An organic carbon budget for an oligotrophic lake in New Hampshire, U.S.A.

Abstract

Autochthonous sources represent 83 % of the total organic carbon inputs for Mirror Lake. The phytoplankton are the major producers, accounting for 90% of autochthonous inputs. Precipitation provided 16 % of total allochthonous carbon inputs; fluvial DOC is the most important allochthonous carbon surce (47 %). Of the total carbon inputs, 83 % are lost through respiration, 7 % by sedimentation and 10 % by fluvial outputs. Parts of this budget are tentative, and need additional study. The weakest area is bacterial production and decomposition; but direct counts of pelagic and benthic bacteria by fluorescence microscopy, and estimation of bacterial production, are under way. Additional information will strengthen the budget by improving confidence limits, but should not significantly change the major findings presented here.