Restoration and Conservation of Rural and Urban Forests

Abiotic (Environmental) and Biotic (Living) Stressors

[photo:] Minocha summer field crew at Hubbard Brook Experimental Forest, New Hampshire ready for sampling foliar and sapwood of trees at Ca-supplemented watershed 3.Making Sense of Biotic and Abiotic Stressors

Northern Research Station scientists are studying trees’ biochemical responses to various stress factors (also known as “stressors”), including pests, pathogens, drought, cold, soil warming, and nutrient deficiencies across the northeastern and north-central United States. Some of these stress factors are “biotic” (caused by living things, such as insects or fungus), while others are “abiotic” (caused by physical factors, such as lightning, fire or pollution).

How Trees Respond to Stressors

Trees respond to stressors in a variety of ways. For example, they may produce more seeds than usual as a survival mechanism or they may go dormant to conserve energy during cold winter months. Responses to stressors can vary by location, species, and variety, and even by individual trees in the same species, variety and location. For example, two trees of the same species, located side by side, might be very different in that the metabolism (the chemical processes needed to maintain life) of one tree favors growth while the metabolism of the other favors resistance to stressors.
Trees can also respond to stressors by changing their metabolism. Sometimes this is accomplished by changes to a tree’s gene expression (the process in which a genetic code produces proteins, which affects an organism’s physical characteristics). These responses, which are usually partially or fully reversible, can help keep the plant alive, but they can come at a cost to the plant’s available energy. If a stressor persists, it can eventually kill the tree.

What This Research Means

By analyzing tree metabolites (the substances needed for metabolism), scientists can better understand how trees resist stress while developing tools to monitor the causes and effects of stressors.

Following are a few ways that Northern Research Station scientists are studying trees stressors and sustainability.

Research Summaries

Stress Monitoring

Abiotic Stress

Biotic Stress

Storms and Other Events

Forest Sustainability

Last Modified: March 19, 2019