Population size of elk increased while the population of aspen tree declined.
Explanation:
As per question, removal of wolves from the system would result in increased elk population due to absence of its predator (wolves). The increased elk population would extensively feed on shrubs and trees like aspen and cottonwood trees. This would cause decline in population size of these shrubs and trees.
After the wolves were removed, the elk population increased. The larger elk population ate more aspen and cottonwood trees. As a result, the tree populations declined.
Hope this helps it was the answer i got on the test!!!
