黄土高原多年生草本根部导水策略空间异质性特征  

Spatial differences of root anatomical traits and hydraulic efficiency of perennial herb species on the Loess Plateau

作　　者：李宗善 陈颖[1,3] 董彦君[1] 焦磊 李兆林 王聪 高光耀 石丽娜 张淑娟 白应飞 LI Zongshan;CHEN Ying;DONG Yanjun;JIAO Lei;LI Zhaolin;WANG Cong;GAO Guangyao;SHI Lina;ZHANG Shujuan;BAI Yingfei(State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;National Observation and Research Station of Earth Critical Zone on the Loess Plateau in Shaanxi,Xi′an 710061,China;Center for Ecological Research,Northeast Forestry University,Harbin 150040,China;School for Geography and Tourism,Shaanxi Normal University,Xi′an 710119,China;Laoshan Bureau of State-owned Ecological Forests,Yan′an 716000,China;Grain to Green Project Management Office of Wuqi Government,Yan′an 716000,China)

机构地区：[1]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [2]陕西黄土高原地球关键带国家野外科学观测研究站,西安710061 [3]东北林业大学生态研究中心,哈尔滨150040 [4]陕西师范大学地理科学与旅游学院,西安710119 [5]延安市劳山国有林管理局,延安716000 [6]延安市宝塔区南泥湾国有生态林场,延安716000

出　　处：《生态学报》2023年第15期6443-6453,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金重大项目(41991233);国家自然科学基金面上项目(42071125,41877539)。

摘　　要：根据多年生草本根部导管解剖结构特征,分析了黄土高原两个气候区草本物种导水结构特征及导水策略对干旱气候条件的适应性特征。结果表明,黄土高原半干旱区(年降雨量小于400 mm)草本物种平均年龄较大(7年),理论导管直径(33μm)、导管面积(680μm~2)和导水效率(1.56 kg m^(-1)MPa^(-1)s^(-1))数值较高,而导管数量(65个)和导管分量(6.2%)数值较低;黄土高原半湿润区(年降雨量大于400 mm)草本物种平均年龄较小(5年),理论导管直径(27μm)、导管面积(550μm^(2))和导水效率(1.12 kg m^(-1)MPa^(-1)s^(-1))数值较低,而导管数量(85个)和导管分量(7.5%)数值较高。黄土高原半干旱区草本物种的导管直径较大、单位面积内的导管数量较少,因而导水效率较高,在干旱胁迫条件下趋向于采取效率优先的导水策略;黄土高原半湿润区草本物种的导管直径较小、单位面积内的导管数量较多,因而导水效率较低,在干旱胁迫条件下趋向于采取安全优先的导水策略。The study of hydraulic xylem adjustments in response to environmental changes so far mainly concentrate on tree and shrub species,whereas the knowledge on xylem anatomy of main roots and its ecological significance for the perennial forb species,is generally limited to only a few cases.Based on the root anatomical traits of perennial herb species,we analyzed the root growth strategies and water transport efficiency in two comparatively climatic zones on the Loess Plateau of China.The results showed that the perennial herb species in the semi-arid area of the Loess Plateau(with annual rainfall of less than 400 mm)had relatively older age(about 7 years),and higher values of theoretical vessel diameter(about 33μm),mean vessel area(680μm^(2)),and mean water transport efficiency(1.56 kg m-^(1)MPa^(-1)s^(-1)),but the number of vessel(65)and the fraction of vessel area(6.2%)were relatively lower.In contrast,the perennial herb species in the semi-humid area of the Loess Plateau(with annual rainfall of over than 400 mm)had relatively younger age(about 5 years),and lower values of theoretical lumen diameter(about 27μm),mean lumen area(550μm^(2))and mean water transport efficiency(1.12 kg m^(-1)MPa^(-1)s^(-1)),but the number of vessel(85)and the fraction of vessel area(7.5%)were relatively higher.Perennial herb species in the semi-arid area of the Loess Plateau had relatively larger lumen diameter and fewer conduits per unit area,and xylem anatomical adjustments prioritized hydraulic efficiency over safety under drought stress.Perennial herb species in the semi-humid area of the Loess Plateau had relatively smaller lumen diameter and more conduits per unit area,and xylem anatomical adjustments prioritized hydraulic safety over efficiency under drought stress.Additionally,the older herb species in the semi-arid region of the Loess Plateau have comparatively larger vessels and higher water transport efficiency.Older herb species had relatively higher biomass and net primary productivity and consequently had greater consum

关 键 词：多年生草本 主根导管 导水效率 导水策略 黄土高原 

分 类 号：S812[农业科学—草业科学]