Institutional biases influencing the ecological interpretation of General Land Office public land survey notes.
Bragg, Don*,1, 1 USDA Forest Service, Monticello, AR, US
ABSTRACT- Long used to help identify presettlement vegetation patterns in the United States, the General Land Office (GLO) public land survey records contain a large amount of semi-quantitative information on the trees used to witness survey corners and lines. Corner trees are frequently used to estimate species abundance and stand density, typically with the point-quarter sampling method. However, this statistical technique comes with assumptions that are violated by the practice of GLO survey corner establishment. For example, the point-quarter system assumes that the nearest trees to plot center are chosen without bias regarding species, distance, and direction. Examination of over 11,400 corner trees from Ashley and Monroe counties in Arkansas found a distinct sinusoidal pattern of azimuths, with strong preferences towards 45, 135, 225, and 315 degrees, and similarly strong avoidance of 0, 90, 180, and 270 degrees. In addition, surveyors preferred trees within 2 and 10 m of the corner, with slightly less than 70% of the entire sample falling within this distance range. Surveyors also favored trees of 25 to 50 cm in diameter (67% of corner tree records). These patterns, in addition to species selection choices, cannot be attributed to either individual surveyor bias or forest patterns, but rather reflect a set of instructions and field practices designed to expedite the work and improve corner relocation. In this paper, I describe the instructions as published by various surveying institutions during the historical GLO period for the state of Arkansas (1815 to 1855), and detail how each practice would have influenced the selection of witness trees and their modern ecological interpretation. It is critical to remember that witness trees were not established by trained ecologists to follow a systematic sampling pattern to express the nature of vegetation conditions, but rather by government surveyors to permit the long-term relocation of property corners as a prelude to settlement.
Key words: point quarter sampling, Arkansas, presettlement, historical ecology
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