Biodiv Sci ›› 2023, Vol. 31 ›› Issue (11): 23276.  DOI: 10.17520/biods.2023276

• Original Papers: Ecosystem Diversity • Previous Articles     Next Articles

Response of soil bacteria and nematodes to litter identity and diversity of dominant plants in a tropical rainforest

Jinhua Liu1,2, Feng Li1,2, Tao Tian1,2, Haifeng Xiao1,2,*()   

  1. 1 School of Chemistry and Environmental Science, Xiangnan University, Chenzhou, Hunan 423099
    2 Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metal Compounds and Applications, Chenzhou, Hunan 423099
  • Received:2023-07-31 Accepted:2023-10-09 Online:2023-11-20 Published:2023-11-09
  • Contact: * E-mail: hfxiao@xnu.edu.cn

Abstract:

Aims: The input of aboveground plant resources into the belowground components is considered a key factor in regulating soil biota communities, as plants serve as the primary energy source for nearly all soil organisms. However, our understanding of how plant litter identity and diversity influence the diversity and communities of soil microorganisms and microfauna remains limited. Therefore, the objective of this study is to investigate the impact of different plant litter identity and diversity on soil bacterial and nematode diversity and communities.

Methods: In this study, soil bacteria and nematodes were selected as the subjects of investigation. Through pot experiments, we first introduced litter from various dominant tropical forest plant species individually, aiming to explore the influence of distinct plant litter identity on the diversity and communities of soil bacteria and nematodes. Subsequently, we established five gradients of litter diversity, including a control (with no added litter), one-species litter (from Sloanea tomentosa), two-species mixed litter (Sloanea tomentosa + Strychnos cathayensis), four-species mixed litter (Sloanea tomentosa + Strychnos cathayensis + Orophea laui + Pometia pinnata), and seven-species mixed litter (Sloanea tomentosa + Strychnos cathayensis + Orophea laui + Pometia pinnata + Ficus virens + Ficus sagittata + Castanopsis indica). The aim was to investigate the impact of varying plant litter diversity on the diversity and communities of soil bacteria and nematodes.

Results: Our results revealed the following: (1) Litter addition significantly increased soil carbon, nitrogen, available phosphorus, available potassium content, and notably raised soil pH. (2) Compared to the control treatment (no litter addition), adding litter from a single plant species led to a decrease in bacterial and nematode diversity. (3) Similarly, adding litter from different individual plant species had significant impacts on both bacterial and nematode communities compared to the control treatment. However, among the various litter addition treatments, only the litter from the Parashorea chinensis significantly differed in bacterial community composition from the other treatments, while differences in bacterial and nematode communities between other treatments were not significant. (4) Litter diversity significantly influenced bacterial and nematode diversity and community composition. Specifically, bacterial and nematode diversity increased with higher litter diversity gradients. Under high diversity conditions (four and seven species), bacterial and nematode communities showed less similarity compared to treatments with lower litter diversity (CK, one, and two species).

Conclusion: These findings suggest that aboveground litter diversity not only directly affects the soil microbial communities, but also influences soil faunal communities at higher trophic levels through cascading effects. The results provide important theoretical references for understanding the relationship between plant and bacterial and nematode diversity and communities, the aggregation effect of soil nutrient patches in tropical forests, the mechanism of biodiversity maintenance, and the potential impacts of the loss of plant diversity on soil ecosystems in the context of global change.

Key words: soil bacteria, soil nematode, litter identity, litter diversity, community composition