Winter Controls on the Distribution of Arboreal Hair Lichens in the Niwot Ridge Biosphere Reserve Keli Baker Winter Ecology Spring 2013 Mountain Research Station, University of Colorado, Boulder

o “Old Man's Beard” o Arboreal hair lichen – Usnea o Conifer substrate o Get most of their winter moisture from winter snow melt (Campbell et al, 2001). o More lichen in subalpine? Background

o Question: What is the distribution and abundance of arboreal hair lichens in the area surrounding the MRS and what winter environmental factors affect their distribution? Introduction

o Hypothesis: The distribution of the arboreal lichens will be affected by snow depth, tree species, wind exposure, stand density and elevation. o Environmental factors change with elevation: o Precipitation o Temperature (Veblen, 1986) o Tree species and stand density (Veblen, 1986) Possible Winter Controls

o Visually measured lichen abundance o Nine 1m x 50m plots o Elevation range: 3,050m (10,000 ft) to 3,200m (10,500 ft) o Developed sale to quantify lichen abundance o Assigned each tree an abundance level from 0 to 4 o Online chi-square calculator comparing: o lichen abundance level frequency o elevation o tree species Methods

o Significant correlation between elevation and lichen abundance o p<<0.001 o Chi square: o Degrees of Freedom: 16 Results

Results o Significant correlation between tree species and abundance o p = o Chi square: o Degrees of Freedom: 2

o Significant correlation between tree species and elevation. o p = o Chi square: 23.7 o Degrees of Freedom: 8 Results

o Lichen abundance affected by: o Preceipitation – in general, more at higher elevations o Elevation – microclimate changes o Stand Structure – density, species composition o Lichen prefers subalpine fir o Lichen found mostly in subalpine Discussion

o Elevation affects lichen abundance because of micro-environmental changes associated with elevation gradients. o Stand structure effects lichen abundance with more lichen: o On subalpine fir substrate o In denser stands o Lichen abundance is confined mostly to subalpine elevations Conclusion

o Gough, L. P The distribution of corticolous cryptogams on Pseudotsuga menziesii (Mirb.) Franco and Abies lasiocarpa (Hook.) Nutt. in the Front Range, Boulder County, Colorado. Ph.D. Thesis, University of Colorado, Boulder. o Berryman, S. et al Estimating Epiphytic Macrolichen Biomass from Topography, Stand Structure and Lichen Community Data. Journal of Vegetation Science 17: Wiley Online Library. 24 Feb Web. o Campbell, J. et al Canopy Microclimate and Arboreal Lichen Loading in Subalpine Spruce–fir Forest. Canadian Journal of Botany 78: NRC Research Press. University of Northern British Columbia, 3 May Web. DOI: /cjb o Peet, R Forest Vegetation of the Colorado Front Range: Composition and Dynamics. Vegetatio 45: o Veblen, T Age and Size Structure of Subalpine Forests in the Colorado Front Range. Bulletin of the Torrey Botanical Club 113: Works Cited

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