广西植物2017，Vol.37Issue(7)：868-880,13.DOI:10.11931/guihaia.gxzw201610025
黄土高原油松天然纯林结构特征的研究
Structural properties of natural Loess Plateau forest stands dominated by Pinus tabulaeformis
摘要
Abstract
The structure of vegetation strongly regulates community function and the future direction of successional processes.In this study, we deployed two sampling plots measuring 60 m × 60 m in natural vegetation dominated by Pinus tabulaeformis, and measured stand spatial properties by calculating uniform angle (W), mingling (M), and dominance (U) indices and by constructing elevation plots.Concurrently, we explored non-spatial attributes of the stands using frequency distribution plots of diameter at breast height (DBH), tree height (TH), and crown area (CA);we also calculated Shannon-Wiener tree height diversity indices.Both vegetation plots were dominated by P.tabulaeformis, which accounted for > 98% of trees in the area.Trees of different dimensions were spatially differentiated in a regular manner (U=0.478) with low species segregation (M=0.019).Tree dispersions in both plots were random in the horizontal plane (W=0.485).We found few small trees (TH ≤5 m) in the plots.Large trees (TH >10 m) made up the greatest proportion of the population (66.9%-84.1%), and their height distribution was clumped.The mean TH diversity index (THD) was 2.35.Most DBH values fell within the 14-34 cm range, and most (58.4%-62.8%) dimensionless CA indices were within the range of 20-40 m2.Recruitment of P.tabulaeformis was dense and unevenly dispersed, suggesting that these populations of mature natural stands were (i) unstable, (ii) tracking a declining trajectory, and (iii) destined for replacement by other species.关键词
油松/天然林/空间结构/非空间结构/角尺度/混交度/大小比数Key words
Pinus tabulaeformis/natural forest/spatial strucutre/non-spatial structure/uniform angle index/mingling/dominance分类
农业科技引用本文复制引用
李远发,叶绍明,王宏翔,胡艳波,赵中华,惠刚盈..黄土高原油松天然纯林结构特征的研究[J].广西植物,2017,37(7):868-880,13.基金项目
国家"十二五"科技支撑计划项目 (2012BAD22B03) （2012BAD22B03）
国家自然科学基金 (31400542) [Supported by National Sci-Tech Support Plan of China (2012BAD22B03) （31400542）
the National Natural Science Foundation of China (31400542)]. （31400542）
