.png){kind=icon}
.png){kind=icon}
Return
Long-Term Damming Effects Gradually Regulate Particulate C: N: P Imbalance Along the Upper Yangtze River, China
.png){kind=icon}
PRE
AI
Z
Z
鲁
H
W
L
W
DOI：10.1029/2025GB008741.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
With intensified dam construction in recent decades, river connectivity has been disrupted, reshaping elemental cycling and aggravating C: N: P imbalances. Here, we investigate how long-term cascade damming regulates particulate C: N: P stoichiometry along the upper Yangtze River in China. We show that the contribution of autochthonous particulate organic carbon (A-POC) gradually increases with reservoir age and hydraulic retention time, particularly near dams. Cascade impoundments stimulate reservoir-induced phytoplankton production that increasingly outweighs terrestrial anthropogenic inputs, leading to a 39% decline in particulate C: N ratios from the upper reach of the Jinsha River to the Three Gorges Reservoir, approaching Redfield ratios. With continued operation, particulate C: N in reservoirs converges toward Redfield thresholds within similar to 30 years of post-impoundment, yet may fall below 6.625 after prolonged impoundment, altering the regulation of particulate C: P and N: P from particulate phosphorus (PP)-dominated control to joint particulate organic matter-PP control. These results reveal the dual role of cascade reservoirs as both disruptors and gradual restorers of elemental balance, with long-term ecological succession fostering stoichiometric convergence. Targeted regulation of phytoplankton biomass and watershed PP inputs is therefore essential for mitigating stoichiometric imbalance and guiding adaptive management in large dammed river-reservoir systems.
Keywords:
cascade reservoirs
redfield ratio
stoichiometry
autochthonous organic carbon
phosphorus
Journal
IF:
5.5
Papers:
3.2K
Citations:
1.7W
Organization
Cited Papers