Climate change and wildfire effects in aridland riparian ecosystems: An examination of current and future conditions

TitleClimate change and wildfire effects in aridland riparian ecosystems: An examination of current and future conditions
Publication TypeGovernment Report
Year of Publication2017
AuthorsSmith DM, Finch DM
Accession NumberSEV.781
Abstract

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.