BOZEMAN, Mont. - A Montana State University ecologist who has studied the movement of water through redwood trees has now received a federal grant to investigate the movement of nitrogen through a western Montana forest.
Concerned about the productivity of mountainous forests across the American West, the U.S. Department of Agriculture's National Institute of Food and Agriculture (NIFA) awarded Jia Hu a four-year grant totaling $466,000.
The grant will allow Hu and her team to sample streams, snow, soil and plants in the Lubrecht Experimental Forest near Missoula over the next three years. During the fourth year, they will analyze their data and submit their findings to NIFA. The goal is to provide baseline information about nitrogen availability and forest productivity. Forest managers will be able to use that information to make decisions leading to healthier forests across the West.
"In order to implement sound nitrogen management strategies across western forests, we need to first understand the nitrogen cycle and then identify the mechanisms responsible for the spatial and temporal patterns of nitrogen availability," said Hu, an assistant professor in ecology and a fellow in the Montana Institute on Ecosystems.
Collaborating with Hu are two faculty members, one specializing in soils and the other in water. Yuriko Yano is a research associate in soil ecosystems and processes at MSU. Kelsey Jencso, who earned his Ph.D. in ecology and environmental science at MSU, is a state climatologist and watershed hydrologist at the University of Montana.
One graduate student and possibly two undergraduates will help with fieldwork, Hu said. Another grad student will take time-lapse photos of the changing snowpack.
"A lot of the proposal has to do with nitrogen during snowpack, so it will be important to take key measurements this spring when the snow is melting," Hu said. "We are trying to do a nitrogen budget of the system. We will measure nitrogen everywhere it could be found."
Yano said she is especially interested in seasonality, the fact that trees are highly active in the early spring but not in the middle of the summer. Among other things, she wants to understand how seasonality affects nitrogen availability. She also wants to study the role of topography, the availability of nitrogen when water takes different forms, and what happens when snowpack declines.
More snow on the ground means warmer soil and happier microorganisms, Yano said. Explaining, she said the bacteria and fungi that break down dead leaves and other organic material in the forest are most active when they're warm.
Hu said the Lubrecht Experimental Forest is an ideal location for answering their questions because it contains a variety of elevations, slopes, trees and plants in one watershed. The 28,000-acre forest in the Blackfoot River drainage has 23 types of soil, six main types of rock and four major types of timber. Western larch and Douglas fir grow on the north-facing slopes. Ponderosa pine dominates the south-facing slopes and bottomlands. Lodgepole pine grows throughout the eastern part of the forest.
Montana is also a good location for the study because it is still relatively pristine compared to the East Coast and other areas, Hu said.
"It's a really interesting place to understand nitrogen because we don't have these outside human systems," Hu said. "We still don't really understand how plants use nitrogen through the growing season."
She added that the high-elevation coniferous forests of the western United States are ideal for exploring nitrogen dynamics. Giving three main reasons, she said, "First, while many nitrogen studies have focused on broadleaf deciduous forests of the eastern U.S., fewer studies have examined nitrogen dynamics in western coniferous forests, where the trees have relatively high nitrogen-use efficiency.
"Second, western forests offer a unique opportunity to examine nitrogen dynamics in ecosystems where nitrogen deposition from human activity is still relatively low. Third, given the heterogeneous landscapes of western U.S. forests, it is imperative to establish the relationship between topography, water and nitrogen dynamics so that we can accurately model future species composition and productivity of forests under changing climate and nitrogen deposition scenarios."
The USDA grant is the third major award for Hu's laboratory in less than a year. Both of her graduate students -- Nate Looker and Justin Martin -- received National Science Foundation Graduate Research Fellowships in 2014. Each fellowship amounted to at least $32,000 a year for three years.
"I feel very lucky," Hu said.
Hu, herself, received two major fellowships before coming to MSU in 2013. One was a $375,000 Australian Research Council Early Career Fellowship, which allowed her to teach and conduct research at the University of Sydney for two years. Another was a $130,000 postdoctoral fellowship that funded her research at the National Center for Atmospheric Research in Boulder, Colo.
Hu has investigated a variety of ecological questions over the years as a plant ecophysiologist who studies the link between water and carbon on scales that might be as small as a leaf or as large as a forest.
In one project, she helped research the movement of water through the redwood trees that grow in northern California and southern Oregon.
In another project, Hu spent four months in Tibet where she studied the effects of climate change and land-use policies on grassland productivity. Since yaks graze on the 14,800-foot-high Tibetan Plateau - sometimes called the "Roof of the World" - part of Hu's job involved herding the animals so they wouldn't trample her solar-powered instruments.
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Hu grew up in the heart of California's Silicon Valley and earned her bachelor's degree in integrative biology from the University of California, Berkeley. She then moved to Colorado where she earned her Ph.D. in ecology and evolutionary biology at the University of Colorado, Boulder.