The Effects of Fire Mitigation
Methods on Vegetation
Species Diversity in Montane
Forest – Nederland, CO
Kristy Campbell
Vegetation Ecology, Summer 2013
CU Mountain Research Center
Background
• Colorado Wildfires cause property damage, but are necessary
for ecosystem restoration and nutrient cycling (Covington et al. 1997).
• The need for methods that protect forest biodiversity while
protecting human lives and property (USDA Forest Service).
The Problem
Research Questions
• Does fire mitigation affect the number
of species (richness) present in an
area?
• How do fire mitigation methods affect
the distribution of vegetative functional
groups?
Hypothesis – Species richness and
functional group distribution may be
influenced by fire mitigation methods.
• Predictions:
• A higher species richness in area of fire
mitigation.
• An increase in coverage from species
of forbs in areas of fire mitigation
(Barney and Frischkenecht 1974).
Methods
•
•
•
•
Ponderosa Pine/Douglas Fir/Lodgepole Pine forest (elevation at about 2600m).
Most data were collected on either a South facing slope or level ground.
4 nested plots (5m x 5m), each containing 2 Daubenmire plots.
Two areas of nested plots
• “thinned”
• forested (unnaffected).
• Random location of plots, but with pseudoreplication
Map provided by USDA Forest Service
Methods
• Each plot was evaluated for species richness and mean
percent coverage of three different functional group
categories – grasses, forbs, and shrubs (tree coverage could
not be measure using Daubenmire plots).
• The mean species richness for each 5m x 5m plot was
calculated by identifying and counting individual species.
• The coverage of species in each Daubenmire plot was
recorded and percent coverage of each of these was
calculated.
• A 2-factor ANOVA was used to evaluate the differences
between treatments (thinned and forested) in terms of
• species richness
• coverage
Species Richness Results
• Total number of species thinned
= 26.
• Total number of species forested
= 23.
• Total number of species found
in both the thinned and
forested areas = 17.
ANOVA RESULTS
Figure 1: Number of Species in three Functional groups
(Grasses, Forbs, and Shrubs) in two areas of forest (Thinned and
unaffected). Error bars are 95% confidence intervals
• Error bars overlap, indicating no significant
difference in mean number of species in
function groups between thinned and
forested areas.
• P-value of treatment type >
0.05
• No significant difference
between thinned and forested
areas.
Percent Coverage Results
(Shrubs absent in all
daubenmire plots)
ANOVA RESULTS
Figure 2: Mean percent coverage of species in two
Functional groups (Grasses, Forbs) in two areas of
forest (Thinned and unaffected). Error bars are 95%
confidence intervals
• Error bars overlap, indicating no
significant difference in mean percent
coverage of species in function groups
between thinned and forested areas.
• P-value of treatment type > 0.05
• No significant difference
between thinned and forested
areas.
Discussion
• Hypothesis – Species richness and functional group distribution may
be influenced by fire mitigation methods.
• Predictions:
• A higher species richness in area of fire mitigation.
• An increase in coverage from species of forbs in areas of fire
mitigation.
• There were slightly more species present in the area of fire
mitigation (26 compared to 23). This is a small difference in total
species richness.
• There were slightly more forbs present in the thinned area (a mean
of 9 compared to a mean of 5.5) and forb coverage was slightly
greater (mean of 4.75 % compared to a mean of 3%). These
differences are not significant, as shown by both the overlapping
error bars, as well as the extremely high P values from the ANOVA
tests.
• My results do not support my hypothesis.
Conclusion
• Results are inconclusive
• Although my results do not support my hypothesis, I cannot
conclude that fire mitigation methods do not affect species of
vegetation and distribution of functional groups.
• Need for greater numbers of samples within the areas I
studied.
• Need for repetition of the study in other areas of fire
mitigation (replication - not pseudoreplication).
• Need for repeated follow-up studies of ecological sucession
occurring over time (Covington, W. et al. 1997).
• Additional research could compare vegetative structure in fire
mitigation areas to vegetative structure in areas with fire.
Acknowledgments
Joseph Graham at the USDA Forest Service emailed me
newsletters and maps with information on the West Magnolia
project. He also helped explain the difference between
Overstory Removal (OST) and thinning as methods of fire
mitigation.
Literature Cited
Barney, M. and Frischknecht, N. 1974. Vegetation Changes
Following Fire in the Pinyon-Juniper Type of West-Central Utah.
Journal of Range Management. 91-96.
Covington, W., Fule, P., Moore, M. Hart, S., Kolb, T., Mast, J.,
Sackett, S., Wagner, M. 1997. Restoring Ecosystem Health in
Ponderosa Pine Forests of the Southwest. Journal of Forestry,
Vol 95. No. 4. 23-29.
USDA Forest Service. Project Details for Fuels Reduction Project
Work in West Magnolia, a High Use Recreation Area Near
Nederland, CO. www.fs.usda.gov/arp.