Legume species are essential components of plant diversity and affect soil biodiversity across various ecosystems. Their effect on the diversity and traits of soil bacteria, particularly in degraded grasslands, remains unknown. This study analysed the relationships among plant diversity, soil traits and legume‐associated rhizobacterial communities in Xiahe (XH) and Maqu (MQ) in Gansu Province, Haibei (HB) in Qinghai Province and Hongyuan (HY) in Sichuan Province in the eastern Qinghai‐Tibetan Plateau (QTP). The diversity index values (coverage, richness, Shannon index and evenness) of legume species were positively correlated with plant diversity. Several soil nutrients (ammonia‐nitrogen, nitrate‐nitrogen, total nitrogen, available potassium, available phosphorus and soil organic matter) and enzymes (urease, sucrase, peroxidase and dehydrogenase) were lower in HB and HY than in XH and MQ. The Shannon index for rhizobacterial diversity was higher in HB and HY than in XH and MQ. In contrast, the diversity index values were higher for geographical locations than for sympatric plant species. Additionally, HB and HY showed 50% fewer positive and negative associations with rhizobacteria than XH and MQ. Functional Annotation of Prokaryotic Taxa analysis indicated a higher relative abundance of nitrate reduction occurred in HB and HY than in XH and MQ, whereas nitrogen fixation occurred at a lower level in HB and HY than in XH and MQ. The Simpson index value for bacterial diversity was positively correlated with plant diversity, legume species diversity and soil multifunctionality. However, the Shannon index value was negatively correlated with these parameters. Changes in the composition of legume‐associated rhizobacteria across different geographical locations are strongly influenced by plant diversity and soil nutrients, reflecting the distribution characteristics of legumes in alpine grasslands.

中文翻译：

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豆科植物相关根际细菌群落对高寒草原植物多样性和土壤性状的响应


豆科植物物种是植物多样性的重要组成部分，影响着各种生态系统的土壤生物多样性。它们对土壤细菌多样性和性状的影响，特别是在退化的草原中，仍然未知。本研究分析了甘肃省夏河市 （XH） 和玛曲 （MQ）、青海省海北省 （HB） 和青藏高原东部 （QTP） 四川省洪原市 （HY） 的植物多样性、土壤性状和豆科植物相关根际细菌群落之间的关系。豆科植物物种的多样性指数值 （覆盖率、丰富度、Shannon 指数和均匀度） 与植物多样性呈正相关。HB 和 HY 中的几种土壤养分（氨-氮、硝酸盐-氮、全氮、速效钾、速效磷和土壤有机质）和酶（脲酶、蔗糖酶、过氧化物酶和脱氢酶）在 HB 和 HY 中低于 XH 和 MQ。HB 和 HY 中根细菌多样性的 Shannon 指数高于 XH 和 MQ。相比之下，地理位置的多样性指数值高于同域植物物种。此外，HB 和 HY 与根际细菌的正相关和负相关比 XH 和 MQ 少 50%。原核生物分类群的功能注释分析表明，HB 和 HY 的硝酸盐还原相对丰度高于 XH 和 MQ，而 HB 和 HY 的固氮水平低于 XH 和 MQ。细菌多样性的 Simpson 指数值与植物多样性、豆科植物物种多样性和土壤多功能性呈正相关。然而，Shannon 指数值与这些参数呈负相关。 不同地理位置豆科植物相关根际细菌组成的变化受到植物多样性和土壤养分的强烈影响，反映了豆科植物在高寒草原的分布特征。