崖柏群落优势乔木种群生态位

Niche of Dominant Arbor Populations in Thuja sutchuenensis Community

采用定量分析方法,对崖柏群落中15个优势乔木种群的重要值、生态位宽度和生态位重叠进行分析。结果表明:崖柏种群的重要值和水平生态位宽度都显著高于其他种群,川陕鹅耳枥、高山栎和华千金榆等种群的水平生态位宽度值较大,虎皮楠、铁杉、中华槭和川鄂山茱萸种群的水平生态位宽度值较小;各种群的水平生态位宽度值与重要值呈显著正相关;崖柏种群对其他种群的水平生态位重叠值高于其他种群对崖柏种群的生态位重叠值,反映出崖柏种群具有较强的竞争能力;崖柏群落优势乔木种群间水平生态位重叠值较小,说明现存崖柏群落结构具有一定的稳定性;高山栎、乌岗栎和青榨槭的垂直生态位宽度值大于崖柏,原因在于崖柏结实母树少,林下更新幼苗、幼树少;崖柏对小叶青冈、城口青冈、乌岗栎和铁杉等种群的垂直生态位重叠值较大,说明它们之间在利用随着高度变化的以光因子为主导的生态资源方面存在较强的竞争。

The niche breadth and niche overlap of 15 main arbor populations in Thuja sutchuenensis forests were analyzed by a quantitative method. The result showed that the importance value and horizontal spatial niche breadth of T. sutchuenensis was the biggest, the horizontal spatial niche breadth of Carpinus fargesiana, Quercus semicarpifolia and Carpinus cordata var. chinensis was bigger than other species, the horizontal spatial niche breadth of Daphniphyllum oldhamii, Tsuga chinensis, Acer sinense and Macrocarpium chinense was smaller than other species. There was a positive correlation between the horizontal spatial niche breadth and the importance value. Thuja sutchuenensis had bigger horizontal spatial niche overlap with other species, this result reflected that T. sutchuenensis had strong capacity in adaptation and competition. The horizontal spatial niche overlap between the dominant species in T. sutchuenensis forests was smaller, this result showed that T. sutchuenensis forests was stability. The height niche of T. sutchuenensis was smaller than that of Quercus semicarpifolia, Q. phillyraeoides and Acer davidii, because the number of mother trees and saplings was smaller. The height niche overlap between Thuja sutchuenensis with Cyclobalanopsis gracilis, C. fargesii, Quercus phillyraeoides and Tsuga chinensis was bigger, the reason for this phenomenon was that these species had stronger interspecific competition in light factors.