A conversão de um plantio de pinus na Floresta Nacional de Chapecó/SC: chuva de sementes e a sinúsia arbórea

Abstract

In the West of Santa Catarina there are few forest remnants in good repair. The Chapecó National Forest (FLONA) is a conservation unit of sustainable use, with approximately 1,590 hectares, of which 400 hectares are occupied by plantations of exotic species. FLONA's challenge is the conversion of exotic plantations into native forest, enhancing the conservation of biodiversity. This work aimed to describe the tree community as to its horizontal structure and diversity; to understand the dynamics of seed rain and to quantify the reinfestation of Pinus spp. offering a grant to FLONA regarding the management of these areas. For this, the phytosociological survey was carried out in three regions: regeneration - with three years of cut of Pinus spp. (REG), under planting of Pinus spp. (PIN) and under planting of Araucária angustifolia (ARA). Ten plots of 20x25m were installed and trees with perimeter at chest height (PAP) ≥15 cm were analyzed. Individuals of Pinus spp. (PAP <15cm) were recorded in the ERP plots. Rainfall of seeds was also collected in REG and PIN, using circular collectors with a total area of 2,17m for REG and 1,80m for PIN. The abundance, diversity and richness of arboreal (three areas) and seeds for REG and PIN were low compared to other studies in southern Brazil. Many individuals of few pioneer and anemocortic species in REG are characteristic of early stage regeneration. These data associated to reinfestation rates by young individuals of Pinus spp. indicate the need for control actions in the suppression of these species, as well as the enrichment of these areas with native species, in order to facilitate local resilience.