Contribution and decomposition of leaf litter in temperate forests of the El Salto region, Durango

Abstract

In order to know the contribution and decomposition of litter as an ecosystem process through which nutrients are transferred to the soil, two study sites (2 500 m²) were evaluated during one year: El Brillante, where the forest structure is conditioned by Quercus sideroxyla and Pinus cooperi var. ornelasii, and Santa Bárbara, with Cupressus lusitanica and Pseudotsuga menziesii and different composition of species; in each one, ten 1 m² litter collectors were installed, in which the collection was made every two weeks. This material was separated into components: leaves, reproductive structure, branches, bark, insects, feces and others (moss, resin and unidentified tissue). To measure foliar decomposition, 160 bags with 10 g of dry litter were distributed per site and reviewed each month. Total litter production was 5.9 (El Brillante) and 3.6 Mg ha^-1 year (Santa Bárbara). Through a regression analysis, the Simple Negative Exponential model was the best to describe the relationship between the initial and final weight in the decomposition. For the decomposition of 50 and 90 % of the mass of the leaves, the time required was 1.6 and 10.8 years, respectively. El Brillante has a higher production of litter, however, the decomposition process is similar to that of Santa Bárbara. The comparison of averages in the litter contribution and decomposition of the foliar fraction for the study sites was carried out with the non-parametric Mann-Whitney U test.