川西大渡河干热河谷优势灌草植物根系特征及固土能力  

Root characteristics and soil-fixing ability of the dominant shrubs and herbs in the dry and hot valley of Dadu River in West Sichuan

作　　者：姚怡宁 宗桦[1,2] 周璐 李荷 冯旭环 YAO Yining;ZONG Hua;ZHOU Lu;LI He;FENG Xuhuan(Department of Landscape,Southwest Jiaotong University,Chengdu 610097,China;Highway Engineering Key Laboratory of Sichuan Province,Chengdu 610097,China;China Railway Second Academy Engineering Group Co.,Ltd.,Chengdu 610031,China;Chengdu Park City Construction and Development Research Institute,Chengdu 610042,China)

机构地区：[1]西南交通大学风景园林系,成都610097 [2]西南交通大学道路工程四川省重点实验室,成都610097 [3]中铁二院工程集团有限公司,成都610031 [4]成都市公园城市建设发展研究院,成都610042

出　　处：《生态学报》2025年第6期2798-2810,共13页Acta Ecologica Sinica

基　　金：国家自然科学基金面上项目(31971716,32271945);成都市中铁二院横向项目(KYY2019132)。

摘　　要：研究选取川西泸定大渡河干热河谷区的6种优势乡土植物,草本有鬼针草(Bidens pilosa)、黄茅(Heteropogon contortus)、艾草(Artemisia argyi)和两头毛(Incarvillea arguta),灌木有假杜鹃(Barleria cristata)和木蓝(Indigofera tinctoria),在生长期(雨季)和衰老期(旱季)分别研究其根系形态和分布特征及含水率变化,通过拉伸实验计算根系的抗拉强度(P)从而计算其根系的黏聚力(C_(r)),厘清影响其固土能力的关键因子。结果显示:(1)从根系的分布来看,6种植物的根面积比(RAR)均随土壤深度增加呈下降趋势,且在生长期和衰老期的变化趋势有所不同。灌木和草本的RAR均值差异不显著。(2)从根系形态来看,黄茅的根长密度和根数显著地超过其他物种,且根系在不同状态下含水率变化最小、持水能力最稳定,在旱季中的生存能力最佳。(3)6种优势植物在衰老期的C_(r)值均显著地高于生长期,表明根系的固土能力在旱季强于雨季。无论在生长期还是衰老期,黄茅根系的P值及C_(r)值均显著地高于其他植物,两头毛则最低。Pearson相关性分析显示,根径和根系含水率是影响P值的关键因子,根径是影响C_(r)值的关键因子。总体而言,黄茅根系的固土能力最优,可在川西干热河谷区生态修复过程中优先推广。Six dominant native plants in the dry and hot river valley of Dadu River in West Sichuan were selected in this study.The herbs selected were Bidens pilosa,Heteropogon contortus,Artemisia argyi,and Incarvillea arguta,and the shrubs were Barleria cristata and Indigofera tinctoria,to study the morphological characteristics,distribution properties,and changes in water content of their roots during the growth and senescence periods,and to calculate the differences in tensile strength(P)and thus cohesive strength(C_(r))of their root systems,by means of tensile tests and to clarify the key factors influencing their variance.Results show:①In terms of root distribution,the root area ratio(RAR)across all six plants tended to decrease with soil depth,with variations between growth and senescence periods.There is no significant difference was found in the mean values of RAR between shrubs and herbs.②In terms of root morphology,among the six plant,the roots of H.contortus had the favorable root length density and root number with the most stable water-holding capacity in different statues,which showed it had the best ability to survive in the dry season.③The C_(r)values of the six dominant plants were significantly higher in the senescence period than those in the growth period,indicating that the soil fixation capacity of root system was stronger in the dry season than that in the rainy season.Both in the growing and senescence periods,the P-values and C_(r)values of H.contortus were significantly higher than those of the other plants.Pearson correlation analysis showed that root diameter and root water content were key determinants of tensile strength,with root diameter being the key factor influencing cohesive strength.Overall,H.contortus had the best soil-binding capacity and should be prioritized in the ecological restoration of the dry and hot river valley in western Sichuan.

关 键 词：干热河谷 优势植物 根系特征 根系黏聚力 固土能力 

分 类 号：R28[医药卫生—中药学]