宏观生态环境动态监测实践--以内蒙古敖汉旗为例

从70年代后期开始,敖汉旗政府和人民开展以植树造林为主的生态环境建设措施,到90年代生态环境已得到明显改善.文章利用RS、GIS技术结合当地政府的统计资料和实测资料分析了生态环境的变化和当地政府建设生态环境的成功经验.     

PFOS/PFOA环境污染行为与毒性效应及机理研究进展

全氟辛烷磺酰基化合物（PFOS）和全氟辛酸（PFOA）是一类新型的持久性有机污染物（POPs）,近年来发现在环境系统中日益广泛分布,并在生物体内蓄积或发生致毒效应.本文首先从PFOS/PFOA在环境中的污染及其水平、在野生动物体内的暴露、对人体的暴露以及污染与暴露变化趋势等4个方面,分析了PFOS/PFOA最新的环境污染与生物暴露情况;从PFOS/PFOA在大气环境中的转运转化过程、在污水污泥中转运转化过程以及在生物体内的蓄积、代谢转化与降解过程等3个方面,阐述了PFOS/PFOA在环境中的迁移转化行为;还概述了最近几年在PFOS/PFOA所导致的生态效应及其可能的机理研究进展.最后,尝试性地提出了今后在PFOS/PFOA污染生态学方面的研究重点.     

Documenting Loss of Large Trophy Fish from the Florida Keys with Historical Photographs

Abstract:  A loss of large vertebrates has occurred in aquatic and terrestrial ecosystems, but data to measure long-term population changes are sparse. Historical photographs provide visual and quantitative evidence of changes in mean individual size and species composition for groups of marine fish that have been targeted by sport fishing. I measured such trends for 13 groups of recreationally caught "trophy" reef fish with photographs taken in Key West, Florida, from 1956 to 2007. The mean fish size declined from an estimated 19.9 kg (SE 1.5) to 2.3 kg (SE 0.3), and there was a major shift in species composition. Landings from 1956 to 1960 were dominated by large groupers ( Epinephelus spp.), and other large predatory fish were commonly caught, including sharks with an average length of just <2 m. In contrast, landings in 2007 were composed of small snappers ( Lutjanus spp. and Ocyurus chrysurus ) with an average length of 34.4 cm (SE 0.62), and the average length of sharks declined by more than 50% over 50 years. Major declines in the size of fish caught were not reflected in the price of fishing trips, so customers paid the same amount for a less-valuable product. Historical photographs provide a window into a more pristine coral reef ecosystem that existed a half a century ago and lend support to current observations that unfished reef communities are able to support large numbers of large-bodied fish.     

A bunch of tiny individuals—Individual-based modeling for microbes

The individual-based (aka agent-based) approach is now well established in ecological modeling. Traditionally, most applications have been to organisms at higher trophic levels, where the importance of population heterogeneity (intra-population variability), complete life cycles and behavior adapted to internal and external conditions has been recognized for some time. However, advances in molecular biology and biochemistry have brought about an increase in the application of individual-based modeling (IBM) to microbes as well. This literature review summarizes 46 IBM papers for bacteria in wastewater treatment plants, phytoplankton in ocean and inland waters, bacteria in biofilms, bacteria in food and other environs, and “digital organisms” and “domesticated computer viruses” in silico. The use of IBM in these applications was motivated by population heterogeneity (45%), emergence (24%), absence of a continuum (5%), and other unknown reasons (26%). In general, the challenges and concepts of IBM modeling for microbes and higher trophic levels are similar. However, there are differences in the microbe population dynamics and their environment that create somewhat different challenges, which have led to somewhat different modeling concepts. Several topics are discussed, including producing, maintaining and changing population heterogeneity (different life histories, internal variability, positive feedback, inter-generation memory), dealing with very large numbers of individuals (different up-scaling methods, including representative space vs. super-individual, number vs. biomass based, discrete vs. continuous kinetics, various agent accounting methods), handling space, simulating interactions with the extracellular environment (hybrid Eulerian–Lagrangian approach), modeling agent–agent interaction (self-shading, predation, shoving) and passive transport (random walk with spatially variable diffusivity, well-mixed reactors). Overall, the literature indicates that the application of IBM to microbes is developing into a mature field. However, several challenges remain, including simulating various types of agent–agent interactions (formation and function of colonies or filaments, sexual reproduction) and even smaller individuals (viruses, genes). Further increases in intracellular detail and complexity in microbe IBMs may be considered the combination of systems biology and systems ecology, or the new field of systems bioecology.     

Simulating population variation and movement within fragmented landscapes: An application to the gopher tortoise (Gopherus polyphemus)

As the human activity footprint grows, land-use decisions play an increasing role in determining the future of plant and animal species. Studies have shown that urban and agricultural development cannot only harm species populations directly through habitat destruction, but also by destroying the corridors that connect habitat patches and populations within a metapopulation. Without these pathways, populations can encounter inbreeding depression and degeneration, which can increase death rates and lower rates of reproduction. This article describes the development and application of the FRAGGLE model, a spatial system dynamics model designed to calculate connectivity indices among populations. FRAGGLE can help planners and managers identify the relative contribution of populations associated with habitat patches to future populations in those patches, taking into account the importance of interstitial land to migration success. The model is applied to the gopher tortoise (Gopherus polyphemus), a threatened species whose southeastern U.S. distribution has diminished significantly within its native range due to agricultural and urban development over the last several decades. This model is parameterized with life history and movement traits of the gopher tortoise in order to simulate population demographics and spatial distribution within an area in west-central Georgia that supports a significant tortoise population. The implications of this simulation modeling effort are demonstrated using simple landscape representations and a hypothetical on land-use management scenario. Our findings show that development resulting in even limited habitat losses (10%) may lead to significant increases in fragmentation as measured by a loss in the rate of dispersions (31%) among area subpopulations.     

渭河谷地的气候干暖化与未来趋势

根据渭河谷地代表测站３２ａ气象实测资料,应用线性回归与趋势分析方法,分析了该区冬春变暖、秋春变干的干暖特征,即５城市平均年增温０．００６４℃,年均减少降水０．１２４８ｍｍ;气候干暖化,尤其以冬春季增温明显,春秋季变干显著,预测该地区未来５ａ的气候仍以士暖化为特点,预计到２００１ａ可能增温０．２℃,年降水减少３０ｍｍ。     

珠海生态示范区可持续发展的制约因素及对策

本文从国土资源、生态、经济、社会四个方面论述了珠海生态示范区可持续发展的制约因素,同时提出了珠海生态示范区实施可持续发展的对策     

四川洪雅县农业气候资源的开发利用

农业气候资源的开发利用既包括农业气候资源在时间、空间和强度上的充分利用,也包括农业生态气候工程建设。从洪雅县农业气候资源的特点和农业生产的实际出发,作者探讨了该县农业气候资源开发利用的途径和方式,为该县农业生产提供了理论依据。     

长江上游流域生态与可持续发展对策

概述了长江上游流域生态环境退化的现状和急需解决的问题,分析了生态环境退化的人为驱动因素和生态建设存在的问题,在此基础上提出了将长江上游作为一个流域整体进行跨地区、跨部门、跨学科的大联合攻关,强调“快速、经济、参与”为指导思想和原则,突出重点生态类型区域,开展关键技术试验示范攻关,发展以资源导向为主的区域经济,从而实现“近期遏制恶化,中期治理恢复,最终持续发展”的分阶段目标。