桥山林区不同坡向麻栎林种群生态位特征分析

Effects of Different Aspects on Niche Characteristics of Plant Populations in Quercus acutissima Forest in Qiaoshan Mountain

为研究天然麻栎林种群生态位特征,应用Levins(LB)、Hurlbert(HB)和Pianka公式,对桥山林区24个400m^2天然麻栎林群落内10种乔木、25种灌木和5种草本的生态位宽度和生态位重叠进行计算、分析。结果表明:1)麻栎和茶条槭为乔木层的优势种群,狼牙刺、胡枝子和南蛇藤为灌木层的优势种群,苔草为草本层的优势种群,它们的生态位宽度较大,对环境资源的利用较充分,坡向对其生态位宽度影响较小;2)乔木层的杜梨、灌木层的卫矛、南蛇藤、胡枝子、鼠李,对光照与水分的要求较苛刻,其生态位宽度受到坡向的影响,而草本层的物种生态位宽度并未受坡向影响;3)阳坡麻栎林乔灌草的生态位重叠值较阴坡偏大,阳坡存在种间竞争使得物种丰富度降低,阴坡应对辽东栎、茶条槭等伴生树种和狼牙刺、胡枝子等生态位宽度较大的灌木进行适当间伐,增大林窗面积,提高植物对环境资源的利用率。

The ecological niche characteristics of the natural Quercus acutissima forest community in Qiaoshan mountain were studied.We calculated and analyzed the ecological niche width and niche overlap of all species in 24 sample plots at different slope directions,through Levins(LB),Hurlbert(HB)and Pianka formula.The results showed that the dominant trees were Quercus acutissima and Acer ginnala,the dominant shrubs were Sophora davidii,Lespedeza bicolor and Celastrus orbiculatus,and the dominant herb was Carex lanceolata.The slope direction had no influence on ecological niche width of these species because of their full utilization of environmental resources.The ecological niche width of Pyrus betulifolia,Euonymus alatus,Celastrus orbiculatus,Lespedeza bicolor and Rhamnus davurica were influenced by the slope direction,because of the limitation of temperature and moisture,but this phenomenon was not found in herbaceous species.Due to the limitation of moisture,in sunny slope plots,species were highly competitive and the richness was low.The ecological niche overlap values of species in sunny slope plots were greater.