中山杉功能性状适应三峡库区消落带研究  

Ecological adaptation of Taxodium ‘Zhongshanshan’ to different water levels in the riparian zone of Three Gorges Reservoir : A functional trait perspective

作　　者：阮宇[1] 胡景涛 肖国生[1] 李俊清[2] 任凭 RUAN Yu;HU Jingtao;XIAO Guosheng;LI Junqing;REN Ping(Chongqing Three Gorges University,Chongqing 404020,China;Beijing Forestry University,Beijing 100091,China;Chongqing Wanzhou Forestry Institute,Chongqing 404188,China)

机构地区：[1]重庆三峡学院,重庆404020 [2]北京林业大学,北京100091 [3]重庆市万州区林业科学研究所,重庆404188

出　　处：《生态学报》2022年第7期2921-2930,共10页Acta Ecologica Sinica

基　　金：三峡水库生态环境保护和灾害防治重庆市2011协同创新中心资助;重庆市科技局项目(cstc2020jcyj-msxmX0073)资助。

摘　　要：植物功能性状研究是生态学的热点,它能够很好地解释植被对环境变化的适应机制。中山杉(Taxodium‘Zhongshanshan’)能够在三峡库区不同水位高度的消落带上生长,但对它在消落带上的适应性研究较少。按水位高度不同,将消落带171—175 m划分为浅水区(SS)、168—171 m为中度水淹区(MS)、165—168 m为深度水淹区(DS)3个样带及对照组(LS),每个样带内随机选取25—30株中山杉,通过测定树高、叶表宽度、叶厚度、非结构型碳水化合物含量、有机酸含量等功能性状,研究中山杉功能性状特征及变化规律。结果表明,深度水淹区(DS)叶片表现出旱生性状,气孔孔径变小,栅栏组织变厚。消落带171 m以上中山杉的生长状况显著优于171 m以下。中度水淹区(MS)根系中的非结构型碳水化合物、可溶性糖、淀粉、酒石酸、苹果酸及柠檬酸含量高,而深度水淹区(DS)却相反,但草酸含量最高。从功能性状比较看,浅水区(SS),水淹期恰好是中山杉生长缓慢的时期,中山杉的生长周期未受到影响,与对照组相比,功能性状差异不显著。中度水淹区(MS),中山杉代谢活跃,水淹胁迫引发的功能性水平上的变化和反应是可逆的,中山杉能够自我恢复,胁迫在中山杉的自身调节能力极限范围内,植株能保持正常的生长发育,具有较强的生活力。与浅水区(SS)相比,中度水淹区(MS)的植株生长状况明显劣于浅水区,但它们的存活率相似,都较高。而深度水淹区(DS)水淹期6个月,高温期2—3个月,胁迫已造成植株受到慢性或不可逆地伤害,退水后,根系不能较快恢复正常代谢,植株生长周期短,生命力变脆弱,随着水淹次数增加,植株易死亡。植株的高度和大小与中度水淹区(MS)差异不显著,但植株存活率低。Plant functional trait is recognized as an effective tool in explaining the adaptive mechanism of vegetation to environmental change. A coniferous tree, Taxodium ′Zhongshanshan′, is widely planted and grows well in the riparian zone of the Three Gorges Reservoir. However, there are few studies on ecological adaptation of T. ‘Zhongshanshan’ to different water levels in the riparian zone. According to the depth of different water levels, the water-level fluctuation zone was divided into three transects: the shallow submergence(SS) of 171—175 m, the moderate submergence(MS) of 168—171 m, the deep submergence(DS) of 165—168 m, and no flooded(LS). A total of 25—30 T. ‘Zhongshanshan’ trees were randomly selected from each transect to analyze the characteristics and their changes of functional traits across different water levels. A series of plant functional traits were measured at each sample tree, mainly including tree height, the width of leaf epidermis, vane thickness, non-structural carbohydrates and organic acid, etc. Our results showed the leaves in DS showed the xerophytic characters, with smaller stomatal aperture and thicker palisade tissue. The growth of T. ‘Zhongshanshan’ above water level 171 m was significantly better than that below 171 m. The contents of non-structural carbohydrates, soluble sugar, starch, tartaric acid, malic acid and citric acid in roots were higher in MS, but the contents of oxalic acid were the highest in DS. We compared the functional traits in different transects. In SS, the flooding period happened to be the slow growth period of T. ‘Zhongshanshan’, which did not affect tree growth. There were no significant differences in functional traits compared with the control group. In MS, when the water receded in February, the climate was just suitable for the sprout of T. ‘Zhongshanshan’, the water stress decreased and the roots of T. ‘Zhongshanshan’ entered into the recovery stage earlier. The functional changes and responses induced by stress were r

关 键 词：功能性状 中山杉 三峡库区 消落带 适应机制 

分 类 号：S791.34[农业科学—林木遗传育种]