1. The Effects of Slope on Tree Well Shape and Sub-Nivean Access Points Paige Pruisner EBIO 4100 Winter Ecology, Spring 2013 Mountain Research Station University of Colorado Boulder

2. How Does Slope Angle Effect Tree Well Shape and Sub-Nivean Burrowing? Snow TreesMammals

3. Upslope Radius Left Radius Right Radius Downslope Radius Upslope Quadrant Right QuadrantLeft Quadrant Downslope Quadrant Upslope Half Downslope Half Field Methods Tree

4. Data Analysis X X Y Y where a, b, c, d, are any number

7. P=0.365

8. Discussion Circularity vs. Slope Angle – Continuity – Steeper slopes – Wind Burrowing preference – No advantage

9. Other Observations

10. Conclusions Insignificant relationship between slope angle and tree well circularity Insignificant relationship between tree well circularity and access point location Insignificant relationship between slope angle and access point location Further research into steeper slopes, wind and forest density effects, hole shape, pathways between trees Acknowledgements: Dr. Tim Kittel and Derek Sweeney for equipment and advising

11. Bibliography Decker, K. L. M., D. Wang, C. Waite, T. Scherbatskoy (2003), Snow Removal and Ambient Air Temperature Effects on Forest Soil Temperatures in Northern Vermont, Soil Sci. Soc. Am. J., 2003 67: 1234–1242, doiL 10.2136/sssaj2003.1234. Hardy, J. P., R. E. Davis, R. Jordan, X. Li, C. Woodcock, W. Ni, and J. C. McKenzie (1997), Snow ablation modeling at the stand scale in a boreal jack pine forest, J. Geophys. Res., 102(D24),29397–29405, doi:10.1029/96JD03096.10.1029/96JD03096 Merritt, J. F., Lima, M. and Bozinovic, F. (2001), Seasonal regulation in fluctuating small mammal populations: feedback structure and climate. Oikos, 94: 505–514. doi: 10.1034/j.1600-0706.2001.940312.x Sturm, M., "Snow distribution and heat flow in the taiga" (1992). Aspen Bibliography. Paper 2488. http://digitalcommons.usu.edu/aspen_bib/2488

12. Appendix

14. Bibliography

15. How Does Slope Angle Effect Tree Well Shape and Sub-Nivean Burrowing? Snow – Insulates (Decker et al., 2003) – Non-uniform distribution (Sturm, 1992) Trees – Modify snow pack (Hardy et al., 1997) Mammals – Shelter (Merritt, 2001)

16. How Does Slope Angle Effect Tree Well Shape and Sub-Nivean Burrowing? Snow TreesMammals Shelter, Food Reproduction/Distribution