The U.S. General Land Office land surveys document trees present during European settlement. However, use of these surveys for calculating historical forest density and other derived metrics is limited by uncertainty about the performance of plotless density estimators under a range of conditions. Therefore, we tested two plotless density estimators, developed by Morisita and Pollard, for two, three, and four trees per survey point under simulated ranges of tree densities, non-uniform densities, and different tree spatial distributions. Based on these results, we developed estimator corrections and determined number of survey points needed for reliable density estimates.
General Land Office
public land survey
Hanberry, Brice B.; Fraver, Shawn; He, Hong S.; Yang, Jian; Dey, Dan C.; Palik, Brian J. 2011. Spatial pattern corrections and sample sizes for forest density estimates of historical tree surveys. Landscape Ecology. 26: 59-68.