Importância, estrutura e dinâmica da comunidade perifítica nos ecossistemas aquáticos continentais

Abstract

Importance, structure and dynamics of the periphytic community in the freshwater aquatic ecosystem. Periphyton is defined as a complex microorganisms community (algae, bacteria, fungi, animals), organic and inorganic detritus that is attached to dead or living, organic or inorganic substrata. It is constituted as an important food for the trophic chains. The periphytic algae are an excellent bioindicators of the quality of the water and of its trophic state. They also have the capacity to accumulate pollution substances as insecticides, herbicides and fungicides, heavy metals and organic matter. The structure of the periphytic community is represented by the organisms composition and by its architecture. The composition is related to the group of organisms and to the organic and inorganic detritus found in the bioderm. The space arrangement of these components is related the architecture. The colonization process in this community is directly influenced by the environmental parameters. Furthermore, the interespecific competition for food and space also that happen in small scales of time (hours or days).