What is the problem at the Great Sand Dunes?
Exotic Plants Invasive exotic plants are of great concern. Fortunately, at present, few nonnative plants have established themselves into the Great Sand Dunes’ ecosystem. However, the park is downwind of a rather large agricultural area which has numerous weed problems. Among these are various species of knapweed, Canada thistle, leafy spurge and whitetop. The highly invasive tamarisk (or salt cedar) is also beginning to appear on the nearby landscape. The geography at Great Sand Dunes literally acts as a sand trap, not only for sand, but also for invasive plants’ seeds.
