From a recent interview with Washingtonian:
These overpopulations bring significant, probably irreversible damage to the environment. The deer have removed ground-dwelling plants from this area. Even if we got rid of all the deer today, the deer have kept those plants from emerging for so many years now that the seed bank has lived out its shelf life.We've made a choice that deer are so cute, we don't mind that they're vastly overpopulated to the point of throwing the entire food chain out of whack. Even though they're wiping out our next generation of native plants and trees, even though they carry ticks & Lyme disease, even though they've made Virginia the seventh-most-dangerous state for car-deer collisions. We're not doing the deer, the environment, or ourselves any favors.
All the animals that depend upon that strata of the forest for food, for cover—all that’s gone. There’s a growing list of forest-dwelling birds whose numbers are on the decline. It’s not just that we have an animal with charisma that everybody likes because of its big brown eyes. It’s a big problem.
There aren’t future generations of the forest. If it’s an acorn trying to sprout, the deer eats the whole thing. When the trees we have die, it’ll all be soccer fields.