三峡库区两种阔叶树幼苗对不同光环境的响应  

Growth and Morphological Response to Different Light Regimes in Seedlings of Two Broad-leaved Tree Species in Three Gorges Reservoir Region

作　　者：秦银林[1] 方兴[2] 陶建平[1] 黄茹[1] 王莲[1] 左娟[1] 张海坦[1] 

机构地区：[1]西南大学三峡库区生态环境教育部重点实验室重庆市三峡库区植物生态与资源重点实验室生命科学学院,重庆400715 [2]重庆师范大学学报(自然科学版)编辑部,重庆400047

出　　处：《重庆师范大学学报（自然科学版）》2009年第2期54-57,共4页Journal of Chongqing Normal University:Natural Science

基　　金：国家科技支撑计划(No.2006BAD03A1006)

摘　　要：研究了三峡库区两种阔叶树香樟(Cinnamomum camphora)和灯台树(Bothrocaryum controversum)幼苗在旷地、林窗和林下三种不同的自然光环境梯度的生长和形态特性对不同光环境的响应。结果显示,在3种不同光环境下生长两年的香樟和灯台树幼苗,株高、基径、地上部分生物量、根生物量和总生物量等绝对生长指标均表现出旷地>林窗>林下,且旷地植株与林下植株均差异显著;在形态可塑性方面,香樟幼苗的根冠比均表现为在不同光环境下差异不显著(p>0.05),灯台树幼苗则表现为旷地植株显著高于林窗和林下植株(p<0.05),表明旷地的灯台树幼苗受到了一定程度的光抑制;两物种细长指数和叶面积比随环境光强减小而增大,而总叶面积和展开叶片数均随环境光强的减小而减小;香樟和灯台树的净同化率和相对生长速率都表现出旷地和林窗植株显著大于林下植株(p<0.05),但两物种间这两个指标在不同光环境中均未表现出显著差异。上述结果说明香樟和灯台树幼苗均在光资源充足的旷地环境下生物量积累最多,但幼苗的适当遮荫能有效地避免光抑制,从而有利于植株更好地生长。Growth and morphology of young seedling of Cinnamomum camphora and Bothrocaryum controversum, two familiar species in Three Gorges Reservoir region, in relation to three fight regimes （open land, gap and understory） are investigated here. We have measured relative indices of the young seedlings in three light regimes which have grown for two years. The results show as follows： in open land, the seedlings of C. camphora and B. controversum demonstrate that the absolute growth （main stem height, collar diameter , shoot biomass , root biomass , and total biomass） is higher than that in gap or understory, while that of the seedlings in open land is significantly higher than that in understory （p 〈 0.05 ）. In respect of morphological characteristics, the root and shoot ratio of the seedlings of C. camphora are not significantly different in three light regimes, but that of the seedling of B. controversum in open land is significantly higher than that in gap or understory （p 〈 0.05 ）, which demonstrate that the seedlings of B. controversum in open land suffered photoinhibition to a certain extent. When the PPFD decreases, the slenderness coefficient and the leaf area ratio of the two species increases, while the total leaf area and the number of leaves decreases. The net assimilation rate and the relative growth rate of the two species both demonstrate that the seedlings in open land or gap land are significantly higher than that in understory （p 〈 0.05 ）. However, the net assimilation rate and the relative growth rate between the two species demonstrated no significant differences at any light regime. These results indicate that the seedlings of C. camphora and B. controversum in open land accumulate the most biomass, and some suitable shelter can keep the seedlings from photoinhibition, which makes seedlings grow quickly.

关 键 词：三峡库区 香樟 灯台树 幼苗 生长 形态 光环境 

分 类 号：Q948.112[生物学—植物学]