南亞熱帶厚殼桂(Cryptocarya Chinensis)不同生活階段種群

本文使用Ripley點格局分析法在不同距離尺度上(0～40m)對南亞熱帶厚殼桂種群分佈格局進行了分析，並把厚殼桂種群依據胸徑和高度大小分為5個年齡級，進行了各年齡級內分佈格局和各年齡級間相互關係研究。結果表明厚勃桂種群整體在不同的空間尺度下呈明顯的聚集分佈，但各年齡級分佈格局不同。低幼齡個體不在不同的空間尺度上均呈明顯聚集分佈，但高齡個體在較小的空間尺度上呈現隨機分佈格局。各年齡級間相互關係研究表明低幼齡個體在中小空間尺度上呈明顯的聚集分佈，在大空間尺度上呈獨立分佈：高齡個體之間以及與低幼齡個體之間在整個空間尺度上多呈獨立分佈。上述結果表明厚殼桂早期生長需適宜的生態環境，後期生長受到種內競爭的影響。

關鍵字

厚殼桂；種內競爭；生活階段；空間格局；空間統計

並列摘要

Two aspects of life stages are important determinants in the spatial pattern of plant populations: one is spatial distribution of individual plants within life stages; the other is spatial association between different life stages. Using Ripley's univariate L(t) and bivariate L(subscript 12)(t) functions, we analyzed the spatial pattern within and between life stages of Cryptocarya chinensis in an 80 m × 80 m plot in lower subtropical China. Based on stem diameter and height, five life stages (Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ) were distinguished. Ripley's univariate L(t) function showed clumped distributions within all life stages, with fine-scale random distributions in old life stages Ⅳ and V. From the bivariate L12(t) function, young life stages Ⅰ, Ⅱ and Ⅲ appeared significantly attractive to each other at local and intermediate distances, but independently distributed regarding old life stages Ⅳ, Ⅴ at almost all distances. The oldest life stage, Ⅴ, was independently distributed relative to other life stages. Considering these results, we inferred that the existence of suitable survival environments (e.g. canopy gaps) are a determinant in shaping the spatial pattern of young life stages of C. chinensis; with increasing body size with growth, intraspecific competition develops, and a fine-scale random distribution appears within old life stages.

並列關鍵字

Cryptocarya chinensis ； Intraspecific competition ； Life stage ； Spatial pattern ； Spatial statistics

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南亞熱帶厚殼桂(Cryptocarya Chinensis)不同生活階段種群

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