Ramos, F.N., José, J. Solferini, V.N. & Santos, F.A.M. 2005. Quality of seeds produced by Psychotria tenuinervis (Rubiaceae): distance from anthropogenic and natural edges of Atlantic forest fragment. 19th Annual Meeting of the Society for Conservation Biology. p. 171.

Anthropogenic edges created by fragmentation and natural edges may disrupt gene flow and affect the quality of seeds produced by plants located in these habitats. The aim of this study was to investigate whether there were differences in the (1) genetic variability, (2) genetic structure, (3) seed mass, and (4) germination rate and velocity of the seeds produced by Psychotria tenuinervis individuals located at anthropogenic edges (AE), natural edges (NE) and forest interior (FI). Among the three habitats, the populations of P. tenuinervis showed no differences in genetic variability or genetic structure (GST =0.07 ± 0.09). However, there was an indication of inbreeding (GIS =0.71 ± 0.08), which was significantly higher on NE (0.82) than on AE (0.74) and FI (0.64). There were no differences in the seed mass, germination rate and velocity among the three habitats, probably because most of them showed within habitats variation. These results suggest that other characteristics of the fragment, such as gaps, edge age and type of matrix exert more influence on seed mass and germination than the distance from the edges. Seed characteristics were not influenced by the genetic pattern of P. tenuinervis, since there was little difference in the genetic variability and structure among and within habitats.