Seed Success of Pentaclethra Macroloba across Soil Types and Seed Densities
نویسندگان
چکیده
Seed dispersal and germination are critical to the fitness of all tree species. Moreover, among most trees the percentage of seeds that become seedlings, or “seedling success”, is very low. We examined seed success of a dominant lowland rainforest species, Pentaclethra macroloba, across a soil moisture gradient. Previous studies have established that P. macroloba has reduced seed germination rates in areas of low moisture and also has density dependant population dynamics. Results from these studies suggest that these density dependent population dynamics may be due to fungal pathogens. We hypothesized that if fungal pathogens are regulating the population but seed germination rates are greater in areas of higher moisture, seed success will be greatest in areas of low seed density and high soil moisture. We surveyed quadrats for seedlings and estimated seed abundance dispersed using seed pods found within quadrats. Our results indicate that seed success is density dependant in alluvial soils but not in non-alluvial. It appears that P. macroloba seedling density is more clumped in non-alluvial soils. Other studies have documented even distributions of adult trees across the landscape. Future studies may consider mechanisms of increasing mortality at intermediate life-stages in non-alluvial habitats that might compensate for the clustered distribution of seedlings.
منابع مشابه
The impact of Pentaclethra macroloba on soil microbial nitrogen fixing communities and nutrients within developing secondary forests in the Northern Zone of Costa Rica
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