【作者】 宋利霞；

【导师】 陶建平；

【作者基本信息】 西南大学 ， 生态学， 2006， 硕士

【摘要】 时空异质性是生境的基本特征。几乎所有植物都是在一定尺度的时空异质性环境中完成其生活史的。在进化过程中，植物可能形成了各种有效利用环境异质性的生态适应对策。克隆生长使得克隆植物在理论上更容易适应于异质性环境。本文以华西箭竹(Fargesia nitida)为研究对象，基于野外调查，研究了该物种在林下、中林窗、大林窗和林缘旷地等四种亚高山暗针叶林林冠环境下的生态适应对策。 对四种林冠环境下华西箭竹分株种群表现结构(株高、基径和生物量)和年龄结构进行了较系统的对比研究。主要研究结果如下：(1)分株水平上，华西箭竹表现结构在四种林冠环境下均有极显著差异，且随林冠郁闭度的减小，分株个体的高度、基径和生物量有递增的趋势(林下＜中林窗＜大林窗)；(2)分株各构件在总生物量中所占比例随林冠环境变化而改变：除林缘旷地外，叶的生物量百分比与林冠郁闭度呈正相关。林缘旷地中，地下茎和根系的生物量百分比均高于其余三种环境；(3)不同林冠环境下分株单位叶面积叶重存在显著差异，且随林冠郁闭度的减小而增大。单叶生物量和单叶面积均以中林窗最大，林缘旷地次之，二者与大林窗或林下均有显著差异。华西箭竹的单株叶片数量以大林窗最大，与其余三种环境有极显著差异；(4)分株种群的死亡率以林下最低，但各种群平均年龄间无显著差异。可见，华西箭竹分株种群对林冠环境变化的反应主要体现在形态和生物量分配上，而非种群的年龄上。 对四种林冠环境下华西箭竹种群的无性系数量特征、无性系根茎特征、基株生物量特征、分株生物量以及分株形态特征进行了较系统的对比研究。主要研究结果如下：(1)从林下→中林窗→大林窗，随林冠郁闭度的减小，华西箭竹的基株密度逐渐降低，而基株分株数逐渐增加。种群的分株密度在四种林冠环境下无显著差异；(2)不同林冠环境间，基株生物量和基株构件生物量差异显著：大林窗中基株的地上部分及旷地中基株的地下部分各构件生物量均是最大，林下环境中基株各构件的生物更多还原

【Abstract】 Heterogeneity in space and in time is the ubiquitous feature of habitats.Almost all plants complete their life histories in temporally and spatially heterogeneous environments at certain scales.In the evolutionary process, plants may have constituted various adaptive strategies to cope with environmental heterogeneity. In principle, clonal growth contributes markedly to the ability of clonal plants to make use of environmental heterogeneity. The bamboo Fargesia nitida, one of the Giant Panda’s main food sources and dominant shrub species of the forest understory, is mainly distributed in the dark coniferous belt (at altitudes of 2450m to 3200m) in western Sichuan and southern Gansu in China. To study ecological strategies of the clonal plant Fargesia nitida to different canopy conditions of sulbalpine dark coniferous forest four experiments were carried out in four different forest canopy conditions, including forest understory(FU),moderate gap(MG), large gap(LG) and forest edge wildernessness(FEW).In order to reveal whether these four canopy conditions affect the ramet structures and to estimate the effect sizes, a field census of Fargesia nitida populations’ age structure, morphological traits(culm height, basal diameter and leaf area) and biomass allocation was conducted in four different forest canopy conditions.The main results showed that:(l) At the ramet level ,the performance structures of the four populations were significantly different(one-way ANOVA, P<0.01), and as the canopy cover decreased the mean height, basal diameter and biomass of the populations increased in the order FU<MG<LG;(2) The modular biomass proportions of ramets varied with different canopy conditions and leaf biomass proportion was positively related to canopy cover except for FEW, in which the biomass proportions of更多还原