Estrutura e composição de macroalgas de manguezais hipersalinos do Rio Grande do Norte, Brasil: Diversidade e suas correlações com as variáveis ambientais

Abstract

Marine and coastal environments in the world have been facing in the last years a notable environmental degradation process. Macroalgae are the main constituent phytobenthics communities, and they are essentials to the establishment of balance and resilience these ecosystems. The mangroves swamps are coastal environments and may be ecotones, because they are an interposition of continental and marine environments overlap, in scalar patterns. The organisms found have become resistants with the strong transition that occur, such as Bostrychietum macroalgae, where they have formed the most homogeneous communities of mangroves swamps wide world. However, the mangrove swamps typically fall within one of two broad categories of classification: mainland or oceanic island. The mainland mangroves are home biological communities resistants with the strong phisico-chemical variations, and of oceanic island mangroves form on shallow banks or in lagoonal areas well separated from the mainland. In Brazil, mangroves swamps are solely of type mainland, which form the major area these forests in the coastal South America. This ecosystemic pattern is normally associate with fluvial systems – the estuaries, and is combined with many biological disorders, such as salinity and flooding tolerance. The estuarines environments which gives different environments in biological diversity, where can check trait plasticity between population. The estuaries can be classified in three categories: Positives, Low -Inflow and Negatives. Brazilian mangroves there are solely Positives Estuaries where the addition of freshwater river, discharge and thaw exceed the loss by evaporation or freezing, where longitudinal density gradients that drive a net volume output to the ocean. But in semi-arid region, Northeast of Brazil, there are some ecosystemics patterns. The estuarine-mangals show negative characters that are hypersaline and/or reverse, because the flow of freshwater systems are barely making them with a longitudinal density gradient with the opposite sign in relation the positive estuaries and salt concentrations rarely exceed 50. Two rivers (Casqueira and Shark rivers), located in setentrional coast of Rio Grande do Norte state, Macau city, have shown how negatives estuaries (hypersaline and reverse), and are composition species of macroalgae many specific and have a very dynamic environment. A pilot study conducted in April 2010 have been showing one ficoflora visually diverse, that have colonized muddy substrates in great abundance unusually and then resembles those typically found in marine environments typical. To contribute to the scientific knowledge of macroalgae found, this study has as main objective: to do a investigation about composition and structure macroalgae of two hypersaline mangroves, so to observe the effects of hipersalinity and physic-chemical patterns in the dynamics of algal communities. Therefore, this work establishes a comparative relationship between communities and population of seaweeds this environments.