Biomasa de raíces finas en cuatro estadíos de sucesión del Bosque Seco Tropical y dos estaciones climáticas, Santa Rosa, Costa Rica

Abstract

In Costa Rica, tropical dry forests had suffered the effects of land change for a long time; Hence, the study of fine roots ( ≤ 2mm diameter) among successional forest stages would allow us to evaluate the degree of these disturbances. I studied fine root biomass up to 40 cm soil depth along a successional gradient in two climatic seasons; rainy (November 2010) and dry (March 2011.The dry season resulted with more fine root biomass; according to the literature this is a strategy to capture water and nutrients from deeper soil layers. The rainy season resulted with no significant differences among total fine root biomass (p>0,05); late forest obtain 361,943 g/m2 of fine root biomass, pastures had 341,760 g/m2 ; early and intermediate forests obtained 313,140 ; 297,651 g/m2 respectively. In the dry season, significant differences where found (p< 0,05) among the following three groups early forest (520,713 g/m2), pastures (224,693 g/m2) and intermediate (362,083 g/m2 ) plus late (419,823 g/m2 ). Finally I compared the total fine root biomass between dry and rainy seasons and only significant differences where found for early stage; rainy (313,140 g/m2) versus dry (520,713 g/m2). I conclude that there is a clear trend of increasing fine root biomass along the successional stages, however no stadistical significant differences were found probably because the sample size and sampling system should be improved.