Diretrizes Técnicas para restauração de áreas degradadas por fogo em remanescentes de Mata Atlântica da Chapada Diamantina, Bahia, Brasil

Abstract

The occurrence of fires in tropical forests have altered the composition and structure of ecosystems through the years. The rising of frequency and its recurrence in the same area lead to a reduction in biodiversity, homogeneity of vegetation, decrease and fragmentation of forest areas and ciliary forest and climatic changes in regional and global scale. In the Chapada Diamantina region, wildfires are frequent during dry season, reaching vast areas, from campestral Cerrado formations, altitude rupestrian fields and Atlantic Forest remnants (Semideciduous Seasonal Forests), associated with important river springs of the state of Bahia. It is up to the government, through its environmental agencies, the enforcement of environmental law in what concerns the reparation of damages caused by fire, regardless the administrative and penal sanctions applied to the environmental lawbreaker. In this sense, this work has the purpose to propose Technical Guidelines on the formulation of restoration projects of fire degraded areas in Atlantic Forest remnants of the Chapada Diamantina region. Such guidelines are designed for the fragments specially located in protected areas, whether on Conservation Unities, Permanent Preservation Areas and Legal Reservations, within IBAMA’s administrative procedures. For so, it was performed a bibliographic review through theoretical referential systematic searches on fire impacts on vegetation, fire ecology, current concepts and techniques on ecological restoration and recovery of degraded areas and research on environmental federal legislation applied to the matter. Based on studies data from the Chapada Diamantina National Park, it was verified that in a 25 year interval (1985-2010) an area of 945 ha of forest remnants was burnt inside the Park (18,25%) and 4.900 ha in its surroundings, adding up to 5.845 ha of burnt forest susceptible of ecological restoration actions. The technical guidelines here proposed were substantiated on three lines of action: 1 – Environmental Diagnosis – evaluation of the landscape at the microbasin scale, considering the presence of natural regeneration, seed banks, colonization, neighboring fragment, use and soil occupation patterns, vegetation phytophysiognomy, connectivity, fire recurrence and others; 2 – Restoration Actions – the first step to be adopted is to identify and isolate the degradation factors of the area being restored and the neighboring forest fragments. According to the environmental diagnosis of the fire degraded area, the restoration techniques to be adopted range from conduction and induction of natural regeneration, thickening, floristic and genetic enrichment, nucleation restoration techniques and full area planting; 3 – Evaluation and Monitoring – the parameters and/or indicators suggested were aggressive exotic grass coverage (%), natural regeneration in the understory (richness/ha), soil coverage by the canopy (%), stratification (number of strata), density (number of individuals/ha) and diversity (number of species/ha).