Climate and Whitebark Pine Establishment in the Alpine Treeline Ecotone

1. Climate and Whitebark Pine Establishment in the Alpine Treeline Ecotone Matt Germino, Idaho State University Co-PI’s and students: Jeremy Littell, University of Washington Lisa Graumlich, University of Arizona Keith Reinhardt, Wake Forest University Eliza Maher, CA Center for Natural Land Management Funded by: NASA, DOE, Andrew Mellon Foundation, NSF, and ISU Research Committee Logistics support from Andy Steele, Grant Fleming, and the lift operators at Grand Targhee Resort

2. Conifer seedlings: point of sensitivity Pinus albicaulis (whitebark pine) Picea engelmannii (Engelmann spruce) Abies lasiocarpa (subalpine fir)

3. Outline: • Spatial and temporal patterns of establishment at treeline reveal climate X neighborhood plant effects on WBP • Experimental manipulation of neighboring vegetation and climate – • past experiments elsewhere, and new experiments on the ‘Ghee!

4. Beartooth Plateau: North-Central Wyoming • 45.02oN • Fir, spruce, whitebark pine • 2900m (9,500ft)

5. Teton Range: West-Central Wyoming • 43.45oN • Fir, spruce, whitebark pine • 3000m (9,800ft)

6. Snowy Range 41.20oN • Snowy Range: South-Central Wyoming • 41.20oN • Fir and spruce • 3200m (10,500ft)

7. B A C a Kuiper’s test, = 0.05 Evidence for importance of initial survival of germinated seedlings: N =121 51 72 80 60 SKY EXPOSURE (% of upper hemisphere) 40 20 Available space Emergent seedlings Established seedlings

8. No tree seedling recruiting in alpine, but many within treeline ecotone • No mortality due to disease or predation • Strong effects of neighboring plants: MAHER & GERMINO, 2006, Ecoscience

9. Experimental verification of direct effects of neighboring plants on conifer seedlings

10. Experimental manipulations indicate direct effects of neighboring plants on seedling establishment MAHER, GERMINO, & HASSELQUIST (2005) Can J For Research

11. From Maher, Germino, and Hasselquist; 2005, Can J Forest Res.

12. Photosynthesis is a key process in plant growth, and photoinhibition can strongly reduce it. From Ball 1994

13. +30 W m-2 LSKY 30% reduction in frost occurrence at treeline, and seedlings have strong positive response (Germino & Smith 1999)

14. Fir Spruce Pine SPECIES DIFFER IN SEEDLING REQUIREMENTS FOR NEIGHBORING PLANT COVER: Less tree cover More tree cover MAHER & GERMINO, 2006, Ecoscience

15. Species differ in sensitivity to frost x sunlight, and this affects tree patterning: pine fir spruce

16. stem cross-section of a 9 yr old subalpine fir (stem diameter = 1.5 mm)

17. Response of yearly log(#establishments) to yearly climate: Climate parameter PP, species interaction Mean daily summer temperature <0.05 <0.0001 Mean daily temperature range n.s. <0.05 Minimum daily temperature <0.05 <0.0001 Snow water content, June n.s. <0.05 Snow water content, October n.s. <0.05 Precipitation n.s. n.s.

19. Space x time: Over all seedlings: P<0.01 Timberline only: P<0.01, r2 = 0.12

20. New DOE NICCR project: -Aimed at bioclimate models for establishing and older conifers at treeline, and annual vs. decadal climate variability -Allows for test of generality of climate-tree concepts

22. Mountain Range Dominant tree species PDO correlation upper treeline lower treeline Zirkel Mountain (NE CO) Picea engelmannii Abies lasiocarpa Juniperus Psuedotsuga menziesii 0.5 Medicine Bow Range (SE WY) Picea engelmannii Abies lasiocarpa Juniperus Psuedotsuga menziesii 0.4 Wind River Range (Central WY) Pinus albicaulis Abies lasiocarpa Psuedotsuga menziesii 0 to 0.2 Beartooth Mountains (NW WY) Pinus albicaulis Picea engelmannii Abies lasiocarpa Psuedotsuga menziesii Pinus contorta -0.3 to 0.4 Teton Range (SE ID to WY) Pinus albicaulis Abies lasiocarpa Psuedotsuga menziesii -0.5 to 0.5 Centennial Mountains (SE ID to MT) Pinus albicaulis Abies lasiocarpa Psuedotsuga menziesii -0.4 Wallowa/Eagle Cap Range (NE OR) Pinus albicaulis Picea engelmannii Abies lasiocarpa Psuedotsuga menziesii Pinus ponderosa -0.4 Goat Rock Mountains (S-Central WA) Abies lasiocarpa Tsuga mertensiana Psuedotsuga menziesii Pinus ponderosa -0.6 North Cascades (N-Central WA) Pinus albicaulis Picea engelmannii Abies lasiocarpa Tsuga mertensiana Psuedotsuga menziesii Pinus ponderosa -0.6

23. Upright panels alter solar heat: • Lexan, -8C • Acrylic, -3C • Flat panels alter LSKY: • Polyethelene, +1°C • Acrylic, +3 °C • Glass, +5°C RECENT CLIMATE EXPERIMENTS --- HERE

24. -8 -5 0 +1 +3 +5 Relative/nominal temperature (C)

28. FROM THE TETONIA ID WEATHER STATION, ARS

31. From new 2007/2008 experiment on Mary’s Saddle

32. Conclusions : • Initial seedling survival is a point of sensitivity • Historic patterns of establishment point to frost X sunlight interactions • Contemporary experiments indicate frost X sunlight effects not as key • Are the differences due to warming, snowpack, slope differences?

34. Louvered open-sided chamber

35. N =121 51 72 134 22 36 117 387 102 80 60 %SKY 40 A B B B A C C B A 20 Plot Init. Est. Plot Init. Est. Plot Init. Est. Tetons Beartooths Snowies a Kuiper’s test, = 0.05 DIFFERENCES IN %SKY AND FROST/LIGHT EFFECTS AMONG MOUNTAINS: -Tall forbs, few grasses Sheel Bansal: -Fewer summer frosts -Doug fir doing OK at timberline! -Elevation effects less detectable