How can the absence of wolves affect elk populations?

There will be alot of elks because the wolves can eat the elk

Wolves prey on Elk. The Elk population is kept under control by the preying of wolves. Without the wolves the elk population would grow substantionally, which would henceforth reduce the vegetation level because with more Elk means more food you the elk needed. With less vegetation means less food for other species such as rabbits, which would cause a substantial decrease in the rabbit population.