Ramirez et al. (2025) Hydrological response to thinning in forest stands: analysis of soil volumetric water content and soil water flux

Identification

• Journal: Frontiers in Forests and Global Change
• Year: 2025
• Date: 2025-11-28
• Authors: H. Ramirez, Alexander G. Fernald, B. Talon Newton, Dawn VanLeeuwen, Manoj K. Shukla
• DOI: 10.3389/ffgc.2025.1648254

Research Groups

• Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP), Chihuahua, Mexico.
• Department of Animal and Range Sciences, New Mexico State University, Las Cruces, NM, United States.
• New Mexico Bureau of Geology & Mineral Resources, New Mexico Institute of Mining & Technology, Socorro, NM, United States.
• Department of Economics, Applied Statistics and International Business, New Mexico State University, Las Cruces, NM, United States.
• Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, United States.

Short Summary

This study investigates the impact of masticator thinning on soil moisture dynamics in a semiarid mixed conifer forest. The findings indicate that thinning increases soil water storage at the soil-bedrock interface and induces upward water flux during dry periods, potentially enhancing forest resilience to drought.

Objective

• To analyze the influence of thinning and scattered slash on shallow soil water flux and soil volumetric water content across different seasons in a mixed conifer forest.

Study Configuration

• Spatial Scale: Sacramento Mountains near Cloudcroft, New Mexico, USA. The study utilized four paired experimental plots (8,100 $m^2$ each) located at ridge and valley positions, with elevations ranging from 2,127 m to 2,748 m.
• Temporal Scale: Data collection spanned approximately 2.8 years, from January 2009 through October 2011, covering five distinct seasonal categories (Snow, Snowmelt, Dry, Rainy, and Fall Dry).

Methodology and Data

• Models used:
  • Darcy-Richards Equation: Used to quantify vertical soil water flux ($q$).
  • RETC (Version 6.02): Used to fit the van Genuchten model for soil water retention curves (SWRC).
  • Gardner’s Equation: Used to calculate unsaturated hydraulic conductivity ($K$).
• Data sources:
  • Soil Sensors: ECHO2-EC-TM sensors for soil volumetric water content ($\theta$) and soil temperature ($T_s$) at depths of 7, 20, and 35 cm.
  • Matric Potential: Heat dissipation sensors (Model 229) installed at 7, 20, and 35 cm depths.
  • Meteorological Data: Tipping-bucket rain gauges for precipitation; shielded thermistors for air and slash cover temperature.

Main Results

• Soil Temperature: Thinning increased soil temperature at 7 cm and 20 cm depths by as much as 2.65 °C and 2.62 °C, respectively, due to increased solar radiation reaching the forest floor.
• Water Storage: Thinned plots maintained significantly higher soil volumetric water content at 35 cm depth (approximately 0.15 $cm^3$ $cm^{-3}$ greater than control plots) during dry periods.
• Water Flux: Thinning treatment led to a predominant upward soil water flux ($< 0.2$ mm $day^{-1}$) during dry and snowmelt seasons. This was driven by hydraulic gradients associated with high surface evaporative demand and potentially hydraulic redistribution by seedlings.
• Hydrological Connectivity: The study suggests that thinning allows for increased water storage at the bottom of the soil column on the rock surface ("rock moisture"), which can be redistributed upward during moisture deficits.

Contributions

• Provides a novel, high-resolution analysis of in-situ soil water flux in thinned semiarid forests, a process rarely quantified in existing literature.
• Demonstrates that masticator thinning with scattered slash can proactively mitigate drought stress by delaying soil moisture depletion and enhancing storage at the weathered bedrock interface.
• Offers empirical evidence supporting forest thinning as a management tool for increasing ecosystem resilience against climate-driven drying in the Southwestern United States.

Funding

• Sacramento Mountains Hydrogeology Study of the New Mexico Bureau of Geology and Mineral Resources.
• New Mexico Agricultural Experimental Station.
• NSF-NM EPSCoR UROP program.
• Hatch/NIFA project reference code #1015539.

Citation

@article{Ramirez2025Hydrological,
  author = {Ramirez, H. and Fernald, Alexander G. and Newton, B. Talon and VanLeeuwen, Dawn and Shukla, Manoj K.},
  title = {Hydrological response to thinning in forest stands: analysis of soil volumetric water content and soil water flux},
  journal = {Frontiers in Forests and Global Change},
  year = {2025},
  doi = {10.3389/ffgc.2025.1648254},
  url = {https://doi.org/10.3389/ffgc.2025.1648254}
}

Generated by BiblioAssistant using gemini-3-flash-preview (Google API)