What important ecological contribution do burrowing organisms make to the environment?

No.1: Burrowing organisms as a very special eco-group,is fully or partly independent from the large nature systeam,so, to know how the Biology circle to run,they are probablly the simple modle,very useful.

No2: Sun or other illuminant were believed by most of us as the first condition for every livingthings from ancient ages to now,like God's first idea in bible. burrowing organisms is quite afew different world.If we can see some planet without enough light,we may consider that it may be or become a biOSphere,for neglectful aliens, or our hunman being.