Ecological Archives E092-043-A2

Kirk M. Stueve, Rachel E. Isaacs, Lucy E. Tyrrell, and Roseann V. Densmore. 2011. Spatial variability of biotic and abiotic tree establishment constraints across a treeline ecotone in the Alaska Range. Ecology 92:496–506.

Appendix B. Photographs of treeline at Denali.

B1
 

   FIG. B1. The photograph faces east across the East Fork Toklat River, north of the Park Road. Shrub tundra and white spruce are in the foreground. The upper tree limit tends to occupy higher elevations on south-facing slopes (~1100 m) (at left), and lower elevations on north-facing slopes (~850 m) (at right). Photograph by Kirk M. Stueve in September 2008.


 

B2
 
   FIG. B2. The photograph faces south to the Alaska Range from the west side of the East Fork Toklat River, north of the Park Road. Shrub tundra and short white spruce (2 m or shorter) are in the foreground (near upper tree limit) with 3 m and taller white spruce in the far background. The abiotic setting (especially elevation and winter sun exposure) tended to be the most important predictor of tree establishment here, but proximity to trees persisted as an important tertiary predictor. Photograph by Kirk M. Stueve in September 2008.

 

B3
 
   FIG. B3. Lower treeline zone with many white spruce trees at least 3–4 m tall. Proximity to trees is the most important predictor of tree establishment here. Rachel E. Isaacs (second author) is in the foreground. Photograph by Kirk M. Stueve in September 2008.

 

B4
 
   FIG. B4. The photograph faces west from the Park Road toward Denali, with shrub tundra and scattered white spruce in the foreground. Photograph by Kirk M. Stueve in September 2008.

 

B5
 
   FIG. B5. Photograph of Kirk M. Stueve extracting a core just below the upper tree limit. Photograph by Rachel E. Isaacs in September 2008.

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