WINTER VEGETATION ECOLOGY FIELD DAY - RESULTS
RETURN TO SYLLABUS
(Schedules etc. subject to modification)

• Results -
  

2019	Transect profiles:  Transect Profile images below Also below, plots of Tree Limit with respect to Snow Depth in terms of Tree DBH, Height, & Density (for Lower Transect) Data - Lower Transect (xlsx) Upper Transect (xlsx) Discussion and Interpretation -- How does the Ribbon Forest and Glade system develop and propagate from West to East under westerly winds in the lee of a geomorphic ridge?  You may wish to refer back to the Google Earth image of the site While these are primarily abiotic factors at work, what biotic factors also play a role?  -- hint: see photo to right What are the differences you observed in the age structure between the Ribbon Forest and the Subalpine Forest proper? -- see illustration in the right panel. Explain which forest (Ribbon vs. Subalpine proper) is predominately structured by abiotic processes vs. biotic ones?  And why these result in the observed age structure? Is there a strong allometric relationship between tree diameter and height for both species?  - see plot in the right panel, lower down. What does allometric mean, and why are such relationships useful? Do you think the relationship would hold for the Subalpine Forest proper? Also see extensive Discussion for 2013 Refer back to the topic's Lessons Points click images to enlarge Lower Transect Upper Transect Tree Limit with respect to Snow Depth - in terms of Tree DBH, Height, & Density Lower Transect click images to enlarge	click images to enlarge Snow mold damage on Engelmann Spruce sapling buried branches [Photo (c) 2013 T Kittel]  Age structure of the Ribbon Forest (green) vs. Subalpine Forest proper (red) y-axis = frequency (=number of individuals in each age class) x-axis = age classes Upper Transect - Allometry Relationship between DBH and Height, by species Linear relationship strong?, similar for the 2 spp.? Do you think the relationship would hold for the Subalpine Forest proper?
	Previous Years
2018	Transect profiles:  Transect Profile images below See Right panel for Tree Limit with respect to Snow Depth in terms of Tree DBH, Height, & Density (for Transect 2) Data - Transect 1 (xlsx) Transect 2 (xlsx) Discussion and Interpretation - see below click images to enlarge Transect 1 Transect 2 Discussion and Interpretation - See Results from deep-snow years (e.g., 2014, 2016) for sharp relationships between snow depth and forest properties (transect profile, tree height & DBH) See Discussion for 2013 (plots & notes) Whiteboard images: Development of Ribbon Forest and Glades (from left to right) - in the lee of a geomorphic ridge (in Brown with hash lines, leftside of figure) - under westerly winds (from Left to Right) Blue - snowbank, Green - moisture from snowmelt Brown = growing season based on duration of snowpack (for 1st snowbank) Purple = area of optimal tree establishment and growth Age structure of the Ribbon Forest vs. Subalpine Forest proper y-axis = frequency (=number of individuals in each age class) x-axis = age classes	click images to enlarge Tree Limit (shown by Tree Diameter) vs Snow Depth - Transect 2 Tree Limit (shown by Tree Height) vs Snow Depth (SnowZ) - Transect 2 Tree Limit (shown by Tree Density) vs Snow Depth (SnowZ) - Transect 2
2017	Transect profiles:  See selected images below, others are in pdfs - Upper, western Transect "Intreeging" (xlsx, pdf; 200k) Lower, eastern Transect "All-Pine" (xlsx, pdf; 200k) Discussion and Interpretation - see 2013 notes, but in terms of this year's data click images to enlarge Upper, western Transect "Intreeging" (*) Lower, eastern Transect "All-Pine" (*)  * See pdf for images showing Tree Limit with respect to Snow Depth in terms of Tree Height, Density, and DBH * See pdf for images showing Tree Limit with respect to Snow Depth in terms of Tree Height, Density, and DBH
2016	2//16 Transect data:  See selected images below Western Transect (xls, 150k) Eastern Transect (xls, 150k) Discussion and Interpretation - see 2013 notes, but in terms of this year's data click images to enlarge Western Transect Transect Profile Tree Limit (shown by Tree Height) vs Snow Depth (SnowZ) - Note strong effect of SnowZ on Tree Ht at intermediate depths - Apparent Tree Limit at SnowZ ~120cm  (Observed SnowZ's go to ~230cm) Eastern Transect Transect Profile Tree Limit (shown by Tree Diameter) vs Snow Depth - Note strong effect of SnowZ on DBH at intermediate depths Apparent Tree Limit at SnowZ ~120cm  (Observed SnowZ's go to ~165cm)	click images to enlarge Western Glade, 2016 - Ribbon Forest photo (c) T.Kittel Relationship between DBH and Height, by species Strong linear relationship, similar for the 2 spp.
2015	2/7/15 Transect graphs:  See selected images below Western Transect (summary plots: pdf, 150k) Eastern Transect (summary plots: pdf, 150k) Discussion and Interpretation - see 2013 notes click images to enlarge Western Transect Transect Profile Tree Limit (shown by Tree Height) vs Snow Depth (SnowZ) - Note strong effect of SnowZ on Tree Ht at intermediate depths - Apparent Tree Limit at SnowZ ~125cm  (Observed SnowZ's go to ~150cm) Eastern Transect Transect Profile Tree Limit (shown by Tree Diameter) vs Snow Depth - Note strong effect of SnowZ on DBH at intermediate depths Apparent Tree Limit at SnowZ ~160cm  (Observed SnowZ's go to 250cm)
2014	2/15/14 Transect graphs:  See selected images below Western Transect "Yeti" (summary plots: pdf, 150k) Eastern Transect "Tauntaun" (summary plots: pdf, 150k) Discussion and Interpretation - see 2013 notes click images to enlarge Western Transect (Yeti group) Transect Profile Tree Limit (shown by Tree Height) vs Snow Depth (SnowZ) - Apparent Tree Limit at SnowZ ~215cm  (Observed SnowZ's go to 275cm) Tree Limit (shown by Tree Diameter) vs Snow Depth - Note strong effect of SnowZ on DBH at intermediate depths, vs that on Tree Ht. for this Transect Eastern Transect (Tauntaun group) Transect Profile Tree Height vs Snow Depth - Note strong effect of SnowZ on Tree Ht at intermediate depths, - No apparent Tree Limit (no high SnowZ's w/o trees) vs as in Western Transect Relationship between DBH and Height, by species Strong linear relationship, similar for the 2 spp.	photos - click to enlarge Western Transect - Glade at 40m Western Transect - Group Yeti in part Eastern Transect - Opening ~10m, Group Tauntaun Eastern Transect - Main Glade at ~30m, Group Tauntaun
2013	2/1/13 Transect 1&2 graphs composite (pdf, 250k) - see below for image of Upper Transect Spreadsheets (do not "Update" on opening) Lower Transect (Summary xls, 160k) Upper Transect (Summary xls, 160k) Discussion -- What are the questions we sought to address in this field study? --  The key ones were: What is the structure of the Ribbon Forests?  Why is this landscape structured into Ribbons and Glades? To illustrate structure of the forest itself, what is the frequency of individuals (# Individuals) in different size classes? Size classes can be by Tree Height [which we plotted in the board, below] or by DBH. How does this contrast to that for the Subalpine Forest proper, based on our casual observations lower down? From the Ribbon Forest results, what relationship did you observe between presence of trees (or the height of trees) and snow depth? In this case, which variable (Tree Ht, Snow Z) is the independent variable and which the dependent? What mechanisms can you suggest that support the argument either way?  [hint: see board discussion, below] That is, How might Snow Z affect Tree Ht? How might Tree Ht influence Snow Z? What is the main story, then, on how the Ribbon Forests are formed, maintained, and propagated? Based on this interpretation -- Which forest (Ribbon Forest vs. Subalpine Forest proper) is predominately structured by biotic processes vs. abiotic ones? How is this reflected in your Size-Class Frequency plots?  What biotic processes are involved? What abiotic processes? Also Refer back to the topic's Lessons Points Interpretation: Readings on the Ribbon Forest – Review readings in LC on Ribbon Forests (p. 89-91 ) "Ribbon Forests and Snowglades" (pdf, 2.4M), pp. 198f. in: Knight, D. 1994. Mountains and Plains. The Ecology of Wyoming Landscapes. Yale Press. click images to enlarge See Transect 1&2 graphs composite (pdf) Whiteboard discussion	click images to enlarge Ribbon Forest Sampling - Upper Transect [Photo (c) 2013 c/o Elizabeth Golden] Ribbon Forest Sampling - Lower Transect Snow mold damage on Engelmann Spruce sapling buried branches [Photos (c) 2013 T Kittel]
2012	2/5/12 Transect 1&2 graphs composite (pdf, 75k) Spreadsheets Transect 1 (Summary xls, 160k) Transect 2 (Summary xls, 160k)
2011	1/23/11 Transect plots composite (pdf, 200k) Spreadsheet (Summary xls, 160k: Team A, Team B)	[photos: TKittel]
2010	Feb 2010 - Transect 1: plots (pdf, 200k), spreadsheet (xls, 260k) Transect 2: plots (pdf, 200k), spreadsheet (xls, 260k) Figure composite (pdf, 1M)          Transect 2 [photos: TKittel]	click image to enlarge
2009	Ribbon Forest (2/28/09) –  Plots:(jpg's, <70k) Transect 1 Profile - SnowZ & Tree Height along transect  SnowZ & Tree Height along transect - with interpretation  N.B. - On the next 3 plots, ignore the minor, rightmost bump on the polynomical fit - this is an artifact of the fit. Tree Height vs. SnowZ Tree DBH vs. SnowZ  Number trees vs SnowZ Tree DBH vs. Ht Data - xls (100k), Selected plots as Handout (pdf, 160k) Blackboard photo (jpg, 700k)
2008	1 March 08 - Ribbon Forest Structure -- Plots in: xls (100k)
2005	Feb 2005 Spruce-Fir Vegetation Survey (xls, 25k)