Predicting historic forest composition using species lists in presettlement land survey records, western New York

Abstract

AbstractQuestionsDo the species lists (SLs) of presettlement land surveys, little used though available for over two million km in the USA, provide useful information on historic forest composition? Do the bearing trees (BTs) and SLs of pre‐settlement land surveys record similar species and relative abundances? Are relative abundances more similar when species in an SL are given equally weighted relative abundances or rank‐weighted relative abundances?LocationTemperate broadleaf forest, western New York, US.MethodsBT and SL data were obtained for the 3 172 953 m of lines surveyed in 1797–9 by the Holland Land Company. The presence and relative abundance of 8394 BTs were compared with 11 192 unique taxon mentions within SLs. Comparisons were made for individual taxa and whole communities, and at the scales of individual line segments and whole town lines. The influence of equal weighting and rank weighting of the SLs on the comparisons was assessed.ResultsThe SLs on a line segment typically recorded more taxa than did the BTs. The species present in BTs and SLs on individual line segments were indicated by Cohen's Kappa to have ‘substantial agreement.’ Correlations between BTs and SLs of all taxa on the same town line increased with the number of BTs and SLs on the town line, and when the relative abundances of SL taxa were modelled using rank weighting rather than equal weighting. Correlations between BTs and SLs for individual taxa were higher for taxa that had more BTs. Correlations between BTs and SLs were also higher when the relative abundances of SL taxa were modelled using rank weighting vs equal weighting.ConclusionsSLs capture greater detail of presettlement forest composition than do BTs. The relative abundance of a taxon mentioned in a presettlement land survey SL can be meaningfully predicted using its rank in an SL and application of a rank weighting model.