Paper No. 1
Presentation Time: 8:00 AM
CLIMATE CHANGE, INSECT INFESTATIONS, AND FOREST FIRES: IMPLICATIONS FOR SNOW COVER, WATER RESOURCES, AND ECOSYSTEM RECOVERY IN A NON-STATIONARY WORLD
Unprecedented levels of tree mortality due to both insect infestation and fire have impacted montane forests in western North America. The effects of these disturbances, and how they interact with ongoing changes in climate, to affect water resources and ecosystem recovery are unclear. Snow cover plays a defining role in how these systems are likely to respond to these disturbances with water stored in seasonal snow packs serving as the major source of surface water resources, groundwater recharge, and plant available water for forest regeneration. Interannual variability in these melt water inputs is large, resulting from variability in both winter precipitation amounts and the fraction of that snowfall subsequently lost through sublimation. Vegetation structure is a major control on these winter vapor losses with recent research suggesting that sublimation losses are minimized in moderately dense forests. Consequently, quantifying how these large scale forest disturbances interact with local climate to control the partitioning of winter snowfall into available water resources represents a critical knowledge gap to effectively responding to these disturbances.
This presentation addresses this knowledge gap through a meta analysis of recent work on snowpack dynamics, hydrologic partitioning, and biogeochemical response in seasonally snow-covered forests in the Intermountain West. Observations include long-term SNOTEL monitoring stations, CZO, LTER, and USDA observations of landsurface-atmosphere water and carbon exchange, and post disturbance observations from recently burned forests and areas of extensive insect-induced forest mortality. Empirical analyses and modeling are being developed to identify landscapes most sensitive to climate change as well as to develop management alternatives that minimize the effects of disturbance on high elevation forests and the services of water provision and carbon storage they provide.