A MATLAB® function for Network Environ Analysis

Network Environ Analysis is a formal, quantitative methodology to describe an object's within system “environ”ment [Patten, B.C., 1978a. Systems approach to the concept of environment. Ohio Journal of Science 78, 206–222]. It provides a perspective of the environment, based on general system theory and input–output analysis. This approach is one type of a more general conceptual approach called ecological network analysis. Application of Network Environ Analysis on ecosystem models has revealed several important and unexpected results [see e.g., Patten, B.C., 1982. Environs: relativistic elementary particles or ecology. American Naturalist 119, 179–219; Patten, B.C., 1985. Energy cycling in the ecosystem. Ecological Modelling 28, 1–71; Fath, B.D., Patten, B.C., 1999a. Review of the foundations of network environ analysis. Ecosystems 2, 167–179], which have been identified and summarized in the literature as network environ properties. To conduct the analysis one needs ecosystem data including the intercompartmental flows, compartmental storages, and boundary input and output flows. The software presented herein uses these data to perform the main network environ analyses and environ properties including unit environs, indirect effects ratio, network homogenization, network synergism, network mutualism, mode partitioning, and environ control. The software is available from The MathWorks MATLAB® Central File Exchange website (http://www.mathworks.com/matlabcentral/fileexchange/loadCategory.do).