宁夏南部黄土丘陵区典型草本根系分布特征
万海霞1,2, 蔡进军3,4, 郭永忠1, 马 璠1, 许 浩1, 韩新生1, 王月玲1, 董立国1

(1.宁夏农林科学院 荒漠化治理研究所, 银川 750002; 2.宁夏农林科学院 固原分院, 宁夏 固原 756000; 3.西北农林科技大学 资源环境学院, 陕西 杨凌 712100; 4.宁夏农林科学院 农业资源与环境研究所, 银川 750002)

黄土丘陵区; 草本根系; 根长密度; 根表面积密度; 根—土结合体

Characteristics of Root Distributions of Typical Herbs in Loess Hilly Region of Southern Ningxia
WAN Haixia1,2, CAI Jinjun3,4, GUO Yongzhong1, MA Fan1, XU Hao1, HAN Xinsheng1, WANG Yueling1, DONG Liguo1

(1.Institute of Desertification Control, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan 750002, China; 2.Guyuan Branch of Ningxia Academy of Agriculture and Forestry Sciences, Guyuan, Ningxia 756000, China; 3.College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; 4.Institute of Agricultural Resources and Environment, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan 750002, China)

loess hilly region; herb roots; root length density; root surface area density; root-soil combination

备注

为揭示宁夏南部黄土丘陵区几种典型草本根系分布特征,采用根钻法和Win RHIZO根系分析系统对草本(百里香、星毛委陵菜、猪毛蒿、长芒草)整根特点、0—30 cm土层分布特征以及表层根—土结合体状况进行了定量分析。结果 表明:(1)各草本根系除长芒草外,大部分具有发达的侧根,细根绝大部分位于土壤浅层。(2)4种草本0—30 cm土层根长密度为2.38～23.56 mm/cm3,各径级根以≤0.5 mm根最大,占总根长密度的73.4%～86.4%。根表面积密度为2.65～28.83 mm2/cm3,百里香以≤0.5 mm根,猪毛蒿以2～3.5 mm根最大,其余草本各级根分布相对均匀。根体积密度为0.61～49.36 mm3/cm3,各径级根百里香以2～3.5 mm根,猪毛蒿以0.5～1 mm根最大,其他草本数值很小。随根径增加各草本的根长密度降低,根体积密度先增后降。(3)草本根长密度主要集中在0—20 cm土层(88.3%～100%),根表面积密度百里香、星毛委陵菜集中在0—10 cm(81.3%～99.3%),长芒草、猪毛蒿集中在0—20 cm(90.9%～100%),两个参数值均随土层深度的增加而减小。(4)根土结合体定量分析认为,百里香、星毛委陵菜、长芒草3种草本固结表层土壤效果较好。

To reveal the distribution characteristics of several typical herb roots in the loess hilly region of southern Ningxia, the bulk root characteristics, root distribution characteristics in 0—30 cm soil layer and root-soil combination in surface soil were quantitatively analyzed by using root drilling method and Win RHIZO root system for different kinds of herbs(Thymus mongolicus Ronn., Potentilla acaulis L., Artemisia scoparia, Stipa bungeana Trin.). The results show that:(1)except for the Stipa bungeana, most of the herb roots have developed lateral roots, and most of the fine roots are located in the shallow layer of soil;(2)the root length densities of the four herbs in 0—30 cm layer range from 2.38 mm/cm3 to 23.56 mm/cm3; the root length density of roots with 0～0.5 mm in diameter is the greatest, accounting for 73.4%～86.4% of the total root length density; the root surface area densities range from 2.65 m2/cm3 to 28.83 m2/cm3, the root surface area densities of the roots of the Thymus mongolicus Ronn. with 0～0.5 mm in diameter and roots of the Artemisia scoparia with 2～3.5 mm in diameter are the largest, and the root surface area densities of the other roots evenly distribute; the root volume densities range from 0.61 m3/cm3 to 49.36 m3/cm3, root volume densities of the roots of the Thymus mongolicus Ronn with 2～3.5 mm in diameter and the roots of Artemisia scoparia with 0.5～1 mm in diameter are the largest, and root volume densities of the other herb values are small; as the root diameter increases, the root length density of all herb decreases, and the root volume density increases first and then decreases;(3)the herb root length density of all plots mainly concentrate in 0—20 cm soil layer(88.3%～100%), the root surface area densities of Thymus mongolicus Ronn.,Potentilla acaulis L. concentrate in 0—10 cm soil layer(81.3%～99.3%), the root surface area densities of Stipa bungeana Trin., Artemisia scoparia concentrate in 0—20 cm soil layer(90.9%～100%); the herb root length density and the root surface area density decrease with the increase of soil layer;(4)quantitative analysis of root-soil combination shows that three herbs, Thymus mongolicus Ronn, Potentilla acaulis L., Stipa bungeana Trin. are effective in consolidating surface soil.