Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (5): 539-551.DOI: 10.17521/cjpe.2020.0330

Special Issue: 青藏高原植物生态学:群落生态学

• Research Articles • Previous Articles     Next Articles

Effects of grass mixed-sowing on soil microbial diversity on the Qingzang (Tibetan) Plateau

JIANG Xin, NIU Ke-Chang*()   

  1. School of Life Science, Nanjing University, Nanjing 210023, China
  • Received:2020-10-10 Accepted:2021-02-04 Online:2021-05-20 Published:2021-03-09
  • Contact: NIU Ke-Chang
  • Supported by:
    the National Natural Science Foundation of China(31870402)


Aims How soil microbial diversity assembly, maintain and change is a key topic of ecology. A large number of studies show that soil microbial biodiversity is controlled not only by soil environment but also by plant species. However, due to strong covariation between the two factors in the field, it remains a challenge to isolate and clarify the role of plant diversity in regulating soil microbial biodiversity. Hence, here, we aim to clarify how plant diversity affects soil microbial diversity in environment-consistent artificial communities.
Methods In this study, we examined differences in species diversity of soil bacteria and fungi among plots subjected single- and mixed-sowing of three grass species with fertilization treatments after 13 years’ experiment on the eastern Qingzang (Tibetan) Plateau. We also analyzed the relationships between soil microbial diversity and edaphic factors as well as plant community attributes.
Important findings (1) The species richness and diversity of soil bacteria, not including soil fungi, significantly and consistently decreased in mixed-sowing plots relative to single-sowing plots, with higher relative abundances in proteobacteria and actinobacteria but lower in acidobacteria, bacteroidetes and planctomycetes in the mixed- sowing plots. (2) Soil pH and total nitrogen content significantly decreased while soil total phosphorus content increased in mixed-sowing plots relative to single-sowing plots. Fertilization significantly increased soil available phosphorus while decreased soil pH and soil humidity. However, variations in these edaphic factors contributed little in variation of soil microbial diversity. (3) Fertilization significantly increased plant aboveground biomass while decreasing richness of present plant species, which was also negatively associated with soil bacterial diversity. In short, this long-term field experiment clearly showed that mixed-sowing of common grass species did not promote diversity of soil microbes. This study provides new insight into management of grasses mixed-sowing artificial grasslands.

Key words: plant diversity, soil microbial diversity, mixed-sowing, diversity begets diversity