Estimating damaged understory based on collisions with harvested trees during final cutting of a shelterwood

We investigated whether collisions of harvested trees with understory might explain the presence of damaged understory spanning an entire forest compartment. Specifying understory damage caused by harvesting operations is necessary to compare the economic advantages of any residual understory against the high expenses of shelterwood harvesting. Existing models for explaining understory damage were unclear and unable to quantify the amount of residual understory. Therefore, we used collisions between felled trees and the understory as explanatory variables and discovered that the collisions may be spatial indicators; however, we have not yet evaluated whether these indicators are applicable across large areas. In this paper, we looked at another final cutting and used the collisions to estimate the damage to the understory again. Results showed that the coordinates of collisions may spatially describe the state of the understory after final cutting, even at an entire forest compartment. This practice suggests that we can intentionally mitigate damage to the understory by avoiding physical impacts to the understory during final cutting. We expect to compare the silvicultural benefits of residual understory and harvesting costs spatially.