Evaluating effects of wind on isolated and clustered trees

In storms and other strong wind events, trees can lose limbs or even be uprooted entirely, potentially causing damage to surrounding structures. Minimizing the damage of falling trees to roads, buildings, and power lines requires understanding the wind limits they can endure.

Wang et al. employed computational fluid dynamics simulations to study the effects of strong winds on both isolated trees and tree clusters. Their simulations can help guide urban planners and forestry managers to create tree arrangements that reduce wind-induced damage.

The researchers simulated the flow field across the canopies of single trees and clusters of different spacing and arrangement. They then calculated the overturning moment coefficients — a reflection of the amount of toppling force experienced — for each tree.

“The overturning moment coefficients of clustered tree canopies are smaller than those of an isolated tree canopy, primarily due to shielding effects, with the largest reduction of 85%,” said author Jingxue Wang. “The corresponding values generally exhibit an increasing trend with the increase in spacing distance between trees due to enhanced channeling effects.”

Furthermore, trees placed in a staggered pattern may exhibit higher overturning moment coefficients than trees in straight rows, due to the lack of shielding from trees in front.

The authors plan to continue to develop their model by introducing more real-world variables, making their data relevant to even more situations.

“The current studies mainly focus on the trees on flat terrain. The next-step study will shift its focus to the aerodynamics of trees in complex terrains, such as mountainous regions,” said Wang.

Source: “Evaluation of the aerodynamic loads over isolated and clustered tree canopies using large eddy simulation,” by Jingxue Wang, Luca Patruno, Haiyang Wang, Ping Wang, and Danyu Li, Physics of Fluids (2025). The article can be accessed at https://doi.org/10.1063/5.0256171 .