Energy Flow and Feedback Control in Ecological and Economic Food Systems

• Published in: Ecological economics Vol. 156; pp. 91 - 97
• Main Author: Jordan, Carl F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2019
• ISSN: 0921-8009; 1873-6106
• DOI: 10.1016/j.ecolecon.2018.09.015

Feedback loops stabilize energy and nutrient flow in ecological food webs and the ecosystems in which they are embedded. In these feedback loops, flow of energy propels nutrients from autotrophs through food chains to decomposers where the nutrients recycle back to autotrophs. An increase or decrease in ecosystem level flows caused by environmental variations triggers an increase or decrease of the populations that comprise the food webs. Conversely, changes in populations cause proportional changes in ecosystem level flows of energy and nutrients, resulting in stability at a different metastable state. In contrast to ecological systems, economic food systems are inherently unstable because they lack effective feedback control. There is inherent system instability caused by incompatibility between the economic system's need to increase farm yield, and the biophysical controls that limit such increase. Money supply that stimulates economic expansion does not generate feedback that could ensure stability of economic food systems and the farms on which they depend.