The Life-System Approach: A System Paradigm in Population Ecology

The life-system concept is a promising theoretical base for the system's approach to population ecology. A revision of the principles of this concept is proposed. To explain population dynamics I examine how quantitative characteristics of its pattern depend on the structure of the life-system. Two aspects of regulation in populations are distinguished : m- and v-stability. The first concerns the stability of the mean value of population density, while the second concerns the stability of density variance. They are characterized by coefficients of m- and v-stability. The contribution of ecological processes and their interactions to these coefficients represents their regulative role in population dynamics. The importance of process interactions is demonstrated using a simulation model of the common pine sawfly Diprion pini L