Patterns and controls of seasonal variability of carbon stable isotopes of particulate organic matter in lakes.

摘要: Carbon stable isotopes (δ(13)C) of particulate organic matter (POM) have been used as indicators for energy flow, primary productivity and carbon dioxide concentration in individual lakes. Here, we provide a synthesis literature data from 32 freshwater lakes around the world to assess variability δ(13)C(POM) along latitudinal, morphometric biogeochemical gradients. Seasonal mean δ(13)C(POM), temporally integrated measure displayed weak relationships with all trophic state indices [total phosphorus (TP), total nitrogen (TN), chlorophyll (Chl a)], but decreased significantly increase latitude, presumably response corresponding decrease water temperature CO(2) concentration. The seasonal minimum also correlated negatively latitude while maximum positively indices, pH, δ(13)C dissolved inorganic (DIC). amplitude (the difference between values) TP Chl concentrations small variations oligotrophic, mesotrophic low eutrophic lakes, which is attributed abundant non-living POM relatively environmental conditions subtropics. was greatest high Greater changes solar light regime may be responsible large productive This provides new insights on factors controlling among global scale.