摘要
TOTAL organic matter(TOM) or total organic carbon(TOC) is often treated as an importantindicator of lake environment. As a matter of fact, TOC is of multi-origin, and can simply bedivided into two parts: autochthonous and allochthonous organic carbon. The autochthonousorganic carbon is mainly controlled by the production of the plankton of lake itse1f; and the al-lochthonous one by climate and environment in the catchment area, e. g. more precipitationand runoff and densely developed vegetation will give rise to more allochthonous organic com-
