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草业学报 ›› 2021, Vol. 30 ›› Issue (3): 28-40.DOI: 10.11686/cyxb2020161

• 研究论文 • 上一篇    下一篇

三江源区不同建植年限人工草地根系动态特征

李洁1(), 潘攀2, 王长庭2(), 胡雷2, 陈科宇2, 杨文高2   

  1. 1.西南民族大学生命科学与技术学院,四川 成都 610041
    2.西南民族大学青藏高原研究院,四川 成都 610041
  • 收稿日期:2020-04-08 修回日期:2020-06-29 出版日期:2021-03-20 发布日期:2021-03-09
  • 通讯作者: 王长庭
  • 作者简介:Corresponding author. E-mail: wangct@swun.edu.cn
    李洁(1995-),女,四川邻水人,在读硕士。E-mail: lmmz159024@163.com
  • 基金资助:
    国家重点研发计划(2019YFC0507701);国家自然科学基金面上项目(31870407);第二次青藏高原综合科学考察研究项目(2019QZKK0302);四川重点研发项目(2018SZ0333);中央高校基本科研业务费专项基金项目(2020NZD03)

Root dynamics of artificial grassland for swards of differing ages in the ‘Three-River Source’ region

Jie LI1(), Pan PAN2, Chang-ting WANG2(), Lei HU2, Ke-yu CHEN2, Wen-gao YANG2   

  1. 1.College of Life Science & Technology of Southwest Minzu University,Chengdu 610041,China
    2.Institute of Qinghai-Tibetan Plateau Research of Southwest Minzu University,Chengdu 610041,China
  • Received:2020-04-08 Revised:2020-06-29 Online:2021-03-20 Published:2021-03-09
  • Contact: Chang-ting WANG

摘要:

根系动态特征能够反映人工草地植物利用土壤资源的效率和群落恢复演替的程度。本研究以三江源区不同建植年限(5、6、9和13年)人工草地植物根系为研究对象,利用“微根管”技术,连续两个生长季(2015年5-9月和2016年5-9月)探究了4个建植年限人工草地根系动态特征。结果表明:地上生物量和丰富度在建植5~9年呈下降趋势,建植9~13年显著上升;土壤理化性质呈“N”字型变化,不同建植年限间差异显著;随建植年限增加,根系寿命、累积生产量和累积死亡量均波动上升,根系的生长和死亡主要发生在0~10 cm土层;根系平均现存量随建植年限增加持续增加,建植6~9年趋于深层化;根系生产量、死亡量和现存量具有明显季节变化,6月为生长高峰期,7月为现存量高峰期,8月为死亡高峰期,建植9年人工草地根系正生长高峰期迟于其他建植年限;建植年限和土层深度直接影响根系寿命,其余环境因子通过影响土壤速效养分或地上生物量间接影响根系现存量。综上所述,建植人工草地能够增加地上生物量和丰富度,改善土壤质量,促进根系现存量的增加,建植6~9年人工草地的二次退化现象只是暂时性过渡阶段,可在此阶段制定合理的人工管理措施来保证土壤养分的稳定输入,加快群落正向演替的进程,从而提高人工草地的群落稳定性和恢复力。

关键词: 人工草地, 建植年限, 根系动态特征, 植物群落特征, 土壤理化性质

Abstract:

In artificial grassland, measurement of root dynamic traits can indicate the efficiency of the vegetation in using soil resources and the progress of plant community restoration and ecological succession. In this study, the root dynamics of artificial grassland established 5, 6, 9 and 13 years previously was investigated in the Three-River Source region. Data were collected for two consecutive growing seasons (May-September 2015 and May-September 2016), utilizing minirhizotron in situ monitoring technology. The results showed that the aboveground biomass and species richness decreased from 5 to 9 years and increased from 9 to 13 years. The soil physiochemical properties similarly changed in a “N” shape over the time series and the differences between different sward establishment years was significant. The majority of root growth and death occurred in the 0-10 cm soil depth, and root longevity, cumulative production and cumulative mortality all fluctuated across the time series of establishment dates. The average root standing crop continued to increase with increase in years established, and numbers of deep roots observed increased between 6 and 9 years after establishment. There were obvious seasonal changes in root production, mortality and standing crop. The growth peak was in June, the standing crop peak was in July, and the death-rate peak was in August, while the seasonal root growth peak of artificial grassland established for 9 years was later than in grassland of other ages. The number of years established and the soil depth directly affected root longevity, and other environmental factors indirectly affected root standing crop by influencing soil available nutrients or aboveground biomass. In summary, planting artificial grassland can promote the soil quality and increase the aboveground biomass, richness and root standing crop. The secondary degradation of planted artificial grassland from 6 to 9 years after establishment is only a temporary transitional stage. Therefore, at this stage, the establishment of suitable artificial management measures can ensure the stability of the soil nutrient status and accelerate the process of plant community succession, thereby improving the vegetation community stability and resilience of artificial grassland.

Key words: artificial grassland, cultivation years, root dynamic traits, plant community characteristics, soil physiochemical properties