年龄对刨花楠胸径生长速率的影响

了解年龄对树木胸径生长的影响,对于研究森林群落结构、功能及碳循环等具有重要意义。代谢生态学认为植物的胸径生长速率正比于其胸径的1/3次幂。然而,最近的研究对该理论提出了质疑。通过分析刨花楠解析木数据,结果表明,胸径生长速率与胸径成异速生长关系,但不同年龄具有不同胸径异速生长指数,不支持代谢生态学的推论。随着年龄增加,刨花楠胸径生长呈现先减小后增加模式,这可能是由于植物对光资源的利用造成的。

Effects of stand age on stem-diameter growth of Machilus pauhoi

Understanding the effects of stand age on tree growth is central to forest ecology because of the significance of growth to forest structure, function and carbon flux. Metabolic theory of ecology predicts that stem-diameter growth scales as the 1/3 power of stem diameter. However, recent researches have challenged the generality of this theory, leading to a vigorous debate. In this paper, we examined data for tree stem-diameter growth of Machilus pauhoi to determine the effects of age on tree growth. Our results show that for the different stand age, M. pauhoi have different scaling exponents for tree stem-diameter growth, which significantly deviate from the one-third scaling law predicted by the metabolic theory of ecology. Furthermore, we argue that the different scaling exponents for tree stem-diameter growth with tree growth are led by the influence of light competition on the scaling of growth with size.