Floss release, seed fall and germination of kapok seeds (<i>Ceiba pentandra</i>) in an urban environment

Abstract

The tropical forest kapok tree occurs widely in urban environments, dispersing thousands of floss during the fruiting season. However, its seedlings are rarely seen around human settlements, raising questions on what factorsmight be limiting its recruitment. We examined the pattern of floss release, seed fall post-dispersal and influences of watering frequency on germination ofCeiba pentandraseeds. Evening,overall, was associated with a significantlyhigher rate and quantity of floss release (p= 0.0001) than were mid-day and morning, correlating well with the speed of wind across the day (rh = 0.666,p= 0.001). Mean dispersal quantity differed significantly between the individual sampled trees, in which the highest dispersal was recorded from trees located in relatively open areas and the lowest was recorded in closed stand trees. Seed fall was higher within100 mdistances than seed fall farther away from dispersing trees, depending on the microsites and weather conditions. Germination started on day 5 onwards and only 15.67% of sown seeds germinated. Watering frequency strongly influenced seed germination while local human activities determined fate of dispersed seeds. We conclude that recruitment ofC. pentandraspecies in the study area may have been limited by environmental and human factors operating at various local and spatial scales.