Flow Profiles Behind a Novel Model Forest Canopy

Accurately characterizing the interaction between vegetation canopies and airflow is essential for understanding biosphere-atmosphere exchange processes such as momentum transport and gas exchange. However, many laboratory experiments rely on simplified canopy models that assume uniform vegetation density, overlooking the vertical heterogeneity observed in real forests. The omission of leaf area density (LAD) profiles limits the ability of wind tunnel experiments to replicate key flow features within the canopy. This study investigates how vertically distributed LAD profiles influence the structure of wind flow and turbulence within and above model forest canopies in a controlled wind tunnel environment. A weighted random distribution of holes of varying sizes in acrylic plates creates the vertical distribution of "foliage" and downstream spacing of the plates sets the LAI, ensuring both flexibility and reproducibility across experimental conditions. Velocity profiles were collected for a range of canopy configurations, highlighting the need for physically representative canopy models in laboratory experiments and the importance of vertical heterogeneity in shaping environmental flow dynamics. This work presents a reproducible methodology for laboratory-scale forest canopy representation and offers new insights into how vertical heterogeneity shapes airflow and mixing in forested environments.