Effect of Thinning Intensity on Litterfall Biomass and Nutrient Deposition in a Naturally Regenerated Pinus Pseudostrobus Lind. Forest in Oaxaca, Mexico

Litterfall is an important component of forest biomass and nutrient cycling, and can have key impacts on soil fertility through its decomposition. However, the effect of forest management on litterfall remains unclear. We evaluate the impact of thinning intensity on the biomass and nutrient content (C and N) of litterfall in Pinus pseudostrobus forest in Oaxaca, Mexico, across two thinning intensities in areas with either high or low residual basal area and across seasons. There was significantly higher litter carbon content in the least intensive thinning treatment, but no significant differences in biomass or nitrogen content between treatments. However, there was a significant correlation between residual basal area and litter biomass at the p < .1 level. We found a clear seasonal pattern in litterfall fluxes, with 1.5 times more litter deposition in autumn's dry season compared to spring. We find that the thinned stand of P. pseudostrobus generated an annual mean litter biomass of 1059.27 +/- 346.04 kg ha(-1) with mean carbon content of 125.31 +/- 46.43 kg ha(-1) and mean nitrogen content of 4.76 +/- 1.43 kg ha(-1). These values present an important contribution for modeling of biomass and nutrient cycling in this ecologically and economically important forest type.