Potencial do banco de plântulas como estratégia para restauração florestal no extremo sul do bioma Mata Atlântica

Abstract

The seedling bank is crucial to the perpetuation of woody communities, represented in tropical regions by a large number of individuals, many of whom do not reach the upper strata. Thus, the present study aimed to evaluate the potential of seedling bank as a strategy to increase species richness in forest nurseries, aimed at ecological restoration of disturbed areas in southern Atlantic Forest biome. The work was divided into three chapters, which are organized according to the objectives: In Chapter I was analyzed the structure of a remaining stretch of seasonal Forest Subtropical and the potential of species to restore degraded areas were identified. Were installed 18 plots of 20 m x 10 m, where it was sampled the vegetation divided into four classes, according to their size: I - Bank of seedlings: 5 cm ≤ height (H) ≤ 55 cm; II - established natural regeneration: H > 55 cm and diameter at breast height (DAP) < 1 cm); III - Intermediate Stratum 1 cm ≤ DAP < 5 cm; and IV - arboreal stratum: DAP ≥ 5 cm. In Chapter II we study the resilience of a plant community after transplantation bank seedlings, conducted under different withdrawal intensities (0, 25, 50, 75 and 100% removal). In this study we used 18 plots (5 m x 5 m), which were subdivided into five subplots of 1 m x 2,5 m (totaling 90 subplots), in each subplot was randomized a removal of intensity. In Chapter III we study the survival and growth of seedlings in the nursery in different size classes. We collected data for survival and height increment, in a completely randomized design, considering five size classes (I - 05-15 cm; II 15,01-25 cm; III 25,01-35 cm; IV - 35,01-45 cm; V 45,01-55 cm), evaluated every two months for a period of ten months. Also considered physiological parameters for the most abundant species, considering two environments (understory and nursery), designed to evaluate the adaptation of transplanted seedlings. Thus, it was found that the Bank of seedlings is a useful tool to increase the number of species produced in nurseries, given that the majority of transplanted species showed good development and the plots where different intensities were applied transplantation has been able to recover the richness and abundance of species present at baseline. Considering forest structure, dynamics of natural regeneration after transplantation and the development of seedlings in the nursery, there is for the region as a species Actinostemon concolor, Nectandra megapotamica, Apuleia leiocarpa, Trichilia elegans, Maytenus aquifolia, Trichilia claussenii and Eugenia rostrifolia.