Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (1): 62-73.DOI: 10.17521/cjpe.2020.0158

• Research Articles • Previous Articles     Next Articles

Effects of Chinese fir plantations with different densities on understory vegetation and soil microbial community structure

DING Kai1, ZHANG Yu-Ting1, ZHANG Jun-Hong1, CHAI Xiong2, ZHOU Shi-Shui2, TONG Zai-Kang1,*()   

  1. 1The State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China
    2Kaihua Forestry Farm, Zhejiang Province, Kaihua, Zhejiang 324300, China
  • Received:2020-05-18 Accepted:2020-12-09 Online:2021-01-20 Published:2021-01-05
  • Contact: TONG Zai-Kang
  • Supported by:
    National Key R&D Program of China(2016YFD060030404)


Aims The aim of the present study was to investigate the responses of understory vegetation to soil nutrients and bacterial communities.
Methods This study investigated the understory vegetation biomasses and species composition as well as soil physical and chemical properties in 17-year-old Chinese fir plantations with three densities (high-density (KH), medium-density (KM), and low-density (KL)) in Kaihua, Zhejiang. The changes of bacterial community structures were analyzed via 16S rDNA high-throughput sequencing techniques.
Important findings The result showed that the total above-ground biomass of the understory vegetation ranged from 0.10 to 2.10 t·hm-2 and the dominant plant species varied in three Chinese fir plantations. The soil pH and available phosphorus content were significantly different between high-density and low-density forest stands. Correlation analysis showed that soil pH was positively correlated with the biomass of herbs, shrubs and the total of understory vegetation, while the content of soil organic matter was just positively related with the last two factors, and the available potassium content was only affected by the biomass of shrub. Based on the analysis of the soil microbial community, the Acidobacteria, Proteobacteria, Actinobacteria, and Chloroflexi were the dominant phyla in the three Chinese fir plantations. Redundancy analysis showed that soil pH, available nitrogen, available phosphorus and available potassium contents played a crucial role in regulating the soil bacterial community structures. Gp2, Gp1, Gp3 and Gp6 were the dominant subgroups of Acidobacteria, accounting for 51.32%- 57.38% of the Acidobacteria. With the decline of the Chinese fir density, the biomass of understory vegetation and the proportion of Gp1 increased, while the proportion of Gp2 and Gp6 decreased and the relative abundance of Gp6 was negatively correlated with soil pH. Obviously, the moderate reduction in stand density of pure Chinese fir forests was beneficial in the growth of understory vegetation and in maintaining a reasonable bacterial community structure, which helps to maintain the soil fertility of the Chinese fir forests and to achieve sustainable management in the long run.

Key words: Chinese fir, understory vegetation, biomass, soil physical and chemical properties, bacteria, Acidobacteria