What's New in Version 4

Welcome to Version 4 (V4) of the Tree Atlas. Assuming that you are familiar with the previous version(s),we list below the main updates in V4:

• Uses newer Forest Inventory Analysis (FIA) data for the period 2001—2016 to estimate relative abundance
• The DISTRIB (habitat suitability model) has been revised (DISTRIB-II) and now uses 45 updated predictor variables and, for future climate scenarios, newer GCM models (CCSM4, GFDL CM3 and HadGEM2-ES) under RCP 4.5 and RCP 8.5 emission pathways. For details please refer to the Peters et al., 2019 paper
• DISTRIB-II uses a dual resolution approach by using both 10-km and 20-km resolution to estimate species relative abundance (see Peters et al., 2019 paper), to take advantage of the FIA's heterogenous plot density.
• We now use the results of the migration model (SHIFT) to estimate natural migration of tree species and understand colonization likelihoods of future suitable habitats predicted by DISTRIB-II. We present maps for many species that combine suitable habitats (HQ) with colonization likelihoods (CL) under future climates (see the Prasad et al., 2016 paper and Iverson et al., 2019a paper
• We have enhanced our regional summary tree tables to summarize spatial information from multiple species via helpful indices in the form of excel tables for many regions of interest (National forests, 1x1 degree grids, etc.). These tables will be helpful for forest managers to gauge species presence now and their dynamics under climate change (potential changes in habitat and capability, potential colonizers etc.), for their region of interest.