Abstract:The spatial pattern of a tree species is an important characteristic for a forest community as it provides critical information about the community structure, species coexistence, and resource use. Such information supports a better understanding of the underlying ecological processes that controlled the development of the observed patterns. The spatial point pattern, which is based on coordinate data sets, was used to analyze the spatial pattern distribution regularity and characteristics of major species, the existing form and the decay class for coarse woody debris (CWD) in a large permanent plot (9 hm2, 300 m×300 m) of a typical mixed broadleaved-Korean pine forest in Xiaoxing′an Mountains. This paper is an important part of the research on forest ecosystems, and it is hoped that the results will provide important theories and foundation data for the management and protection of typical mixed broadleaved-Korean pine forest. The results revealed the presence of greater differences in the densities of different diameter at breast height (DBH)-classes which followed the normal distribution (DBH class Ⅱ > DBH class Ⅲ > DBH class Ⅳ > DBH class Ⅰ), and the total CWD density was 368.8 n/hm2. Acer ukurunduense (27.8 n/hm2) and Betula costata (26.1 n/hm2) were the major broadleaved tree species while Pinus koraiensis (41.6 n/hm2) was the major coniferous tree species. The CWD of most of the coniferous species increased with increasing DBH in a J-shape curve, while Abies nephrolepis presented a partially normal shaped curve within the scale of 150 m. The numbers of unidentified species and shrub were 23.6% and 18.7% of the total, respectively. The patterns of total CWD changed from a clumped to a uniform distribution with increasing scale, and the maximum intensity of assemblage (IA) (0.40) was under the scale of 40 m. The different DBH classes were clumped in different scales, and the IA decreased with increasing DBH-class. The distribution patterns of DBH class Ⅱ, Ⅲ and Ⅳ for total CWD changed from clumped to random, and the maximum IA also appeared at the scale of 40 m. The CWD of the different species showed different spatial patterns according to the DBH-class, due to the self thinning process, disturbance patterns and environmental change of the forest community. Overall, clumped and the change from random to clumped distribution were the two forms. The CWD with different existing forms changed from clumped to random with increasing scale. The dividing scale of uprooted blow-down, stumped and standing dead trees was 120 m and that of breakage at rootstock, breakage at trunk and trunk segment was 60 m. The variation of CWD according to decay class showed different trends with increasing scale. Decay class 1 changed from clumped to random, decay class 2 from clumped to uniform, and the others tended to a clumped distribution in the scale of < 150 m. The IA and scale of the different decay classes increased with increasing scale. We attributed the spatial pattern of CWD in this broadleaved-Korean pine forest to long-term interactions between the community and the natural environment, and suggested that the results also reflected the natural regeneration pattern and mechanisms of this kind of forest.