Evaluación de la descomposición de biomasa foliar bajo diferentes tipos de cobertura forestal en un ecosistema altoandino al sur del Ecuador

Abstract

The dynamics of forests include several processes, among them: the decomposition rate, nutrient cycle, carbon reserve, etc. The studies within this field are relevant, but they are limited. Human intervention and land use change put forest systems at risk, for this reason, it is important to know about the behavior of some factors involved in the leaf litter decomposition of some forest cover. The objective of the research was to evaluate the effect that forest cover type has on the rate of decomposition in four types of forest stands: primary forest (LBP), (L = Llaviucu), secondary forest (LBS), secondary forest under eucalyptus (LBSE) and secondary forest under pine (LBSP). The estimation of the decomposition rate was made through field incubation techniques using litter bags, with a sampling frequency of two weeks, for 224 days. The remaining weight was calculated with the weight difference (initial, final) of the sample, to then determine the rate of decomposition (k) and its relation to different variables. The forest that showed the fastest decomposition was LBSE (k = -0.00236), LBSP a slower decomposition (k = -0.00159), and LBP and LBS showed a similar decomposition. Time, leaf coverage, slope and relative humidity were variables that correlated with the weight loss of some coverages according to the Spearman correlation. The rate of decomposition is affected by the presence of exotic species such as pine and eucalyptus, showing a difference in the percentage and speed of decomposition, compared to native species.