View article

Soil respiration is one of the largest terrestrial fluxes of carbon dioxide (CO 2) to the atmosphere. Hence, small changes in soil respiration rates could have large effects on atmospheric CO 2. In order to assess CO 2 emissions from diverse European soils with different land-use types and climate (soil moisture and temperature), we conducted a laboratory incubation experiment. Emission measurements of CO 2 under controlled conditions were conducted using soil monoliths of nine sites from a European flux network (ÉCLAIRE). The sites are located all over Europe–from the United Kingdom in the west to Ukraine in the east, and from Italy in the south to Finland in the north–and can be separated according to four land-use types (forests, grasslands, arable lands and one peatland). Intact soil cores were incubated in the laboratory in a two-way factorial design, with temperature (5, 10, 15, 20 and 25∘ C) and water-filled pore space (WFPS; 5, 20, 40, 60 and 80%) as the independent variables, while CO 2 flux was the response variable. The latter was measured with an automated laboratory incubation measurement system. Land use generally had a substantial influence on carbon dioxide fluxes, with the order of CO 2 emission rates of the different land-use types being grassland> peatland> forest/arable land (P< 0.001). CO 2 efflux responded strongly to varying temperature and moisture content with optimum moisture contents for CO 2 emissions between 40 and 70% WFPS and a positive relationship between CO 2 emissions and temperature. The relationship between temperature and CO 2 emissions could be well described by a Gaussian …