Contrasting Greenhouse Gas Emissions from Urban and Forested Rivers: Implications for Land Use Management

Greenhouse gases (GHGs) play a critical role in driving climate change, yet the mechanisms governing their emissions from rivers in different land-use settings remain underexplored. This study examines GHG emissions from 2 contrasting river systems in Shenzhen, China: the highly urbanized Dasha River and the relatively undisturbed, forested Dongchong River. N 2 O, CH 4 , and CO 2 emission fluxes were measured alongside their environmental variables. Results revealed that the urban Dasha River exhibited substantially higher CH 4 emissions but lower CO 2 and N 2 O emissions compared to the Dongchong River. CH 4 fluxes in the Dasha River were associated with elevated nutrient inputs and hypoxic conditions, whereas CO 2 emissions in the Dongchong River were driven by high terrestrial organic carbon inputs and aerobic respiration. N 2 O fluxes were influenced by differing nitrogen dynamics in each river. This comparative analysis highlights the critical role of urbanization in shaping riverine GHG emissions and underscores the importance of targeted management strategies to mitigate aquatic GHG contributions to climate change.