金塔绿洲不同林龄多枝柽柳根系分叉数与分支角度的关系  

Relationship between root forks and branch angle of Tamarix ramosissima at different stand ages in oasis of Jinta County

作　　者：白雪 赵成章 康满萍 BAI Xue;ZHAO Chengzhang;KANG Manping(College of Geography and Environmental Science,Northwest Normal University,Research Center of Wetland Resources Protection and Industrial Development Engineering of Gansu Province,Lanzhou 730070,China)

机构地区：[1]西北师范大学地理与环境科学学院,甘肃省湿地资源保护与产业发展工程研究中心,兰州730070

出　　处：《生态学报》2021年第5期1878-1884,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41861009,41461013)。

摘　　要：根系构型影响根系空间分布和营养吸收效率,反映了植物适应环境胁迫的生存策略。采用标准化主轴估计(Standardized major axis estimation,SMA)的方法,分析了甘肃金塔北海子国家湿地公园3年生和6年生多枝柽柳(Tamarix ramosissima)根系分叉数与分支角度的异速生长关系。结果表明:随着林龄的增长,湿地群落盖度、高度逐渐增加,多枝柽柳种群的盖度、密度、高度和地上生物量以及根系深度、分叉数、比根长、比表面积、各级根系直径随之增加,根系分支角度和根冠比逐渐减小;多枝柽柳根系分叉数与分支角度回归方程的标准主轴斜率逐渐增大(P<0.05),随着林龄的增长,多枝柽柳根系分叉数的增加速度逐渐大于根系分支角度的生长速度,二者在林龄间呈现出差异化的异速生长关系。随着林龄的增长,多枝柽柳根系构型模式由"扩散型"转变为"紧缩型",体现了种群应对生境胁迫和竞争的生态适应机制。The root architecture influences root spatial distribution and resorptiton efficiency of nutrients,which may reflect the plant growth strategies to adapt to the environmental stresses.This paper studied the relationship between root forks and branch angle of Tamarix ramosissim at three-year and six-year.The study site was located in Jinta Beihaizi Wetland Park of Gansu Province with the method of standardized major axis estimation(SMA).The height,density and above-ground biomass of the wetland communities were recorded from 5 m×5 m grids at two plots with six replicates.Seventy-two plants of Tamarix ramosissim were selected;the above-ground parts of those plants were cut while the roots were collected by excavating the whole root system,and both were taken back to the lab.In the laboratory,the roots were scanned with Win-RHIZO to measure the root forks and root length.The individual roots was dissected according to the branching order,starting from the distal end of the root system that was numbered as the first order and then increasing sequentially with each branch from the first order to the third order roots.The biomasses of different plots were put in an oven and dried(at 80℃for 12 h),and then measured.Similarly,the soil moisture content was also measured by oven-drying(at 105℃for 24 h).The results showed that with the increasing stand ages,the density,cover,height of the plant community increased,while the root-shoot ratio,root branch angle decreased,the specific cover,density,height,above biomass,root depth,root forks,specific root length and specific root surface area increased,and diameter of different root orders increased.In addition,with the increasing stand ages,the standardized major axis slope of regression equation in the scaling relationships between root forks and branch angle increased(P<0.05).Additionally,the increase speed of the root forks was greater than the growth speed of the root branch angle,and the allometric relationship between root forks and branch angle of Tamarix ramosissima

关 键 词：林龄 分叉数 分支角度 异速生长 多枝柽柳 根系构型 

分 类 号：S793.5[农业科学—林木遗传育种]