Dynamic Interactions of Snow and Plants in the Boreal Forest, Winter 2011-2012 Revealed by Time-Lapse Photography and LiDAR

Abstract

As winter progresses, snow accumulates on the ground and plants of the boreal forest. On their passage to the ground, the falling snowflakes encounter physical obstacles like the complex structure of tree branches and shrubs. These cause the fall trajectories to deviate, and in some cases even stop, before a snowflake reaches the forest floor. After deposition, wind and gravitational settlement further affect the snow distribution. Because of these snow-vegetation interactions, snow gets distributed in the forest along vertical and the horizontal directions in a complex way.

To better understand these interactions between snow and plants, we designed an experiment, in the boreal forest near Fairbanks, Alaska (see panorama below) where we used a ground-based LiDAR (Light Detection And Ranging) to record the 3D geometrical evolution of the snowpack, the flexure of vegetation under snow loads, and the snow deposition on the ground during the winter of 2011-2012. In parallel, we set up a time-lapse camera to record loading and unloading of tree branches, and a weather station to record atmospheric conditions.