Anthropogenic control of coupled changes in organic and inorganic carbon burial in karst landscape: Sediment evidence from two lakes of subtropical China

•There existed synchronous variations in organic and inorganic carbon of Karst lakes.•Sediment carbon flux was enhanced with lake damming, and agricultural expansion.•Eutrophication increased lake algal production and TOC burial.•TIC flux was significantly higher than that of TOC in our less-impacted deep lake.•Catchment land uses altered coupled changes in organic and inorganic carbon burial.