BIOMASS, CARBON, AND NUTRIENT DYNAMICS OF SECONDARY FORESTS IN A HUMID TROPICAL REGION OF MÉXICO

Abstract

Tropical secondary forests have the capacity to function as large carbon and nutrient sinks and may offset losses resulting from deforestation and land use. In the heavily deforested Los Tuxtlas Region of Mexico, aboveground biomass as well as aboveground and mineral soil C, N, S, and P pools were quantified in 11 secondary forest sites. These sites ranged in age from 6 mo to 50 yr following abandonment and had experienced between 1 and 30 yr of land use prior to abandonment. Total aboveground biomass (TAGB) increased with increasing site age and ranged from 4.8 Mg/ha in a recently abandoned site to 287 Mg/ha in the 50-yr-old secondary forest site. Results indicate that secondary forests would reach TAGB levels equivalent to those of primary forests in the Los Tuxtlas Region after 73 yr. Furthermore, mean annual aboveground biomass accumulation (ABA) of secondary forests was strongly and inversely related to the duration of prior land use. Aboveground pools of C, N, S, and P were also positively correlate...