植物生态学报 ›› 2018, Vol. 42 ›› Issue (11): 1094-1102.doi: 10.17521/cjpe.2018.0140

• 研究论文 • 上一篇    下一篇

西藏高寒草原群落植物根系属性在降水梯度下的变异格局

周玮1,李洪波2,*(),曾辉1   

  1. 1北京大学深圳研究生院城市规划与设计学院, 深圳 518055
    2中国科学院地理科学与资源研究所, 北京 100101
  • 收稿日期:2018-06-11 接受日期:2018-10-16 出版日期:2018-11-20 发布日期:2019-03-13
  • 通讯作者: 李洪波 E-mail:lihongboxy@163.com
  • 基金资助:
    国家重点研发计划(2016YFC0501802)

Variations of root traits in three Xizang grassland communities along a precipitation gradient

ZHOU Wei1,LI Hong-Bo2,*(),ZENG Hui1   

  1. 1School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
    2Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2018-06-11 Accepted:2018-10-16 Online:2018-11-20 Published:2019-03-13
  • Contact: Hong-Bo LI E-mail:lihongboxy@163.com
  • Supported by:
    Supported by the National Key R&D Program of China(2016YFC0501802)

摘要:

根系功能属性及其变异性能够介导物种共存及环境适应策略, 但强烈的环境约束作用能够引起不同物种间根系属性的趋同性。为了研究西藏高寒草原群落中植物根系属性变异规律, 并阐明不同物种资源获取和适应策略的多样性, 该文对西藏高寒草原不同的环境梯度进行了研究。作者自东向西沿着降水梯度在那曲、班戈和尼玛3个自然草原群落进行群落调查, 并采集了共计22种植物。测定了每种植物的一级根直径、一级侧根长度和根系分支强度3个关键根系属性。结果表明: 在西藏高寒草原群落中, 不同物种根系直径普遍较小, 且种间变异非常小(22.76%), 其中86%的物种一级根直径集中在0.073 mm到0.094 mm之间; 相较于直径较粗的物种, 直径越细的物种分支强度越高, 侧根越短。在群落尺度上, 植物主要通过增加根系直径、侧根长度, 降低分支强度的方式来适应水分的减少; 而在物种尺度上, 植物适应水分变化的策略则呈现多样性。

关键词: 属性变异, 适应策略, 根系分支, 根直径, 根长度, 高寒草原

Abstract:
Aims Root functional traits and their variations mediate coexistence and adaptive strategy of plant species. Yet, strong environmental constraints may induce convergence of root traits among different plant species. To study the variations of root traits and clarify the diverse adaptive strategies across plant species, we sampled three alpine grasslands along a precipitation gradient in the Xizang Plateau.
Methods In three grassland communities along a precipitation gradient: Nagqu, Baingoin and Nyima from east to west of Xizang Plateau, we collected 22 coexisting plant species and measured three key root traits: 1st-order root diameter, 1st-order lateral root length and root branch intensity.
Important findings The main results showed that: (1) the root of plants in the alpine grassland was generally thin, and the interspecific variation was also small (22.76%); (2) the root diameter of 86% plant species was in the range from 0.073 mm to 0.094 mm. Compared with the thick-root species, thin-root species had a higher root branching intensity, but shorter lateral root length. In addition, at community-level, plants mainly increased root diameter and lateral root length, but reduced root branching intensity to adapt to the decreasing precipitation; while at species-level, the plant species exhibited diverse adaptive strategies along the precipitation gradient.

Key words: trait variation, adaptive strategy, root branching, root diameter, root length, alpine grassland