Objective This study aims at providing a theoretical basis for the optimization and adjustment of the spatial structure of the Platycladus orientalis ecological forest and the optimization of the spatial structure of other ecological forest in the region by analyzing the spatial structure of P. orientalis ecological forest and evaluating its management urgency.

Method Based on the data field-measured at P. orientalis ecological forest in Jiulongshan of Beijing, the spatial structure characteristics of P. orientalis ecological forest were analyzed by using seven spatial structure parameters including the mingling, dominance, uniform angle index, crowding, stand layer index, open degree and competition index. 10 indices were selected to conduct the evaluation index system of management urgency from the aspects of density, pattern, competition and mingling, and the standards were established. Meanwhile, the management urgency of P. orientalis ecological forest was evaluated.

Result The spatial structure of the P. orientalis ecological forest was relatively simple, the pattern of distribution was random, the tree species composition was single, the trees of non-mixture and low-mixture were dominant, and showed a trend of single aggregation. The tree size differentiation was insignificant, and the P. orientalis was in an obviously dominant position and with higher stand density. It contained a higher proportion of dense and very dense trees; most trees were in the middle and upper layers, and its layer index was 0.288, suggesting that the layer structure was not obvious; the stand open degree and competition index were 0.274 and 0.318 respectively, which were in the state of insufficient growth space and moderate competition. The management urgency index of the P. orientalis forest was 0.8, and its grade of management urgency were particularly urgent, indicating that most characteristics of P. orientalis ecological forest did not meet the standards. It is needed to take effective measures to optimize the forest allocation and improve forest condition in order to achieve sustainable development of P. orientalis ecological forest.

Conclusion Analyzing the stand spatial structure and evaluating its management urgency can find the unreasonable characteristics of forest structure, and develop the adjustment measures of space structure, so as to promote the development toward the healthy and stable direction for P. orientalis ecological forest, and achieve continuous gain of the ecological, economic and social benefits.