Coarse woody debris mass and its nutrients stock in tropical seasonal rain forest in Xishuangbanna, Southwest China

Based on the investigation at three 1 hm² plots, the coarse woody debris (CWD) mass in a tropical seasonal rain forest in Xishuangbanna, southwest China was estimated, with its nutrients stock measured. The CWD mass on the three plots was averagely 16. 2 t - hm^-2, occupying approximately 4% of the living aboveground biomass, among which, snag, fallen tree, fallen tree debris, and large branches accounted for 32.5 %, 33.2%, 12.6%, and 21.7%, respectively. The CWD mass estimated by this study was lower than that in tropical rain forests in Brazil and Southeast Asia, and its N, P, K, Ca, and Mg stock was 61.8, 3.4, 30.4, 118.3, and 16.5 kg · hm^-2, respectively. Fallen tree had the largest proportion of nutrients stock (31.9%-44.8% of the total), followed by snag (21.5%-28.7%), large branches (14.4%-28.9%) and fallen tree debris (10.30%-25.5%), and snag had higher C/N, C/P and N/P ratios than the others.