FOREST LITTER PRODUCTION VARIES WITH SEASON AND ELEVATION GRADIENT IN CHIAPAS, MEXICO

Abstract

Background. Forest litterfall is a fundamental process of ecosystem nutrient cycling, also, it is a source of energy for the development and propagation of wildfire. Understanding the temporal dynamics of litter production and storage is critical for sustainable management and conservation of forest ecosystems. Objective. To quantify the monthly production and storage of forest litter in an elevation gradient. Methodology. We selected forest sites at three elevations: 670, 775, and 1010 masl, corresponding to pine, oak, and tropical lowland forest ecosystems in Nambiyugua hill, Chiapas, Mexico. Sixteen sampling sites with a radius of 11.28 m were established for tree measurements, and 48 litter traps of 0.50 m2 were installed to collect monthly litterfall for a year. To sample ground litter eight 30 by 30 cm2 quadrats were used in each site. The fallen woody material was measured with the planar intersection method. Litter samples were oven-dried at 60 °C for 72 h and separated into leaves and other plant parts. One-way ANOVA was used to test the significant differences between forests. Results. The highest total loads of litter and fallen woody material were obtained in the pine forests of upper elevation with 29.01 t ha-1. The highest litter production was obtained in January and April, with a mean of 1.34 ± 0.19 and 0.74 ± 0.13 t ha-1 respectively in pine forests. In the oak forest, the highest production occurred in March, with 1.08 ± 0.25 t ha-1; while the lowland forest reached the highest production in January with 0.85 ± 0.26 t ha-1, with a decreasing trend in June. Implications. Understanding the seasonal variability in litter production and forest fuel loads is crucial for forest productivity, carbon sequestration, and wildfire prevention Conclusions. The production of forest fuels was different among the ecosystems representing the elevation gradients. The highest monthly production of litter was registered during the January-May period for the pine and oak ecosystems but in November - January in tropical lowland forests.