Analisis de sistemas y ecologia

Systems Analysis and Ecology Author(s): M. B. Dale Source: Ecology, Vol. 51, No. 1 (Jan., 1970), pp. 2-16 Published by: Ecological Society of America Stable URL: http://www.jstor.org/stable/1933596 . Accessed: 06/01/2011 15:34
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SYSTEMS ANALYSIS

AND ECOLOGY'

M. B. DALE2 School of Natural Resources, University of Michigan, Ann Arbor,Michigan
Abstract. Systems analysis is defined as the use of scientific method with conscious regard for the complexity of the object of study. It has strong relationships with problem solving, in that the same four phases-lexical, parsing, modelling, and analysis-are identifiablein both. Examination of each of these phases reveals some of the problems involved in the use of systems methods inecology. A model of a precipitation-evaporationsystem is presented as an example. Problems in experimenting with models of systems and with control, optimization, and comparisonof such models are considered.
INTRODUCTION SYSTEMS ANALYSIS, SYSTEMS, ECOSYSTEMS AND

Systems analysis has been presented as a desirable framework on which the investigation and comparison of ecosystems can be hung. Thisapproach has been especially emphasized by the productivity subgroups of the International Biological Program (IBP). Claims of the importance of systems analysis are not restricted to ecology, for in other fields the results of employing these methods have been claimed to give additional insight and clarity (see e.g. Halmos and Vaughan 1950, Bush and Mosteller 1955, Glanzer and Glaser 1959, Orcutt1960, Harary and Lipstein 1962, Keeney, Koenig and Zemach 1967). Examples of explicit use of systems methods in ecology are few (Olson 1963, Patten 1965, Holling 1966, Watt 1968), and it is by no means clear from these examples what systems analysis is, what it does, what restrictions it imposes, nor how the variety of ecology (or more precisely ecological methodology) can be attached to thisframework. This paper attempts to clarify some of the questions an ecologist must answer and the problems he must resolve before using systems methods, and to introduce some of these methods in the context of a general systems approach. It does not provide the mathematical, statistical, and other details of the use of the methods, although it is hoped that sufficient references are included to enable theinterested ecologist to obtain this information. Necessary definitions are provided and the general nature of systems considered. The relationship between systems analysis and problem solving is established, and the ecosystem is examined in the framework of the problem-solving processes. An example of a systems model is presented and the problems of investigating and manipulating systems and of...