中文关键词土壤养分土壤酶土壤细菌群落多样性适生植物消落带三峡水库 英文关键词soil nutrientssoil enzyme activitydiversity of soil bacterial communitysuitable plant speciesriparian zoneThree Gorges Reservoir

作者	单位	E-mail
李丽娟	西南大学生命科学学院, 三峡库区植物生态与资源重点实验室, 三峡库区生态环境教育部重点实验室, 重庆 400715	39763186@qq.com
李昌晓	西南大学生命科学学院, 三峡库区植物生态与资源重点实验室, 三峡库区生态环境教育部重点实验室, 重庆 400715	lichangx@swu.edu.cn
陈春桦	西南大学生命科学学院, 三峡库区植物生态与资源重点实验室, 三峡库区生态环境教育部重点实验室, 重庆 400715
杨治华	西南大学生命科学学院, 三峡库区植物生态与资源重点实验室, 三峡库区生态环境教育部重点实验室, 重庆 400715
陈雪梅	西南大学生命科学学院, 三峡库区植物生态与资源重点实验室, 三峡库区生态环境教育部重点实验室, 重庆 400715

中文摘要 植物通过根系分泌修饰根际土壤微环境.从植物根系-土壤-微生物三者密切关联的根际土壤微环境角度，研究三峡消落带植被修复重建后根部土壤微生态动态特征，对于认识和评估消落带退化土壤环境的生态修复工作具有重要意义.从三峡库区忠县石宝寨汝溪河消落带植被修复示范基地采集人工植被中4种优势植物落羽杉（Taxodium distichum）、立柳（Salix matsudana）、狗牙根（Cynodon dactylon）和牛鞭草（Hemarthria altissima）的根际与非根际土壤，探究其根际与非根际土壤的养分含量与酶活性差异，同时通过高通量测序进行细菌群落多样性分析，以阐明三峡消落带不同物种逆境胁迫下的生长适应性以及养分利用策略.结果表明：①三峡库区消落带4种适生植物根系活动导致根际与非根际土壤养分含量产生显著差异，主要表现为根际土壤有机质、全氮、碱解氮以及有效磷的显著富集，而钾素在不同物种间的根际效应变化趋势并不一致；②蔗糖酶、脲酶以及酸性磷酸酶在4种适生植物中均表现出正向根际效应（R/S>1），但由于不同物种生理特征的差异，不同物种根系活动对3种土壤酶的激活效应存在差异；③高通量测序结果显示，库区4种适生植物根际与非根际土壤细菌群落多样性特征并无显著差异，变形菌门、酸杆菌门、绿弯菌门、放线杆菌门、拟杆菌门、浮霉菌门、蓝藻门、厚壁菌门、硝化螺旋菌门、芽孢杆菌门、未知细菌门以及泉古菌门在消落带4种适生植物根部土壤环境中相对丰度最大，对于4种适生植物的营养吸收、疾病抵抗以及消落带逆境适应均发挥着重要的作用. 英文摘要 Plants modify the soil microenvironment through root exudation. It is important to study the dynamic changes of soil ecosystem from the perspective of root-soil-microbe interactions after vegetation restoration in the riparian zone of the Three Gorges Reservoir (TGR). The rhizosphere and bulk soils of Cynodon dactylon, Hemarthria altissima, Taxodium distichum, and Salix matsudana were collected from the vegetation restoration demonstration base of Ruxi River to explore the differences in nutrient contents and enzyme activities between the rhizosphere and bulk soils. At the same time, the diversity of the bacterial community in the rhizosphere and bulk soils was also investigated using the high throughput sequencing method, with the aim to clarify the growth adaptabilities and nutritional utilization strategies within a more precise rhizosphere range. The results showed that ① Suitable plants enhanced the transformation efficiency of rhizosphere nutrients in different ways to improve their adaptability to the soil environment in the TGR. Compared with bulk soil, root activities had significant effects on nutrient contents in the rhizosphere. Among them, SOC, AN, TN, and AP were enriched significantly to a certain degree, while the changes of potassium were not consistent in different plant species. ② In the process of vegetation restoration, the deposition of litter and root secretion indirectly regulated soil enzyme activity. Invertase, urease, and acid phosphatase, all exhibited positive rhizosphere effects (R/S>1) in these four suitable plant species. However, considering the differences in root structure and physiological characteristics between herbaceous and woody plants, the rhizosphere effect of these three enzymes in four plants was different. ③ The results of high-throughput sequencing showed that there was no significant difference in bacterial community diversity between the rhizosphere and bulk soil of four suitable plant species in the TGR. In addition, Proteobacteria, Acidobacteria, Chloroflexi, Actinobacteria, Bacteroidetes, Planctomycetes, Cyanobacteria, Firmicutes, Nitrospirae, Gemmatimonadetes, WS3, and Crenarchaeota were the twelve most abundant bacterial phyla in the rhizosphere and bulk soils, serving the ecological functions of nutrition absorption and disease suppression. Their colonization was found to be beneficial to the stress resistance of plants growing in harsh riparian ecosystems in the TGR.

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