转基因植物环境安全性研究进展

随着转基因植物在全球范围内的广泛种植,其环境安全性问题也日益受到重视。对转基因植物的环境安全性问题进行了综述,主要从转基因植物的杂草化、基因漂移、对非靶标和靶标生物的影响等方面阐述了转基因植物对生态环境的影响。     

Plants and altitude--revisited

The importance of modelling and the integration of all environmentalfactors as they change with time is emphasized in relation tothe evaluation of plant response to altitude.     

Plants Replacing Plants: The Future of Community Modeling and Research

Over the past few decades, several conceptual and mathematical models of plant community organization and dynamics have been put forward. While each of these models has attempted to explain important plant community patterns by attributing them to some aspect of plant niches, or to a higher-level process, their predictive success has been very limited. Here I explore why this has happened by reviewing and summarizing each model individually by highlighting the plant community pattern each is trying to explain and predict, by identifying the mechanisms, tolerances, and/or processes authors propose are producing those patterns and describing how they work within the model, and by examining the assumptions of each model. I then discuss common misconceptions and shortcomings among the models, and finally propose a unifying synthesis and comprehensive framework that can serve as a basis for future plant community modeling and research. This synthesis is composed of three key ideas (1) that plant-plant replacements are the “fundamental process” of plant communities which produce every community-level terrestrial plant pattern, (2) that plants respond to mechanisms and tolerances which work both in spaces inside plants and in those spaces outside plants that influence them and/or they may be able to influence, and (3) that those responses make up plant niches which may be able to predict how plants replace themselves over time and space. Consequently I suggest to future field researchers that the best way to understand plant community patterns is to study plant-plant replacements, first by sampling long-term vegetation plots in order to map them, and then by manipulating mechanisms and tolerances in field experiments in order to understand what causes them.     

Yucatec Maya Medicinal Plants Versus Nonmedicinal Plants: Indigenous Characterization and Selection

Medicinal plants are an important part of the environment as it is perceived by Mexican indigenous groups. The aim of this study, which was conducted over a period of 18 months in three Yucatec Mayan communities, is to better understand the selection criteria for medicinal plants. An important group of selection criteria are the flavor and aroma of plants. The absence of smell or taste indicates that the taxon has no potential medical value. Medicinal plants are more often considered to be sweet or aromatic (to smell good) or astringent, while a similar percentage of medicinal and nonmedicinal plants are considered bitter, spicy, acidic, or bad smelling. The relationship between the ethnobotanical data obtained for the individual plants and the secondary plant products (natural products) prominent in each species is specifically addressed in this paper. It shows that an understanding of the indigenous concepts used to distinguish medicinal from nonmedicinal species has considerable heuristic value.