Moderate clipping stimulates over-compensatory growth of Leymus chinensis under saline-alkali stress through high allocation of biomass and nitrogen to shoots

• Published in: Plant growth regulation Vol. 92; no. 1; pp. 95 - 106
• Main Authors: Ma, Huimin, Zheng, Congcong, Gao, Yingzhi, Baskin, Carol C., Sun, Hao, Yang, Haijun
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2020; Springer Nature B.V
• Subjects: Agriculture; Biomass; Biomedical and Life Sciences; China; compensatory growth; Dominant species; Environmental stress; field experimentation; Grazing; Labeling; Leymus chinensis; Life Sciences; Nitrogen; Nitrogen isotopes; Organs; Original Paper; Plant Anatomy/Development; plant growth; plant nitrogen content; Plant Physiology; Plant Sciences; Shoots; Urea; China; Clipping; Saline-alkali stress; Compensatory growth; N allocation
• ISSN: 0167-6903; 1573-5087
• DOI: 10.1007/s10725-020-00622-3

Leymus chinensis , a dominant species in the Songnen Plain of northeast China, has a strong ability to resist grazing and tolerate saline-alkali stress. Compensatory growth is a positive response of plants, when subjected to grazing or clipping stress; however, little information is available on how plant nitrogen allocation strategies affect compensatory growth under saline-alkali stress. A field experiment using two saline-alkali levels and three clipping levels was conducted in conjunction with the belowground 15 N-urea labelling method. Irrespective of clipping and salt-alkali stress, moderate clipping significantly promoted allocation of newly-absorbed nitrogen (N) to shoots, resulting in high biomass and over-compensatory growth of L. chinensis . However, severe clipping dramatically decreased uptake of total 15 N by 20% under saline-alkali conditions, resulting in under-compensatory growth, and plants allocated more N to stem bases than to other plant organs, showing a conservative N allocation strategy. Our results suggest that plants have different nitrogen allocation strategies under different combinations of environmental stresses.