by Emily Bernhardt

1. The effects of fire severity and site moisture on functional properties of black spruce forests in interior Alaska by Emily Bernhardt

2. Functional diversity • Relative abundance of functionally different kinds of organismsWalker, B. 1992. • Plant functional types (PFT) • Assemblage of species with certain similar plant functional attributes (traits)Skarpe, C. 1996 • Defined by ecological properties in question Naemm and Li 1997 • Functional redundancy • Taxonomically distinct species that perform the same functional role in the ecosystem Walker, B. 1992; Micheli and Halpurn 2003

3. What factors make a black spruce forest stay a black spruce forest • If black spruce as a forest type has definable characteristics: • Self replacing low severity fire • Cold / wet / acidic soils • Permafrost • Does an alteration of one (fire regime) affect the communities ability to maintain the others? • By altering the community composition, thereby altering the communities ability to maintain BS forest type characteristics, resulting in a change of forest type

4. Hypothesis Post-fire change in species composition will alter functional properties of re-growth and residual vegetation in relation to burn severity/site moisture

5. Burn severity Site moisture L H H H H L L L

6. Sampled 5 individuals per species Measured Hard / soft traits Rooting depth CPCRW sites Conducted Reléve

7. Examining changes in functional diversity • Analyzed changes in 3 ways • 1) Created list of plant traits for boreal species • 2) Hypothesized trait relationships with burn severity and site moisture • 3) Reported observed trait relationships • How plant traits are distributed across study sites

8. Plant traits for each species

9. Hypothesized trait relationships

10. Hypothesized trait relationships

11. trait average within site Species trait value independent of site species trait average across all sites Site trait value independent of species trait average of all species within a site for each trait site within BS/SM type all sites

12. 2 tables were created from these data Species trait value for each sampled year

13. Site trait value for each sampled year H H L H L H L L H L

14. Determining how traits relate in ecosystem • A ordination represents a species (or site) of interest in ordination space, where the species location along the axis represents its similarity to other species located along the axis • Using data collected from reléve

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20. Preliminary results • Certain traits appear to respond similarly to burn severity and site moisture and can potentially become a PFT group • Site / species table: • Species with similar trait values often have different growth forms • Low moisture sites have lowest trait values • From ordination: • Growth form is not a good functional type grouping variable • Burn severity and site moisture were accurately determined • Low burn severity sites have similar trait values

21. Final product – species trait matrix Measured

22. Hypothesized trait relationships

23. JFSP UAF – Biology department Teresa Hollingsworth Terry Chapin Field crew and technical advisement Christa Mulder, Emily Tissier, Jamie Hollingsworth, Mark Winterstien, Gretchen Garcia, Kate McGlone, Brian Charlton, Katie Villano and Dana Nossov References Naeem, S. and S. Li. 1997. Biodiversity enhances ecosystem reliability. Letters to nature 390:507-509. Micheli F., and B.,S. Halpurn. 2005. Low functional redundancy in costal marine assemblages. Ecology letter 8:391-400. Skarpe, C. 1996. Plant functional types and climate in a southern African savanna. Journal of vegetation science 7:397-404. Walker, B. 1992. Biodiversity and ecological redundancy. Conservation Biology 6:18-23. Acknowledgments

24. Plant functional type example Growth form popular But may not be appropriate or validly explain community response Used a a sort of base line to compare functional type groupings against Constant trait general traits with little to no variation (growth form) Variable trait plastic morphological traits (plant height)

25. Rooting depth measurements in C P C R W sites (burned and unburned) Measured rooting depth of each individual • 8 burned sites • 2 of each site moisture/burn severity • 4 unburned sites • Sampling design • 30m belt transect • 5 individuals of each species

26. Response and effect groups • In relation to ecosystem characteristics of interest • Flammability • Permafrost • Acidity • N-fixation • Site moisture

27. Examining changes in functional diversity • Assign species into functional groups based on their growth form (evergreen vs. deciduous) • Create a list of constant and variable traits • Separated into • Response of plants to fire regime (tolerance, disturbance response) • Effect of plants on fire regime (flammability, formation of permafrost, nitrogen fixation)

28. Trait Value Categorization • All measured trait values standardized • Trait values categorized by site for each species • abundance value multiplied by trait value • Trait values calculated between sites by species • Trait values totaled to give a species trait value • Trait values calculated for site • Species trait values totaled to give a site trait value 3