Reconstruction of Forest and Grassland Cover for the Conterminous United States from 1000 AD to 2000 AD

Spatially explicit reconstruction of historical land cover change is a prerequisite for more comprehensive understanding environmental changes. Anthropogenic activities have dramatically altered the conterminous United States (CONUS), encroaching heavily on primary vegetation. However, few datasets exist that depict trajectory forest and grassland changes in CONUS over last millennium, previous efforts only focused reconstructions four centuries. By integrating remote sensing-derived use/cover (LUCC) data potential vegetation data, we determined extent natural (PENF) (PENG) CONUS. Based qualitative analysis trends driving forces changes, devised method subtracting reconstructed cropland (1000–2000 AD) built-up (1850–2000 from PENG PENF to reconstruct 5 min × grid dataset at 13 time-points past millennium. The results showed underwent slow decline (1000–1600 AD), an accelerated (1600–1800 dramatic (1800–1950 finally, recovery (1950–2000 study period. modelled fraction decreased 49% 1000 AD 33% 2000 AD, representing 32% area reduction, whereas 37% 22%, 42% reduction. reduction occurred primarily 200 years, with reductions accounting 86% 97% total respectively. Spatially, than 80% was originally covered by forests grasslands, loss mainly eastern Great Plains After 1930s, farmland abandonment began central CONUS, simultaneously protection laws. Federal government regeneration programs resources Shelterbelt Project all contributed slowdown cover.