Great use of Daniil's plugin.
For the first scene, I actually like it rather bare. Heck a lot of caribou migration shots are done with vegetation either completely under the snow, or none visible in aerial shots. Tundra plants don't work off heat transpiration, and work only off UV transpiration, and do not grow tall. Mainly ground cover besides the long strands of grasses.
Natural landscapes for Caribou are pretty barren besides populations in lower hemisphere, which are usually a result of domestication and farming.