Forest Management and Warming Effects on a Century of Salt River Streamflow
Marcos D. Robles, Dale S. Turner, and Jeanmarie A. Haney
Colorado River Basin
Recent studies suggest that climate change has altered the flow and provision of water from western US rivers to downstream cities and natural communities, but fewer studies have examined hydrological influences related to a century of fire suppression. This study evaluated the effects of changing forest and temperature conditions on 20th century flow patterns in the Salt River in central Arizona. Seasonal and annual flows declined by 8-29% in the first half of the century which coincided with a 10-fold increase in ponderosa pine forest densities. Based on a scientific review, there is strong evidence that changes in forest structure contributed to these flow declines. In the 2nd half of the century, warmer temperatures led to earlier timing of peak spring flows of almost 2 weeks but had negligible direct effects on flow magnitudes. These results suggest that forest change had effects on flow well before anthropogenic warming and that large-scale restoration projects hold some promise of recovering seasonal flows.
Aerial view of the Parks West restoration site overseen by TNC. Taken March 16, 2020.
Conservancy staffers, Dale Turner and Amanda Rebore, helping to map the Sabn Pedro River in Arizona. They use a GPS unit to denote the end of the water flow on the LowerSan Pedro River. They hiked through the Conservancy’s San Pedro Preserve.
Our Approach to Science
The Nature Conservancy’s conservation science program in Arizona engages stakeholders and expertise in applied science and policy to develop new information, ideas, and tools that can help solve some of our most pressing challenges affecting people and nature
Explore Our Science
We are working with partners and stakeholders to accelerate the pace and scale of forest restoration for a healthy Arizona
Mapping the Status of River Streams
Wet/dry mapping provides a low-cost, river-wide snapshot of hydrologic conditions for rivers with interrupted perennial surface flows.
Every June groups of volunteers walk the entire 170 mile length of the San Pedro River and record where it is wet and where it is dry during the hottest, driest time of the year. Twenty years’ worth of data on summertime surface flows in the San Pedro River within the San Pedro Riparian National C[…]
Arizona, Geo Region
Forest Restoration Benefits, Topic
Jamie L Peeler, Lisa McCauley, Kerry L Metlen, Travis Woolley, Kimberley T Davis, Marcos D Robles, Ryan D Haugo, Karin L Riley, Philip E Higuera, Joseph E Fargione
Identifying opportunity hot spots for reducing the risk of wildfire-caused carbon loss in western US conifer forests
As both the climate and wildfire crises intensify and investments are made to dramatically increase the pace of forest restoration across dry forests in the western U.S. through the Wildfire Crisis Strategy, an understanding of where Nature-Based Solutions are the most optimal in lessening climate i[…]
Arizona, Colorado River Basin, Western U.S.
Climate Change, Forest Restoration Benefits
Collaboration, USDA ARS
Ravindra Dwivedi, Joel A. Biederman, Patrick D. Broxton, Kangsan Lee, Willem J.D. van Leeuwen, Jessie K. Pearl
Forest density and snowpack stability regulate root zone water stress and percolation differently at two sites with contrasting ephemeral vs. stable seasonal snowpacks
Much of the western United States depends on high elevation snowpack in forested watersheds for water supply, wildlife habitat, and recreation in both adjacent and downstream communities. The forest-snow-water relationship is well studied in areas with stable – that is, cold – seasonal s[…]