Where Does the Rain Go?

Millions of people depend on the forests of the Southern Appalachian Mountains for drinking water. As climate, land use, and land cover changes alter the forest structure in these mountains, they also alter water budgets. “The Southern Appalachian Mountains are a humid montane environment – they are essentially a cooler version of the tropics,” explains…  More 

Species Selection for Woody Biomass Production

In the southeastern U.S., short-rotation woody crops are a significant part of a growing renewable energy supply. A USDA Forest Service study examines how growing different tree species for bioenergy may have impacts on water yield. “Loblolly pine has long been considered the go-to woody bioenergy species in the South,” says Peter Caldwell, research hydrologist…  More 

How Drought and Thinning Affect Water Balances in Southeastern Pine Plantations

Evapotranspiration – the combination of water evaporation and plant transpiration – is an essential process for forests and water supply and climate. This is particularly true in the Southeastern U.S. where evapotranspiration from forested watersheds can return 50 to 90 percent of annual precipitation to the atmosphere. Until now, there has been a gap in…  More 

Estimating Ecosystem Water Use

For more than a decade, U.S. Forest Service and Chinese scientists have collaborated to understand how human activities affect carbon and water cycles in managed ecosystems. Working through the U.S.-China Carbon Consortium, scientists share data from a network of eddy covariance flux towers across the two countries. The towers measure the flow of water vapor,…  More 

Forests, Water, Climate, and Management

Across the globe, forests cover about a quarter of all land and are important sources of clean water. A new book, edited by U.S. Forest Service Southern Research Station (SRS) scientist Devendra Amatya, examines the interactions between forests, water, climate, and management. The book, Forest Hydrology: Processes, Management and Assessment, was recently published by the…  More 

Open or Shut: How Trees Respond to Drought at the Leaf Level

Trees pull water into their roots, where some of it moves up the trunk against the pull of gravity. This upward movement, which is described by the cohesion-tension theory, is possible because of the chemical nature of water. Water molecules are attracted to each other (cohesion), so just before a water molecule evaporates from the…  More 

International Evapotranspiration Symposium: April 7 – 10, 2014, Raleigh, NC

  Register now for Evapotranspiration: Challenges in Measurement and Modeling from the Leaf to the Landscape Scale and Beyond. An important part of the hydrologic water cycle is plant water use (transpiration) and evaporation from earth and ocean surfaces. Together, these two processes are called evapotranspiration. Scientists and engineers studying climate, ecosystem productivity, water use,…  More