Vegetation-driven shifts in soil bacterial community structure: Insights from karst rocky desertification mitigation in southwestern China

Abstract: Karst Rocky Desertification (KRD) presents a substantial obstacle to ecological restoration in southwestern China, significantly hindering regional economic growth and the lives of locals. Despite advancements in prevention and management, a significant gap persists in studies on the influence of various plant species on soil bacterial communities. This study utilised 16S rDNA Illumina sequencing technology alongside measurements of soil physicochemical properties, employing 12 composite soil samples collected through a five-point sampling method. We discovered that (1) Vegetation restoration is successful in the ecological rehabilitation of KRD, improving soil nutrient levels. (2) Alpha diversity remained constant, while beta diversity showed significant variation, reflecting the stability of soil core functions and the networked adaptation of bacterial communities to environmental fluctuations. (3) Vegetation restoration influences the reorganisation of soil bacterial populations, requiring careful manipulation of soil characteristics to facilitate desertification management. The pH value is a crucial regulatory element affecting microbial functional communities via direct physiological stress and indirect resource constraints. Prioritising pH management is advisable, as well as integrating the selection of acid/alkaline-tolerant flora and lime adjustments with other artificial efforts to maintain an alkaline environment, enhancing microbial metabolism and ecosystem service activities. This strategy benefits KRD regions ecologically, socially, and economically.

摘要：喀斯特石漠化（Karst Rocky Desertification, KRD）是中国西南地区生态修复进程中的重大阻碍，严重制约区域经济增长与当地民众的生产生活。尽管石漠化防治与管理工作已取得长足进展，但针对不同植物物种对土壤细菌群落影响的研究仍存在显著缺口。本研究采用16S rDNA Illumina测序技术（16S rDNA Illumina sequencing technology），并同步开展土壤理化性质（soil physicochemical properties）测定，通过五点取样法（five-point sampling method）采集了12份复合土壤样本。研究结果显示：（1）植被修复可有效推进喀斯特石漠化的生态修复工作，提升土壤养分水平；（2）土壤细菌群落的α多样性（Alpha diversity）维持稳定，而β多样性（Beta diversity）则呈现显著差异，这反映出土壤核心功能的稳定性，以及细菌群落对环境波动的网络适应性机制；（3）植被修复会驱动土壤细菌种群的重构，因此需精准调控土壤特性以助力石漠化治理。pH值是调控微生物功能群落的关键因子，可通过直接生理胁迫与间接资源限制发挥作用。研究建议优先开展pH值调控工作，同时结合耐酸碱植物筛选与石灰改良等人工措施，维持土壤碱性环境，以强化微生物代谢与生态系统服务功能。该策略可从生态、社会与经济多维度惠及喀斯特石漠化地区。