Overview & Applicability
The Climate Change Atlas can help to answer a range of questions concerning current and projected suitable habitat (year 2100) for 147 bird species in the eastern U.S.
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, tree habitat) help to drive species distributions, offering some guidance on species sensitivity to large-scale climate differences. The Atlas supply 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. Maps can be viewed via the Atlas online interface, or with the program Google Earth.
For certain pre-defined regions, the Atlas also provides data on how the overall grouping of species habitats within that area might change under future climates. Currently, projections are provided for each state and geographic region and for each national forests/grassland, national park and ecoregion.
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 Bird Atlas. The current online version of the Atlas was released in 2014 and includes descriptions of environmental and tree characteristics that influence habitat suitability under 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 Bird Atlas, inputs include data on current bird distribution from the Breeding Bird Survey as well as data on climate, elevation, and tree species distributions. See the Bird Atlas for a full list of inputs.
Atlas outputs primarily include spatial and numerical representations of current and future suitable habitat. Measurements of suitable habitat distribution and change are given in incidence value. Incidence is calculated from the number of years (from 1981-1990) that a species was observed on the Breeding Bird Survey routes selected by the USGS. Incidence value ranges from 0 to 1.
Restrictions and limitations
The Atlas should be used at an appropriate scale; analyses are done at the level of 20×20 km cells, 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 interactions, ramifications of full annual cycle influences (e.g., migration wintering habitat change), as well as future land use changes and other individual life history traits, all of which are difficult to quantify.
To see a full list of strengths and limitations for the DISTRIB model used in the Atlas, please see this list.
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 Atlases are available online for both Trees and Birds.
Tree Atlas citation:
Landscape Change Research Group. 2014. Climate change atlas. Northern Research Station, U.S. Forest Service, 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., 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. https://www.treesearch.fs.usda.gov/pubs/13412
For Modification Factors/Adaptability of tree species:
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. https://treesearch.fs.usda.gov/pubs/38643
For habitat suitability models on birds:
Matthews, S. N., L. R. Iverson, A. M. Prasad, and M. P. Peters. 2011. Potential habitat changes of 147 North American bird species to redistribution of vegetation and climate following predicted climate change. Ecography 260:1460-1472. https://treesearch.fs.usda.gov/pubs/39841