Chin J Plan Ecolo ›› 2017, Vol. 41 ›› Issue (4): 439-449.DOI: 10.17521/cjpe.2016.0331

Special Issue: 入侵生态学

• Orginal Article • Previous Articles     Next Articles

Effects of glyphosate on interspecific competition between Solidago canadensis and Imperata cylindrica

Chun-Feng GU1,2, Xiao-Qi YE2, Ming WU2,*(), Xue-Xin SHAO2, Sheng-Wu JIAO2   

  1. 1College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou 310036, China
    and
    2Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Wetland Ecosystem Research Station of Hangzhou Bay, State Forestry Administration, Fuyang, Zhejiang 311400, China
  • Received:2016-10-27 Accepted:2017-02-28 Online:2017-04-10 Published:2017-05-19
  • Contact: Ming WU

Abstract:

Aims The extensive use of herbicide to control invasive plants would change the relationship between alien and neighboring plants. In order to provide data for rational use of herbicide and a theoretical reference for further studies on the ecological effects of glyphosate, we explored the variation of the relationship between an invasive plant Solidago canadensis and a native plant Imperata cylindrica when they were sprayed glyphosate.
Methods A replacement series experiment was conducted from June to August 2016 in Wetland Ecosystem Research Station of Hangzhou Bay, State Forestry Administration, to examine the effects of glyphosate at seven concentration levels (0, 0.3, 0.6, 0.9, 1.2, 1.5, 1.8 mL·L-1) on the growth and interspecific competition of S. canadensis and I. cylindrica.
Important findings (1) Glyphosate treatment significantly inhibited the growth of S. canadensis and I. cylindrica (p < 0.05). During the test, cumulative growth of height and leaf number of S. canadensis were apparently reduced with the increase of glyphosate concentration, but the leaf number of S. canadensis treated with 0.3- 1.5 mL·L-1 glyphosate was re-growing with time, while the one treated with 1.8 mL·L-1 was mostly dead. The withering rate of tiller and green leaf of I. cylindrica also significantly increased with the increase of glyphosate concentration, and the growth indices of this plant treated with 0.3-0.6 mL·L-1 were also re-growing with time. (2) Glyphosate treatment significantly affected interspecific competition (p < 0.05), which diminished as the glyphosate concentration increased. (3) Interspecific competition has significant influence on the biomass allocation of S. canadensis (p < 0.05). When facing competition, S. canadensis would allocate more organic matter to root and thus increase the ratio of root to shoot. Competition only inhibited the tiller number and total biomass of I. cylindrica, but insignificantly affected its ratio of root to shoot. (4) The interaction between glyphosate treatment and S. canadensis-I. cylindrica interspecific relationship also significantly influenced the biomass of S. canadensis and I. cylindrica (p < 0.05), but insignificantly affected the root/shoot ratio of two plants. Different plants have different tolerance to glyphosate stress. Compared with native plant I. cylindrica, S. canadensis has stronger tolerance to glyphosate. Low-concentration glyphosate could decrease the competitive intensity between S. canadensis and I. cylindrica, which may disturb the structure and dynamics of plant communities.

Key words: herbicide, invasive plant, native plant, growth, interspecific relationship