SPATIAL AND TEMPORAL PATTERNS OF DENITRIFICATION IN A RIPARIAN FOREST

1. This study estimated the importance of in situ denitrification in the nitrate buffering capacities of a riparian forest. 2. Spatial and temporal patterns of in situ denitrification were investigated along a riparian catena. 3. Highest rates of in situ denitrification (up to 78 mgN m(-2) day(-1)) were measured in the riparian forest soils in late winter and early spring. Lowest rates (3 mgN m(-2) day(-1)) were measured in summer and autumn. 4. Whatever the season considered, 30 m of riparian buffer strip were enough to remove all the nitrates coming through the groundwater. 5. Rehabilitation of riparian zones with riparian vegetation together with the maintenance of waterlogged conditions induced by riverflow regulation appear to be a good point from which to start the restoration of buffering capacities of river ecosystems against nitrogen loads.