Presentation on theme: "Winter Invertebrate Composition as a Function of Elevation How does invertebrate richness, diversity, and abundance change throughout an elevational gradient?"— Presentation transcript:
Winter Invertebrate Composition as a Function of Elevation How does invertebrate richness, diversity, and abundance change throughout an elevational gradient? Amanda TynanWinter EcologySpring 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? 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: 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: Site 1: 3 Invertebrates Site 2: 6 Invertebrates Site 3: 9 Invertebrates Invertebrates Found: Spider Moth Larva Snow Fly Collection Day 2: Site 1: 5 Invertebrates Site 2: 6 Invertebrates Site 3: 11 Invertebrates 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: 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.