Perspectives on the age and distribution of large wood in riparian carbon pools
Canadian Journal of Fisheries and Aquatic Sciences
Most knowledge of carbon budgets is derived from the productivity and sequestration of carbon in terrestrial and marine ecosystems. Less is known of carbon stored in riparian areas associated with lakes and rivers. Case studies of the age distribution of carbon in aquatic large wood (C1w) from two different landscapes with different drainage patterns were established using tree-ring and 14C dating. Cumulative negative exponential distributions of the age of C1w ranged over periods from 1000 to 9485 years. Large woody debris had mean residence times of 261 years in small oligotrophic lakes and 350-800 years in a stream reach. Large wood can reside for an order of magnitude longer in freshwater-riparian ecosystems than in comparable above-ground terrestrial ecosystems. Although riparian areas make up only a small fraction of most landscapes, they may account for a relatively larger proportion of aged C1w than is stored above ground in terrestrial ecosystems.