Abstract: In September 2009, a cruise investigation was conducted to study the partial pressure of water body dissolved carbon dioxide (pCO₂) in the mainstream and Xiangxi River of the Three Gorges Reservoir Area in autumn. The pCO₂ in the surface water of the mainstream and Xiangxi River was 920-1140 and 150-240 μatm, respectively. At the joint area of mainstream and distributaries, the pCO₂ had a minimum of 368 μatm in surface water, and increased markedly with increasing water depth, being the maximum (1300 μatm) at 10 m depth and keeping stable downward. The CO₂ flux of the mainstream and Xiangxi River was 83.7±14.1 and -4.74±1.15 mmol·m^-2·d^-1, respectively, indicating that the mainstream was a sink, while Xiangxi River was a source of CO₂. Therefore, when evaluating the influence of reservoir construction on the CO₂ flux in reservoir’s surrounding regions, it would be necessary not only considering the local basins, but also investigating the entire study area comprehensively.

Key words: sewage sludge compost, turfgrass, growth, photosynthetic characteristics.