Timing of Tree Density Increases, Influence of Climate Change, and a Land Use Proxy for Tree Density Increases in the Eastern United States

Long-term observations inform relationships among changes in vegetation, climate, and land use. For the eastern United States, I compared timing of tree change, comprised density diversity increases, with climate as measured by change point detection Palmer Modified Drought Index (PMDI) that accounts for water balance, two prairie ecological provinces, four grassland landscapes, forest landscapes. Historical evidence supplied documentation increases between approximately 1860 1890 provinces grasslands bordering forests. Additionally, because paralleled when area reached ≥25% agricultural use, categorized landscapes increased to during 1860, 1880, 1900, 1920. One method identified no significant PMDI points 1800s. The other found southern province, forests, had 1855 1865 an interval relative dryness. Only one points, which occurred dryness or were continuous historical variation. Inconsistent moisture availability did not provide correlations comprehensive but use corresponded based on timing, magnitude direction mechanism. threshold may critical missing component allows progression analysis effects vegetation.