Abstract:

This study aimed to investigate relationships between fruit traits and seed dispersal in a subtropical evergreen broad-leaved forest. Fruit composition and fruit phenology were monitored using 240 seed traps distributed over 10 separated stand patches in a fragmented forest in Dujiangyan City, Sichuan Province, Southwest China. A total of 10,542 mature fruits, belonging to 42 woody plant species of 36 genera and 24 families, were collected between April 2009 and December 2010. The peak of fruiting and fruit abundance occurred during autumn (between September and December) when there is less rainfall. Plant families with higher species richness included Fagaceae (17%), Lauraceae (12%), and Rosaceae (10%), while other families included only 1-2 fruiting species. Seed dispersal by animals was the most dominant dispersal mode (88.1% of species) while anemochory (wind dispersal) was the mode for other species. Seeds of animal-dispersed species were mainly dispersed by frugivorous birds (52.4%), followed by scatter-hoarding rodents (19.0%) and frugivorous birds and mammals combined (16.7%). Drupes (48%), nuts (17%), and cones (10%) were the most common fruit types. Species with black fruits (39%) and red fruits (21%) were most common and were dispersed by fruigivorous birds, while species with brown nuts (29%) were also common and were mainly dispersed by scatter-hoarding animals. Most fruiting species (64.3%) had relatively small fruits (<10 mm in diameter), and were mainly dispersed by birds, while those with larger fruits (>10 mm in diameter) were mainly dispersed by wind or rodents. Our study indicates that most of fruiting woody species occur during autumn (later wet season and early dry season) and fruit traits of these plants have been adapted by animal-mediated seed dispersal in the Dujiangyan subtropical forest.

Key words: fruit traits, fruiting phenology, seed dispersal, subtropical forest, Dujiangyan, environmental factor, fruit phenology