Environmental and Microbial Controls on Dissolved Organic Matter Across Aquatic Ecosystems

Dissolved organic matter (DOM) is a key component of the global carbon cycle, yet its molecular evolution across major aquatic ecosystems remains unclear. We analyzed 141 samples from glaciers, mountain rivers, coastal waters, and the open ocean using FT-ICR MS, microbial 16S rRNA sequencing, and environmental measurements. DOM composition exhibited increasing homogenization and recalcitrance along the land-to-ocean continuum. The universal DOM pool, dominated by lignin-like molecules, increased from 65% in glaciers to 97% in the open ocean and was primarily regulated by environmental factors. In contrast, the non-universal DOM pool declined sharply and was strongly influenced by microbial communities, especially in glacier and open-ocean systems. These findings reveal distinct environmental and biological controls on DOM transformation and provide new insights into carbon cycling processes across connected aquatic ecosystems.

Presentation Preference: Standard Oral (12 Minutes)

Primary Presenter: Yongqin Liu, Institute of Tibetan Plateau Research, Chinese Academy of Sciences (yqliu@itpcas.ac.cn)

Authors:

Yongqin Liu, Institute of Tibetan Plateau Research, Chinese Academy of Sciences  (yqliu@itpcas.ac.cn)