Population structure of mahogany (Swietenia macrophylla King) in the Municipal Protected Area – Curichi La Madre Urban Park, Santa Cruz de la Sierra – Bolivia

Abstract

Timber forest species plantations not only have economic but also ecological value. In this context, the present exploratory and descriptive study was carried out in a forest plantation of mara (Swietenia macrophylla King), established in the 80s in the Curichi La Madre Municipal Protected Area of the city of Santa Cruz de la Sierra, with the objective to evaluate the population structure, including the horizontal and vertical structure of this population. To do this, all the mara individuals were located, distributed in three spots, then the diameter and total height were measured, grouping them into 5 size categories, from seedlings to adult trees, distributed in 5 diameter classes and 3 height classes. With the ArcGIS 10.2 program, the mapping of the spatial distribution of the individuals was carried out and with the Excel program, all the data were analyzed, including the natural regeneration index. The mara population recorded a total of 1,534 individuals, presenting the typical inverted “J”-shaped curve, with individuals in all size categories, but with a higher percentage in the seedling category. Each spot presented a different abundance of individuals (891, 373 and 270), with spot 1 obtaining the greatest regeneration. In the horizontal structure, the 20-30 cm diameter class obtained the highest abundance of individuals in general and in each spot. In the vertical structure, the middle stratum (12 to 16 m) obtained the highest percentage of the population. In conclusion, this plantation presented a good population structure, with individuals recorded in all size categories and having a good percentage of adult trees, turning the APM Curichi La Madre into a potential seed bank for this important forest species.