1. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Steve Markstrom U.S. Geological Survey Lakewood, Colorado

2. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Climate Change Effects on Western Riparian Forests:  Flood Timing, Tree Seed Dispersal Timing,  and Seedling Establishment  Patrick Shafroth & Laura Perry (USGS-FORT)  Lauren Hay, Roland Viger, & Steve Markstrom (USGS- MoWS)  Glen Liston (CSU-CIRA)  David Blodgett & Nathaniel Booth (USGS-CIDA)

3. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Cottonwood and Willow Establishment Cottonwoods and willows have specific requirements for germination and establishment Small, short-lived, non-dormant seeds Must land on bare, moist surfaces to survive Only establish in occasional years with the right conditions

4. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Seedlings that germinate on moderately high surfaces desiccate as floodwaters recede Seedlings that germinate on low surfaces are scoured away by ice and floods Base flow Recruitment band Too high – drought stress Too low – ice and flood scour

5. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Research Question: Will warming associated with climate change decouple the timing of seed dispersal from spring floods?

6. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Precipitation-Runoff Modeling System (PRMS)

7. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Coarse Resolution PRMS model for South Platte River, Front Range in Colorado 25,000 km2 184 Stream Segments 368 HRUs

8. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Stream Gage Information and PRMS Parameter Regionalization

9. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov PRMS Stream Flow Calibration USGS 06752000 CACHE LA POUDRE RIVER AT MOUTH OF CANYON, NEAR FORT COLLINS, CO

10. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov PRMS Stream Flow Calibration USGS 06724000 ST. VRAIN CREEK AT LYONS, CO.

11. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov PRMS Stream Flow Calibration USGS 06729500 SOUTH BOULDER CREEK NEAR ELDORADO SPRINGS, CO.

12. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov PRMS Stream Flow Calibration USGS 06715000 CLEAR CREEK ABV WEST FORK CLEAR CREEK NR EMPIRE CO

13. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov PRMS Stream Flow Calibration USGS 06701500 SOUTH PLATTE RIVER BELOW CHEESMAN LAKE, CO

14. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Seed dispersal phenology Weekly site visits, 2010 and 2011 7-10 trees per species per site

15. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov PRMS simulation showing timing of stream flow for 1995 snow melt season

16. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov PRMS coarse resolution stream segment nodes

17. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov Evaluation of snow melt timing with PRMS model: Historical record Climate projections Land use changes Geography and topography

18. American Water Resources Association 2012 Annual Conference Jacksonville, Florida November 13, 2012 markstro@usgs.gov http://wwwbrr.cr.usgs.gov/mows