Soil carbon dioxide fluxes in a mixed floodplain forest in the Czech Republic

Floodplain forests belong among the most productive, dynamic and diverse ecosystems on Earth. Only few studies have focused on the carbon dioxide fluxes of these ecosystems. Therefore, this study investigated the spatial heterogeneity in soil CO2 efflux in a floodplain forest located in the southeast of the Czech Republic. The study also examined which environmental parameters influence soil CO2 efflux. Moreover, using these obtained measurements a soil CO2 efflux model was applied. To achieve the aims of this study, soil CO2 efflux on 30 positions in 16 campaigns was measured from May to November during the growing season 2016. The efflux during the experiment period ranged from 1.59 to 8.54 mu molCO(2) m(-2) s(-1). The highest soil CO2 effluxes were observed during the summer period while the lowest values were measured during the autumn. A strong relationship between soil CO2 efflux and soil temperature was found (R-2 = 0.79). The estimated mean Q(10) for the whole 30 positions was of 2.23. We determined that the spatial heterogeneity of soil CO2 efflux was 20% during our study. The cumulative amount of carbon forest floor released from our experimental forest site calculated from our model was 7.4 (+/- 1.1) tC ha(-1) y(-1) for 2016. Such data are important for developing our knowledge and understanding about carbon dynamics and to improve carbon models for these ecosystems types. (C) 2017 Elsevier Masson SAS. All rights reserved.