Every June, cottonwood trees (Populus deltoides var. occidentalis) release clouds of silky-haired seeds that can be carried for miles on wind and flowing water, and give the species its common name. The cottonwood is the most important native tree species of the High Plains, but its specialized riparian habitat is thinly scattered across the landscape. Seed dispersal is one of the primary ecological processes through which a species interacts with its landscape on the metapopulation level.