Forest structures may be analyzed by considering both spatial and non-spatial aspects. These aspects are generally considered independently with little attention focusing on their association. However, the relationships between spatial and non-spatial structures may aid in explaining the characteristics of forests from various perspectives. In this paper, we analyzed the spatial structures of a mixed pine-oak forest with different-sized trees and the relationships among stand spatial structural parameters. This forest, located in the Nanpan River Basin in Southwest China, was in the early stage of succession. Our results showed that: (1) most species populations and trees of different sizes were nearly randomly distributed; (2) the degree of mixture gradually increased with an increase in individual plant size; (3) dominance increased with increasing individual size and could be well modeled by a negative exponential function; (4) there were no clear differences in mixture or distribution patterns among small-, medium- and large-sized trees in vertical layers, but large-sized trees were usually more dominant than small- and medium-sized trees; and (5) the distribution patterns of trees of different sizes had no association with species mixing or dominance, although there was a significant correlation between the degree of mixing and dominance. These findings indicate that tree size directly relates to the non-spatial structure of forests while also predicting their spatial structure characteristics accurately.

中文翻译：

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演替初期次生林不同大小树种的空间结构

可以通过考虑空间和非空间方面来分析森林结构。这些方面通常被独立考虑，很少关注它们的关联。然而，空间和非空间结构之间的关系可能有助于从不同角度解释森林的特征。在本文中，我们分析了不同大小树木的松橡混交林的空间结构以及林分空间结构参数之间的关系。这片森林位于西南南盘河流域，处于演替初期。我们的研究结果表明：（1）大多数物种种群和不同大小的树木几乎是随机分布的；(2)混合程度随着单株大小的增加而逐渐增加；(3) 优势随着个体大小的增加而增加，并且可以用负指数函数很好地建模；(4)小、中、大乔木在垂直层次上的混合分布格局没有明显差异，但大乔木通常比中小乔木占优势；(5) 不同大小树木的分布格局与物种混合或优势无关，尽管混合程度和优势之间存在显着相关性。这些发现表明，树木大小与森林的非空间结构直接相关，同时也能准确预测其空间结构特征。(4) 小、中、大乔木在垂直层次上的混杂分布格局没有明显差异，但大乔木通常比中小乔木占优势；(5) 不同大小树木的分布格局与物种混合或优势无关，尽管混合程度和优势之间存在显着相关性。这些发现表明，树木大小与森林的非空间结构直接相关，同时也能准确预测其空间结构特征。(4)小、中、大乔木在垂直层次上的混合分布格局没有明显差异，但大乔木通常比中小乔木占优势；(5) 不同大小树木的分布格局与物种混合或优势无关，尽管混合程度和优势之间存在显着相关性。这些发现表明，树木大小与森林的非空间结构直接相关，同时也能准确预测其空间结构特征。(5) 不同大小树木的分布格局与物种混合或优势无关，尽管混合程度和优势之间存在显着相关性。这些发现表明，树木大小与森林的非空间结构直接相关，同时也能准确预测其空间结构特征。(5) 不同大小树木的分布格局与物种混合或优势无关，尽管混合程度和优势之间存在显着相关性。这些发现表明，树木大小与森林的非空间结构直接相关，同时也能准确预测其空间结构特征。