The study looked at how forestry vehicles driving through a forest from 1970 to 2015 affected the plant life on the forest floor. They found that managed forests had more changes in vegetation compared to unmanaged ones, likely due to changes in forest harvesting practices. The heavy vehicles created habitats suitable for certain plants and increased species richness in the forest. Overall, forest management, especially the use of heavy vehicles, was the main driver of changes in the forest's plant life, impacting both the types of plants present and the overall diversity in the area.