Topography shapes the carbon allocation patterns of alpine forests

Area of Science:

• Ecology
• Forest Science
• Biogeochemistry

Background:

• Topography significantly influences alpine forest structure by controlling nutrient and water availability.
• Limited understanding exists on how fine-scale topography affects forest carbon allocation within broader environmental contexts.

Purpose of the Study:

• To investigate the impact of microtopography and elevation on alpine forest carbon allocation patterns.
• To analyze the interactions between microtopographic features and elevation in shaping forest carbon dynamics.

Main Methods:

• Utilized field data from 89 forest plots in the northern Tibetan Plateau.
• Employed a high-resolution (1 m²) digital elevation model (DEM).
• Applied a linear mixed-effects model to analyze carbon allocation patterns.

Main Results:

• Plants allocate more carbon to roots and have lower aboveground carbon stocks (ACS) at low and high elevations due to resource limitations.
• Microtopographic heterogeneity significantly alters carbon allocation, with effects varying across the elevation gradient.
• Specific microhabitat features (wetness, aspect) influence ACS and below- to aboveground carbon stock ratios (RBA) differently at low versus high elevations.

Conclusions:

• Elevation and microtopography are key drivers of carbon allocation in alpine forests.
• Forests exhibit distinct responses to microtopographic variations depending on the broader elevational context.
• Understanding these complex interactions is crucial for predicting alpine forest responses to environmental change.