XVI International Botanical Congess

We studied the effects of forest fragmentation on the reproductive biology of the Guanacaste tree in the dry forests of Costa Rica. We compared the rates of pollen deposition onto the stigma, fruit set, seed production per fruit, out-crossing rates and progeny vigor among trees from continuous forest with trees left in pastures. Isolated trees were less likely to produce fruits and produced less seeds per fruit than trees from continuous forest. We did not find significant difference in out-crossing rates, but progeny from isolated trees tend to have lower values for the correlation of paternity. The progeny of isolated trees are less vigorous than progeny of trees in continuous forest. The role of selective abortion of fruits and seeds on the regulation of progeny vigor is discussed.