| Popis: |
Ultrafiltration was used to try to determine the origin of dissolved organic carbon ("DOC") in Mirror Lake, New Hampshire. The distribution of molecular weights of DOC was relatively constant with depth and season, with a predominance of highmolecular weight (> 100,000 daltons; 31%) and moderate-molecular weight compounds (1,000 to 10,000 daltons; 36%). The distribution of molecular weights of DOC in the lake was distinctly different from that of the DOC which entered the lake in stream water, soil solution, or precipitation. Lake water is relatively enriched in DOC above 100,000 daltons; this high-molecular weight DOC is apparently produced within the lake. One autochthonous source of DOC above 100,000 daltons is that produced during algal growth and decomposition. An input/output budget of the DOC for each molecular weight class suggested that most of the DOC in the lake resides in the lake for several years. |
