Microclimate modelling from forest core to edge

Quantifying forest microclimate dynamics is vital for improving our understanding of ecosystem processes, biodiversity patterns, and carbon sequestration. While existing mechanistic microclimate models effectively simulate conditions within forest cores, they often fail to capture the complexities inherent to forest edges. This limitation is increasingly critical as forest fragmentation creates more edge environments, profoundly influencing microclimate gradients.

To address this gap, we developed a high-resolution microclimate model capable of simulating temperature and radiation gradients from forest core to edge. This novel model integrates 3D heat transfer and 2D radiative processes for 3D explicit forest scenes constructed from terrestrial laser scanning, allowing to account for the unique spatial patterns of microclimate in forest edges. By integrating these mechanisms in full 3D, our model provides a realistic representation of fragmented forest microclimates.

The initial site for applying our model is a 135 m transect in a temperate forest in Gontrode, Belgium. Along this transect, various microclimate sensors are installed, including TMS-4 sensors and an ultrahigh-resolution (25 cm) distributed temperature sensor using optical fiber technology. The model successfully simulates the observed spatial gradients along the transect for different times of the day and across seasons. Moreover, we observe that without including lateral radiation or horizontal heat transfer, microclimate gradients cannot be modelled accurately. These processes are, therefore, essential for simulating microclimates near forest edges.