Efecto de la fragmentación del hábitat sobre la calidad de las semillas en Lapageria rosea

Abstract

Habitat fragmentation is commonly associated to a reduction in plant fitness, because the reduction in the number of seeds produced. However habitat fragmentation might also affect plant fitness through a reduction in the quality of the seeds produced, as for example in seed viability, seed size or in seed germination. These factors could be affected because small populations size and high degree in isolation, frequently found in fragments, could induce to the loss of genetic population variability and the expression of inbreeding depression. Here I show the effect of forest fragmentation on the quality of seeds produced in Lapageria rosea, quality being measured as seed viability, seed size and seed germination. I collected seeds from the Maulino forest in central Chile, specifically from plants living in forest fragments and continued forest. Seed viability, seed size and seed germination capacity was estimated under laboratory conditions. Results indicated that seeds from forest fragments and from continuous forest have similar percentages of viability, although these percentages are more variable among fruits from forest fragments. Moreover, seeds from forest fragments are smaller than seeds from continuous forest. Finally, seeds from fragments have less germination capacity than seeds from continued forest. These reductions could determinate a negative effect on seedling establishment in fragmented populations and possibly in the long term population survival.