Microbial carbon pump promotes refractory organic carbon accumulation in karst waters: Coupled responses of bacterial communities and dissolved organic matter under thermal stratification - Jia Qin; Xinlu Su; Yikun Jia; Peng Chen; Qiufang He; Wen Lai; Tao Zhang; Jianhong Li; Junbing Pu (Journal of Hydrology, 2026)