The effects of clear-cutting on soil CO2, CH4, and N2O flux, storage and concentration in two Atlantic temperate forests in Nova Scotia, Canada

Abstract

The effect of clear-cutting on in situ carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) trace gas exchange between soil and atmosphere was studied during one growing season in two Atlantic temperate forest sites located in Nova Scotia, Canada. The flux, the storage and the concentration (four depths) of the three main greenhouse gases (GHGs) were measured up to ten times in 2005 (between March and November) in two clear-cut and two forest plots (paired sites). Air temperature and soil moisture were also monitored simultaneously with GHG. All three GHG showed high temporal variability and variability between plots during the time covered by this study. Our results also showed that there was still a treatment effect on GHG three years post-harvest. Clear-cutting increased CO2 production and storage in one of our site and CH4 uptake in both sites, but was inconsistent for N2O during the sampling period. With the exception of CO2, the correlation between GHG, and air temperature and soil moisture was absent. This suggests that GHG emissions in these two Acadian forests are mainly affected by other biological and physical factors. Finally, our study showed that measures of one GHG could not be used to infer measures of another GHG.