By Lizzie Wasilewska

Forest recovery is an incredibly complex and frequently unpredictable process. It often requires outside help, but there are also ways in which forests heal themselves. Researchers recently discovered that nitrogen — a chemical that plays a major role in the formation of cells in many organisms — is crucial to trees’ ability to recover from environmental damage; with sufficient nitrogen, damaged forest ecosystems can heal with surprising speed and fullness.

For their study, published last month in Nature, the researchers began by selecting forest plots that had been damaged by agricultural use in recent decades. They compared these forests to mature forests — each around 300 years old — from the same area. Their results show that forests have an amazing capacity for regrowth after damage. The young trees in their study accumulated biomass quickly, and on a broad scale, the forests recovered with surprising rapidity.

Nitrogen plays a central role in their recovery process; the younger and quickly recovering trees have especially high nitrogen demand. In an interview with mongabay.com, researcher Sarah Batterman said, “We found that during the period when forests are recovering rapidly, typically in the first few decades, they have a really high nitrogen demand.” According to the study, after about 12 years, the forests’ reliance on nitrogen rapidly declined as their overall health increased.

The results have important implications for climate change, since the ability of forests to heal themselves also means that they can more effectively synthesize carbon dioxide, which in turn allows forests to better moderate global temperatures.

But faced with a climate changing more rapidly than many forests can adapt to, the ability of forests to heal themselves is threatened. In 2009, American Forests co-chaired a Climate Change Work Group in order to develop effective strategies for aiding forest restoration, including climate change mitigation and adaptation strategies. This is one of several ways in which American Forests contributes to discussions of climate change and forests More information can be found here.