Cataloging Information
Fire & Wildlife
Birds
Aridland riparian ecosystems are limited, the climate is changing, and further hydrological change is likely in the American Southwest. To protect riparian ecosystems and organisms, we need to understand how they are affected by disturbance processes and stressors such as fire, drought, and non-native plant invasions. Riparian vegetation is critically important as foraging, resting, migrating, and breeding habitat to birds and other animal species in the southwestern United States. Fremont cottonwood (Populus fremontii), Arizona sycamore (Platanus wrightii), and other woody species provide birds with nesting sites and foraging opportunities, some of which are absent or rare in adjacent plant communities. The structurally diverse, species-rich vegetation along many southwestern streams supports high densities of territories and nest sites for a variety of birds including several species of high conservation priority. Survival and reproduction of woody riparian plants is largely determined by periodic floods and droughts. As in other regions, rivers and streams of the American Southwest have been heavily altered by human activity, resulting in significant changes to disturbance regimes. Hydrological models, incorporating greenhouse gas emission scenarios, project that these changes will be exacerbated by climate change. In this report, we review the ecohydrology of southwestern streams and share results from our study sites along the Middle Rio Grande to describe effects of hydrological changes, wildfire, and invasions on plant communities and riparian-nesting birds. We also examine climate change projections and output from population models to gauge the future of aridland riparian ecosystems in an increasingly arid Southwest.