Coarse woody debris decomposition assessment tool: Model development and sensitivity analysis.

Area of Science:

• Forest Ecology
• Biogeochemical Cycles
• Decomposition Dynamics

Background:

• Coarse woody debris (CWD) is vital for forest ecosystems, supporting biodiversity and influencing nutrient cycling and carbon storage.
• Understanding CWD decomposition is crucial for accurate forest carbon budget estimations.

Purpose of the Study:

• To develop and validate a process-based model for assessing CWD decomposition and carbon movement in forests.
• To analyze the sensitivity of CWD decomposition to various ecological drivers across diverse North American climates.

Main Methods:

• A process-based model was created using literature, field data, and expert knowledge.
• Sensitivity analysis was performed using 89 North American climate datasets, varying temperature, precipitation, and altitude.
• Model inputs included wood properties (size, density, species, position) and environmental conditions.

Main Results:

• CWD decomposition rates are significantly influenced by climate, latitude, and altitude, affecting decomposer activity.
• Decomposition accelerates with higher temperatures and precipitation but slows at higher latitudes and altitudes.
• Fungi were identified as the primary decomposers (over 50% mass loss), while termites contributed significantly (0-40%) in tropical and subtropical zones.

Conclusions:

• The model accurately simulates CWD decomposition rates across a wide range of North American environments.
• Climate and location are dominant factors controlling CWD decomposition, with wood traits also playing a role.
• Fungal dominance in decomposition is consistent across most regions, highlighting their ecological importance.