Pervasive alterations to snow-dominated ecosystem functions under climate change.

Area of Science:

• Ecohydrology
• Climate Change Science
• Terrestrial Ecosystems

Background:

• Climate change projections indicate warming temperatures and reduced snowpack, impacting ecosystems and water resources.
• Understanding changes in ecohydrological variability is crucial for adaptation and mitigation strategies.
• Assessing variability helps evaluate trends, extreme events, and potential ecological tipping points.

Purpose of the Study:

• To characterize projected changes in the mean state and variability of ecohydrological processes.
• To analyze these changes in snow-dominated regions of the Northern Hemisphere.
• To utilize a single-model Large Ensemble with advanced terrestrial ecosystem representation.

Main Methods:

• Employed a single-model Large Ensemble approach.
• Incorporated sophisticated terrestrial ecosystem representation.
• Focused on historically snow-dominated regions in the Northern Hemisphere.

Main Results:

• Projected widespread snowpack reductions, earlier snowmelt, longer growing seasons, drier soils, and increased fire risk.
• Increased variability in winter snowmelt is expected to cause growing-season water deficits and more stochastic runoff.
• Declining snowpack diminishes its buffering capacity, making runoff quantity and timing more episodic and less predictable.

Conclusions:

• Warming and declining snowpack reduce the predictability of annual runoff, impacting water resource management.
• Ecosystem stress and water resource availability face significant challenges due to altered ecohydrological functions.
• Pervasive alterations to ecohydrological function are likely consequences of projected climate change.