黄土高原柴松群落空间结构

Spatial structure of Pinus tabulaeformis f. shekannesis community on Loess Plateau

利用角尺度、大小比数和混交度3个林分空间结构参数,分析了黄土高原柴松(Pinus tabulaeformisf.shekannesis)群落的空间结构特征。结果表明:1)该林分的树种组成为柴松:辽东栎(Quercus liaotungensis)∶其他树种=7∶2∶1,林分密度为3064株.hm-2,柴松种群优势度明显。2)柴松林林分平均混交度为0.33,处于弱度混交到中度混交过渡时期,种间隔离程度较小。3)柴松林林分平均角尺度为0.57,整个林分呈团状分布。4)林分平均胸径大小比为0.52,平均树高大小比为0.53,林木大小比数的分布较为均匀。胸径大小比和树高大小比在反映林木生长优势方面具有一致性。

Three spatial structure indices of stand, i.e., neighborhood pattern, neighborhood comparison, and mingling, were used to analyze the spatial structure of Pinus tabulaeformis f. shekannesis community on Loess Plateau. The tree species composition in the stand was 7：2：1 for P. tabulaeformis f. shekannesis, Quercus liaotungensis, and other tree species. The stand density was 1325 trees·hm2, and P. tabulaeformis f. shekannesis population was on an obvious dominant position. The average mingling in P. tabulaeformis f. shekannesis stand was 0.33, showing that the stand was at the transition period of weak mixed status to moderate status, and the isolation degree of the stand was moderate. The average neighborhood pattern of the stand was 0.57, indicating that the stand was assembly distributed. The average neighborhood comparison of DBH and tree height in the stand was 0.52 and 0.53, respectively, and the distribution of neighborhood comparison was quite even. The average neighborhood comparison of DBH and tree height was in great consistent advantage in reflecting tree growth.