{"title":"The composition and functional roles of soil autotrophic microorganisms in vegetation restoration of degraded karst forest","authors":"Yu Dai, Lipeng Zang, Guangqi Zhang, Qingfu Liu, Mingzhen Sui, Yuejun He, Shasha Wang, Chunjie Zhou, Danmei Chen","doi":"10.1007/s10342-024-01723-8","DOIUrl":null,"url":null,"abstract":"<p>Autotrophic microorganisms play a significant role in atmospheric CO<sub>2</sub> fixation and soil organic carbon (SOC) sequestration in diverse ecosystems, but little is known about their role in karst forests. To investigate the composition and changes of autotrophic microbial communities during degraded karst forest restoration, the related functional genes and microorganisms from three restoration stages (shrubbery, TG; secondary forest, SG; old-growth forest, OG) were examined through metagenomic sequencing. Their underlying drivers and contributions to SOC were investigated using structural equation modeling (SEM) and regression analysis. Karst forest restoration resulted in the synchronous recovery of above-ground plants and soil conditions. When TG was restored to OG, soil autotrophic CO<sub>2</sub> fixation microbes changed significantly, indicated by an increase in microbial functional strength and diversity. Among the six examined functional pathways, the rTCA cycle contributed the most (0.074–0.082%), while the WL pathway contributed the least (0.008–0.010%) to CO<sub>2</sub> fixation functions. Except the Calvin cycle, genes involved in the other five pathways showed an increase with karst forest restoration. SEMs further revealed that soil pH and available nitrogen directly drive the increase in microbial autotrophic CO<sub>2</sub> fixation functions. In karst forests, autotrophic CO<sub>2</sub>-fixing microorganisms play a crucial role in enhancing SOC, particularly through the DC/4-HB cycle, 3-HP/4-HB cycle, and WL pathway. Soil microbial communities involved in autotrophic CO<sub>2</sub> fixation were predominantly attributed to Proteobacteria (43.02–32.42%) and Actinobacteria (18.83–30.89%), although their contributions varied across different stages. These results highlight the significant contribution of autotrophic microorganisms to the SOC of karst forests and enhance our understanding of the microbial mechanisms behind soil C sequestration.</p>","PeriodicalId":11996,"journal":{"name":"European Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Forest Research","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1007/s10342-024-01723-8","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"FORESTRY","Score":null,"Total":0}
引用次数: 0
Abstract
Autotrophic microorganisms play a significant role in atmospheric CO2 fixation and soil organic carbon (SOC) sequestration in diverse ecosystems, but little is known about their role in karst forests. To investigate the composition and changes of autotrophic microbial communities during degraded karst forest restoration, the related functional genes and microorganisms from three restoration stages (shrubbery, TG; secondary forest, SG; old-growth forest, OG) were examined through metagenomic sequencing. Their underlying drivers and contributions to SOC were investigated using structural equation modeling (SEM) and regression analysis. Karst forest restoration resulted in the synchronous recovery of above-ground plants and soil conditions. When TG was restored to OG, soil autotrophic CO2 fixation microbes changed significantly, indicated by an increase in microbial functional strength and diversity. Among the six examined functional pathways, the rTCA cycle contributed the most (0.074–0.082%), while the WL pathway contributed the least (0.008–0.010%) to CO2 fixation functions. Except the Calvin cycle, genes involved in the other five pathways showed an increase with karst forest restoration. SEMs further revealed that soil pH and available nitrogen directly drive the increase in microbial autotrophic CO2 fixation functions. In karst forests, autotrophic CO2-fixing microorganisms play a crucial role in enhancing SOC, particularly through the DC/4-HB cycle, 3-HP/4-HB cycle, and WL pathway. Soil microbial communities involved in autotrophic CO2 fixation were predominantly attributed to Proteobacteria (43.02–32.42%) and Actinobacteria (18.83–30.89%), although their contributions varied across different stages. These results highlight the significant contribution of autotrophic microorganisms to the SOC of karst forests and enhance our understanding of the microbial mechanisms behind soil C sequestration.
期刊介绍：
The European Journal of Forest Research focuses on publishing innovative results of empirical or model-oriented studies which contribute to the development of broad principles underlying forest ecosystems, their functions and services.
Papers which exclusively report methods, models, techniques or case studies are beyond the scope of the journal, while papers on studies at the molecular or cellular level will be considered where they address the relevance of their results to the understanding of ecosystem structure and function. Papers relating to forest operations and forest engineering will be considered if they are tailored within a forest ecosystem context.
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