Abstract: Coarse wood debris (CWD) plays an important role in the nutrient cycling and carbon dynamics in forests, but little is known on the relationships between CWD storage and its spatial distribution. In this paper, an investigation was conducted on the CWD distribution in a 1-hm2 plot of a tropical seasonal rain forest in Xishuangbanna. In the plot, the CWD with diameter ≥ 10 cm made up 68.02% of the total
biomass of litterfalls, and around 45.72% of the CWD was at the medium or late stage of decomposition. The majority of large size CWD distributed on the slopes of 15°-25°, and their saturated water contents increased with their decay degree, which would help to improve the local water and nutrient condition. The distribution of CWD was affected by wind direction and local humid and hot environment, but the angle of the CWD laid on the ground tended to be random. The CWD storage and distribution would greatly contribute to the habitat heterogeneity and species diversity in tropical seasonal rainforests.

Key words: human activity, landscape structure, landscape composition dissimilarities, buffer, Daqingshan Nature Reserve.