Symposium Introduction

To maintain the circulation of substances in sitsteme requires stock inorganic molecules in a digestible form, and three functionally different groups

Organisms: producers, consumers and decomposers .

Producers act autotrophic (using as a source for construction of its body inorganic compounds) organisms capable to build their bodies from inorganic compounds. Consumers - is heterotrophic organisms (all living beings in need of organic food origin) that consume organic matter of producers or other consumers and transforming it into new forms. Decomposers live by dead organic matter, converting it into inorganic compounds.

Role consuments perform mainly in the nature of animals, their activity maintain and accelerate the cyclic migration of atoms in complex ecosystems and diverse. In areas where there are, for example, community formed only from the micro-organisms, the cycle of atoms can consuments implemented without the expense of the other two groups.

The scale of the ecosystem in nature is extremely varied. Not the same as the degree closure to keep the animal circulation of matter, ie repeated involving the same atoms in the cycles. As some ecosystems can consider, for example, a pillow of lichens on the trunk of a tree and meadow, and forest, and ocean and the desert, and the entire surface of the Earth, busy lives.