Objective To analyze the structural characteristics of Cunninghamia lanceolata Coppice Forest and provide a basis for optimizing and adjusting the stand structure and accurately improving the forest quality.

Methods Based on the Cunninghamia lanceolata Coppice Forest in the Shanxia Forestry of the Subtropical Forestry Experiment Center, the diameter distribution was fitted by the Weibull distribution, and the univariate and bivariate distribution characteristics of the stand spatial structure parameters, the degree of dominance of the tree species, and the structural diversity of the stand were analyzed by the quantitative analysis of the stand spatial structure, and the significance test of differences was carried out by the method of the genetic absolute distance.

Results The species composition of the three stands was dominated by coppice sprouts mixed with a small number of broad-leaed trees, with the Shannon-Winner index ranging from 0.933 to 1.039, and the Simpson's diversity index was less than 0.5, resulting in low species diversity; The diameter distribution of the stand showed a left-skewed monoclinal curve, with a tendency towards an inverted "J" shape; The mean angular scales of the uphill and downhill stands at Sanbanqiao and Qilikeng uphill and downhill were 0.503, 0.486, and 0.500, respectively, all of which belonged to the category of random distribution. The stand level mixing was 0.345, 0.404, and 0.409, respectively, and the stand as a whole was in a state of transition from weak to moderate mixing; Structural diversity index values were low in three stands with 1.423, 1.349 and 1.649 respectively. The uniform angle index-mingling and neighborhood comparison binary distributions showed some regularity, but the mingling-neighborhood comparison binary distribution varied in a relatively complex manner, and the regularity was not obvious.

Conclusion The species composition of Cunninghamia lanceolata coppice forests is relatively simple, the tree species diversity and stand structure diversity are low, and the DBH distribution and tree distribution pattern initially have the characteristics of natural forests. It is necessary to improve the stand quality through optimization and adjustment of the stand structure.