Distância do fragmento florestal, características e densidade das árvores isoladas influenciam na dispersão de sementes no pasto

Abstract

Pasture creation resulting in forest fragmentation could restrict seed dispersal around these remnants. However, it is possible that some factors in a fragmented landscape could improve seed dispersal. We aim to verify whether (i) distance from forest fragments, (ii) density of isolated trees, as well as (iii) if some plant characteristic influence seed dispersal in pastures. This study was carried out in six pastures near forest fragments with a range of isolated tree densities. In each landscape, we installed 18 seed traps (total=108 traps), distributed over 6 distance classes from the edge of forests (0, 5, 10, 20, 40 and 80m). We performed GLM analyses that were compared by AIC. We collected 8162 seeds and found 26 species: 4722 anemochorous, 3304 epizoochorous, 72 autochorous, and 64 endozoochorous seeds. Our results show that proximity to forests fragments, having a greater isolated tree density in pastures, and including isolated trees of greater height and canopy cover promote seed dispersal in pastures for endozoochorous, anemochorous, and autochorous species but reduce it for the epizoochorous ones. These results may help restoration in pasture or assist in implementing silvopastoral systems in order to improve seed dispersal in this harsh habitat that promotes better connectivity between forest fragments in this landscape.