中文摘要：

利用角尺度和大小比数结构参数,对陕西省榆林市珍稀沙生植物保护基地内不同梯度密度下的樟子松人工林林分空间结构进行了分析。结果表明：1）从角尺度取值来看,各样地林木个体分布以均匀分布为主,且核心区林木数量随林分密度的增加而减少;2）以分枝角为度量的大小比数反映各样地林木的大小分化程度,可信度较高。因此,通过分枝角的评价指标来评估樟子松单木的竞争优势及造林后防风固沙效果是可行的。研究结果可为探索毛乌素沙地樟子松建群种的植物固沙模式选择及管护治理工作提供理论支撑。

英文摘要：

In our research,uniform angle index and neighborhood comparison were applied to different densities of Mongolian pine plantation to analyze their stand structure characteristics.The results showed that （1 ）Evenness distribution was the main spatial characteristics for the most of stands,and number of trees in the core area decreases with the density increasing.（2）The neighborhood comparison measured by branch angle was a visibly higher,thus,it is possible to evaluate the ranch angle index to achieve its predominance status among individuals competition and to enhance its effect on desertification.The conclusions of this study can provide important support for afforestation and forest management in this region.