The expected potential native vegetation of the Kittitas Valley, central Washington: A soils-based approach to the reconstruction of vegetation landscapes

Research on the Kittitas Valley in central Washington State was conducted to establish the type and areal extent of the native vegetation for the period immediately prior to Euroamerican settlement in the 1870s. The establishment of an objective ecological baseline from which the effects of past and proposed rural resource management activities may be measured and evaluated would provide resource managers the opportunity to more holistically assess full landscape potential by framing the process within the land's long-term evolutionary potential rather than upon present conditions currently accepted as “normal.”; Past efforts to reconstruct native vegetation landscapes have largely been based on the documentary record, most notably the field notes of the General Land Office (GLO) surveyors. Previous reconstructions have been lacking both in terms of spatial resolution and plant community composition. The research presented here proposes a methodological approach focused primarily upon the use of soils as indicators of both the extents and types of the pre-Euroamerican vegetation.; The physical and biological components, cultural factors, past land uses, and the documentary record of the vegetation of the study area were examined. Separate reconstructions were developed using the 1867–72 GLO field notes, 1936 U.S. Department of Agriculture soil survey, 1996 Natural Resources Conservation Service soil survey, and the investigator's own 1998 Road Survey of remnant patches of native vegetation. Comparisons were made between various landscape reconstructions.; The reconstruction based on the 1996 NRCS soil survey provides the most accurate and detailed iteration. Comparison of the 1998 Road Survey data to the 1996 NRCS data indicated very good correspondence (0.447 ≤ κ _w ≤ 0.525) indicating that, where remnant native vegetation can yet be found in the study area, it provides a fairly accurate indicator of the pre-Euroamerican vegetation landscape as hypothesized by the 1996 NRCS soils data. Comparison of the 1998 Road Survey data to the 1936 USDA data indicated only marginal agreement (0.330 ≤ κ_w ≤ 0.416). This study's findings suggest the use of soils as indicators of the type and spatial extent of the pre-Euroamerican settlement vegetation is a valid and appropriate methodology.