Climate Change Effects on Pennsylvania's Forests

What is climate change and why is it happening?

• Climate change is a change in the usual or expected temperatures. Changes in temperature affect local weather conditions by disrupting normal patterns of rainfall and local temperature ranges.
• The term 'global warming' is often used in place of climate change, but this term is misleading because what is important are the changes in weather patterns, not just the temperature.
• Changes in climate are the result of increased greenhouse gases, which absorb radiation and trap heat inside Earth's atmosphere.
• The volume of greenhouse gases introduced since the Industrial Revolution (1760-1840) suggests that human activity is a significant source of additional greenhouse gases.

What is changing?

Higher Temperatures

• Temperatures in the Mid-Atlantic region are projected to increase on average by 5.27 to 9.11°F by the end of the century.
• The greatest warming will be in summer and fall.

Precipitation

• More winter precipitation will come as rain, which will impact snowpack.
• Total precipitation is projected to increase, but it will be distributed unevenly, with more in colder months and less rain in warmer months.
• More intense precipitation events and longer gaps between rain events could cause drier soil conditions later in the growing season.
  • This may cause physiological drought for forest vegetation and impact precipitation-dependent wildlife, such as salamanders.

Climate Change Effects on Forest Ecosystems and Industry

• It is predicted that there will be a change in species distributions and a loss of diversity. Changes include:
  • Northern species that are close to the southern extent of their range may face increased stress and decreased vigor, causing declines in populations.
  • Southern or temperate species will be favored and may have increases in suitable habitat and biomass.
  • Recruitment and regeneration will be affected because seedlings are more vulnerable to increased temperatures and drought.
• Increased occurrences of insect outbreaks.
  • Forest pests and pathogens can respond rapidly to a warming climate and will be able to damage forest ecosystems already stressed by changes in climate.
  • Hemlock woolly adelgid will likely become worse.
• New invasive species
  • Invasive species, insects, and diseases will be able to expand their range northward with warmer temperatures.

Potential Economic Impacts on Natural Resources

• There is expected to be increased harvesting in northern regions (Canada, Russia) due to faster-growing trees.
• New sources of timber will likely impact associated markets, generally leading to lower prices.
• Climate-economic models predict a 35% drop in prices for solid wood over the next 25 years.
• Increased wood volume may also open supply for other markets, such as wood biomass energy.

If you have any questions or are interested in collaborating with FOCCE, please reach out to Melissa Kreye at mxk1244@psu.edu 

Resources

• Climate Change Response Framework "Climate Change Tree Atlas Results for Regions in Pennsylvania"
• Kirilenko, Andrei P. and Roger A. Sedjo. 2007. Climate change impacts on forestry (PDF). Proceedings of the National Academy of Sciences
• Northern Institute of Applied Climate Science (NIACS)
• NASA Global Climate Change