The antarctic cryptoendolithic ecosystem: Relevance to exobiology

Cryptoendolithic microorganisms in the Antarctic desert liver inside porous sandstone rocks, protected by a thin rock crust. While the rock surface is abiotic, the microclimate inside the rock is comparatively mild. These organisms may have descended from early, pre-glaciation Antarctic life forms and thus may represent the last outpost of life in a gradually deterorating environment. Assuming that life once arose on Mars, it is conceivable that, following the loss of water, the last of surviving organisms withdrew to similar insulated microenvironments. Because such microscopic pockets have little connection with the outside environment, their detection may be difficult. The chances that the Viking lander could sample cryptoendolithic microorganisms in the Antarctic desert would be infinitesimal.     

五氯酚在土壤生态系统中的环境行为研究进展

五氯酚在世界范围内广泛使用,在曾经使用过五氯酚的国家和地区的土壤和沉积物可以检测到五氯酚的残留,甚至残留五氯酚可通过食物链危及人类健康。综述了五氯酚在土壤生态系统中的吸附机制与影响因素、化学降解、生物降解及其影响因素、生物富集、生态毒理机理和效应。同时结合目前国内外的研究现状,提出了五氯酚在土壤生态系统中环境行为新的研究方向。     

A study of enzyme polymorphism in the antarctic amphipod Paramoera walkeri Stebbing

Summary Studies concerning the evaluation of the genetic structure and the mechanisms of genetic adapation to the Antarctic environment were carried out on two population samples (A and B) of the amphipod Paramoera walkeri Stebbing collected in two different areas of the Terranova Bay during the Italian Antarctic Expedition 1987/1988. The analyses of the level of genetic variability were conducted on starch gel. The electrophoretic results on the twenty two loci examined reveal a very low amount of genetic polymorphism in both populations with an average observed heterozygosity of 0.6% in population A and 0.7% in population B. The two populations can be considered part of a single breeding unit on the basis of the Student test for paired observations since the differences in single-locus heterozygosity for seven polymorphic loci are not significant (P>0.70). A possible explanation of the observed low genetic polymorphism is discussed in terms of genetic adaptation, as suggested by some results obtained in studies on enzyme activity carried out at the level of the PGI locus.     

海洋生态环境污染研究概况

阐述了海洋生态环境污染的来源和危害,探讨其解决方法。     

环境科学国际合作的理论机制研究

迄今科学界尚无形成系统的国际科学合作理论,也鲜有就环境科学国际合作进行理论研究。首次从全球资源配置的角度来看待环境科学国际合作。通过国际合作,环境科学在内在科学动力和外在社会动力的驱动下,促使全球科学资源和社会资源向有利于环境学科自身发展的方向流动和积聚。其中,配置科学资源遵循"最优要素选择原则",配置社会资源遵循"最小省力原则",两种内在动力和两个调节手段共同构成了环境科学国际合作的理论机制。     

Methodological challenges in assessing the environmental status of a marine ecosystem: case study of the Baltic Sea

Assessments of the environmental status of marine ecosystems are increasingly needed to inform management decisions and regulate human pressures to meet the objectives of environmental policies. This paper addresses some generic methodological challenges and related uncertainties involved in marine ecosystem assessment, using the central Baltic Sea as a case study. The objectives of good environmental status of the Baltic Sea are largely focusing on biodiversity, eutrophication and hazardous substances. In this paper, we conduct comparative evaluations of the status of these three segments, by applying different methodological approaches. Our analyses indicate that the assessment results are sensitive to a selection of indicators for ecological quality objectives that are affected by a broad spectrum of human activities and natural processes (biodiversity), less so for objectives that are influenced by a relatively narrow array of drivers (eutrophications, hazardous substances). The choice of indicator aggregation rule appeared to be of essential importance for assessment results for all three segments, whereas the hierarchical structure of indicators had only a minor influence. Trend-based assessment was shown to be a useful supplement to reference-based evaluation, being independent of the problems related to defining reference values and indicator aggregation methodologies. Results of this study will help in setting priorities for future efforts to improve environmental assessments in the Baltic Sea and elsewhere, and to ensure the transparency of the assessment procedure.     

锶同位素在森林生态系统研究中的进展

放射性成因锶同位素(87Sr/86Sr)作为一种有效的示踪工具,对理解陆相生态系统结构有极其重要的作用.而非传统稳定同位素δ88/86Sr可以揭示以前所忽略的阳离子在植被中的迁移过程.本文对锶元素在森林生态系统中的循环过程以及定量计算方法进行了综述,阐明了利用放射性成因锶同位素87Sr/86Sr在低温地表迁移过程中不分馏的特性示踪物质来源以及循环途径,利用非传统稳定锶同位素δ88/86Sr来示踪生态系统中生物分馏过程,以及锶元素在植被中的内循环机理,总结采用锶同位素在环境响应和生态系统演化的应用.指出非传统稳定锶同位素与放射性成因锶同位素联立应用将是其在陆地生态系统研究中的发展方向.     

Monitoring environmental change in an ecosystem

The monitoring and analysis of the processes taking place in an ecosystem is a key issue for a sustainable human activity. A system of populations, as the biotic component of a complex ecosystem is usually affected by the variation of its abiotic environment. Even in nearly natural ecosystems an abiotic effect like climatic implications of global warming may cause important changes in the dynamics of the population system. In ecosystems involving field cultivation or any industrial activity; the abiotic parameter in question may be the concentration of a substance, changing, e.g. as a result of pollution, application of a pesticide, or a fertilizer, etc. In many cases the observation of the densities of each population may be technically complicated or expensive, therefore the question arises whether from the observation of the densities of certain (indicator) populations, the whole state process of the population system can be uniquely recovered. The paper is aimed at a methodological development of the state monitoring, under the conditions of a changing environment. It is shown, how the technique of mathematical systems theory can be applied not only for the approximate calculation of the state process on the basis of the observed data, even under the effect of an exogene abiotic change with known dynamics; but in certain cases, also for the estimation of the unknown biological effect of the change of an abiotic parameter. The proposed methodology is applied to simple illustrative examples concerning a three-species predator-prey system.     

Predicting ecosystem metaphenome from community metagenome: A grand challenge for environmental biology

Elucidating how an organism''s characteristics emerge from its DNA sequence has been one of the great triumphs of biology. This triumph has cumulated in sophisticated computational models that successfully predict how an organism''s detailed phenotype emerges from its specific genotype. Inspired by that effort''s vision and empowered by its methodologies, a grand challenge is described here that aims to predict the biotic characteristics of an ecosystem, its metaphenome, from nucleic acid sequences of all the species in its community, its metagenome. Meeting this challenge would integrate rapidly advancing abilities of environmental nucleic acids (eDNA and eRNA) to identify organisms, their ecological interactions, and their evolutionary relationships with advances in mechanistic models of complex ecosystems. Addressing the challenge would help integrate ecology and evolutionary biology into a more unified and successfully predictive science that can better help describe and manage ecosystems and the services they provide to humanity.     

Implications of flexibility in European Community environmental law: exemptions from environmental objectives in the Water Framework Directive

The present article is a brief review of the legal characteristics of water quality objectives and legally permissible exemptions from these objectives, as enacted in the EC Water Framework Directive. Six different types of exemptions have been identified in total. These vary markedly in the legal premises of their feasibility, ranging from the set deadlines for the environmental objectives to application of less stringent environmental objectives for certain water bodies.     

A conceptual framework to assess the effects of environmental change on ecosystem services

A new conceptual framework is presented for the assessment of the impacts of environmental change drivers on ecosystem service provision and the policy and management responses that would derive from the valuation of these impacts. The Framework for Ecosystem Service Provision (FESP), is based on an interpretation of the widely-used Drivers-Pressures-State-Impact-Response (DPSIR) framework. FESP differs from the DPSIR by offering clarity in the definitions of the various DPSIR components as well as introducing novel elements of relevance to the ecosystem service approach. The value of a common framework lies in making the comparison across competing services accessible and clear as well as highlighting the conflicts and trade-offs between not only multiple ecosystem services, but also multiple service beneficiaries. The framework is explicit, for example, in recognising as state variables not only the attributes of the Ecosystem Service Providers (ESPs), but also the attributes of the Ecosystem Service Beneficiaries (ESBs). That a service depends as much on the attributes of the people whose well-being benefits from the service as on the attributes of the biology providing the service is an important step in integrated social-ecological thinking. FESP also identifies the mechanisms of either mitigation or adaptation to the environmental change problem through the effect of these response strategies on specific pressure or state variables. In this way, FESP can contribute to the policies and strategies that are used to support conservation management. This paper describes the principles of FESP and presents some indicative examples of its practical implementation.     

Biospheric foundations of the ecosystem approach to environmental management

The ecosystem approach to environmental management inter-relates social, economic and environmental factors. Its incorporation into the Great Lakes Water Quality Agreement of 1978 changed the focus of the Agreement from water in a political context to politics in an ecosystem context. Because ecosystems are open and dependent on Biospheric processes for their continued operation, the Biosphere (global ecosystem) emerges as a globally integrating factor in ecosystem management. Influences leading to development of the ecosystem approach in the Great Lakes Basin included: a politically shared resource in jeopardy, pollution, a common drinking water source, common enemies, advances in ecosystem theory, citizen groups, international political institutions, common economic and cultural ties, and a sense of crisis. A rationale is presented for viewing nations as politically defined ecosystems.     

Anadromous species and the new international law of the sea

Abstract

This article examines the evolution of international law relating to anadromous species, focusing exclusively on salmon and primarily considering the period since World War II. The discussion concerns major international harvesting in the western North Pacific, eastern North Pacific, and the North Atlantic. Unilateral actions are also described. Special attention is given to the relevant articles of the 1982 Convention on the Law of the Sea and to developments since its conclusion. Evidence is assessed for considering that the customary international law of the sea now recognizes the authority of the state of origin of salmon to prohibit high seas harvesting of salmon.