The relationship between snow depth and soil respiration in upper montane winter environments Claire...

The relationship between snow depth and soil

respiration in upper montane winter environments

Claire HiersemanWinter Ecology

Spring 2013Mountain Research Station,

University of Colorado, Boulder

Background: Literature• Soil Respiration happens in winter (Oechel et

al 1997)• The differences in snow depth may relate to

differences in CO2 flux (Grogan 2012).• 40-50cm of snow insulate ground temps from

atmosphere (Larsen et al 2012).• In areas with greater than 1m of snow, the

snow depth might be more important than other factors (Grogan 2012).

Background: Field Day

What is the snow depth threshold for soil

respiration to occur, as measured by CO2 flux?

Methods

Results

LinearP=0.027ExponentialP=0.027

Results

P-value: 0.0268

One tail unpaired t-test without equal variances

Results• Controls tell an interesting

story• Suggests that snowpack

quality is important

Discussion• Linear or exponential? Linear is most

parsimonious• Threshold at approximately 30cm• Snowpack quality

Conclusions• Snow depth is likely a significant factor in the

amount of respiration that occurs• More precise manipulations should be done in

future to articulate precise threshold

Take home point• The microbes are active in winter under the

snowpack• Snowpack affects the amount of respiration

that is occurring

Works CitedGrogan, P. “Cold season respiration across a low arctic landscape: the

influence of vegetation type, snow depth, and interannual climatic variation.” Bio One 44.4 (2012): 446-456. DOI: http://dx.doi.org/10.1657/1938-4246-44.4.446

Larsen, K., Grogan, P., Jonasson, S., and Michelsen, A. “Respiration and Microbial dynamics in two subarctic ecosystems during winter and spring thaw: effects of increased snow depth.” Arctic, Antarctic and Alpine Research 39.2 (2007): 28-276.

Mikan, C., Schimel, J., and Doyle, A. “Temperature controls of microbial respiration in arctic tundra soils above and below freezing.” Soil Biology and Biochemistry 34 (2002): 1785-1795.

Oechel, W., Vourlitis, G., and Hstings, S. “Cold season CO2 emissions from arctic soils.” Global Biogeochemcial Cycles 11.2 (1997): 163-172.