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 

Frogs, Toads, and Ephemeral Wetlands

When ephemeral wetlands swell with water, frogs and toads congregate to breed and lay their eggs,which hatch into tadpoles. “That’s risky business,” says U.S. Forest Service research ecologist Katie Greenberg. “Wetlands could dry before tadpoles metamorphose into juveniles.” If ephemeral wetlands dry out before the tadpoles develop lungs and become froglets or toadlets, an entire…  More 

Air, Water, and Wavelets

We know air temperature has increased over the last 15-20 years, and that it will continue to do so on an unprecedented scale. But we are still learning exactly how this air trend impacts water. As it turns out, air temperature is linked to changes in our streams — affecting things like flow, soil moisture,…  More 

Drier Weather, Drier Fuels

Dry weather – and huge wildfires – are common. “Climate change would modify fuel moisture and wildland fires dramatically across the United States,” says Yongqiang Liu. Liu is a U.S. Forest Service research meteorologist who recently investigated climate impacts on fuel moisture. His study was published in the journal Ecohydrology. Weather quickly influences fuel moisture…  More 

Shifting Window of Growing Seasons

When winter comes to an end, it’s no mystery that warming temperatures and spring rains bring new life. Wildlife emerges, flowers bloom, and brilliant green leaves begin to fill the ground and the forest canopy—all part of their seasonal cycle known as phenology. Observers know those green leaves don’t appear at the same time every…  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 

Topography and Drought

The planet is changing, and the hydrologic cycle will change along with it. Extreme droughts – as well as extremely wet weather – are expected to become more frequent and more intense. “These changes may interact with topography to affect species composition in unexpected ways,” says Chelcy Miniat. Miniat is a researcher and project leader…  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 

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 

Mangroves of Mozambique

Whether small and shrubby or tall and majestic, mangroves have an unusual ability – they are specially adapted to grow in brackish water, and can tolerate ocean waves lapping at their stilt-like roots. As stands mature, soil and decaying plant matter becomes captured in the intricate web of their roots. “The soil in mangrove ecosystems…  More