Undergraduate Honors Theses

Thesis Defended

Spring 2013

Document Type

Thesis

Department

Environmental Studies

Abstract

Forest structures play an essential role in regulating water resources through its influence on snow processes and nutrient cycling. With future climate concerns regarding the availability of water and carbon stocks and anticipated increases in disturbances, it is critical to understand the impact of multiple disturbances in rapid succession. This study assesses the potentially compounding effects of fire individually, in combination with a prior stand-replacing blowdown, and with a logged blowdown on snowmelt timing and summer soil temperature and moisture in a subalpine forest of Colorado. In addition, post-disturbance legacies of the microenvironment (CWD and seedlings) were included to find their potential influences on these variables. Topography was the dominant predictor for snowmelt date, overwhelming the effects of canopy loss on snow processes post-disturbance. However in 2010, the fire melted later than the control and later than the fire + logged + blowdown. Summer soil moisture, coarse woody debris, and seedling density were not significant among treatments. However, temperature profiles through the summer showed significantly warmer temperatures in disturbed than the intact forest. The fire + logged + blowdown had the highest temperatures, however, after excluding topography effects, the fire + blowdown and fire + logged + blowdown behaved similarly, but were significantly warmer than the fire-only disturbance. These results suggest that these compounded disturbances created unique conditions in comparison to the burn. Trends were still significant 9 years following the fire and may have long-term implications for future forest management practices.

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