ESTRUTURA TRÓFICA E COMPOSIÇÃO DA NEMATOFAUNA EM UM ECOSSISTEMA COSTEIRO DE DUNAS

Abstract

Nematodes are abundant metazoans in all ecosystems with some species surviving in extreme conditions. The sand dunes are dynamic systems and are always in a state of successional change in terms of succession and only recently has the distribution and succession of soil animals in coastal dunes been given wider attention. This research focused on to describe the trophic structure of nematode community associated with two stages of a vegetation succession in a coastal moving sand dunes ecosystem in the north shore of the Rio Grande do Norte State. Five sites were classified in two stages of an ecological succession defined as "beach" and "deflation hollows among dunes" where samples of soil, roots and shoots were collected. Nematodes were extracted from the soil by centrifugal flotation procedure and from the roots by this method associated to blender trituration and classified in families and trophic groups according to feeding habits. The structure of nematode fauna was described by maturity index, plant parasite index and modified maturity index and fungal feeders/bacterial feeders and omnivores+predators/bacterial feeders+fungal feeders+plant parasites rates. The ecosystem was characterized by low diversity of families which composed trophic groups, low values of maturity indexes and omnivores+predators/bacterial feeders+fungal feeders+plant parasites ratio and low abundance of dorylaimids. These datas reflected high level of disturbance which this habitat faces.