Carbon dioxide efflux during the flooding phase of temporary ponds

Abstract

ABSTRACTCarbon dioxide efflux during the flooding phase of temporary ponds Small water bodies, such as temporary ponds, have a high carbon processing potential. Nevertheless, despite the globaloccurrence of these systems, the carbon effluxes from such water bodies have been largely overlooked. In this study, weexamined the intra- and intersystem variability of carbon dioxide (CO 2 ) effluxes from a set of Mediterranean temporaryponds during the flooding phase, a hot-spot for biogeochemical cycling in temporary systems. The CO 2 effluxes showedhigher variability among the various sections of each pond (i.e., inundated, emerged-unvegetated and emerged-vegetated)than among the ponds. The emerged-vegetated sections showed the highest CO 2 effluxes per unit area and tended to drivethe total effluxes at the whole-ecosystem scale. The mean CO 2 efflux (121.3±138.1 mmol m –2 d –1 ) was in the upper rangefor freshwater ecosystems. The CO 2 effluxes were not related to catchment properties but rather to the organic content of thesediments,especiallyintheemergedsectionsoftheponds.Ourresultsindicatethattemporaryponds,especiallytheiremergedsections, are important sources of CO