Mountain runoff vulnerability to increased evapotranspiration with vegetation expansion. PNAS 111:39 pp 140710-14075.
Title
Mountain runoff vulnerability to increased evapotranspiration with vegetation expansion. PNAS 111:39 pp 140710-14075.
Abstract
Climate change has the potential to reduce surface-water supply by expanding the activity, density, or coverage of upland vegetation, although the likelihood and severity of this effect are poorly known. We quantified the extent to which vegetation and evapotranspiration (ET) are presently cold-limited in California’s upper Kings River basin and used a space-for-time substitution to calculate the sensitivity of riverflow to vegetation expansion. We found that runoff is highly sensitive to vegetation migration; warming projected for 2100 could increase average basin-wide ET by 28% and decrease riverflow by 26%. Kings River basin ET currently peaks at midelevation and declines at higher elevation, creating a cold-limited zone above 2,400 m that is disproportionately important for runoff generation. Climate projections for 2085–2100 indicate as much as 4.1 °C warming in California’s Sierra Nevada, which would expand high rates of ET 700-m upslope if vegetation maintains its current correlation with temperature. Moreover, we observed that the relationship between basin-wide ET and temperature is similar across the entire western slope of California’s Sierra Nevada, implying that the risk of increasing montane ET with warming is widespread.
Begin Date
2014-09-30
Originator Name
Goulden, M.L. and R.C. Bales. 2014. PNAS 111:39 pp 140710-14075. This article is a PNAS Direct Submission
Supplemental Information
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas. 1319316111/-/DCSupplemental.
Location
Global or not applicable
Keywords
Climate Change, Evapotranspiration, Temperature, Vegetation
Limits on Use
No Restrictions
Progress
Complete
Resource Type
Document
Resource Owner
Pax
To the owner of Mountain runoff vulnerability to increased evapotranspiration with vegetation expansion. PNAS 111:39 pp 140710-14075.