Microplastic pollution promotes soil respiration: A global‐scale meta‐analysis

• Published in: Global change biology Vol. 30; no. 7; pp. e17415 - n/a
• Main Authors: Zhao, Shuling, Rillig, Matthias C., Bing, Haijian, Cui, Qingliang, Qiu, Tianyi, Cui, Yongxing, Penuelas, Josep, Liu, Baiyan, Bian, Shiqi, Monikh, Fazel Abdolahpur, Chen, Jing, Fang, Linchuan
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.07.2024
• Subjects: Autotrophic microorganisms; Biomass; Carbon - analysis; Carbon - metabolism; Carbon dioxide; Carbon Dioxide - analysis; Carbon Dioxide - metabolism; Carbon dioxide emissions; Chloroflexi; climate; Components; Cyanobacteria; Dissolved organic carbon; Emission analysis; Fluorescein diacetate; global change; global climate change; Heterotrophic microorganisms; hydrolases; Meta-analysis; microbial biomass; Microbiomes; Microbiota - drug effects; Microorganisms; Microplastic pollution; Microplastics; Microplastics - analysis; Plastic debris; Plastic pollution; pollution; Respiration; Soil; Soil - chemistry; Soil analysis; Soil bacteria; soil CO2 emission; soil enzyme activities; Soil Microbiology; Soil microorganisms; soil organic C; soil organic carbon; Soil Pollutants - analysis; Soil pollution; soil respiration; Soils; Substrate inhibition; soil enzyme activities; soil microorganisms; soil CO2 emission; global climate change; microplastics; soil organic C
• ISSN: 1354-1013; 1365-2486; 1365-2486
• DOI: 10.1111/gcb.17415

Microplastic (MP) pollution likely affects global soil carbon (C) dynamics, yet it remains uncertain how and to what extent MP influences soil respiration. Here, we report on a global meta‐analysis to determine the effects of MP pollution on the soil microbiome and CO2 emission. We found that MP pollution significantly increased the contents of soil organic C (SOC) (21%) and dissolved organic C (DOC) (12%), the activity of fluorescein diacetate hydrolase (FDAse) (10%), and microbial biomass (17%), but led to a decrease in microbial diversity (3%). In particular, increases in soil C components and microbial biomass further promote CO2 emission (25%) from soil, but with a much higher effect of MPs on these emissions than on soil C components and microbial biomass. The effect could be attributed to the opposite effects of MPs on microbial biomass vs. diversity, as soil MP accumulation recruited some functionally important bacteria and provided additional C substrates for specific heterotrophic microorganisms, while inhibiting the growth of autotrophic taxa (e.g., Chloroflexi, Cyanobacteria). This study reveals that MP pollution can increase soil CO2 emission by causing shifts in the soil microbiome. These results underscore the potential importance of plastic pollution for terrestrial C fluxes, and thus climate feedbacks. Microplastic (MP) pollution is a significant global environmental challenge with the potential to impact soil carbon dynamics, necessitating a systematic assessment of its effects on soil respiration. We provide evidence that MPs increased the soil C pool (in part very likely because plastic‐carbon was captured as soil C) and microbial biomass thereby promoting soil CO2 emission. This study enhances our understanding of how MPs influence soil CO2 emissions by regulating the soil microbiome and underscores potential feedback mechanisms related to climate impacts at the Earth system level, thereby providing guidance for future research and policy development.