Data_Sheet_1_Effect of poplar ecological retreat project on soil bacterial community structure in Dongting Lake wetland.docx

As an important environmental protection measure, the Poplar Ecological Retreat (PER) project aims to restore the ecology of the Dongting Lake (DL, China’s second largest freshwater lake) wetland. And its ecological impact is yet to be revealed. This study selected soil bacterial community structure (BCS) as an indicator of ecological restoration to explore the ecological impact of PER project on DL wetland. Soil samples were collected from reed area (RA, where poplar had never been planted, as the end point of ecological restoration for comparison in this study), poplar planting area (PA), poplar retreat for 1-year area (PR1A) and poplar retreat for 2 years area (PR2A), then their soil properties and BCS were measured. The results showed that the PER project caused significant changes in soil properties, such as the soil organic matter (SOM) and moisture, and an increase in the diversity and richness index of soil BCS. The Shannon-wiener index of RA, PA, PR1A and PR2A were 3.3, 2.63, 2.75 and 2.87, respectively. The number of operational taxonomic units (OTUs) changed similarly to the Shannon-wiener index. The Pearson correlation analysis and redundancy analysis (RDA) showed that the poplar retreat time, SOM and moisture content were the main factors leading to the increase of BCS diversity. All of these indicated that after the implementation of the PER project, the ecology of the lake area showed a trend of gradual recovery.

作为一项重要的环境保护措施，柳树生态退耕（PER）项目旨在恢复我国第二大淡水湖洞庭湖（DL）湿地的生态平衡。该项目对生态影响的揭示尚待揭晓。本研究选取土壤细菌群落结构（BCS）作为生态恢复的指标，以探究PER项目对洞庭湖湿地生态影响。土壤样本分别从芦苇区（RA，即本研究中生态恢复的终点，柳树从未种植的区域，用于比较）、柳树种植区（PA）、柳树退耕1年区（PR1A）和柳树退耕2年区（PR2A）采集，随后对其土壤特性和BCS进行了测量。研究结果表明，PER项目对土壤特性，如土壤有机质（SOM）和水分含量，产生了显著的影响，并增加了土壤BCS的多样性和丰富度指数。RA、PA、PR1A和PR2A的Shannon-Wiener指数分别为3.3、2.63、2.75和2.87。操作分类单元（OTU）的数量变化与Shannon-Wiener指数相似。Pearson相关分析和冗余分析（RDA）表明，柳树退耕时间、SOM和水分含量是导致BCS多样性增加的主要因素。所有这些迹象均表明，在实施PER项目后，湖泊区域的生态环境呈现出逐步恢复的趋势。