Plant Invasion Patterns at Global and Regional Scales

From the moment of colonization, humans have carried non-native plants around the world with them. “The introductions are changing the world’s biogeography,” says U.S. Forest Service research ecologist Qinfeng Guo. “Understanding the mechanisms behind invasion patterns is critically important.” Invasion patterns vary depending on the scale. At finer scales, invasions are often related to competition.…  More 

30 Years of Nitrogen Fertilization in Spruce-Fir Forest

Rocks and sediments bind up almost 98 percent of all nitrogen. The remaining 2 percent is in motion, part of a global chemical cycle that includes humans, bacteria, plants, and the atmosphere. “Plants need nitrogen to grow,” says U.S. Forest Service research ecologist Steve McNulty. “However, excess nitrogen can harm plants.” Nitrogen and sulfur can…  More 

Don’t Forget the Soil Fauna

When U.S. Forest Service Southern Research Station research ecologist Mac Callaham and post-doctoral researcher David Coyle, D.B. Warnell School of Forest Resources, were teaching a class together at the University of Georgia, they decided to involve their students in writing a manuscript. The paper aimed to call attention to a subject that in recent years…  More 

Eastern Trees Move North & West

After analyzing extensive data collected on 86 tree species in the eastern U.S., researchers found that most trees have been shifting their ranges westward or northward in response to temperature and precipitation changes. Scientists from Purdue University, North Carolina State University, and the U.S. Forest Service collaborated on the study, which was recently published in…  More 

The Most Vulnerable Trees

What do water locust, Texas walnut, chalk maple, pyramid magnolia, two-wing silver bell, and butterbough all have in common? They’re among the U.S. tree species most vulnerable to climate change, according to a study by North Carolina State University (NCSU) and the U.S. Forest Service. The Forest Service Forest Health Protection program sponsored the study,…  More 

Exotic Plants May Dominate After a Fire, But Not for Long

Land managers expect that exotic invasive plants will quickly move in following a disturbance, especially after a fire. Though exotics initially might have an edge over native plants on burned ground, this may not always be so as time goes on, according to a U.S. Forest Service study. Qinfeng Guo, a research ecologist with the…  More 

Fire Frequency & Hardwood Regeneration

The mighty oak is a critical component of southern forests—for wildlife habitat, acorn production, and hardwood timber—but forests are changing, and its future is uncertain. A long-running U.S. Forest Service experiment studied the use of prescribed fire to control competition from shade-tolerant tree species like red maple, American beech, and blackgum. The study area, located on…  More 

NASA Proposal Selected for Funding

Forests – and other plant communities – pull carbon dioxide gas out of the air and store it, or convert it into forms the rest of life on earth can use. “The conversion of carbon dioxide gas into other carbon-containing forms is called primary productivity,” says U.S. Forest Service scientist Jim Vose. Productivity in the…  More 

Forests, Farms, or Houses?

Molecules relentlessly cycle from one form to another. “Simple human activities, such as building homes, can affect these cycles,” says U.S. Forest Service research soil scientist Jennifer Knoepp. For example, trees growing near streams affect the way nitrogen and other nutrients move from the land to the water. “Riparian zones play a critical role in…  More 

Stream Crossings and Water Quality

In many situations, the adage “dirt doesn’t hurt” is true. One important exception is when soils erode, and rain washes the sediments into streams. Johnny Boggs, a biological scientist with the U.S. Forest Service Eastern Forest Environmental Threat Assessment Center, recently led a study on preventing stream sedimentation in forests. Sedimentation impacts water quality and can…  More