Ontogenetic States, Effective Density, and Classification of Plant Populations

Uranov (1975) formulated a theory of the age structure of plant populations and, in particular, defined the index of ageness Δ. On the basis of this theory, the concepts of the energy efficiency of plants in a certain ontogenetic state and the average efficiency of a population (ω) are introduced. A new classification of populations with respect to the types of age structure is proposed which is based on both the Δ and ω values and, accordingly, is named the delta-omega classification. The notion of effective population density is defined. This parameter takes into account different "loads" of plants in different ontogenetic states on the environment and is quantitatively equal to the product of the population density and ω. The proposed approaches and methods are illustrated by data on the distribution of age states in different plant species.[PUBLICATION ABSTRACT]