Urban Forest Health
Urban Forest Health
Taxonomy Machine Name
sector_urban_forest_health
Taxonomy Alias
urban_forest_health
Disabled
Boreal and northern tree species in the Midwest are generally expected to decline in suitable habitat under climate change, while temperate tree species, grasslands, savannas, and woodlands may expand by the end of the century.
When considering the potential for ecosystem conversions, species migration is a critical issue. It is not necessarily communities that move, but instead species that move and then form new communities. Species distribution models have also indicated that species may respond individually to future climate change, with suitable habitat expanding for some species and declining for others.
Climate change will amplify many existing stressors to forest ecosystems in the Midwest, such as invasive species, insect pests and pathogens, and disturbance regimes.
Forest ecosystems throughout the Midwest Region are exposed to a range of natural, introduced, and anthropogenic stressors. Stressors such as invasive plants, forest pests, diseases, droughts, and floods are expected to become more damaging under climate change, and these factors may interact in unpredictable ways.
Climate conditions will increase fire risks in in the Midwest by the end of the century.
Different modeling approaches generally conclude that future climate conditions will increase the risk of wildfire across the Midwest. Annual fire probability, calculated solely with climate data and physical principles, is projected to increase by 20% to 80% across the Midwest by the end of the century. The incidence of atmospheric conditions that contribute to large and erratic fire behavior, measured by the Haines Index, is also projected to occur more frequently by the end of the century.
The annual frost-free season is expected to increase by roughly 30 days in the Midwest by the end of the century.
The freeze-free season is defined as the period of time between the last spring frost (daily minimum temperature below 32 degrees F) and the first fall frost. The length of the annual freeze-free season has been increasing since the 1980s, and all climate models agree that it will continue to increase in the future. The frost-free season is projected to increase 10 days by early this century (2016–2045), 20 days by mid-century (2036–2065), and possibly a month by late century (2070–2099) compared to the period 1976–2005 according to a higher climate scenario (RCP8.5).
A majority of climate models suggest that precipitation in the Midwest will increase in the winter, spring, and fall by the end of the century, but models generally project slight decreases in summer precipitation.
The means of several climate models indicate that winter and spring precipitation may increase from 10 to 30% across the Midwest by the end of the century, with larger projected increases further north in the region. Fall precipitation may increase only slightly. Summer precipitation is projected to decrease by less than 10% across the Midwest by the end of the century, according to an average of multiple climate models.
The frequency of intense precipitation will continue to increase across the Midwest under climate change.
The Midwest has already experienced a large increase in the frequency of heavy precipitation events. For example, storms in the 99th-percentile category increased by 42% from 1958 to 2016 across the region. Intense rainfall is expected to continue to occur more frequently, across different storm classes. For example, rain events that historically had an expected return of 5 years are expected to occur every 2-3 years by the end of the century. Large storms are also expected to deliver more rainfall as well.
Average annual precipitation is projected to increase slightly across the Midwest over the next century.
Annual precipitation has generally increased by 5 to 10% across the Midwest compared to the early 20th century, although there have been greater increases as well as slight decreases. There is uncertainty between different climate scenarios for future precipitation projections in the Midwest. Generally, it is expected that annual precipitation will continue to increase slightly across the region, with an additional 2-4 inches of rain per year by the middle of the century across most of the region.
The frequency and intensity of cold waves is expected to decrease across the Midwest by the middle of the century (2036-2065).
Daily low temperatures are projected to increase substantially across the Midwest, particularly under a higher climate scenario (RCP 8.5). For example, the coldest day of the year is expected to be about 9.4 degrees Fahrenheit warmer by the middle of the century (2036-2065), according to an average of 32 climate models under scenario RCP 8.5. The Midwest is also expected to experience 20 to 40 fewer days per year below 32 degrees Fahrenheit by the middle of the century.
The frequency and intensity of heat waves is expected to increase across the Midwest by the middle of the century (2036-2065).
Daily extreme temperatures are projected to increase substantially across the Midwest, particularly under a higher climate scenario (RCP 8.5). For example, the hottest day of the year is expected to be about 6.7 degrees Fahrenheit warmer by the middle of the century (2036-2065), according to an average of 32 climate models under scenario RCP 8.5. The Midwest is also expected to experience 5 to 40 more days above 90 degrees Fahrenheit by the middle of the century.