Elevated CO 2 Affects the Soil Organic Carbon Fractions and Their Relation to Soil Microbial Properties in the Rhizosphe
- PDF / 2,048,814 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 55 Downloads / 214 Views
ORIGINAL PAPER
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 Shuping Huang 1,2 & Xueshi Huang 3 & Ben Fang 4 Received: 17 October 2019 / Accepted: 20 February 2020 # Sociedad Chilena de la Ciencia del Suelo 2020
Abstract As the global climates change, elevated CO2 and soil contamination by heavy metal co-occur 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. Cd decreased DOC (30.1%), MBC (24.9%), bacteria (21.5%), actinomycetes (15.9%), and enzyme activities. Elevated CO2 offsets 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. Keywords Elevated atmospheric CO2 . Cd-contaminated soil . Soil organic carbon fractions . Rhizosphere microbial properties . Robinia pseudoacacia L. seedlings
1 Introduction The atmospheric concentration of carbon dioxide (CO2) has been steadily increased during the last 12 years at the rate of
* Shuping Huang [email protected] 1
School of Geographic Sciences, Xinyang Normal University, Xinyang 464000, People’s Republic of China
2
Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, Xinyang Normal University, 237 Changan Road, Xinyang 464000, People’s Republic of China
3
Faculty of Resources & Safety Engineering, China University of Mining & Technology, Beijing 100000, People’s Republic of China
4
Scholl of Environment Science and Engineering, Chang’an University, Xi’an 710054, People’s Republic of China
1.9 μmol mol−1 year−1 and is anticipated to be as high as 550 μmol mol−1 by the middle of the twenty-first century (IPCC
Data Loading...
