空间分子生态学——分子生态学与空间生态学相结合的新领域

分子标记、基因流、种群空间动态是当前生命科学研究中的热点领域。RFLPs、RAPDs、微卫星等新的分子标记的不断涌现,促进了这些领域的飞速发展。对种群空间动态研究中的等级岛屿模型、距离隔离模型、脚踏石模型、集合种群模型等方面许多令人瞩目的进展做了介绍。同时还介绍了遗传距离、基因流及其测度、基因突变模型、3S技术、空间精确性种群模型和基因频率的空间自相关等热点领域。最后,就空间分子生态学存在的问题与前景进行了讨论,指出了空间分子生态学可能的发展方向。     

An Introduction to Ab-Initio Molecular Dynamics Schemes

Abstract

We present some of the basic concepts and procedures which allow to perform ab-initio molecular dynamics calculations. The emphasis is given on writing the basic density functional theory equations and derive them for plane wave norm conserving pseudo-potential applications. The main features of the conjugate gradient minimisation procedure to access the total energy of periodic systems are presented and a brief conclusive introduction to dynamical calculations is given.     

Microbial Biofilms: from Ecology to Molecular Genetics

Biofilms are complex communities of microorganisms attached to surfaces or associated with interfaces. Despite the focus of modern microbiology research on pure culture, planktonic (free-swimming) bacteria, it is now widely recognized that most bacteria found in natural, clinical, and industrial settings persist in association with surfaces. Furthermore, these microbial communities are often composed of multiple species that interact with each other and their environment. The determination of biofilm architecture, particularly the spatial arrangement of microcolonies (clusters of cells) relative to one another, has profound implications for the function of these complex communities. Numerous new experimental approaches and methodologies have been developed in order to explore metabolic interactions, phylogenetic groupings, and competition among members of the biofilm. To complement this broad view of biofilm ecology, individual organisms have been studied using molecular genetics in order to identify the genes required for biofilm development and to dissect the regulatory pathways that control the plankton-to-biofilm transition. These molecular genetic studies have led to the emergence of the concept of biofilm formation as a novel system for the study of bacterial development. The recent explosion in the field of biofilm research has led to exciting progress in the development of new technologies for studying these communities, advanced our understanding of the ecological significance of surface-attached bacteria, and provided new insights into the molecular genetic basis of biofilm development.     

Restoration Ecology and Invasive Riparian Plants: An Introduction to the Special Section on Tamarix spp. in Western North America

River systems around the world are subject to various perturbations, including the colonization and spread of non‐native species in riparian zones. Riparian resource managers are commonly engaged in efforts to control problematic non‐native species and restore native habitats. In western North America, small Eurasian trees or shrubs in the genus Tamarix occupy hundreds of thousands of hectares of riparian lands, and are the targets of substantial and costly control efforts and associated restoration activities. Still, significant information gaps exist regarding approaches used in control and restoration efforts and their effects on riparian ecosystems. In this special section of papers, eight articles address various aspects of control and restoration associated with Tamarix spp. These include articles focused on planning restoration and revegetation; a synthetic analysis of past restoration efforts; and several specific research endeavors examining plant responses, water use, and various wildlife responses (including birds, butterflies, and lizards). These articles represent important additions to the Tamarix spp. literature and contain many lessons and insights that should be transferable to other analogous situations in river systems globally.