"Em que contexto de paisagem a restauração passiva é favorecida?: evidências a partir da diversidade do banco de sementes"

Abstract

Anthropic activity causes high rates of landscape fragmentation, which threaten biodiversity worldwide. In this context, the recovery of ecosystems has become an increasingly important strategy to ward off extinction. The development of strategies to prioritize restoration at low costs are viable and attractive alternatives. However, this process depends on factors such as seed dispersion capacity, which may be affected by the landscape. This study aims to evaluate the influence of landscape structure on seed bank and its potential dispersal. We selected 10 landscapes, immerse into at least two of these three types of matrices: sugar cane, cattle pasture and coffee. Seed bank was collected into the matrix at pre-established distances from forest patches. Furthermore, we performed bird sampling in the same matrices. To examine the relation between the seed bank and the landscape, we used linear and non-linear models. Competing landscape models included: amount of forest, patch shape complexity, isolation and matrix permeability. We found that the landscape structure directly and indirectly affects the seed bank via dispersing birds. The landscape directly influences the maintenance of the dispersing birds, indirectly affecting the zoochoric seed bank and, consequently the possibility of successful restoration. Higher matrix permeability, more regular shapes, higher connectivity among fragments and higher percentage of forest ensures higher rate of occurrence of dispersing birds, which in turn, ensure the maintenance of the zoochoric seed bank. Thus, through the understanding of these direct and indirect effects, we suggest the structural aspects of the landscape must be considered in management decisions and restoration strategies of forest areas.