Mating system and genetic diversity of progenies before and after logging: a case study of Bagassa guianensis (Moraceae), a low-density dioecious tree of the Amazonian forest

The logging of large trees in tropical forests causes a decrease in the density of reproductive individuals, which likely affects the pattern of pollen dispersal and the mating system of the remaining trees in the population. Here, we investigate the impact of logging on mating system and genetic diversity of the low-density, thrip-pollinated, dioecious tree Bagassa guianensis within a 500-ha plot at Tapajós National Forest, Pará State, Brazil. Mating system parameters of the logged population were estimated using mixed-mating model. Six microsatellite loci were used to genotype 232 seeds from ten remnant female trees over three seasons (2006, 2007, and 2008). The data were compared with the mating system of the unlogged population of B. guianensis (18 female trees, 488 seeds) in the same plot. The overall number of alleles found in the open-pollinated progenies decreased after logging (K = 71 before logging and K = 57 after logging, considering the three after logging seasons pooled), ...