Population dynamics of an economically important palm tree (Jessenia bataua) in the Ecuadorian Amazon.

摘要

The economic botany, population size structure, reproductive ecology, and seed and seedling ecology of an economically important palm species (ungurahua, Jessenia bataua) from the Ecuadorian Amazon were the focus of this study. Field and experimental data were used to construct a holistic model of the population growth dynamics of this palm. Sensitivity analyses and model simulation were conducted to explain and predict what the effects of changing several environmental parameters have on the biomass of this species.; Informal interviews with native Siona people indicate that this species has several functions to people in the Ecuadorian Amazon, the most important being the consumption of the fruits. The fruits yield a high quality oil, which may be used in the treatment of lung ailments and hair loss.; The population size structure of ungurahua on harvested plots were compared to the size structure on unharvested plots. Harvested areas had a significantly different structure, mostly due to the large number of seedlings. It was speculated that this may be in part due to how people process the fruits for consumption.; This species appears to reproduce every other year and fruit production on a per tree basis varies from approximately 500-7000 fruits. Fruit and seed dispersal by terrestrial rodents, particularly Myoprocta prattii, is important. Dispersal distances vary a great deal (.5-27.5 m) but average about 5 m. Seed predation by bark beetles appears to be important in seed germination and seedling establishment.; Light availability plays an important role in seedling growth and survivorship as indicated by greenhouse and field studies. Higher light quantities stimulate greater growth but also higher mortality in seedlings in the field; however, in greenhouse studies, greater light availability resulted in less growth and higher mortality.; The results of the model show that a prolonged dry season may benefit the population of ungurahua. Canopy removal treatments indicate that higher light levels may contribute to greater growth. Finally, it is concluded that cutting only the infructescences is far more sustainable than felling adults when harvesting the fruits.