Comunidades vegetais em áreas de degelo na Antártica marítima: revisão e estudo de caso

Abstract

The Terrestrial vegetation in Antarctica is restrict in the ice-free areas,comprised the most part by moss and lichens. The first collections of botanical specimens were made by explorers, only in decades from 1820 to 1830 they start the cientific expeditions for the austral land. James Clark Ross did the fourth circumnavigation (1839/1943) and the more important scientific expeditions in the XIX century with J. D. Hooker, the first professional botanist to visit Antarctica were collected species for lichens and mosses in the Antarctic Peninsula and King George Island. The Antarctic Treaty, signed in 1959, increase the botanical initiatives in the austral region. Brazil was admitted as a consultative member of the Antarctic Treaty in 1983, the creation of the Brazilian Antarctic Program (PROANTAR). At 25 year Brazilian researches working with plant communities in the ice-free areas of Antarctic coordinated for professor phD Antonio Batista Pereira (UNIPAMPA) when developing a significative studies with ecological and taxonomical approaches for terrestrial algae, mosses, liverworts, lichens and macroscopic fungi. The aim of this study was done a review in the literature about the flora and phytosociology reported to Elephant, King George, Nelson and Deception Islands of the South Shetland archipelago, Maritime Antarctica, and to assess evaluating the succession of plant communities in Stinker Point, Elephant Island, from data obtained in phytosociological austral summer of 1991/92 and 2011/12, in order to obtain data that contribute to the environmental impact assessment in this area through indicators such as diversity and vegetation coverage. This study is divided in two parts. The first is a review about the floristic characteristics for the phytossociology data to better understand the interactions of plant species in the South Shetland Islands. Tables listing the species of Antarctic moss, liverwort and lichen found in those islands were showed in this study. For the phytossociological study we used the index to ecological significance for the species found in the studies done in those islands, and for the Stinker Point, Elephant Island, we used the Shannon index, index for the maximum diversity and the index of Pielou. In the second chapter, we done a phytossociology study in Stinker Point, Elephant Island in the austral Summer 2011/12 and this result was compared to the data for the phytossociological study done in the same place during the austral Summer 1991/92 comparing the changes for the communities and the populations. For the first chapter, Sanionia uncinada (Hedw.) Loeske was the specie had more IES in all the places studied. Particularly characteristic for each island as observed in this study. In the second chapter, we related the increase for the areas coverage for the plants communities and the changes in the plant species structure for these communities in the twenty years.