Variación de la caída de la hojarasca fina a través de diferentes tipos de suelos y regiones en la amazonia.

Abstract

El presente trabajo busca establecer la variación de la caída de la hojarasca fina y la dinámica del carbono a través ésta en bosques amazónicos sobre suelos contrastantes como uno de los componentes para medición de la Productividad Primaria Neta de los bosques de la cuenca del Amazonas. En algunos de los lugares donde se realizó este estudio y en otros lugares de la cuenca se están desarrollando estudios paralelos que buscan establecer la dinámica del carbono a través de los diferentes componentes de la PPN, incluyendo la producción de hojarasca fina, bajo los protocolos establecidos por RAINFOR y PANAMAZONIA.

Litterfall is an important component of Aboveground Net Primary Productivity because it is a very dynamic carbon pool, and because trees invest a high proportion of the carbon they fix through photosynthesis to produce leaves and reproductive structures. We measured the fine litterfall in forests in different soils in Amazonia (Podsol, Oxisol, Ultisol and Histosol) at the Chiribiquete and Amacayacu National Natural Parks, the Río Calderón Forest Reserve (Western Amazonia, Colombia), and the Nouragues Research Station (Eastern Amazonia, French Guiana). Eight 1ha plots were previously established on the different soils and 25 0.5m2 litter traps were setup in each plot. Litter was collected twice monthly during an interval of at least 1 year. I found significant differences in litterfall among the plots, exhibiting a rank of litter production between 4.05 and 9.49 Mg ha-1 y-1 (or 2.03 and 4.75 Mg C ha-1 y-1). The lower values were found in Podsol sites and the higher ones in Oxisol sites. Litter production tended to increased as rainfall decreased and temperature increased. I found a wide range of values in neighboring plots and in plots belonging to distant regions. Hence, in Amazonian forests, litterfall is strongly influenced by local climatic and edaphic properties, more than by regional ones.