Winter Controls on the Distribution of Winter Controls on the Distribution of Arboreal Hair Lichens in the Niwot Ridge Arboreal Hair Lichens in the Niwot Ridge

Biosphere ReserveBiosphere Reserve

Keli BakerKeli BakerWinter EcologyWinter Ecology

Spring 2013Spring 2013Mountain Research Station, University of Mountain Research Station, University of

Colorado, Boulder Colorado, Boulder

o “Old Man's Beard”o Arboreal hair lichen – Usneao Conifer substrateo Get most of their winter moisture from winter

snow melt (Campbell et al, 2001).o More lichen in subalpine?

BackgroundBackground

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

IntroductionIntroduction

o Hypothesis:Hypothesis: The distribution of the arboreal The distribution of the arboreal lichens will be affected by snow depth, tree lichens will be affected by snow depth, tree species, wind exposure, stand density and species, wind exposure, stand density and elevation.elevation.

o Environmental factors change with elevation:Environmental factors change with elevation:o PrecipitationPrecipitationo Temperature (Veblen, 1986)Temperature (Veblen, 1986)o Tree species and stand density (Veblen, 1986)

Possible Winter Possible Winter ControlsControls

o Visually measured lichen abundanceo Nine 1m x 50m plotso Elevation range: 3,050m (10,000 ft) to 3,200m

(10,500 ft)o Developed sale to quantify lichen abundanceo Assigned each tree an abundance level from 0 to

4o Online chi-square calculator comparing:

o lichen abundance level frequencyo elevationo tree species

MethodsMethods

o Significant correlation between elevation and lichen abundanceo   pp<<0.001<<0.001o Chi square: 105.252o Degrees of Freedom: 16

ResultsResults

ResultsResultso Significant correlation between tree species Significant correlation between tree species

and abundanceand abundanceo   p p = 0.00073547= 0.00073547o Chi square: 14.43o Degrees of Freedom: 2

o Significant correlation between tree Significant correlation between tree species and elevation.species and elevation.o pp = 0.00256282 = 0.00256282o Chi square: 23.7Chi square: 23.7o Degrees of Freedom: 8 Degrees of Freedom: 8

ResultsResults

o Lichen abundance affected by:Lichen abundance affected by:o Preceipitation – in general, more at Preceipitation – in general, more at

higher elevationshigher elevationso Elevation – microclimate changesElevation – microclimate changeso Stand Structure – density, species Stand Structure – density, species

compositioncompositiono Lichen prefers subalpine firLichen prefers subalpine firo Lichen found mostly in subalpineLichen found mostly in subalpine

DiscussionDiscussion

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 substrateo In denser stands

o Lichen abundance is confined mostly to subalpine elevations

ConclusionConclusion

o Gough, L. P. 1973. 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. 2006. Estimating Epiphytic Macrolichen Biomass from Topography, Stand Structure and Lichen Community Data. Journal of Vegetation Science 17: 157-70. Wiley Online Library. 24 Feb. 2009. Web.

o Campbell, J. et al. 2001. Canopy Microclimate and Arboreal Lichen Loading in Subalpine Spruce–fir Forest. Canadian Journal of Botany 78: 537-55. NRC Research Press. University of Northern British Columbia, 3 May 2001. Web. DOI: 10.1139/cjb-79-5-537

o Peet, R. 1981. Forest Vegetation of the Colorado Front Range: Composition and Dynamics. Vegetatio 45: 31-75.

o Veblen, T. 1986. Age and Size Structure of Subalpine Forests in the Colorado Front Range. Bulletin of the Torrey Botanical Club 113: 225-240.

Works CitedWorks Cited

Works Cited

Preacher, K. J. (2001, April). Calculation for the chi-square test: An interactive calculation tool for chi-square tests of goodness of fit and independence [Computer software]. Available from http://quantpsy.org.