复合生态系统非线性累积效应响应因子的阈值模型

基于流域系统累积环境效应的产生机理，以系统动力学特征和累积环境效应-反应过程特征曲线为依据，分析了复合生态环境承载力及其适应性，提出并建立了非线性累积效应响应的指标阈值模型及因子响应程度的客观、动态量化方法。模型的建立对系统可持续发展的评估决策具有一定的指导作用。     

Prey odor discrimination by ingestively naive coachwhip snakes(Masticophis flagellum)

Summary Ingestively naive hatchling coachwhip snakes(Masticophis flagellum) detected integumentary chemicals from several potential prey species and discriminated them from chemical stimuli from other animals and from distilled water, strongly suggesting a genetic basis for these abilities. The strongest responses were to lizard and snake stimuli, which form a major part of the diet. Variable responses to chemical cues from other taxa are discussed. Responses by coachwhip snakes to prey chemicals appear to be highly specific, as suggested by the stronger reaction to vomodors of sympatric than of allopatric lizard species. The highly developed use of chemical cues by the diurnal, visually oriented coachwhip snake emphasizes the general importance of chemical senses to predation by nonvenomous snakes, regardless of the involvement of vision.     

Weaning in the guinea pig (<Emphasis Type="Italic">Cavia aperea</Emphasis> f. <Emphasis Type="Italic">porcellus</Emphasis>): Who decides and by what measure?

Offspring should be selected to influence maternal effort to maximize their own fitness, whereas mothers are selected to limit investment in present progeny. In mammals, this leads to a conflict over the amount of milk provided and the timing of weaning. The intensity and time course of such conflict has so far mostly been investigated experimentally in altricial rodents. However, it is expected that offspring options for conflict will depend on developmental state. We therefore investigated in the highly precocial domestic guinea pig (Cavia aperea f. porcellus) who decides over nursing performance and weaning and how pup state influences these decisions. Specifically, we tested whether a threshold mass of pups predicts weaning time. By exchanging older litters against neonates and vice versa, we produced a situation in which females differed in lactational stage from the cross-fostered pups. Our results indicate that females decide about the timing of weaning, as cross-fostered younger pups were weaned at a much younger age than controls and older pups benefited from continuing lactation of foster mothers. Growth rates did not differ in the treatment groups, and different weaning ages resulted in differing weaning mass refuting the hypothesis that weaning is based on a threshold mass of offspring. This constitutes clear evidence that in a precocial rodent, the guinea pig, decisions about maternal care are primarily determined by maternal state and little influenced by pup state despite the extreme precociality of offspring. We suggest that precocial pups show little resistance to early weaning when food is abundant, as they reach sufficient nutritional independence by the middle of lactation to enable independent survival.     

Metapopulation Extinction Risk under Spatially Autocorrelated Disturbance

Abstract:  Recent extinction models generally show that spatial aggregation of habitat reduces overall extinction risk because sites emptied by local extinction are more rapidly recolonized. We extended such an investigation to include spatial structure in the disturbance regime. A spatially explicit metapopulation model was developed with a wide range of dispersal distances. The degree of aggregation of both habitat and disturbance pattern could be varied from a random distribution, through the intermediate case of a fractal distribution, all the way to complete aggregation (single block). Increasing spatial aggregation of disturbance generally increased extinction risk. The relative risk faced by populations in different landscapes varied greatly, depending on the disturbance regime. With random disturbance, the spatial aggregation of habitat reduced extinction risk, as in earlier studies. Where disturbance was spatially autocorrelated, however, this advantage was eliminated or reversed because populations in aggregated habitats are at risk of mass extinction from coarse-scale disturbance events. The effects of spatial patterns on extinction risk tended to be reduced by long-distance dispersal. Given the high levels of spatial correlation in natural and anthropogenic disturbance processes, population vulnerability may be greatly underestimated both by classical (nonspatial) models and by those that consider spatial structure in habitat alone.     

臭气浓度标准的制定方法

本文首先介绍了天津市恶臭污染物排放标准中臭气浓度标准制定的程序、方法、步骤及有关参数确定要素。并将天津市的臭气浓度排放标准与日本、美国及我国台湾省的同类标准进行了分析比较。     

有机物生物降解极限浓度的探讨

讨论了有关有机物生物降解极限浓度（Smin)的定义，介绍了热力学测定方法、动力学测定方法和扩散测定方法等3种测定极限浓度的方法。正确测定有机物生物降解极限浓度对开发微量有机物生物高度净化新技术，寻求提高现有生物处理技术净化效果的途径，污染环境的修复等都具有极其重要的意义。     

Assessing the risk of soil contamination in the Swiss Jura using indicator geostatistics

The probability that the concentrations of toxic substances in soil or other medium exceed tolerablemaxima at any unsampled place can be estimated by indicator geostatistics. The method is developed and used to estimate and map the risk of contamination by cadmium, copper and lead in the topsoil of a 14.5 km 2 region in the Swiss Jura. It combines both direct measurements of metal concentrations and thecalibration of a geological map, and it shows that the risk of toxicity is least on Argovian rocks. Two approaches are proposed to divide a region into safe' and 'hazardous' zones on the basis of probability maps. The first declares as contaminated all places where the risk of contamination exceeds a given threshold. The second approach first evaluates the financial costs that might result from a wrongdeclaration, after which the site is allocated to a class so as to minimize that cost. The risk of exposure for humans and animals is generally greater for contaminated agricultural land than for forest soil, and so land use is taken into account in both procedures.     

富营养化水体中藻类生长限制因素的确定及其应用

在富化营养化的巢湖，围隔实验结果表明磷和其它营养元素不是水体藻类的生长限制因素、藻类生长的正磷酸盐阈值浓度为０．０１９ｍｇ／ｌ，它低于巢湖实际浓度。湖水的矿物性浊度很高，净生产力在一米水深以下呈现负值，数据表明学强在大数时间是藻类生长的限制因素。在巢湖治理过程中，需大幅降低流域内的磷负荷，使湖水平均溶解态总磷浓度从目前的０．０４９ｍｌ／ｌ降到０．０１９ｍｇ／ｌ以下。因此巢湖在治理和恢复是一个缓慢的     

二氧化氯预氧化工艺处理微污染黄河水研究

对二氧化氯预氧化工艺替代预加氯系统处理低温、含异味和较高色度的黄河原水进行了综合研究.与预氯化、混凝沉淀系统相比,二氧化氯预氧化、混凝沉淀系统对藻类的去除率提高了30%～40%,使嗅和味的阈值降低了10～20,但CODmn和氨氮的去除率的变化不明显.由于进水色度变化较大,对色度的去除率变化也不明显.运行证明,该系统改造后对降低以微污染黄河水为水源的北方给水处理厂冬季运行过程中的出水嗅和味的阈值、增加藻类的去除率具有明显的效果,同时,运行费用也较低.     

资源环境承载力评估新视角:行星边界框架的源起、发展与展望

将人类活动规模与强度控制在自然生态系统可承载限度之内,是可持续发展理论的核心要义。行星边界框架所秉持的“地球系统观”,为资源环境承载力评估提供了新视角,一经提出便在国际可持续发展领域引发极大关注与热烈讨论。本文系统阐述了行星边界框架的理论基础及其内涵演进,着重论述了该框架在国家、省域、市域和组织等不同尺度的发展与应用,深入探讨了其面临的挑战与改进方向,并与传统资源环境承载力研究范式进行了比较。研究表明:行星边界框架以复杂系统稳态和突变理论为基础,是历史经验与科学研究有机结合的产物。作为对现有资源环境承载力评估体系的有益补充,该框架由全球尺度向区域尺度拓展时,遵循自上而下分配与自下而上整合两条路径。当前行星边界框架中关于生物物理过程的尺度效应与交互机制的阐述较为薄弱,导致其变量选取与边界设置仍存较大争议,在与环境影响评价相整合、向社会经济维度拓展等方面面临方法学挑战。今后应从理论基础、技术方法、实践应用等方面继续深化研究,提升行星边界框架在可持续发展目标（SDGs）等全球重大公共议题中的政策价值。