Dealing with the “Mixed Units” Problem in Ecosystem Network Analysis

Abstract

Ecology is often defined as the study of the relationships between organisms and their environment. The quantitative analysis of interconnections between species and their abiotic environment has therefore been a central issue. The mathematical analysis of interconnections is also important in several other fields. Practical quantitative analysis of interconnections in complex systems began with the economist Wassily Leontief (1941) using what has come to be called Input-Output (I-O) Analysis. More recently, these concepts, sometimes called Flow Analysis, have been applied to the study of interconnections in ecosystems (Hannon 1973, 1976, 1979, 1985a,b,c; Costanza & Neill 1984). Related ideas were developed from a different perspective in ecology, under the heading of Compartmental Analysis (Barber et al. 1979, Patten & Finn, 1979; Funderlic & Heath, 1971; Hett & O’Neill, 1971). We refer to the total of all variations of the analysis of ecological or economic networks as Network Analysis (See Field et al. 1989, Chapter 1 of this volume for distinctions among the various forms of network analysis).