Close-to-nature management (CTNM) has been proposed as a promising forestry management approach to improve the structure and quality of forests, which integrates wood production and ecological service functions. Research on the effect of CTNM on the univariate and bivariate distribution of the spatial structure of forest stands provides a scientific basis for the evaluation of CTNM implemented in forestry. Here, we analyzed and compared the spatial-structure characteristics of Masson pine (Pinus massoniana) plantations (young, middle-age, and near-mature stages) under CTNM 8 years after selective cutting and unmanaged control. We used univariate and bivariate distribution of three spatial-structure parameters: mingling (M), dominance (U), and uniform-angle index (W). Results showed that the effect of CTNM on spatial structure was more remarkable in middle-aged and near-mature Masson pine forests compared with the young forest. CTNM significantly improved mingling degree and promoted the horizontal distribution, thereby changing from a cluster to a random distribution. Moreover, CTNM improved the proportion of trees with a high mixing degree and random distribution and the proportion of trees having a micro-structure of random distribution with a high degree of mixture and dominance with a high degree of mixture in middle-aged and near-mature Masson pine forest. Overall, the implementation of CTNM 8 years ago showed a positive effect on the improvement of the spatial structure of Masson pine forest, but the present spatial structure is suboptimal. Further implementation of CTNM to adjust the mingling and uniform-angle index is necessary, and CTNM according to this method of frequency distribution of stand structure parameters can improve the success of forest management.

中文翻译：

---

接近自然的管理积极改善了马森松林林分的空间结构

近自然管理（CTNM）已被提出作为一种有前途的林业管理方法，以改善森林的结构和质量，将木材生产和生态服务功能相结合。研究CTNM对林分空间结构的单变量和双变量分布的影响，为评价林业实施的CTNM提供了科学依据。在这里，我们分析并比较了在有选择采伐和无节制控制的8年后CTNM下马尾松（Pinus massoniana）人工林（年轻，中年和近成熟阶段）的空间结构特征。我们使用三个空间结构参数的单变量和双变量分布：混合（M），优势（U）和均匀角索引（W）。结果表明，与幼龄林相比，中，近成熟马尾松林中CTNM对空间结构的影响更为显着。CTNM显着提高了混合程度，并促进了水平分布，从而从群集变为随机分布。此外，CTNM提高了中年和近年高混合度和随机分布树木的比例，以及具有高混合度和具有高混合度优势的具有随机分布的微观结构的树木的比例。马森成熟的松树林。总体而言，八年前CTNM的实施对改善马尾松林的空间结构产生了积极影响，但目前的空间结构并不理想。