Liu et al. (2025) Young Versus Old: Does Forest Age Regulate Water and Dissolved Carbon Processes Belowground?

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Water Resources Research
• Year: 2025
• Date: 2025-12-29
• Authors: Fiona S. Liu, Devon Kerins, Shreya Ramesh, Pamela Sullivan, Sharon Billings, Daniel R. Hirmas, Hoori Ajami, Alejandro N. Flores, Catalina Segura, Li Li
• DOI: 10.1029/2025wr040838

Research Groups

H.J. Andrews Experimental Forest, Oregon, USA

Short Summary

This study investigates how hydrological flow paths and dissolved carbon processes belowground differ between young and old forests. It reveals that young forests exhibit lower streamflow and deep groundwater contributions, along with distinct dissolved organic and inorganic carbon cycling patterns compared to old forests, highlighting the significant role of forest age in subsurface carbon dynamics.

Objective

• To determine how hydrological flow paths and dissolved carbon processes belowground differ between young and old forests.

Study Configuration

• Spatial Scale: Three pairs of young-old forests at the H.J. Andrews Experimental Forest, Oregon, USA (catchment/plot scale).
• Temporal Scale: Analysis comparing a 57-year-old plantation (young forest) and a naturally regenerated approximately 500-year-old forest (old forest).

Methodology and Data

• Models used: Process-based hydro-biogeochemical model (BioRT-HBV).
• Data sources: Streamflow and dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) observational data.

Main Results

• The young forest (57-year-old plantation) exhibited lower streamflow and smaller deep groundwater contributions (20%) compared to the old forest (approximately 500-year-old, 30%).
• Dissolved organic carbon (DOC) was primarily produced in shallow soil, but its fate diverged with depth: transformed into DIC in the young forest and further produced in the old forest.
• This led to contrasting export patterns: DOC flushing (increases with discharge) in the old forest and DOC dilution (decreases with discharge) in the young forest.
• These differences are likely attributed to variations in subsurface structures, including deeper, denser roots in old forests.
• Across all old forests, higher DOC and DIC concentrations were observed.
• Consistent DIC dilution patterns were found across sites, but DOC patterns were variable.
• Numerical experiments suggest that diverse DOC behaviors result from interactions among forest age, geology, and hydrological connectivity.

Contributions

• Provides novel insights into the poorly understood below-ground hydrology and biogeochemical processes in young versus old forests.
• Highlights the previously overlooked significant role of forest development and age in subsurface carbon cycling.

Funding

Not specified in the abstract.

Citation

@article{Liu2025Young,
  author = {Liu, Fiona S. and Kerins, Devon and Ramesh, Shreya and Sullivan, Pamela and Billings, Sharon and Hirmas, Daniel R. and Ajami, Hoori and Flores, Alejandro N. and Segura, Catalina and Li, Li},
  title = {Young Versus Old: Does Forest Age Regulate Water and Dissolved Carbon Processes Belowground?},
  journal = {Water Resources Research},
  year = {2025},
  doi = {10.1029/2025wr040838},
  url = {https://doi.org/10.1029/2025wr040838}
}