Transcript Trail Disturbance in the Alpine Meadow

+
Trail Disturbance in the
Alpine Meadow on Arapaho
Pass and Mount Yale
Marieta Bialek
Vegetation Ecology 2013
Mountain Research Station
University of Colorado at Boulder
+ Alpine Vegetation
(above 3360m)

Controls (USNVC)






Snowmelt
Wind
Permafrost
Short Growing Season
 Plants adapted to
conserving moisture
Disturbance factor: Hiking
Trails.
Trampling reduces density of
vegetation and increases
erosion. (Klug, Scharfetter-Lehrl, Scharfetter
2002 citing (Grabherr, 1985)

Plants resistant to trampling
include turf-forming
graminoids, forbs matted,
creeping, or in rosettes (Cole, Monz
2002)
Moss Campion, Silene acaulis: Matted forb
Alpine Avens, Geum rossii : Creeping forb
+
Importance of human disturbance
on alpine plant communities

Diversity primarily limited by temperature stress

Disturbance and competition a secondary role.

A predicted result of global warming is a shift in the equilibrium
between stress, disturbance, and competition in alpine
ecosystems (Kammer, Mohl 2002).
Forget-me-nots
+
Question

Is there a disturbance effect on the
trailside communities of alpine
vegetation on Arapaho Pass and Mount
Yale?

Does the effect differ among two
different alpine sites (Arapaho Pass,
Mount Yale)
Arapaho Pass
+
Hypothesis

Alternate Hypothesis

There is a significant difference in communities near the
trail and away from the trial.

Predictions:

Species richness reduced alongside trails.



Study on trampling shows a reduction in species richness (Klug
et al. 2002).
More resistant plants where disturbance effect is lower.
Null Hypothesis

There is no difference in communities.
+
Site 1: Arapaho Pass

Indian Peaks Wilderness

Elevation: 3620m

Community: Alpine Meadow

6 degrees slope

128 degrees SE

Topography: Ridge exposed
to high winds and weather
+ Site 2: Mount Yale

Collegiate Peaks Wilderness
(near Buena Vista)

Elevation: 3810m

Community: Alpine Meadow

24 degrees slope

260 degrees SW
+
Methods

50m transect along trail

Daubenmire Plot pairs
 Trail, 3m Off Trail

Measures
 Species Richness
 Average Height (cm)
 Use ANOVA to assess the difference
in each site and for trail plots and off
trail plots
 Number of resistant and non-resistant
species
 Chi-Squared test

Replication & Random sampling
 5 plot pairs at Arapaho site
 3 plot pairs at Mount Yale

Limitations
 Time: small sample size
 Knowledge of plant species (mistakes)
+
Species Richnes

Two factor ANOVA test not
significant all p values >0.05

Disturbance: 0.87

Both (Disturbance X Site): 0.44

Sites (Yale vs Arapaho): 1
+
Arctic Sandwort
Height of Vegetation

Two-factor ANOVA

Results:

Disturbance: p=0.17

Both (disturbance X sites): p=0.06

Sites (Yale vs Arapaho): p=0.0001

Heights were not significantly
different on Trail and off Trail

Significantly different between sites
+
Resistance

Chi-Squared Test

p= 0.10

Not significantly different
between sites

More resistant species on
Arapaho Pass

More non-resistant species on
Mount Yale
+
Discussion

Strength of disturbance effect varies
with different conditions and
topography

Mount Yale showed highest
difference in average height and
species richness

Arapaho pass plants already
adapted to harsher conditions


Ridge exposed to high winds
Slope only facing one direction
Plant mechanisms important on the
effect of trampling (Cole, Monz 2002).
Future Research

Mount Yale vegetation more
protected



# individuals

Species Diversity:
Shannon-Weiner Index

Evenness (E)

Total percent cover on the 50m
transect

Comparing the disturbance
effect among many sites
+
References

Cole, David and Christopher Monz. 2002. Trampling Disturbance of
High-Elevation Vegetation, Wind River Mountains, Wyoming, U.S.A.
Journal of Arctic, Antarctic, and Alpine Research. 34(4): 365-376

Kammer, Peter and Adrian Mohl. 2002. Factors Controlling Species
Richness in Alpine Plant Communities: An Assessment of the
Importance of Stress and Disturbance. Journal of Arctic, Antarctic,
and Alpine Research. 34(4): 398-407

Klug, Brigitte, Gabriele Scharfetter-Lehrl and Ernst Scharfetter. 2002.
Effects of Trampling on Vegetation above the Timberline in the
Eastern Alps, Austria. Journal of Arctic, Antarctic, and Alpine
Research. 34(4): 377-388

United States National Vegetation Classification. 2013. <usnvc.org>
+
Apendix

Species Identification Charts

Frequency of Species

Soil Samples
+
Species identification
+
Frequency of Species

More dominant species in
the trail plots

Three species found in 5/5
trail plots

Alpine Avens Geum rossii
, Graminoid 1, Moss
Campion Silene acaulis

All are resistant plants
+
Soil

Darker on Arapaho Pass

Site differences

Mount Yale SW facing, larger
slope

Arapaho Pass on an exposed
ridge slightly SE facing