Symposium Introduction

Maintaining optimal in these conditions the number is called homeostasis population. homeostatic capabilities populations differently expressed in species. They are implemented through the interaction of individuals.

Thus, the population as a group association, have a number of specific properties that are not inherent to each individual. Group particular - are the main characteristics of the populations. These include:

1) the number - the total number of individuals allocated to the territory;

2) density - the average number of plants per unit area or volume, occupied population of space; population density can be expressed as through the mass of the members of the population per unit area;

3) the birth rate - the number of new individuals that have come out per unit time in result of reproduction;

4) mortality - an indicator reflecting the number of deaths in a population of individuals for a certain period of time;

5) increase in population - the difference between births, an increase can be as positive or negative;

6) growth rate - the average increase per unit time. Populations characterized by a certain organization. Distribution of individuals on territory, the ratio of groups by sex, age, morphology, physiological, behavioral and genetic characteristics reflect the structure population. It is formed on the one hand, on the basis of general biological properties of the form, and on the other - under the influence of abiotic environmental factors and population other species. structure of populations is , therefore, adaptive nature . Different populations of one species have both similar features of the structure and distinctive, characterizing specific environmental conditions in their habitats.