Forested watershed
This system is adapted to frequent low- to moderate-intensity fire and should be able to withstand an increase in wildfire frequency. However, if fires are too severe, some species may experience detrimental impacts.
This system is characterized by soils that are saturated during the cool season and dry during the summer. This soil moisture pattern is expected to be intensified in the future as winter and spring precipitation increases and summer or fall precipitation decreases. Although projected changes are in the direction characteristic of flatwoods, if they are too extreme it could be detrimental.
Wet bottomland forests are already at the wettest, lowest elevation areas on the landscape. If conditions become too dry, as are projected for later in the summer or fall under some scenarios, there are no lower, wetter lower places where the species could migrate.
Very few species are able to withstand the prolonged flooding characteristic of wet bottomland forests. Therefore, even a loss of a few species could dramatically alter community composition.
If conditions become drier, as are projected to occur under some models during the summer or fall, some mesic bottomland species may be able to migrate into areas previously occupied by wet bottomland species. If that occurs, the mesic bottomland specis may out-compete some wet bottomland species.
Model projections for more common species like boxelder, red maple, and cottonwood are more reliable and project stable or increasing habitat suitability. However, the models available are not equipped to capture the complex hydrologic processes that occur in these systems, so actual habitat suitability might differ from what is projected.
Impact model projections suggest habitat suitability for green ash will persist across a range of climate scenarios. However, emerald ash borer is likely to arrive in the area and dramatically reduce ash populations for reasons other than climate change.
These species are relatively rare across the landscape as a whole. In order for model projections to be reliable, there needs to be a large enough sample size to properly characterize current, and thus future, habitat suitability. Therefore, there is not enough information to reliably predict habitat suitability for some of these rare species.
This community type is characterized by prolonged, frequent flooding and wet, poorly drained soils. The dry conditions that are possible later in the growing season may be too dry for some species.
Because both heavy precipitation and some drier conditions are expected to occur with climate change, heavier flooding in lower elevation areas and drier conditions in higher elevation areas may narrow the range of places suitable for mesic bottomland forests.
