Prescribed fire effects on soil carbon, microbial communities, and nutrient cycling in pine plantations

Overview

This research program investigates how varying prescribed fire return intervals influence soil organic matter dynamics, microbial community structure, and nutrient cycling in pine plantation systems. The work addresses a critical gap in mechanistic understanding of how shifting fire regimes control climate feedbacks from coupled soil carbon and nutrient cycles, including emissions of trace gases such as methane, nitrous oxide, and other reactive nitrogen species. Findings will support more informed forest management decisions under projected increases in wildfire severity driven by climate change.

Technical specifications

Core research capabilities and methods:

• Solid-state 13C nuclear magnetic resonance (NMR) spectroscopy combined with molecular mixing models to differentiate burn severities and characterize changes in soil organic matter composition
• Gene sequencing and quantitative PCR to assess shifts in soil microbial community composition and nitrogen-cycling assemblages
• Soil trace gas flux measurements to quantify emissions of methane, nitrous oxide, and reactive nitrogen species
• Field flow fractionation coupled with Fourier transform ion cyclotron resonance mass spectrometry to describe the colloid composition of leached soil carbon materials
• Laboratory mesocosm experiments linking fire frequency to nitrogen-cycle feedbacks and microbial-driven soil nitrogen cycling

Key applications and benefits:

• Improved prediction of climate feedbacks from managed forest soils under altered fire regimes
• Evidence-based guidance for prescribed fire scheduling in pine plantation management
• Characterization of dissolved organic matter leaching and its implications for aquatic ecosystems
• Mechanistic insights into how fire severity alters soil carbon solubility and decomposability

Technology readiness level

The research builds on preliminary work demonstrating that NMR spectroscopy and molecular mixing models can differentiate burn severities and alterations in soil organic matter composition, and that fire can produce dramatic shifts in soil microbial community composition. The proposed program represents an expansion of these prior efforts, with future validation planned through integrated field sampling, advanced analytical characterization, and controlled mesocosm experiments. The work is at the fundamental research stage, generating new scientific knowledge and tools to support forest management and climate mitigation strategies.