Microclimate temperature effects propagate across scales in forest ecosystems.

Area of Science:

• Forest Ecology
• Climate Modeling
• Ecosystem Dynamics

Background:

• Forest canopies critically influence subcanopy environments, affecting biodiversity and ecosystem functions.
• Empirical microclimate research is often limited to local scales and short durations, hindering understanding of long-term forest dynamics.

Purpose of the Study:

• To develop and implement the first dynamic forest landscape model incorporating microclimate temperature buffering.
• To investigate the effects of microclimate temperature buffering on simulated forest dynamics and ecosystem outcomes at landscape scales.

Main Methods:

• Adapted the iLand individual-based forest landscape model to integrate microclimate temperature effects on decomposition, bark beetle development, and seedling establishment.
• Simulated forest dynamics with and without microclimate buffering in a European mountain landscape under historical climate and disturbance regimes.

Main Results:

• Microclimate buffering effects scaled from local to landscape levels, increasing average total carbon by 2% and cumulative net ecosystem productivity by 21% over 1,000 years.
• Inclusion of buffering led to a 9% increase in Norway spruce and a 12% decrease in European beech basal area.
• Local bark beetle development rates decreased by 16%, resulting in a 45% reduction in landscape-scale bark beetle-induced mortality.

Conclusions:

• Microclimate temperature buffering nonlinearly scales from stand to landscape and over millennial timescales.
• Dynamic simulation models are crucial for upscaling microclimate effects in space and time.
• Microclimate buffering demonstrably alters forest dynamics at landscape scales.