不同海拔典型竹种枝叶大小异速生长关系

为了分析竹子枝-叶大小间的权衡关系,本研究对武夷山不同海拔典型竹种(毛竹、箬竹、肿节少穗竹、毛竿玉山竹和武夷山玉山竹)小枝的叶片总质量、茎质量、单叶质量和出叶强度等性状进行测定.结果表明: 随海拔升高,5个竹种间小枝上总叶质量与茎质量的异速生长指数呈显著下降趋势.竹种内,毛竹、箬竹和肿节少穗竹总叶质量与茎质量在不同海拔上均拥有共同异速生长指数(分别为0.94、0.85、0.84).毛竿玉山竹和武夷山玉山竹的叶茎质量也存在共同异速生长指数(0.79).除武夷山玉山竹外,竹子单叶质量与出叶强度之间均呈显著的负相关关系.5个竹种的单叶质量和出叶强度之间存在共同异速生长指数-1.12.总之,竹类植物的小枝总体上倾向于在低海拔环境中着生更多的叶片,而在高海拔生境下则投资更多的生物量到茎的构造上.尽管竹种间小枝的茎投资随海拔升高而增加,但其基于茎质量的出叶强度策略取决于叶片大小的构建而不是海拔生境差异.

Allometry between twig size and leaf size of typical bamboo species along an altitudinal gradient

To investigate the trade-off between the twig size and leaf size, we measured the total leaf mass, stem mass, individual leaf mass and leafing intensity of typical bamboo’s (Phyllostachys edulis, Indocalamus tessellatus, Oligostachyum oedogonatume, Yushania hirticaulis and Yushania wuyishanensis) twigs at different altitudes in Wuyi Mountain. The results showed that the exponents of the scaling between total leaf mass and stem mass on twigs significantly decreased with increasing altitude for all the five bamboo species. The common scaling exponents of total leaf mass vs. stem mass for P. edulis, I. tessellatus and O. oedogonatum were 0.94, 0.85 and 0.84, respectively. A common slope of 0.79 was observed in total leaf mass vs. stem mass in Y. hirticaulis and Y. wuyishanensis. There was significant negative correlation between individual leaf mass and leafing intensity among bamboo species, except Y. wuyishanensis. A common slope of -1.12 existed between individual leaf mass and leafing intensity for five bamboo species. In conclusion, bamboos at low altitudes tended to support more leaf biomass while preferring to invest more to stem biomass at high altitudes. Although the stem mass investment of different bamboo’s twig increased with altitude, the leafing intensity strategies based on stem mass were determined by the leaf size construction rather than altitude.