Limited VolunteerThe importance of riverine and riparian habitat in the Southwest cannot be overemphasized; the wetland ecosystems of the Southwest are among the rarest habitat types in the Western Hemisphere. Of the 106 forest types identified in North America, the western cottonwood/willow forest association has been identified as the rarest. In Arizona and New Mexico, riparian habitat accounts for less than three tenths of one percent (.003%) of all the land and yet 80% of all vertebrates and over 50% of bird species in the American Southwest are dependent upon it. It is estimated that in the past 200 years, 92% of the historic wetlands in the middle Rio Grande have been lost and the impacts of climate change are further reducing these and other critical riverine and wetland habitats.