晋西皇姑梁小流域人工植物群落优势种生态位和种间关系研究

Niche and interspecific association among dominant species in the planted communities at Huangguliang small watershed in the western Shanxi province

在野外102个样方调查数据和双向指示种分析法(TWINSPAN)分类的基础上,采用生态位宽度、生态位重叠、χ2检验和Spearman秩相关系数,对晋西皇姑梁小流域12个群落的12个优势种的生态位和种间关系进行了研究。结果表明:乔灌层Levins生态位宽度较大的种为油松、柠条锦鸡儿、沙棘。12个优势种组成的66个种对中,Pianka重叠指数≥0.4的种对占总对数的45.45%。呈极显著和显著关联的种对数较少,正负关联比均小于1。说明该小流域人工植物群落结构简单,种间资源竞争较激烈,仍处于演替的初、中期阶段。优势种华北落叶松与沙棘,沙棘与鹅观草呈显著正相关,它们均为地带性物种,生态适应性强,可作为皇姑梁小流域人工植被恢复的优选物种进行混种,而油松与小叶杨、小叶杨与沙棘或柠条锦鸡儿等种对间呈极显著负相关,在植被恢复中不宜混种。根据Spearman秩相关系数结果,将12个优势种划分为3个生态种组。

Based on the field investigation data of 102 plots and the results of two-way indicator species analysis（ TWINSPAN） classification,the niche breadth,niche overlap,χ2-test and Spearman rank correlation coefficient were used to analyze the interspecific relationship of 12 dominant species in the planted communities at Huangguliang small watershed in the western Shanxi province. The results showed that the Levins niche breadth of Pinus tabulaeformis,Caragana korshinskii and Hippophae rhamnoides were the highest in the tree layer and shrub layer,respectively. The value of Pianka niche overlap index（ Qik） was above 0. 4 for more than 45. 45%species-pairs. The interspecific associations of most species-pairs among the 12 dominant species were not significant（ p 0. 05）,which indicated that the planted communities at Huangguliang small watershed had simple community structures and fierce competition for interspecific resource. Accordingly these planted communities were still at the early or middle stage of succession. The dominant species pairs of Hippophae rhamnoides and Larix principis-rupprechtii or Roegneria Kamoji showed significant positive correlation,these zonal species had strong ecological adaptability for tolerating drought and poor soil fertility,and thus could be planted in such combinations in actual revegetation practice at Huangguliang small watershed in the western Shanxi province. While the species-pairs of Pinus tabulaeformis and Populus simonii,Populus simonii and Hippophae rhamnoides or Caragana korshinskii had significantly different negative correlations,and thus should not be planted in such pairs in actual revegetation practice. Based on Spearman＇s rank correlation coefficients,the 12 dominant species were divided into three ecological species groups.