大蜀山短毛椴落叶阔叶林优势种群生态位特征

Niche characteristics of dominant plant populations of Tilia breviradiata deciduous broad-leaved forest in Dashushan,Hefei

为了更好地了解优良园林树种短毛椴(Tilia breviradiata)的种群特征及其在群落中的功能作用,采用定量分析方法对大蜀山短毛椴群落优势种的种群生态位进行了研究。结果表明:该群落乔木层优势种中短毛椴、化香(Platycarya strobilacea)、朴树(Celtis tetrandr)、麻栎(Quercus acutissima)和小叶栎(Q.chenii)具有较大的生态位宽度,其B(L)i值分别为7.0350、3.8302、3.7147、3.5713、3.0506,B(sw)i值分别为2.0125、1.4509、1.3460、1.3300、1.2331;而层间植物紫藤(Wistaria sinensis)生态位宽度最小,B(L)i值和B(sw)i值仅有1.8556和0.6537。群落优势种之间生态位重叠值和生态位相似性比例值较小,物种之间对资源的需求相似性不高。生态位宽度较大的短毛椴与化香、牛鼻栓(Fortunearia sinensis)和锐齿槲栎(Quercus aliena Blume var.acuteserrata)的生态位重叠较高。随着群落的进一步演替,短毛椴更新幼苗的生态位宽度优势将逐步衰退,其优势地位有下降的可能。选择合适的恢复和保存方法为短毛椴更新层个体发育创造适宜的生境是保护该物种的有效途径。

The niche characteristics of dominant tree and shrub populations in Tilia breviradiata deciduous broad-leave forest were analyzed using a quantitative method in Dashushan of Hefei. The niche breadth, niche overlap and interspecific association were discussed in this paper via Levins, Shannon-Wiener and Pianka＇s algorithms. The results showed that the niche breadths of T. breviradiata were big, the Levins and Shannon-Wiener niche breadths of T. breviradiata in the tree layer was 7.035 0 and 2. 012 5 respectively. Niche similarities of main tree species was low. The niche overlap of T. breviradiata with others in tree layer was in range from 0. 32 to 0. 76, the niche overlap of T. breviradiata with Phyllostachys strobilacea, Fortunearia sinensis, Quercus aliena Blume var. acuteserrata was relatively high. The niche breadths of P. nidularia, Symplocos paniculata and the dominant species in shrub layer were also high. So did the niche overlaps among the species with the same or similar environmental requirements. Those between the species of broad niche breadth with other species were much greater, while the niche similarities among species with low niche breadths were large.