– Winter Ecology

Introduction  Global Climate Change  How microbs may be affected by snowpack depth  Temperature/precipitation trends

Question  Are CO 2 respiration levels determined by the amount of snow pack above the soil as well as the precipitation and temperature amounts around the area?

Methods/Data CollectionMethods/Data Collection  Snow pits dug near C-1 site  Snow pits dug near Mountain Research Station  Snow depths range from 3-70 cm  Search for variation in snow depths for sites  CO 2 fluxes range from ppm

Methods: CalculationsMethods: Calculations  Graphed Data Points  Trendline and Equation  Function Calculations Mean Slopes 8 Mean R SD SE 1.4

Compilation of Snow Depth and CO 2 Flux Data Snow Depth (cm) Mean CO2 Flux (ppm) SE (+/-)

Summary of Snow Depth Data  Increased respiration with increased snow depth  Almost linear growth of CO 2 flux with snow depth  Possible source of error at one of the sites

Climatological Snow Water Equivalent Data of Niwot Station (Feb-April) (Natural Resources Conservation Services, 2010)

C-1 Annual Precipitation Summary Data (Mountain Research Station, 2010)

Summary of Precipitation Data  Snotel data: Only available for months Feb-April (Natural Resources Conservation Services, 2010)  Shows no significant increase/decrease  C-1 data: Annual data compilation (Mountain Research Station, 2010)  Shows no significant increase/decrease

C-1 Annual Air Temperature Summary Data (Mountain Research Station, (2010)

Average Soil Temperatures vs. CO 2 Flux Mean CO2 Flux (ppm) Ave Temp (deg C) Snow Depth

Summary of Temperature Data  C-1 data: Air temperature has been increasing since 1952 (Mountain Research Station, 2010)  Soil Temp data: No significant relationship between soil temp/CO 2 flux and soil temp/snow depth

Results  There was an increase in CO 2 flux with increased snow depth  No significant change in the amount of precipitation occurring near sites  Increase of air temperature near sites  Therefore, air temperature is a concern since temperature affects snow depth  Soil temperature data not significant enough to have an affect on the focus of my data

Discussion: Snow Depth Data vs. CO 2 Flux  Winter CO 2 flux is dependent upon snow depth  More analysis regarding global climate change and long term affects on snow depth and CO 2 flux under the snow pack  Assessment of air and soil temperature changes in the area may help in analysis

Discussion: Precipitation vs. CO 2 Flux  Snotel data shows no increase/decrease in snow water equivalent data for the years  MRS data showed no significant signs of increase/decrease precipitation but possibly still affects snow depth  More analysis needed since temp and precip relate to each other  If one increases, should the other decrease/increase?  Other data shows that ‘nutrient cycling activity’ is in relation to the amount of ‘snow cover’ on the ground during the season (Groffman et al, 2009)

Discussion: Air/Soil Temperature vs. CO 2 Flux  Air temperatures have been increasing since 1952  Chaotic correlation between soil temperature and CO 2 flux as well as soil temperature and snow depth  Possibly due to site error  Other data shows that if ‘atmospheric CO 2 ’ increases over time, so will the ‘rates of soil respiration’ (Jackson et al, 2009)

Conclusion  CO 2 flux has a direct correlation to snow depth  Can not tell if precipitation correlates to CO 2 flux  However, it should since snow depth does correlate  Air temperature has been increasing and will therefore affect snow depths

Questions?

References  Groffman PM, Hardy JP, Fisk MC, Fakey TJ, Driscoll CT. (2009). “Climate Variation and Soil Carbon and Nitrogen Cycling Processes in a Northern Hardwood Forest”. Ecosystems. 12(6),  Jackson RB, Cook CW, Pippen JS, Palmer SM. (2009). “Increased below ground biomass and soil CO 2 fluxes after a decade of carbon dioxide enrichment in a warm-temperate forest”. Ecological Society of America. 90(12),  Mountain Research Station. (2010). C-1 Annual Summary (1). Retrieved February 14,  Natural Resources Conservation Services. (2010). Snow Course and Monthly SNOTEL Data Tables. Retrieved February 14, ftp://ftp.wcc.nrcs.usda.gov/data/snow/snow_course/table/history/colorado/05j42s.txt.