Changes in the composition and structure of the arboreal vegetation in an area impacted by the livestock in the corregimiento of Santa Cecilia, Pueblo Rico, Risaralda

Abstract

In order to determine the changes in the composition and structure of the arboreal vegetation in an impacted area (75 ha) by livestock during the period 2015-2017, all the individuals of arboreal size present in a plot of 0.25ha (50x50 m). The samplings carried out allowed to register 199 individuals belonging to 14 families and 19 species. The best represented families in terms of species richness were: Moraceae with 3, followed by Malvaceae, Melastomataceae and Urticaceae with 2 species each. At the species level, Vismia angustifolia (Spearhead) with 12 individuals, Jacaranda sp. (gualanday or pinguasí) and Lacistema aggregatum (mountain coffee) with 9 individuals each, and Himatanthus articulatus (mamancallo) with 8 individuals. The species composition was similar throughout the samplings, however, in 2016 the species Apeiba membranacea was recorded, and Brosimum utile in 2017. The diametric average of the individuals ranged between 18 and 19 cm. The growth dynamics of the trees shows that despite the fact that the forest has not reached its maturity, the individuals of the highest classes decrease their growth rate over the years. On the other hand, mortality and recruitment varied between the evaluated periods. For the period 2015-2016, there was no mortality, however, 10 individuals were recruited, for a total of 65 trees for this period, representing an increase of 0.363 m2, equivalent to 16% of the basal area with respect to 2015 (1.897 m2). Despite the little variation in the structural and composition parameters, the families and species obtained as the successional stage progresses, demonstrating the tendency of recovery of attributes of diversity, composition, and functionality of the ecosystem.