Influências do ambiente de borda na composição e estrutura de um fragmento de mata atlântica na RPPN fazenda São Pedro de Pilar, AL

Abstract

The forestry domain of the Atlantic Forest stands out for its high biodiversity in a highly fragmented and threatened landscape. Given this scenario, strategies have been adopted to guarantee the conservation of the remaining areas, such as the creation of areas protected by conservation units. However, it is important to evaluate the ecological effects of fragmentation so that these areas can achieve their objectives. This study investigated the effects of the edge environment on the structure and composition of a forest fragment in Alagoas, within a conservation unit categorized as a Private Natural Heritage Reserve (RPPN). Thirty plots of 100 m2 each were allocated, covering the edge to the interior of the fragment. All arboreal individuals with Circumference at Breast Height - CAP ≥ 15 cm were sampled. Phytosociological parameters, diversity and evenness indices were calculated for comparison between three environments (A): A1- edge, A2- edge-interior transition, and A3- interior of the fragment. In total, 144 tree individuals were sampled, with emphasis on the Fabaceae family in terms of number of species. Most of the species found belonged to the group of initial secondary and pioneer species, indicating a stage of vegetation regeneration. The diameter distribution indicated stable vegetation, suggesting a continuous process of regeneration, possibly driven by favorable environmental conditions and the absence of significant disturbances in the environment. In addition, a lower density and diversity of species in the edge environment (A1) was observed, the which can be attributed to greater exposure to factors such as wind, sunlight and the influence of human activities, which interfere with the establishment and survival of species, highlighting the priority of this environment to establish management and restoration measures aimed at conserving biodiversity in this Unit of Conservation of the Atlantic Forest. Therefore, the implementation of restoration and management measures is suggested, with the recommendation to investigate the intensity of the impacts and the distance in relation to the forest edge, to contribute to the construction of the Conservation Unit's Management Plan and carry out the introduction of species at a more advanced successional stage through enrichment planting. Finally, carry out continuous monitoring to evaluate the effectiveness of these interventions in the restoration progress and adapt management strategies to guarantee the conservation of the area.