Abstract: There is great uncertainty about the short- and long-term effects of precipitation increases on soil-atmosphere trace gas fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in temperate forests. We conducted two analyses: a field study to test whether short-term heavy precipitation events affect these fluxes as well as a meta-analysis of studies evaluating these effects in forests around the world. In the field study, four daily additions of water increased CO2 emissions but did not alter CH4 and N2O fluxes. However, the metaanalysis found that long-term increases in precipitation markedly altered fluxes of all three gases. These results suggest that the influence of short-term precipitation pulses may not be as important as long-term changes in precipitation. The mechanisms underlying long-term change are likely complex.
Keywords: Increased precipitation; Carbon dioxide; Methane; Nitrous oxide