境中金属生物毒性的机理性模型.模型理论起源于自由离子活度模型(FIAM)和鱼鳃络合模型(GSIM),考虑了自由金属离子的活度以及自然环境存在的其他离子(如Ca2+、Na+、Mg2+、H+)、非生物配体(如可溶性有机质、氯化物、碳酸盐、硫酸盐)和生物配体的竞争.目前,在水生生态系统中,基于鱼鳃络合模型的框架基础,通过生物化学实验手段并结合数学方法,建立了预测铜、锌、银、镍对Rainbowtrout(虹鳟鱼)、Fatheadminnow(黑头呆鱼)和Daphniamagna(水蚤)的急、慢性毒性的BLM版本,并积极探索其在陆地生态系统中的应用.虽然生物配体模型在实验室模拟条件下取得了较为满意的结果,但其中包含着一些假设,在实际应用中还具有一定的局限性,尤其是陆地生态系统生物配体模型的发展还需要做许多研究工作.本文主要论述了生物配体模型的理论基础、实现手段和应用情况,讨论了生物配体模型的优势和局限性并对其未来研究方向进行了展望.     

卤代脂肪烃鱼类急性毒性QSAR模型研究

采用量子化学方法对27个卤代烃化合物进行结构优化和频率分析计算,提取其组成、拓扑、几何、静电和量子化学等结构参数描述符,运用启发式方法筛选最佳的结构参数,并建立黑头呆鱼急性毒性线性回归模型和非线性的支持向量机回归模型.模型方程表明卤代烃化合物导致黑头呆鱼的急性毒性可以应用KH1、IC0、EHOMO-LUMO三个参数解释,几何形状,疏水性能和反应活性是影响鱼类急性毒性的主要因素.两个模型均具有较强的模型稳定性、预测性和可信性,可用于准确预测卤代烃在鱼体内的急性毒性.     

运用QSPR预测有机磷农药的色谱保留值

通过计算43种有机磷农药的各种结构参数,运用多元线性回归分析方法比较了适用于有机磷农药色谱保留值的定量关系表达式,建立了有机磷农药结构参数对色谱保留值的QSPR模型.模型分析表明:磷酸酯与硫逐磷酸酯两类有机磷农药的模型非交叉验证相关系数R2分别为0.991和0.998,标准误差SE分别为0.0539和0.2874,交叉验证相关系数Q2分别为0.976和0.990,标准偏差Scv分别为0.086和0.610.在已知磷酸酯与硫逐磷酸酯两类有机磷农药结构参数的情况下,此模型可有助于有机磷农药的色谱分析.     

面向我国化学物质环境管理的计算毒理学模型评估思路及建设路径

计算毒理学模型正逐渐成为我国化学物质环境管理的重要工具之一.为了推动建立面向我国化学物质环境管理的计算毒理学模型评估方法体系,掌握模型评估核心技术,本文分析了我国发展和评估计算毒理学模型的必要性,总结了我国计算毒理学模型评估的管理需求,系统梳理了美国、欧盟、国际经济合作与发展组织(OECD)的模型评估方法.研究发现,发达国家普遍建立了一套相对完善的计算毒理学模型评估技术,构建了包含模型开发、评估、验证和应用的模型生命周期评估体系.当前,我国尚未建立计算毒理学模型评估技术方法,借鉴发达国家的经验做法,构建具有我国国情特征的计算毒理学模型评估体系,指导我国计算毒理学模型征集与评估工作,具有重要意义.     

钢纤维增强混凝土拉伸本构模型

研究了钢纤维增强混凝土中纤维和基体之间的粘结力特性与拉伸本构关系.首先根据其受力特点提出了几点假设条件,建立了以τ-s曲线和统计理论为基础的钢纤维增强混凝土直接拉伸本构关系模型,该模型考虑到了影响钢纤维增强混凝土断裂性能的基体软化特性和纤维拔出特性,同时将对粘结力特性的研究成果引入到拉伸本构模型,因而使这个模型更加符合实际性状.所得成果对钢纤维混凝土的强度分析、结构设计和工程应用有着重要意义.图3,参2.     

Representation of the world's biophysical conditions by the global protected area network

Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.     

Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators

Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.     

Democracy versus development: New urban debates

The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.     

A framework to measure the wildness of managed large vertebrate populations

As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.     

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     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.     

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.     

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.