Pedosphere (2): 554--567, 2026
ISSN 1002-0160/CN 32-1315/P
©2026 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Impact of organic carbon composition on bacterial community assembly in organic and mineral soil layers under phosphorus addition in a Robinia pseudoacacia plantation |
Ahejiang SAILIKE1, Yujie LIANG1, Rong FU1, Hongjian HAO1, Rong WANG1, Ning PENG2, Shicai LI1, Zhouchang YU1, Fangxin ZHENG1, Wei ZHANG1 , Yangyang LIU1, Peizhi YANG1, Zhixin ZHANG1 |
1 College of Grassland Agriculture, Northwest A&F University, Yangling 712100 (China)
2 College of Life Sciences, Northwest A&F University, Yangling 712100 (China) |
| ABSTRACT |
| Increasing phosphorus (P) inputs significantly affect the nutrient cycle of terrestrial ecosystems. The community structure and assembly processes of soil bacteria, which are the primary participants in nutrient cycling within terrestrial ecosystems, are affected by P inputs. However, the assembly processes and driving mechanisms of soil bacterial communities in artificial forest ecosystems in response to P inputs remain unclear. Therefore, in this study, an experiment was conducted in an artificial Robinia pseudoacacia forest on the Loess Plateau to investigate the effects of P additions (0, 0.5, 1, 2, and 4 g P m-2 year-1) on soil organic carbon (SOC) composition, bacterial community characteristics (total, abundant, and rare taxa), and assembly processes in the organic horizon (OH) and mineral horizon (MH). The results showed that P addition significantly changed soil physicochemical properties, such as available P (AP), SOC content, and SOC composition in terms of labile and recalcitrant SOC fractions. The proportion of labile SOC fraction increased in OH and decreased in MH, whereas the recalcitrant SOC fraction showed the opposite trend. In OH, the proportion of eutrophic bacteria increased, whereas the proportion of oligotrophic bacteria decreased. In contrast to those in OH, the changes in eutrophic and oligotrophic bacteria in MH exhibited the opposite trend. The diversity of bacterial communities in OH did not change significantly with increasing P levels. In MH, the diversity of total and rare taxa increased, while the diversity of abundant taxa decreased. Under P addition, the total and rare bacterial taxa showed stochastic assembly, whereas the assembly of abundant taxa shifted from stochastic to deterministic processes in OH and from deterministic to stochastic processes in MH. The partial-least squares path modeling revealed that under P addition, the assembly of total and rare bacterial communities in OH and MH was regulated by AP and labile SOC fraction, respectively. Meanwhile, the assembly of abundant taxa in OH and MH was influenced by labile and recalcitrant SOC fractions, respectively. Our findings highlight the critical role of SOC composition across different bacterial taxa, with abundant taxa exhibiting heightened sensitivity to environmental filtration and the availability of SOC resources. Our study provides new insights into the community assembly and driving mechanisms of soil bacteria in artificial forest soils under P addition. |
| Key Words: abundant taxa,afforestation,artificial forest,bacterial community assembly,mineral horizon,organic horizon,rare taxa,soil organic C |
| Citation: Sailike A, Liang Y J, Fu R, Hao H J, Wang R, Peng N, Li S C, Yu Z C, Zheng F X, Zhang W, Liu Y Y, Yang P Z, Zhang Z X. 2026. Impact of organic carbon composition on bacterial community assembly in organic and mineral soil layers under phosphorus addition in a Robinia pseudoacacia plantation. Pedosphere. 36(2): 554-567. |
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