Transcript Winter Invertebrate Richness as a Function of Elevation

Winter Invertebrate Composition
as a Function of Elevation
How does invertebrate richness, diversity, and
abundance change throughout an elevational gradient?
Amanda Tynan
Winter Ecology
Spring 2014
CU Mountain Research Station
Outline
• Invertebrates
• Role in Ecosystem
• Context of Winter
• Hypothesis for Research
• Methods
• Results
• Abundance
• Species Richness
• Species Diversity
• Discussion
• What does this all mean?
• Conclusions
Invertebrates’ Role
• Why should we care?
•
•
•
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Keystone species to ecosystem function (Urry, 2014)
Decomposition (Alaska)
Food sources (Alaska)
Indicators for disturbance (Alaska)
• What are they doing in the winter?
• Freeze Tolerance vs. Freeze Avoidance (Marchand, 1996)
Introduction: Invertebrates in the
Winter
• Can elevation affect invertebrate populations?
– Hypothesis: There will be a statistically significant difference in
composition of invertebrates along an elevational gradient.
– Null Hypothesis: There will be no statistically significant correlation
between elevation and invertebrate composition.
Methods
• Collection Techniques:
•
•
•
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Beat sheet, bark peeling
Lodgepole pine (mature), 2m from trail/road
Replication of study (2x)
Sample 10 trees/visit to site
• Sites:
• Site 1: North of C1/elevation: 10,500’
• Site 2: MRS/elevation: 9,500’
• Site 3: Pk to Pk/elevation: 8,750’
• Analysis:
• Invertebrate Richness
• Invertebrate Abundance
• Species Diversity
Beat Sheet – Google Images
Results
Collection Day 1:
Collection Day 2:
• Site 1: 3 Invertebrates
• Site 2: 6 Invertebrates
• Site 3: 9 Invertebrates
• Site 1: 5 Invertebrates
• Site 2: 6 Invertebrates
• Site 3: 11 Invertebrates
Invertebrates Found:
• Spider
• Moth Larva
• Snow Fly
Snow Fly – Google Images
Spider Under Bark – Photo by Amanda Tynan
Results
• Abundance:
• Site 1: 8
• Site 2: 12
• Site 3: 20
• Invertebrate Richness
• Site 1: 2 (Moth, Snow Fly)
• Site 2: 2 (Moth, Snow Fly)
• Site 3: 3 (Moth, Snow Fly, Spider)
• Species Diversity:
• Site 1: 0.42857
• Site 2: 0.30303
• Site 3: 0.64737
Results
Number of Individuals
Invertebrate Composition
7
6
5
4
3
2
1
0
Moth Larva
Spider
Snow Fly
1
2
3
4
5
6
Site
Abundance
Moth Larva R² = 0.51923
12
Snow Fly R² = 0.75
Number of Individuals
10
Spider R² = 0.75
8
6
Spiders
4
Snow Fly
Moth Larva
2
0
-2
0
1
2
Site
3
Results: Evidence of Activity?
• Exit Holes
• Beetle Larva Paths In Trunk
• Vertical Splitting
• Dead and Dying
Trees
Exit Holes and Woodpecker
Punctures - Photo by Amanda Tynan
Vertical Split – Photo by Amanda Tynan
Discussion
• Elevation as surrogate for temperature?
• Implications for invertebrate distribution and
rising global temperatures?
• Lab experiments reinforce hypothesis for
correlation between elevation and
invertebrate composition – how does this
differ from other animals we have talked
about?
• What about snow cover?
Conclusions
• Limitations to project – a call for larger
samples, more replication, and inclusion of
other abiotic factors associated with elevation
• Invertebrate abundance, richness, and
diversity are a function of elevation
• Global warming changing invertebrate ranges
and biogeography?
Thanks to…
• T. Kittel for this awesome class
• D. Sweeney for the gear
• Jessica for keeping me company on the hikes
to my site 
References
(1) Alaska. Alaska Department of Fish and Game. Wildlife Action Plan Terrestrial Invertebrates. Doc. Appendix 4. Print.
(2) Kloc, C. J. And Chown, S. L. (1997). Critical thermal limits, temperature tolerance and water balance of a sub-Antarctic catepillar Pringleophaga marioni
(Lepidoptera: Tineidae). J. Insect Physiol. 43, 685-694.
(2) Marchand, Peter. Life in the Cold. An Introduction to Winter Ecology. 3rd ed. N.p.: University Press of New England, 1996. Print.
(3) Somme, Lauritz. "The physiology of cold hardiness in terrestrial arthropods." European Journal of Entomology 96.1 (1999): 1-10. Print.
(4) Storey, Kenneth B., and Janet M. Storey. "Frozen and Alive." Scientific American (1990): 92-97. Print.
(5) Urry, Lisa A. Campbell Biology in Focus. N.p.: Pearson Books, 2013. Print.