Symposium Introduction

The speed with which producers of the ecosystem fix solar energy chemical bonds of the synthesized organic matter, determines productivity community. Organic matter, created by plants for unit time, called primary production community . The production expressed quantitatively in damp or dry weight of plants or energy units - equivalent to the number of joules.

gross primary production - amount of matter created plants per unit time at a given rate of photosynthesis. Part of production goes to the maintenance of life of the plants (spent breathing). This part can be quite large, it ranges from 40 to 70% gross. The rest of the set up of organic matter characterizes net primary production, which represents the amount of growth plants, the energy reserve for consumers and decomposers. Transforming into supply circuits, it goes to replenish the mass of heterotrophic organisms. Growth per unit time mass consumers - this secondary production community . It is calculated separately for each trophic level, because mass increment of Each of them is due to the energy coming from the previous one.

Heterotrophs, including in the food chain, live in the end due net primary production community. In various ecosystems, they spend it with varying completeness. If the rate of primary production in the supply circuits behind growth of plants, it leads to a gradual increase in the total biomass producers. Under biomass refers to the total mass of organisms present group or the community at large. part of the biomass is expressed as equivalent energy units.