DISTRIB-II: forest types of eastern United States and potential departure under climate change

Modeled habitat suitability for 104 eastern United States trees species under 1981-2010 climate conditions and projected future conditions (2070-2099) were created using a statistical modeling approach that correlates mean importance values (e.g., relative abundance) to environmental data such as climate, elevation, and soil. The importance values were used to train a latent Dirichlet allocation model to define 11 forest types. Swapping 30-year mean climate conditions for a baseline period (1981-2010) with projections for the future (2070-2099) results in potential suitable habitat representing a species potential abundance and was used to estimate possible departures in the current forest type communities. Downscaled future climate projections were obtained from the NASA Earth Exchange Downscaled Climate Projections (NEX-DCP30) program. Output from three general circulation models (GCM) were used to explore possible changes in habitat suitability resulting from climate change and included the NCAR Community Climate System Model (CCSM4), NOAA Geophysical Fluid Dynamics Laboratory Coupled Model 3 (GFDL CM3), and Met Office Hadley Global Environment Model 2 - Earth System (HadGEM2 - ES). Projections under the representative concentration pathways (RCP) 4.5 and 8.5 were used to encapsulate the range of plausible increases in greenhouse gases during this century. The resulting vector digital data include climate information, dominant forest type, summed importance value of dominant forest type species community, and summed importance value of other potential species.Defining forest types based on species modeled habitat suitability provides a landscape-level classification of the dominant species community. Attempting to quantify the potential departure from the current forest type under future climate scenarios by accounting for the potential change in climate conditions and possible changes to habitat suitability for tree species reflects the complex interactions and response each contribute.For more information about these data, see Peters et al. (2022, https://doi.org/10.1007/s10980-022-01436-6), Iverson et al. (2019; https://doi.org/10.3390/f10110989), and Peters et al. (2019; https://doi.org/10.1002/ece3.5445). Additional information and products are available at https://doi.org/10.2737/Climate-Change-Tree-Atlas-v4. This data publication supersedes any data associated with Iverson et al. (2008; https://doi.org/10.1016/j.foreco.2007.07.023).