Effects of Regulated Water Flows on Regeneration of Fremont Cottonwood

Abstract

The reduction in extent of riparian forests in the southwestern United States has been a topic of recent concern. The effect of dams on downstream river flow and the consequent modification of the riparian habitat was studied along the lower Salt River in central Arizona. Dams were found to change the magnitude of river flows and change the seasonal timing of flows in such a way that the habitat appeared less adapted for regeneration of Populus fremontii. Modification of river flow patterns, therefore, appears likely to have been a significant factor causing change in vegetation along the Salt River.