Articles
ECOLOGY, MANAGEMENT AND CONSERVATION OF POTENTIALLY ORNAMENTAL PALMS
The variability of life forms, the structure of palm communities in the tropical forests and the multiple useful products obtained from them make palms an important resource for developing sustainable agricultural and horticultural systems.
To aid in the preparation of management plans for sustainable use, data on the growth, survival and reproduction of palm populations in natural conditions should be taken.
We estimated transition probabilities for each size class of three species of palms and obtained Lefkovitch matrices to estimate the populations’ finite growth rates (
= 1.0142 for Astrocaryum mexicanum; = 1.3623 for Chamaedorea alternans; and = 1.0184 for Reinhardtia gracilis var. gracilior). This indicates that under present conditions these palm species populations could remain close to equilibrium or increase if not harvested.Elasticity analyses showed that fecundity had a relatively low value which in demographic terms indicate that fecundity makes a low contribution to the population growth rate.
Therefore, we simulated various seed collection regimes.
While reductions of 100% of the fruits produced by A. mexicanum palms do not have any effect on the population rate of increase, reductions larger than 40% in R. gracilis var. gracilior cause a decrease in the population rate of increase.
On the other side reductions greater than 90% in Chamaedorea alternans will drop values well below the equilibrium, indicating that regeneration will be insufficient to balance natural mortality rates.
We suggest a management strategy consisting of collecting different proportions of seeds in each species for establishing long-term plantations to use this species as ornamentals without affecting their population growth rates in their natural environments.