Spatial and Temporal Soil Respiration in the Subalpine Kenneth T. Eggering Winter Ecology: Spring 2013

Introduction It has long been understood that once snowpack begins to melt in late spring soil microbial activity changes in alpine ecosystems." (Lipson & Schmidt, 2004) A better understanding of how alpine microbial life behaves prior to spring is still needed.

Hypothesis A: There is a daily difference in soil respiration in non snowcovered sites due to temperature fluctuations B: Both covered and exposed sites are "flatlined": a flat rate of respiration, and a flat rate of no respiration respectively

Methods Site selection (uncovered): Choose two plots on a south facing slope with vegetation/litter, and sunny throughout the day Site selection (covered): Choose areas with minimum of 40 cm snow depth (decoupled from air temperature) in Aspen forest area for digging snowpit Observations: Using PP system, made observations in 3 hour intervals (battery issues) Data collection on Friday and Saturday with PP system

Results T-test used to determine if there was a day-to-day difference at each uncovered site. Hypothesis A: Reject the null. There appears to be a daily difference in respiration.

Exposed Site: Friday battery died

Exposed Site: Saturday

Snow covered sites: Saturday 8AM 11AM 1PM 4:30PM

Summary Soil respiration in exposed areas appears to be minimal (expected), but also variable day-to-day. P<.05 Snow Covered areas appear to vary based on OM. Areas with snowcover were statistically different than areas with no snowcover

References Xia, J., Han, Y., Zhang, Z., & Wan, S. (2009). "Effects of diurnal warming on soil respiration are not equal to the summed effects of day and night warming in a temperate steppe". Biogeosciences, Lipson, D. A., and S. K. Schmidt. "Seasonal Changes in an Alpine Soil Bacterial Community in the Colorado Rocky Mountains." Applied and Environmental Microbiology 70.5 (2004): 2867-879. Print.