Modelación de la hojarasca en un bosque secundario húmedo tropical: Transición Orinoquía-Amazonía, cuenca del Orinoco, Guaviare-Colombia.

Abstract

In a successional phase of the Orinoquia-Amazonia transitional humid tropical secondary forest, in the Guaviare river basin (municipality of San José del Guaviare, Colombia), the fall of fine litter (CHF) was studied during the period from February 2020 to January 2021. The CHF was collected using 29 randomly distributed litter collectors in a plot measuring 140 by 240 m, 20 m from each other (Fig. 3) and with an area of 0.2 m2. The material was separated by components (leaves, branches, reproductive structures, detritus and undefined material). The dry weight of the fine litter was obtained and the leaves were determined to species. To determine and compare the ordering of the most producing species of leaf litter, an analysis of variance (ANOVA) and a principal component analysis (PCA) were applied. The maximum CHF (p <0.05), occurred in December (49.225 ± 28.840 g / col, with a standard error (ET) of = 5.355) and the minimum in June and July (16.135 ± 6.183; 15.470 ± 4.897 g / col, respectively with ET = 1.148; 0.909). The accumulated leaf litter (HFA) in time exhibited a square trend due to the adjustment of the generalized linear model (Distribution: Poisson and identity: Quadratic) y = 0.454 x2 - 0.788 (R2 = 0.8102), which by means of this effect analysis mixed (fixed: days and random: collector), it was possible to estimate the confidence interval of the mean annual HFA production at 195.804 g / col. year, with maximum and minimum values of 217.693 -173.914 g / col. year. The CHF components with the highest contribution were leaves (56.52%) and branches (24.96%), followed by reproductive structures (5.59%) and lastly detritus (12.92%). The species with the highest leaf litter production was Capirona decorticans with (2.208 ± 5.032 g / col. Year, with ET = 0.269) and Terminalia amazonia the species with the highest information, with a correlation coefficient of 0.994 with respect to the first main component. Precipitation is the variable most associated with the production of fine litter for the successional lowland forest, which indicates that the water deficit controls production through abscission in response to the lack of water in the system.