西双版纳热带雨林幼树C、N、P的生态化学计量比对海拔变化的响应

Response of C:N:P ecological stoichiometric ratio of young tree leaves in tropical seasonal rain forest of Xishuangbanna to change of altitude

在西双版纳选取热带山地雨林和热带季节雨林中4种优势种幼树,测定了幼树叶中C、N、P的生态化学计量特征,目的在于揭示雨林树种对环境变化的生态适应策略。结果表明:(1)山地雨林幼树叶中碳含量平均值为478.67 mg·g-1,高于季节雨林的463.33 mg·g-1;(2)幼树叶中P含量季节雨林显著高于山地雨林,平均值分别为1.92 mg·g-1和0.93 mg·g-1;(3)幼树叶中C︰N季节雨林和山地雨林的平均值基本相当,分别为27和27.4,但树种间差异较大;(4)叶中C︰P和N︰P均表现出季节雨林显著低于山地雨林的特征,2种雨林的平均值分别为254.2、606.9和9.7、21.4。4种雨林幼树叶中具有较高的碳含量,而山地雨林具有更高的碳蓄积能力;幼树叶中C、N、P的生态化学计量比对海拔变化的响应较为显著。

For better understanding ecological adaptability of the species living in different tropical rain forest types across a altitude of change in Xishuangbanna to environmental change, the ratio of C：N：P of leaves of four kinds of young tree species coming from tropical seasonal rain forest and tropical montane rain forest in different altitude in were measured. These findings show that （1） the mean of C content of leaf for species living in montane rain forest was higher than that in seasonal rain forest, which were 478.67 mg.g-1 and 463.33 mg.g-1 respectively; （2） the mean of P content of leaf for species living in seasonal rain forest was higher than that in montane rain forest, which were 1.92 mg.g-1 and 0.93 mg.g-1 respectively; （3） the mean of C：N of leaf for was evenly split between seasonal and montane rain forest, which was 27 and 27.4 respectively; （4） both C ： P and N ： P of leaf of young tree living in seasonal rain forest were significant lower than that in montane rain forest. The means ofC ： P and N ： P for 2 kinds of rain forest types were 254.2, 606.9 and 9.7, 21.4 respectively. In conclusion, the C content of all young trees were relatively high, and the C storage ability of these species in montane rain forest was higher than that in seasonal rain forest. The response of C ： N ： P of leaf of young tree to altitude of change was obvious.