LITTERFALL IN Pinus greggii Engelm. AND Pinus cembroides Zucc. PLANTATIONS, IN COAHUILA, MÉXICO

Abstract

This research was carried out to evaluate litterfall kinetics in two coniferous plantations (Pinus greggii Engelm. and P. cembroides Zucc.) planted in 1992, growing under similar environmental conditions in the Sierra de Arteaga, Coahuila, México. Litterfall was collected at both sites from 15 randomly distributed litter traps, over monthly time intervals along one year (February 2009 – February 2010). Traps of 1 m² were made from wooden a frame and metallic mesh of 1 mm x 1 mm. Kruskal-Wallis (95 %) non-parametric test was used to detect significant differences of litterfall components (needles, branches and male cones) among species and sampling dates. Principal component analysis and Stepwise regression were employed to evaluate relationships of litterfall and climatic factors. Litterfall was higher (P < 0.05) in P. greggii (2.98 ± 5.18 g m^-2/month) than in P. cembroides (2.71 ± 6.01 g m^-2/month), equivalent to 1072 and 976 kg ha^-1/year, respectively. Needle litter comprised about 92.3 ± 8.1 % of total litterfall for Pinus gregii and 94.3 ± 3.8 % for P. cembroides. The results show that litterfall inputs be affected by tree species and by environmental factors, mainly wind and temperature.