金塔绿洲荒漠交错带沙蓬根系分形特征  

Fractal characteristics of Agriophyllum squarrosum roots in desert⁃oasis ecotone in Jinta County,Gansu Province

作　　者：任杰 赵成章 赵夏纬 马俊逸 李子琴 苟芳珍 REN Jie;ZHAO Chengzhang;ZHAO Xiawei;MA Junyi;LI Ziqin;GOU Fangzhen(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》2020年第15期5298-5305,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41861009,41461013)。

摘　　要：根系分形结构是植物根系构型应对环境异质性的表型可塑性,可反映植物对生长环境的适应结果。在黑河中游的金塔北海子国家湿地公园,按照立地条件选择丘间低地、缓平沙坡和坡顶平地3种生境类型,采用全根挖掘和Win⁃RHIZO根系分析仪相结合的方法,研究了绿洲荒漠交错带一年生植物沙蓬(Agriophyllum squarrosum)的根系分形结构。结果表明:从丘间低地到坡顶平地植被群落的高度、盖度、地上生物量、土壤含水量、紧实度和土壤容重逐渐减小,沙蓬根系分形维数呈减小趋势,而根系分形丰度呈增大趋势;不同立地条件下沙蓬根系分形维数和分形丰度间呈负相关关系,沙蓬根系分形维数与分形丰度在丘间低地和坡顶平地均存在极显著负相关关系(P<0.01),在缓平沙坡样地呈显著负相关关系(P<0.05)。沙蓬根系分形维数和分形丰度间“此消彼长”的权衡关系,体现了沙生植物应对生境胁迫的表型可塑性机制。The fractal structure of root system is the result of phenotypic plasticity of plant root architecture in response to environmental heterogeneity,which reflects the adaptation strategy of plants to the growth environment.The study site was located in Beihaizi National Wetland Park,Jinta county,Gansu province,China(40°13′22″—40°17′2″N,98°41′24″—98°52′33″E),with the altitude 1215—1261 m and the average annual temperature 9.6℃.According to the site conditions,and three kinds of habitats were selected:interdunal depression,gentle sand slope,and slope crest.At the same time,the root fractal structure of Agriophyllum squarrosum was studied by root excavation and win-Rhizo root analyzer.The results showed that the vegetation community height,coverage,aboveground biomass,soil moisture content,compactness and soil bulk density decreased gradually from interdunal depression to slope crest with the change of habitats.As to the Agriophyllum squarrosum population,its density,height and fractal dimension of root system tended to be greater while its fractal abundance smaller.The fractal dimension of Agriophyllum squarrosum root system had a very significantly negative correlation with its fractal abundance in both interdunal depression and slope crest(P<0.01),as the same in both of gentle sand slope(P<0.05).The process of the transformation of root configuration from diffusion to density reflects the adaptive mechanism of the plants to deal with various habitat stresses under different site conditions.

关 键 词：绿洲荒漠交错带 沙蓬 分形维数 分形丰度 金塔北海子国家湿地公园 

分 类 号：Q948[生物学—植物学]