采用样方调查法研究了安徽铜陵叶山次生阔叶混交林不同坡位5 个样带中20 个主要树种的重要值,并对其中14 个主要树种的生态位宽度(包括Levins 和Hurlbert 生态位宽度)、生态位相似比例和生态位重叠值进行了计算和分析。结果表明:各样带中的树种组成明显不同,麻栎(Quercus acutissima Carr.)的重要值在Q2 样带中最高,而马尾松(Pinus massoniana Lamb.) 的重要值则随着海拔的升高逐渐增大并在Q5 样带中达到最高;5 个样带中麻栎的重要值总和最高,达195. 481,说明麻栎在该次生阔叶混交林中占有明显优势。该群落主要树种麻栎、苦槠[Castanopsis sclerophylla (Lindl.) Schott.]、白栎(Quercus fabri Hance)、青冈栎[Cyclobalanopsis glauca (Thunb.) Oerst.]、石栎[Lithocarpus glaber (Thunb.) Nakai]和山鸡椒[Litsea cubeba (Lour.) Pers.]的Levins 生态位宽度值分别为0. 666、0. 664、0. 653、0. 609、0. 594 和0. 541, Hurlbert 生态位宽度值分别为0. 856、0. 862、0. 756、0. 613、0. 717 和0.514,这些主要树种的2 项生态位宽度指标均较大且排列顺序基本一致,进一步说明麻栎为该次生阔叶混交林的优势种。该群落中,生态位宽度高的树种间生态位相似比例和生态位重叠值都较高;生态位相似比例在0. 3 以上的种对有58 个,占总种对数的63. 7%;生态位重叠值在0. 4 以上的种对有53 个,占总种对数的58. 2%,说明该群落尚未演替至稳定的常绿阔叶林群落状态。

By plot investigation method, important value of twenty main tree species in five sample belts with different slope positions of secondary broad-leaved mixed forest in Yeshan of Tongling of Anhui Province was researched, and niche breadth (including Levins’ and Hurlbert’ s niche breadths), niche proportional similarity and niche overlap value of fourteen main tree species among them were calculated and analyzed. The results show that the tree species composition of different sample belts is obviously various, the important value of Quercus acutissima Carr. in Q2 sample belt is the highest, while that of Pinus massoniana Lamb. increases gradually with rising of altitude and reaches the highest value in Q5 sample belt; the total important value of Q. acutissima in five sample belts is the highest with a value of 195. 481, meaning that Q. acutissima has a dominant position in this secondary broad-leaved mixed forest. In this community, Levins’niche breadth value of Q. acutissima, Castanopsis sclerophylla (Lindl.) Schott., Quercus fabri Hance, Cyclobalanopsis glauca ( Thunb.) Oerst., Lithocarpus glaber (Thunb.) Nakai and Litsea cubeba (Lour.) Pers. is 0. 666, 0. 664, 0. 653, 0. 609, 0. 594 and 0. 541, respectively, and their Hurlbert’s niche breadth value is 0. 856, 0. 862, 0. 756, 0. 613, 0. 717 and 0. 514, respectively, the two niche breadth indexes of these main tree species all are higher and their arrangement order is essentially consistent, further meaning that Q. acutissima is dominant species of this secondary broad-leaved mixed forest. In this community, niche proportional similarity and niche overlap value among tree species with higher niche breadth all are higher; there are 58 species-pairs with niche proportional similarity of above 0. 3, accounting for 63. 7% of the total species-pair number; there are 53 species-pairs with niche overlap value of above 0. 4, accounting for 58. 2% of the total species-pair number, meaning that this community has not been evolving to steady evergreen broad-leaved forest community.