A marmot's burrow
It has been suggested by researchers such as Art Kruckeberg that marmot burrows are play a part in shaping the ecosystem of some high mountain meadows. The meadows exist because there are no trees in the area and that allows for meadow vegetation to thrive. However, trees can eventually take over a meadow area and turn it into forest.
Marmots play a role in assisting trees in taking over meadow areas. When a burrow is dug, the result is a pile of fresh soil at the entrance to the burrow. It has been suggested that this fresh soil provides a nice area for tree seedlings to emerge. Once those seedlings grow up, they drop cones and more trees are born. Eventually, the pockets of trees converge to create a forested area. However, this takes substantial hundreds or thousands of years. A fire can easily claim the forest and turn it back into a meadow where the whole process can start again.