Environmental Variables Associated with the Location of Arborglyphs in the Eastern Sierra Nevada, Alpine County, California
AuthorConnolly, Nicholas James
AdvisorBerry, Kate A.
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Arborglyphs are a unique form of expression created by Basque sheepherders. The sheepherder's arborglyphs are in part a type of history, art, and literature that is inherently linked to location. Arborglyphs disintegrate as the aspen trees they are on die so it is important to locate and document them before they are lost. This research was guided by three questions: a) which environmental variables are associated with the location of arborglyphs, b) are arborglyphs carved more frequently on the uphill side of the tree, and c) does the Taylor Grazing Act influence quantity of arborglyphs? Nine environmental variables were investigated as they related to the location of arborglyphs. The environmental features studied were: elevation, aspect, slope, distance to surface water, depth to water table, soil drainage, soil depth, precipitation, and temperature. These variables were analyzed in a geographic information system implementing a weights of evidence analysis and each of the environmental variables proved to be correlated (at the 90 percent level) to the location of the arborglyphs. Six of these variables - elevation, slope, soil depth, aspect, precipitation, and distance to surface water - are recommended to land managers as being particularly useful in locating arborglyphs. The second analysis in this study involved the placement of arborglyph on an individual tree with respect to slope and was done with arborglyphs on all slopes and then again with arborglyphs on slopes greater than ten degrees. No correlation was found. The third analysis considered whether the Taylor Grazing Act of 1934, which has been identified as contributing to the decline of Basque sheepherding in the American West, was associated with a decrease in arborglyphs. In examining dated arborglyphs before and after the Taylor Grazing Act, a noticeable decline was found in the quantity of arborglyphs in the post-1934 period.