Plant Population Biology: An Overview

Abstract

Population biology is a synthetic discipline that makes predictions regarding the adaptive behavior of plants through the formulation of models or hypotheses. Four main kinds of models in population biology are recognized: functional models, optimality models, growth models, and compartment models. Profitable areas for future research are indicated. Population biology is a synthetic discipline with the aim of understand- ing the mechanisms that govern the growth and reproduction of individuals and populations in order to be able to make predictions regarding future states under normal or abnormal environmental conditions. Its domain includes areas that until recently were considered to belong exclusively to the classical disciplines,of genetics, physiology, ecology, and systematics- such as gene frequency and its change in populations (genetics), energy harvesting and carbon allocation (physiology), interactions of individuals and populations in space and time (ecology), and characteristics of the life cycle (systematics). The final goal of population biology is to understand how an individual, a population, and a community function. According to Heslop-Harrison (1964) population biology makes the following propositions: 1) wide ranging species show variation over space in morphological and physiological characteristics; 2) much of this variation can be correlated with habitat differences; 3) much of this variation has a genetical basis; and consequently 4) that part of the variation that is corre- lated with habitat and that has a genetical basis is due to the action of natural selection in molding locally adapted populations from the pool of genetical variation available to the species as a whole.