Subject
- Aspen -- Effect of browsing on -- Yellowstone National Park1
- Aspen -- Protection -- Yellowstone National Park1
- Aspen -- Yellowstone National Park -- Growth1
- Bison -- Food -- Environmental aspects -- Yellowstone National Park1
- Browse (Animal food) -- Yellowstone National Park1
- Browsing (Animal behavior) -- Environmental aspects -- Yellowstone National Park1
- Elk -- Food -- Environmental aspects -- Yellowstone National Park1
- Food chains (Ecology) -- Environmental aspects -- Yellowstone National Park1
- Wolves -- Reintroduction -- Environmental aspects -- Yellowstone National Park1