Endangered Animal..

Caribou : endangered due to loss of their diet. Increased precipitation due to rising temperatures have caused the mosses and lichens, which are an important part of their winter diet, to be buried in thick layers of snow. The availability of food in summer has also decreased, which threatens their existence.

https://sites.google.com/a/jeffcoschools.us/tropical-biome-jessie-fell-and-shea-mcmanus/threats-against-the-tundra/endangered-species

The caribou would affect the tundra if it was remove because , the predators wouldn't have nothing to prey on .