标题：Elevated CO2 Affects the Soil Organic Carbon Fractions and Their Relation to Soil Microbial Properties in the Rhizosphere of Robinia pseudoacacia L. Seedlings in Cd-Contaminated Soils

作者：Shuping Huang, Xueshi Huang, Ben Fang

来源出版物：Journal of Soil Science and Plant Nutrition

DOI: 10.1007/s42729-020-00205-1

出版年: 2020

文献类型：Article

语种：英文

摘要：As the global climates change, elevated CO₂ and soil contamination by heavy metal co-occure in natural ecosystems, which are anticipated to affect soil organic carbon fractions (SOC) and their relation to soil microbial activities, but this issue has not been extensively examined. We investigated the response of SOC and their relation with soil microorganisms and enzyme activities in rhizosphere soils of Robinia pseudoacacia L. seedlings to elevated CO₂ plus cadmium (Cd)-contamination. We found that elevated CO₂ significantly (p < 0.05) stimulated total organic carbon (TOC) (8.6%), dissolved organic carbon (DOC) (32.6%), microbial biomass carbon (MBC) (13.5%), bacteria (11.6%), fungi (20.9%), actinomycetes (15.3%), urease (20.1%), dehydrogenase (15.8%), invertase (11.1%), and β-glucosidase (11.9%), and DOC, MBC, bacteria, actinomycetes, urease, and invertase presented smaller growth trend in the range of 500-700 μmol mol^-1 CO₂ than in the range of 385-500 μmol mol^-1 CO₂. While Cd decreased DOC (30.1%), MBC (24.9%), bacteria (21.5%) actinomycetes (15.9%), and enzyme activities. Elevated CO₂ offset the negative effect of Cd on SOC and microbial activities (except for TOC and L-asparaginase). Procrustes rotation test was used to determine the drivers (elevated CO₂, Cd, and CO₂ + Cd) of the relation between SOC and microbial activities, revealing the correlations between SOC, soil microorganisms, and enzyme activities were higher under elevated CO₂ than under elevated CO₂ + Cd. Our results suggest elevated CO₂ could stimulate soil fertility and microecological cycle in the rhizosphere microenvironment exposed to heavy metal by affecting the relationship between SOC and soil microbial properties.

关键词： Elevated atmospheric CO₂; Cd-contaminated soil; Soil organic carbon fractions; Rhizosphere microbial properties; Robinia pseudoacacia L. seedlings.

论文连接: https://link.springer.com/article/10.1007/s42729-020-00205-1