Details
Original language | English |
---|---|
Article number | 176273 |
Number of pages | 11 |
Journal | Science of the Total Environment |
Volume | 954 |
Early online date | 14 Sept 2024 |
Publication status | E-pub ahead of print - 14 Sept 2024 |
Abstract
The priming effect, i.e., the changes in soil organic matter (SOM) decomposition following fresh organic carbon (C) inputs is known to influence C storage in terrestrial ecosystems. Microplastics (particle size <5 mm) are ubiquitous in soils due to the increasing use and often inadequate end-of-life management of plastics. Conventional polyethylene and bio-degradable (PHBV) plastics contain large amounts of C within their molecular structure, which can be assimilated by microorganisms. However, the extent and direction of the potential priming effect induced by microplastics is unclear. As such, we added 14C-labeled glucose to investigate how background polyethylene and PHBV microplastics (1 %, w/w) affect SOM decomposition and its potential microbial mechanisms in a short-term. The cumulative CO2 emission in soil contaminated with PHBV was 42–53 % higher than under Polyethylene contaminated soil after 60-day incubation. Addition of glucose increased SOM decomposition and induced a positive priming effect, as a consequence, caused a negative net soil C balance (−59 to −132 μg C g−1 soil) regardless of microplastic types. K-strategists dominated in the PHBV-contaminated soils and induced 72 % higher positive priming effects as compared to Polyethylene-contaminated soils (160 vs. 92 μg C g−1 soil). This was attributed to the enhanced decomposition of recalcitrant SOM to acquire nitrogen. The stronger priming effect associated in PHBVs can be attributed to cooperative decomposition among fungi and bacteria, which metabolize more recalcitrant C in PHBV. Moreover, comparatively higher calorespirometric ratios, lower substrate use efficiency, and larger enzyme activity but shorter turnover time of enzymes indicated that soil contaminated with PHBV release more energy, and have a more efficient microbial catabolism and are more efficient in SOM decomposition and nutrient resource uptake. Overall, microplastics, (especially bio-degradable microplastics) can alter biogeochemical cycles with significant negative consequences for C sequestration via increasing SOM decomposition in agricultural soils and for regional and global C budgets.
Keywords
- Biogeochemical cycles, Carbon sequestration, Microbial community, Microplastics, Priming effect, Soil organic matter decomposition
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Engineering
- Environmental Science(all)
- Environmental Chemistry
- Environmental Science(all)
- Waste Management and Disposal
- Environmental Science(all)
- Pollution
Sustainable Development Goals
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In: Science of the Total Environment, Vol. 954, 176273, 01.12.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Microplastic contamination accelerates soil carbon loss through positive priming
AU - Zhou, Jie
AU - Feng, Wenhao
AU - Brown, Robert W.
AU - Yang, Haishui
AU - Shao, Guodong
AU - Shi, Lingling
AU - Gui, Heng
AU - Xu, Jianchu
AU - Li, Feng Min
AU - Jones, Davey L.
AU - Zamanian, Kazem
N1 - Publisher Copyright: © 2024
PY - 2024/9/14
Y1 - 2024/9/14
N2 - The priming effect, i.e., the changes in soil organic matter (SOM) decomposition following fresh organic carbon (C) inputs is known to influence C storage in terrestrial ecosystems. Microplastics (particle size <5 mm) are ubiquitous in soils due to the increasing use and often inadequate end-of-life management of plastics. Conventional polyethylene and bio-degradable (PHBV) plastics contain large amounts of C within their molecular structure, which can be assimilated by microorganisms. However, the extent and direction of the potential priming effect induced by microplastics is unclear. As such, we added 14C-labeled glucose to investigate how background polyethylene and PHBV microplastics (1 %, w/w) affect SOM decomposition and its potential microbial mechanisms in a short-term. The cumulative CO2 emission in soil contaminated with PHBV was 42–53 % higher than under Polyethylene contaminated soil after 60-day incubation. Addition of glucose increased SOM decomposition and induced a positive priming effect, as a consequence, caused a negative net soil C balance (−59 to −132 μg C g−1 soil) regardless of microplastic types. K-strategists dominated in the PHBV-contaminated soils and induced 72 % higher positive priming effects as compared to Polyethylene-contaminated soils (160 vs. 92 μg C g−1 soil). This was attributed to the enhanced decomposition of recalcitrant SOM to acquire nitrogen. The stronger priming effect associated in PHBVs can be attributed to cooperative decomposition among fungi and bacteria, which metabolize more recalcitrant C in PHBV. Moreover, comparatively higher calorespirometric ratios, lower substrate use efficiency, and larger enzyme activity but shorter turnover time of enzymes indicated that soil contaminated with PHBV release more energy, and have a more efficient microbial catabolism and are more efficient in SOM decomposition and nutrient resource uptake. Overall, microplastics, (especially bio-degradable microplastics) can alter biogeochemical cycles with significant negative consequences for C sequestration via increasing SOM decomposition in agricultural soils and for regional and global C budgets.
AB - The priming effect, i.e., the changes in soil organic matter (SOM) decomposition following fresh organic carbon (C) inputs is known to influence C storage in terrestrial ecosystems. Microplastics (particle size <5 mm) are ubiquitous in soils due to the increasing use and often inadequate end-of-life management of plastics. Conventional polyethylene and bio-degradable (PHBV) plastics contain large amounts of C within their molecular structure, which can be assimilated by microorganisms. However, the extent and direction of the potential priming effect induced by microplastics is unclear. As such, we added 14C-labeled glucose to investigate how background polyethylene and PHBV microplastics (1 %, w/w) affect SOM decomposition and its potential microbial mechanisms in a short-term. The cumulative CO2 emission in soil contaminated with PHBV was 42–53 % higher than under Polyethylene contaminated soil after 60-day incubation. Addition of glucose increased SOM decomposition and induced a positive priming effect, as a consequence, caused a negative net soil C balance (−59 to −132 μg C g−1 soil) regardless of microplastic types. K-strategists dominated in the PHBV-contaminated soils and induced 72 % higher positive priming effects as compared to Polyethylene-contaminated soils (160 vs. 92 μg C g−1 soil). This was attributed to the enhanced decomposition of recalcitrant SOM to acquire nitrogen. The stronger priming effect associated in PHBVs can be attributed to cooperative decomposition among fungi and bacteria, which metabolize more recalcitrant C in PHBV. Moreover, comparatively higher calorespirometric ratios, lower substrate use efficiency, and larger enzyme activity but shorter turnover time of enzymes indicated that soil contaminated with PHBV release more energy, and have a more efficient microbial catabolism and are more efficient in SOM decomposition and nutrient resource uptake. Overall, microplastics, (especially bio-degradable microplastics) can alter biogeochemical cycles with significant negative consequences for C sequestration via increasing SOM decomposition in agricultural soils and for regional and global C budgets.
KW - Biogeochemical cycles
KW - Carbon sequestration
KW - Microbial community
KW - Microplastics
KW - Priming effect
KW - Soil organic matter decomposition
UR - http://www.scopus.com/inward/record.url?scp=85204242166&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2024.176273
DO - 10.1016/j.scitotenv.2024.176273
M3 - Article
C2 - 39278478
AN - SCOPUS:85204242166
VL - 954
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
M1 - 176273
ER -