sentences:  Like other aspens, it spreads extensively by suckers (root sprouts), which may be produced up to 40 m from the parent tree, forming extensive clonal colonies.This often makes the job of clearing unwanted trees from an area especially difficult, as new suckers will continue to sprout from the extensive root system for up to several years after all surface growth has been eliminated.Eurasian aspen is a water and light demanding species that is able to vigorously colonize an open area after fire, clear cutting or other kind of damages.