College of Life Sciences, Zhejiang University, No. 866 Yuhangtang Road, Hangzhou, 310058, Zhejiang Province, China.
Microb Ecol. 2022 Feb;83(2):393-407. doi: 10.1007/s00248-021-01746-3. Epub 2021 Apr 23.
Ecological processes (e.g., nutrient cycling) in riparian zones are often affected by land-use type and flooding. The extent to which land-use types and flooding conditions affect soil microorganisms and their ecological functions in riparian zones is not well known. By using high-throughput sequencing and quantitative PCR (q-PCR), we tested the effects of three land-use types (i.e., forest, wetland, and grassland) and two flooding conditions (i.e., landward locations and waterward locations within the land-use types) on soil microbial communities and microbial functional genes in the riparian zones of a reservoir. Land-use type but not flooding significantly affected soil microbial community composition at the phylum level, while both land-use type and flooding significantly affected the orders Nitrosotaleales and Nitrososphaerales. Alpha diversity was higher in the wetland and forest regardless of flooding conditions. Functional gene abundance differed among the three land-use types. Archaeal amoA (AOA) and nirS genes were more abundant in the wetland than in the grassland or forest. Bacterial amoA (AOB), nirK, nirS, and nosZ genes were more abundant in the waterward location than in the landward location but only in the wetland. Soil pH, moisture, and concentrations of soil organic matter and total soil nitrogen were significantly associated with the composition of archaeal and bacterial communities as well as with their gene abundance. This study revealed that soil microorganisms putatively involved in nitrogen cycling in riparian zones were more affected by land-use type than flooding.
河岸带的生态过程（如养分循环）通常受到土地利用类型和洪水的影响。土地利用类型和洪水条件对河岸带土壤微生物及其生态功能的影响程度尚不清楚。本研究采用高通量测序和实时定量 PCR（q-PCR）技术，测试了三种土地利用类型（森林、湿地和草地）和两种洪水条件（土地利用类型内的陆地位置和水域位置）对水库河岸带土壤微生物群落和微生物功能基因的影响。土地利用类型而非洪水显著影响了土壤微生物群落的门水平组成，而土地利用类型和洪水均显著影响了硝化螺旋菌目和硝化球菌目。无论洪水条件如何，湿地和森林的α多样性均较高。三种土地利用类型的功能基因丰度存在差异。湿地中古菌 amoA（AOA）和nirS 基因的丰度高于草地或森林。细菌 amoA（AOB）、nirK、nirS 和 nosZ 基因在湿地的水域位置的丰度高于陆地位置，但仅在湿地中如此。土壤 pH 值、水分、土壤有机碳和总氮浓度与土壤微生物群落组成及其基因丰度显著相关。本研究表明，河岸带中参与氮循环的土壤微生物受土地利用类型的影响大于洪水。
