Overview & Applicability
The Climate Change Atlas can help to answer a range of questions concerning current and projected suitable habitat (year 2100) for the majority of tree species within the eastern U.S. forests.
For each species included in the Atlas, information is provided on species characteristics, life history and current distribution. Users can see which factors (e.g. temperature, elevation, soil properties) help to drive species distributions, offering some guidance on species sensitivity to large-scale climate differences. The Atlas offers maps and numerical summary data that show how each species' suitable habitat is projected to change under three different climate models, for both high and low emissions scenarios. Additionally, for some species, maps depicting the colonization likelihood of potential suitable habitat are provided. Maps can be viewed via the Atlas online interface, or geospatial data can be obtained from https://doi.org/10.2737/RDS-2019-0029.
For certain pre-defined regions, the Atlas provides data on how the overall grouping of species habitats within that area might change under future climates. Currently, projections are provided for ecoregions (Bailey’s 2007), national forest/grasslands, national parks, national climate assessment regions (2016), one-degree grids, states, urban areas, watersheds.
Additional background on this tool and its uses can be viewed in this video tutorial:
Researchers at the USDA Forest Service Northern Research Station (NRS) first developed a modeling framework in 1996 to assess potential changes in habitat for common tree species in the eastern United States. Since then, the model has gone through several improvements, leading to the development of the DISTRIB model which is the basis for the Tree Atlas. The current online version of the Atlas was released in 2020 and includes descriptions of tree characteristics that affect their adaptability to climate change. See the Atlas publications page for a list of documents related to the development and use of this model.
Inputs and Output
The model inputs are pre-defined by the researchers, so no user-collected data is required. For the Tree Atlas, these defined inputs include data on current tree species distributions from the Forest Inventory and Analysis (FIA) program, as well as datasets that fall under categories of: climate, elevation, and soil characteristics. A full list of model inputs can be found on the Tree Atlas site.
Atlas outputs primarily include spatial and numerical representations of current and future suitable habitat. Measurements of suitable habitat distribution and change are given in importance value (e.g., relative abundance). Importance value is a measure of abundance that accounts for both tree basal area and number of stems, ranging from 0 - 100.
Restrictions and limitations
The Atlas should be used at an appropriate scale; analyses are done at the level of both 10×10 and 20×20 km cells within a hybrid network, so fine scale interpretations (e.g., single cell) may be inappropriate. It is also important to note that there are several uncertainties inherent in this type of species distribution model. For example, there is a considerable range in projected future climate conditions depending on which climate model is used and which emissions scenario is chosen to represent future conditions. The Atlas deals with this by providing projected suitable habitats for a range of different climate models and emissions scenarios, and by averaging the projected suitable habitat under each emission scenario.
In addition, the model predicts suitable habitat better for some species than for others. A reliability index is included in the Atlas to reflect this. The reliability scores are based on the statistical techniques used to create the model, but also accounts for how good the predictor variables are at describing where species are located. Projections for species with low reliability scores should be interpreted with caution.
Finally, the model is only predicting where suitable habitat may be in the future. It cannot predict where species themselves will be located, since that depends on factors such as species migrations, land use changes, biological factors (e.g. regeneration, dispersal, competition) and disturbances (e.g., fire, insects, pollution), all of which are difficult to quantify. Therefore, colonization likelihoods and adaptability ratings should be evaluated to help interpret the potential changes in suitable habitat.
To see all of the strengths and limitations for the DISTRIB model used in the Atlas, please see this list [PDF].
Accessing the tool and additional information
Please see the NRS Atlas homepage to begin exploring the models, to view tutorials on how to use the Atlas, and for additional resources: https://www.fs.usda.gov/nrs/atlas.
Publications relevant to the Climate Change Atlas are available on the Tree Atlas site.
Tree Atlas citation:
Peters, M.P., Prasad, A.M., Matthews, S.N., & Iverson, L.R. 2020. Climate change tree atlas, Version 4. U.S. Forest Service, Northern Research Station and Northern Institute of Applied Climate Science, Delaware, OH. https://www.fs.usda.gov/nrs/atlas.
It is also recommended that the following publications be cited along with the atlas citation, depending on what you used:
For habitat suitability models on trees:
Iverson, L.R, Peters, M.P., Prasad, A.M., & Matthews, S.N. (2019). Analysis of Climate Change Impacts on Tree Species of the Eastern US: Results of DISTRIB-II Modeling. Forests, 10(4), 302. doi: 10.3390/f10040302 https://www.fs.usda.gov/treesearch/pubs/57857
Peters, M. P., Iverson, L. R., Prasad, A. M., & Matthews, S. N. (2019). Utilizing the density of inventory samples to define a hybrid lattice for species distribution models: DISTRIB‐II for 135 eastern U.S. trees. Ecology and Evolution. doi: 10.1002/ece3.5445 https://www.fs.usda.gov/treesearch/pubs/58353
Iverson, L. R., Prasad, A. M., Peters, M. P., & Matthews, S. N. (2019). Facilitating Adaptive Forest Management under Climate Change: A Spatially Specific Synthesis of 125 Species for Habitat Changes and Assisted Migration over the Eastern United States. Forests, 10(11), 989. doi: 10.3390/f10110989 https://www.fs.usda.gov/treesearch/pubs/59105
Prasad, A. M., Iverson, L. R., Matthews, S. N., & Peters, M. P. (2016). A multistage decision support framework to guide tree species management under climate change via habitat suitability and colonization models, and a knowledge-based scoring system. Landscape Ecology, 31(9), 2187–2204. doi: 10.1007/s10980-016-0369-7 https://www.fs.usda.gov/treesearch/pubs/50748
Prasad, A. M., Gardiner, J. D., Iverson, L. R., Matthews, S. N., & Peters, M. (2013). Exploring tree species colonization potentials using a spatially explicit simulation model: implications for four oaks under climate change. Global Change Biology, 19(7), 2196–2208. doi: 10.1111/gcb.12204 https://www.fs.usda.gov/treesearch/pubs/43705
Iverson, L. R., A. M. Prasad, S. N. Matthews, and M. Peters. 2008. Estimating potential habitat for 134 eastern US tree species under six climate scenarios. Forest Ecology and Management 254:390-406. http://www.fs.usda.gov/treesearch/pubs/13412
For Adaptability of tree species:
Iverson, L. R., S. N. Matthews, A. M. Prasad, M. P. Peters, et al. (2012). Development of risk matrices for evaluating climatic change responses of forested habitats. Climatic Change 114(2): 231-243. doi: 10.1007/s10584-012-0412-x. https://www.fs.usda.gov/treesearch/pubs/41221
Matthews, S. N., L. R. Iverson, A. M. Prasad, M. P. Peters, and P. G. Rodewald. 2011. Modifying climate change habitat models using tree species-specific assessments of model uncertainty and life history factors. Forest Ecology and Management 262:1460-1472. http://www.fs.usda.gov/treesearch/pubs/38643