中亚热带喀斯特常绿落叶阔叶混交林典型树种的木质部解剖与功能特征分析  

Analysis of xylem anatomy and function of representative tree species in a mixed evergreen and deciduous broad-leaved forest of mid-subtropical karst region

作　　者：倪鸣源 ARITSARA Amy Ny Aina 王永强 黄冬柳 项伟 万春燕 朱师丹 NI Ming-Yuan;ARITSARA Amy Ny Aina;WANG Yong-Qiang;HUANG Dong-Liu;XIANG Wei;WAN Chun-Yan;ZHU Shi-Dan(Guangxi Key Laboratory of Forest Ecology and Conservation,College of Forestry,Guangxi University,Nanning 530004,China;State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources,College of Forestry,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学亚热带农业生物资源保护与利用国家重点实验室,南宁530004 [2]广西大学林学院广西森林生态与保育重点实验室,南宁530004

出　　处：《植物生态学报》2021年第4期394-403,共10页Chinese Journal of Plant Ecology

基　　金：广西八桂青年学者项目;广西自然科学基金(2017GXNSFBA198188)。

摘　　要：树木木质部主要由导管、纤维和薄壁组织组成,分别具有运输、支撑和贮存的生理功能。由于木质部空间限制,一种组织比例的增加会导致其他组织比例的降低,因而可能表现出权衡关系。分析木质部组织比例和权衡关系有助于了解植物的生理生态适应性。该研究选择中亚热带喀斯特常绿落叶阔叶混交林21种典型树种(10种落叶树种, 11种常绿树种),测定枝条木质部各组织比例,计算水力相关指标并分析性状之间的相关性。结果表明:(1)与全球木质部解剖数据对比分析,喀斯特树种木质部趋向具有较高比例的薄壁组织;(2)喀斯特树种导管组织比例与薄壁和纤维组织比例之间没有显著的相关性,但是薄壁和纤维组织比例之间有显著的权衡关系;(3)常绿和落叶树种的木质部水力运输安全性(导管壁加固系数)和效率性(理论导水率)均具有显著的权衡关系,但是这两个类群线性回归的截距存在显著差异,即在相同的理论导水率条件下,落叶树种比常绿树种具有较高的导管壁加固系数(安全性),可能与常绿树种具有更多的轴向薄壁组织有关。喀斯特树种木质部解剖特征表明薄壁组织的贮存功能对喀斯特树种(尤其是常绿树种)的干旱适应具有重要作用。Aims Vessel,fibers,and parenchyma are the main components of tree xylem.They are responsible for water transport,mechanical support,and water and nutrients storage.Given the limited xylem space,consistent investment in one type of tissue would constrain the space available for other types of tissue,thus resulting in a possible trade-off among different tissues in their fractions.Analysis of the fractions of tissue types in xylem and the trade-off would contribute to better understanding of the eco-physiological adaptation of plants.Methods We selected 21 characteristic tree species(10 deciduous and 11 evergreen)from a mixed evergreen and deciduous broad-leaved forest located in the mid-subtropical karst region,and measured their xylem tissue fractions.In addition,we calculated the hydraulic-related structural traits in xylems and examined the correlations among various traits.Important findings Compared to the global average values of xylem tissue fractions,the karst tree species tended to have a higher proportion of parenchyma.The fraction of vessel lumen was not correlated with fiber and parenchyma fractions across the tree species investigated.Instead,a significant trade-off was observed between fractions of fiber and parenchyma.A trade-off between the hydraulic efficiency(i.e.theoretical hydraulic conductivity)and safety(vessel wall reinforcement)was observed across both the deciduous and the evergreen tree species.The two contrasting group of karst trees differenced significantly in the intercepts of the lines for trade-offs.For given conductivity,the deciduous tree species exhibited stronger vessel well reinforcement(safety)than the evergreen tree species,which might be due to the fact that evergreen trees species had more axial parenchyma.Hence,this study revealed the specificity of xylem anatomy in karst tree species.Water and resource storage in xylem parenchyma are vital to karst trees(evergreens in particular)for their adaptation to the water-limiting environment.

关 键 词：导管组织 薄壁组织 纤维组织 导管壁加固系数 理论导水率 权衡 

分 类 号：S718.5[农业科学—林学]