Estratégias de reabilitação de áreas degradadas em empreendimentos hidrelétricos na Amazônia, Tucuruí - PA

Abstract

The construction of Tucurui hydroeletric demanded the opening of 15 degraded areas. Of these, nine were flooded by the dam and six stayed submitted to environmental factors, establishment of a continuous process of degradation. In 1998 it was initiate the enlargement of the installed capacity of UHE, opening of new loan area and introduce the Program of Recovery of Degraded Areas (PRAD) to rehabilitate the old areas and to mitigate the impacts in the new areas. Several strategies were developed, and for this study was evaluated the stones used as fauna scape cover and agents inductors of seed dispersion, use of pruning residues and gardening to measure the rehabilitation of degraded area, as the reforestation with different compositions of species. The development of the regeneration was used as bioindicators of the efficiency of the strategies, where the samples were colected using the method of points. The stones induced the formation of an ecosystem differentiated inside of the degraded area and it was constituted in a nucleus of resilience inductor of emerging properties up to 4m of it distances. The use of the residue was evaluated in the fifth year of development and it presented 85 spontaneous species in the rainy season and 48 in the dry season when compared with the control area, with 9 and 8 species, respectively, shown the importance of this technique for activities of rehabilitation of degraded areas in the Amazonia. The reforestations presented differentiated levels of development of the regeneration, proportionate for the different composition of species; the control area after 25 years evidenced incipient levels of vegetable colonization and inertial tendency of degradation.