Influence of Hydroperiod on Litter Conversion to Soil Organic Matter in a Floodplain Forest

Abstract

Abstract Lignin and cellulose dynamics were followed for 23 mo during degradation of foliar litter in an oligotrophic floodplain forest located in south Georgia. Litter was placed in microcosms, which were subjected to hydroperiod variation in terms of duration and nutrient inflow. Treatments were compared in terms of rates of lignin and cellulose loss and the degree to which a theoretical asymptotic value of the ratio of lignin to lignin plus cellulose (LCI) was approached. Flooding strongly stimulated loss rates of lignin and cellulose, and results suggest that a single, relatively brief flooding event promoted loss rates to the greatest extent. The elevation of N inflow reduced lignin degradation rates compared with other flooding treatments. Observed temporal patterns of LCI ratios did not follow theorized patterns and may suggest that, in warm climates such as south Georgia, lignin loss is greater than in boreal forest systems where theoretical LCI relationships were developed.