Methane and carbon dioxide fluxes from poorly drained adjacent cultivated and forest sites

Abstract

Methane and carbon dixoide fluxes at the soil surface were measured in Ottawa, on adjacent cultivated (corn) and forest (temperature woodland) sites using closed chambers compared to the forest soil, rates of CO2 emissions and CH4 uptake were lower in the cultivated soil. Temperature had little effect on methane uptake by the forest soil suggesting that gas diffusion was rate limiting. The spatial variability for methane uptake in the forest soil was found to be much larger than that previously observed for soil carbon dioxide production but is lower than that reported for nitrous oxide production. For fluxes larger than 0.15 mg m-2 d-1, the number of sites necessary to estimate the average flux with a precision of 10% ranged from 7 to 452 -from Authors