Many non-native species, such as yellow star thistle ("Centaurea solstitialis"), are able to produce a long tap root that allows them to out-compete the native plants for available water.
Danes ima okoli 30 medvedov oznake na ušesih in vedo za njihov DNA tako da, ko medved povzroči škodo, lahko parkovni nadzornik ugotovi, kateri medved povzroča težave.