中文摘要：

以管涔山常见野生灌木土庄绣线菊Spiraea pubescens为材料,选择10%~20%、30%~40%、50%~60%和100%4种相对光强水平,研究了不同森林光环境下生长的土庄绣线菊成年植株的光合特性、光合色素含量、比叶面积、高茎比和生物量分配特征,调查了土庄绣线菊在生理生态特征上的光适应性和表型可塑性,为森林生态系统的维护和恢复提供依据。结果表明：深度遮荫（10%~20%）相对于全光照下土庄绣线菊成年植株最大净光合速率、叶绿素a/b降低,胞间/大气CO2浓度比、叶绿素a含量、类胡萝卜素/叶绿素总量、比叶面积升高。高径比、根生物量比、茎生物量比和地上地下生物量比的极值出现在中度（50%~60%）或轻度（30%~40%）遮荫下。随着遮荫的加剧,蒸腾速率、叶生物量比未发生变化。土庄绣线菊生理可塑性和生物量分配可塑性均较低。土庄绣线菊对不同光环境的生理生态响应说明它是耐阴兼性喜光的,对光环境的适应性强,这与土庄绣线菊分布广泛的特点相一致。

英文摘要：

Naturally regenerated adult plants of Spiraea pubescens growing in four different light environments（10%~20%,30%~40%,50%~60% and 100% transmittance levels） in Guancen Mountains were selected to investigate the photosynthetic parameters and pigment contents,SLA,H/D and biomass allocation patterns of Spiraea pubescens under field conditions.Furthermore,acclimation to low light and phenotypic plasticity of Spiraea pubescens were investigated.The results show that the Amax and Chl a/b ratios under deep shade（relative light intensity 10%~20%） were lower than that of full exposure（100%）,Ci/Ca,Chla,Car/Chl,SLA under deep shade（10%~20%） were higher than that of full exposure（100%）.The maximum values of H/D ratios,RMR and SMR were observed under moderate or slight shade.Transpiration rate and LMR were not affected by changes in light intensities.Morphological plasticity and physiological plasticity of Spiraea pubescens were low.Ecophysiological responses to different light regimes of Spiraea pubescens show the characteristics of a shade intolerant species,but the characteristics of a shade intolerant species was also observed.Moreover,the different ecophysiological responses of Spiraea pubescens were corresponding with its ecological distributions.