Contaminated soils are widespread and contamination is known to impact several biotic soil processes. But it is still not clear to what extent soil contamination affects soil carbon efflux (CO2) occurring through soil microfauna respiration. Regarding the large stocks of organic carbon (Corga) stored in soils, even limited changes in the outputs fluxes may modify atmospheric CO2 concentration with important feedbacks on climate. In this study, we aimed at assessing and quantifying how soil respiration is affected by contamination. For that, we performed a quantitative review of literature focusing on 1) soil heterotrophic respiration measurements thus excluding autotrophic respiration from plants, 2) soil copper contamination, and 3) the influence of pedo-climatic parameters such as pH, clay content or the type of climate. Using a dataset of 389 data analyzed with RandomForest and linear mixed statistical models, we showed a decrease in soil CO2 emission with an increase in soil copper contamination. Specific data from ex-situ spiking experiments could be easily differentiated from the ones originated from in-situ contamination due to their sharper decrease in soil Corga mineralization. Interestingly, ex-situ spikes data provided a threshold in soil Cu contents for CO2 emissions: CO2 emission increased for inputs below 265 mgCu.kg−1 soil and decreased above this concentration. Data from long-term in-situ contaminations due to anthropogenic activities (industrialization, agriculture, … ) also displayed an impact on soil carbon mineralization, much particularly for industrial contaminations (smelter, sewage sludge, … ) with decreased in CO2 emissions when Cu contamination increased. Soil pH was identified as a significant driver of the effect of Cu on CO2 emissions, as soil C mineralization was found to be more sensitive to Cu contamination in acidic soils than in neutral or alkaline soils. Conversely the clay content and the type of climate did not significantly explain the responses in soil C mineralization. Finally, the collected data were used to propose an empirical equation quantifying how soil respiration can be affected by a Cu contamination. The decrease in soil CO2 emissions cannot be related, however, in a role of C sink as it comes together with a decrease in soil microbial biomass.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.