Wang Haocai, Wang Hang, Crowther Thomas W, Isobe Kazuo, Reich Peter B, Tateno Ryunosuke, Shi Weiyu
Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station, School of Geographical Sciences, Southwest University, Chongqing 400715, China.
Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province, Kunming 650228, China.
ISME Commun. 2024 Oct 23;4(1):ycae128. doi: 10.1093/ismeco/ycae128. eCollection 2024 Jan.
There is growing awareness of the need for regenerative practices in the fight against biodiversity loss and climate change. Yet, we lack a mechanistic understanding of how microbial community composition and functioning are likely to change alongside transition from high-density tillage to large-scale vegetation restoration. Here, we investigated the functional dynamics of microbial communities following a complete vegetation successional chronosequence in a subtropical zone, Southwestern China, using shotgun metagenomics approaches. The contents of total soil phosphorus (P), available P, litter P, and microbial biomass P decreased significantly during vegetation succession, indicating that P is the most critical limiting nutrient. The abundance of genes related to P-uptake and transport, inorganic P-solubilization, organic P-mineralization, and P-starvation response regulation significantly increased with successional time, indicating an increased microbial "mining" for P under P limitation. Multi-analysis demonstrated microbial P limitation strongly inhibits carbon (C) catabolism potential, resulting in a significant decrease in carbohydrate-active enzyme family gene abundances. Nevertheless, over successional time, microorganisms increased investment in genes involved in degradation-resistant compounds (lignin and its aromatic compounds) to acquire P resources in the litter. Our study provides functional gene-level insights into how P limitation during vegetation succession in subtropical regions inhibits soil microbial C metabolic processes, thereby advancing our understanding of belowground C cycling and microbial metabolic feedback during forest restoration.
人们越来越意识到在应对生物多样性丧失和气候变化的过程中需要采用再生实践。然而，我们缺乏对微生物群落组成和功能如何可能随着从高密度耕作向大规模植被恢复的转变而发生变化的机制性理解。在这里，我们利用鸟枪法宏基因组学方法，在中国西南部亚热带地区沿着一个完整的植被演替时间序列研究了微生物群落的功能动态。在植被演替过程中，土壤总磷（P）、有效磷、凋落物磷和微生物生物量磷的含量显著下降，这表明磷是最关键的限制养分。与磷吸收和运输、无机磷溶解、有机磷矿化以及磷饥饿反应调节相关的基因丰度随着演替时间显著增加，这表明在磷限制下微生物对磷的“开采”增加。多分析表明，微生物的磷限制强烈抑制碳（C）分解代谢潜力，导致碳水化合物活性酶家族基因丰度显著下降。然而，随着演替时间的推移，微生物增加了对参与降解抗性化合物（木质素及其芳香族化合物）的基因的投入，以在凋落物中获取磷资源。我们的研究提供了功能基因层面的见解，以了解亚热带地区植被演替过程中的磷限制如何抑制土壤微生物的碳代谢过程，从而增进我们对森林恢复过程中地下碳循环和微生物代谢反馈的理解。
