Pima County Regional Flood Control District Monthly Brown Bag Series

Ecological Novelties on a Desert River: The Effects of Water Management and Land Degradation on the Santa Cruz River, Arizona

When: Wednesday, December 14, 2016, 12–1 PM
Where: 9th Floor Public Works Building, 201 N. Stone, Tucson AZ, 85701
Speaker: Jesse Minor, School of Geography & Development, UA

The combined effects of land degradation, land-use changes, and a variety of water management practices have created a series of novel ecological communities in riparian systems across the southwestern United States. Despite their ahistorical characteristics, novel ecological assemblages provide critically important ecological and hydrological functions. The Santa Cruz River of southern Arizona provides ideal perspective into the particular ways in which long-term climatic changes, historical land degradation, and modern water management strategies produce areas with differential ecosystem function and habitat value. The present-day Santa Cruz River is characterized by perennial effluent flows and spontaneous creation of stable riparian communities in formerly ephemeral stretches of the river, and by the degradation of riparian gallery forests in other areas. Grade control structures, check dams, and experimental recharge projects seek to manage the flow of water and enhance groundwater infiltration in particular areas. Finally, a series of in-stream and floodplain restoration projects has created isolated areas of habitat between otherwise degraded stretches of the river. Ultimately, successful management strategies must consider novel ecologies and degraded systems across scales ranging from individual species and small patches of habitat to integrated landscapes.