Delaware: Plants and Wildlife

Increases in frequency and intensity of flooding, drought, wildfires and invasion of non-native plant species are predicted to accelerate and cause rapid transformation of the landscape and the ecosystems supported. A significant increase in summer drying is expected to change tree species composition in forested regions and lead to an overall decrease in Delaware’s forested lands by 10-20%. With warmer conditions, it is expected that much of the forested lands will be replaced by grasslands and pasture. Changing climate has the ability to increase the occurrences of wildfires by increasing drought conditions, increasing insect pest and disease pressure with a longer growing season, and causing tree-community shifts to more fire-prone species. Increased wildfire events will increase the rate at which invasive plant species will be able to encroach on forested lands.

Initial increases in forest growth may be observed in response to elevated levels of atmospheric CO2, but within a short amount of time forests will begin to be adversely affected by high amounts of ground-level ozone. Ground-level ozone is damaging to trees and plants.With lengthened growing seasons and warmer temperatures, the growth and reproductive capability of forest pest insects will be increased and their geographical range will spread.

Maritime forests of Delaware are especially at risk from the effects of climate change and will be adversely affected by increases in storm frequency, temperature, and saltwater infiltration. Invasive plant and wildlife species better adapted to hotter and drier conditions predicted by climate change models have a higher chance of successfully over-taking native species which are likely to experience a decreases in their geographic range due to stress from climate change. These stresses include drying of wetland habitat, increase in frequency and severity of extreme weather events, and changes in atmospheric composition. The slow rate of sediment accretion in wetlands is likely to cause increased inundation and flooding as sea levels rise in these wetlands, causing an increase in saltwater intrusion and adversely affecting plant and wildlife species. It is expected that a 20-inch rise in sea level will inundate 50% of wetlands in the Delaware Bay.