Progress in theoretical vegetation science

Book Review

Progress in theoretical vegetation scienceG. Grabhett, L. Mucina, M.B. Dale and C.J.F. ter Braak (Eds.), Vol 83. Dordrecht: Kluwer Academic Publishers, 1990, 276 pages, £95.00. ISBN 0-7923-0507-1     

Reflections on the phytosociological approach and the epistemological basis of vegetation science

Summary It is tried to identify the logical basis of the phytosociological method. Both the inductive and the deductive approach are discussed. The starting point can be summarized with the axiom vegetation is organized in communities. Some problems related to the use of numerical methods and computers are discussed.This paper was written under the auspices of the Programma finalizzato Qualità dell'Ambiente of the C.N.R. (Roma) Subprogetto 5 Metodologie matematiche e basi di dati. I thank the following people for helpful comments: E. Feoli, D. Lausi, P. Nimis, E. Pignatti Wikus (all at the Istituto Botanico, Trieste), D. Dal Maso (Istituto di Matematica, Trieste), E. van der Maarel (Botanisch Laboratorium, Nijmegen).     

大尺度陆地生态系统科学研究的理论基础及其技术体系之探讨

大尺度的陆地生态系统科学研究是在生物多样性保护、应对全球气候变化、区域生态环境治理及全球社会经济可持续发展的科技需求背景下应运而生的生态学及生态系统科学前沿领域,并在我国的生态文明建设社会实践中快速发展.本文在系统论述大尺度陆地生态系统科学研究的科技使命基础上,重点梳理和探讨了区域及大陆尺度的生态系统科学研究理论基础和...     

The role of expert systems in vegetation science

An area of artificial intelligence known as experts systems (or knowledge-based systems) is being applied in many areas of science, technology and commerce. It is likely that the techniques will have an impact on vegetation science and ecology in general. This paper discusses some of those impacts and concludes that the main effects will be in areas of applied ecology especially where ecological expertise is needed either quickly (e.g. disaster management) or across a wide range of ecological disciplines (e.g. land management decisions). Expert systems will provide ecologists with valuable tools for managing data and interacting with other fields of expertise. The impact of expert systems on ecological theory will depend on the degree to which deep knowledge (i.e. knowledge based on first principles rather than on more empirical rules) is used in formulating knowledge bases.     

鸟类栖息地片段化研究的理论基础

栖息地片段化是导致许多森林鸟类种群下降的主要原因之一,而对栖息地片段化的形成及其影响的研究已是成为鸟类生态学的研究热点之一。介绍了鸟类栖息地片段化研究的理论基础,即岛屿生物地理学理论、景观生态学理论以及集合种群理论等,并阐述了鸟类栖息地片段化研究范式转变的原因。     

Graph theoretical analysis of the phytosociological structure of plant communities: The theoretical basis

Summary A method employing samples of variable size is assumed and shown to be useful in the detection of unidirectional associations of one species with another, whether caused by direct influence or by coincidence of ecological requirements. The pattern of these associations from a signed digraph (directed graph), the graph theoretical properties of which give insight into the phytosociological structure of the plant community. The properties of transitivity, balance, homogeneity, reachable sets and types of subgraphs are examined.From a thesis submitted to the University of Toronto in partial fulfilment of the requirements for the degree of Master of Science.     

Structure of theory in vegetation science

In order to help evaluate progress in vegetation science, we present an outline of the components of theory. Theory has both empirically and conceptually based components, and is tied together by a hierarchical framework. Theory is related to observable phenomena to further the most general goal of science, understanding. More specific tactics to advance understanding include explanation, generalization, and testing. Different components of theory permit the operation of specific tactics. Most components of theory are exemplified by one or more aspects of vegetation science. However, there are some conceptual and empirical components in need of further development. We conclude that vegetation science does in fact conform to the contemporary view of a developing theory, and that this theory can serve as a fruitful guide to research and application of concepts to the field.     

Theoretical vegetation science on the way

Some historical notes are presented on the start and early development of the Working-Group for Data-Processing, now Working-Group for Theoretical Vegetation Science, of the International Association for Vegetation Science. One of the major outcomes of the first period of activities in the Working-Group has been the creation of a phytosociological coding and retrieval system to be used in combination with multivariate methods. One branch of classical phytosociology which could have profited much from the Working-Group's achievements, i.e. syntaxonomy, never developed fully into a numerical syntaxonomy and, in fact, it did not develop much at all over the last 20 yr.The next phase in the development of the Working Group is characterized by a strong emphasis on vegetation dynamics. First, these dynamical studies concentrated on real sequences of data from permanent plots, which were treated with the numerical methods available. Later, dynamical models started to be developed in order to predict succession and other forms of long-term vegetation dynamics, for which real data are not available.The third phase, which has been entered only recently, is characterized by an overall emphasis on vegetation theory, from which both the most appropriate choice of numerical methods in any particular case, and dynamical phenomena can be approached. Moreover, vegetation theory is of fundamental importance for the development of the plant community concept and of vegetation typology.In addition, some remarks are made on the growing need for vegetation ecology to cooperate with experimental ecophysiology and population ecology.     

Explanation and prediction in vegetation science

A definition of vegetation science is given, spanning 6 levels of integration and stressing the interrelations among them. The problems of realism are discussed. The selection of levels is related to the adequate correspondence between conceptualization and research aims. Pattern and process are introduced as the central concepts of vegetation science. The perception of reality is dependent on the spatial and temporal scale chosen. The concept of noise is discussed in relation to stochasticity and randomness of events. Traces of essentialism are found both in classification of communities and habitat ecology. Classification is important, particularly the coexistence of alternative classification approaches. Organicism as a basis of vegetation research is rejected because the organismic view is inadequate on higher integration levels. The concept of function is redefined in a non-teleologic way.Present vegetation ecological research is inductivistic. One possible alternative to inductivism is falsificationism. The major domain of this approach is hypothesis testing, which will become more important. Progress can only be reached by a maximum degree of communication among scientific individuals.Predictive ecology is partly based on historic explanation, partly on complementary approaches. Characters of vegetation worthwhile to be predicted are listed and the necessary requirements for vegetation science to become predictive are discussed. A major requirement is the development of succession and life-history theory. A further elaboration of the individualistic concept will be a main task of vegetation science in the near future.     

The place of the Zürich-Montpellier method in vegetation science

An outline of the various approaches to the study of vegetation is given in historical perspective. Emphasis is laid on the Zürich-Montpellier method which has benefited from the rise of statistical methods in vegetation science. It is argued that the Zürich-Montpellier approach represents a scientifically sound, versatile and efficient classification method in vegetation science.