Fig. 4: Relationship between temperature seasonality and organic carbon burial during the Holocene.
From: Temperature seasonality regulates organic carbon burial in lake
a During the Early to Mid-Holocene (EMH), elevated summer temperatures enhanced both net primary productivity (NPP) and heterotrophic respiration (HR), with NPP consistently exceeding HR and resulting in an increased flux of organic carbon (OC) into sediments. b Lower winter temperatures during the EMH suppressed HR, favoring the preservation of OC in sediments. c In the Mid-to Late Holocene (MLH), decreased summer temperatures reduced both NPP and HR compared to the EMH, resulting in a diminished flux of OC into sediments. d Rising winter temperatures during the MLH intensified HR, leading to greater decomposition of OC stored in sediments. The cyclic diagram illustrates the positive feedback mechanism among OC decomposition, CO2 emissions to the atmosphere, and climate warming. OCB=organic carbon burial. NPP, HR and NPP-HR are expressed in gC/m²/day. The plus sign (+) represents the amount of OC entering sediments, with more plus signs indicating a higher amount. The thickness of the arrows corresponds to the intensity of each process, with thicker arrows indicating greater intensity. Detailed data comparisons are provided in Supplementary Table 4.
