Montana State Ecologist To Examine Response Of Grassland Forage To Climate Variability

Bozeman – For agricultural producers around the state, forage plants are a key element of cattle grazing as well as helping maintain soil nutrition, preventing erosion and providing a food source for wildlife. Now, funding from the U.S. Department of Agriculture's National Institute for Food and Agriculture, or NIFA, will let a Montana State University scientist begin exploring how those crops respond to changes in water availability.

Andrew Felton, College of Agriculture's Department of Land Resources and Environmental Sciences assistant professor, plans to see how the timing of precipitation throughout the year influences the growth of forage crops, which include grasses, shrubs and flower species consumed by grazing animals. Alongside colleagues from the University of Nevada, Reno and Chapman University, he will analyze the water inside plant samples to determine when that water fell as rain or entered the ecosystem as snowmelt. In this way, the team will trace the seasonal origin of water used by different forage species.

"There's been a lot of research on the drivers of variation in forage growth from year to year. The common wisdom is that it's primarily driven by variation in growing season rainfall," said Felton. "But when you do that correlation, you see that there's a ton of unexplained variation. It hasn't really been mechanistically demonstrated where the water those plants are using originated."

Felton's project is one of 26 proposals nationwide funded through a competitive process by a NIFA program focused on sustainable agroecosystems. The work received nearly $300,000 out of a total of $12.7 million spread across the country. The work will include three broad sections, Felton said.

The first of those research sections involves field work at sites around Montana, Colorado, Nebraska and North Dakota to collect forage crop samples. Felton said that while the region is one of the largest intact grassland ecosystems left in the world, this element of it is surprisingly understudied.

"There's been a lot of focus on the tall grass prairie in the southern and central plains, but it seems to me that far less is known about the northern plains," Felton said. "And that's interesting because it's so expansive and intact. There's a lot of basic knowledge about this whole eco-region that we really know relatively little about."

Once the field samples are collected, Felton will work with collaborators in Nevada and students in his own lab to conduct isotopic analysis on those samples. That process examines the chemical makeup of the water in the crops to identify when that water originally came into the ecosystem - whether through summer rain or spring snowmelt.

"The water in snow and the water in rain have different isotopic signatures," said Felton. "You can analyze the water in the plant tissue and also in the soil itself to understand where that water originated. Once we analyze that data and understand where the water is coming from, we'll see if we can link that to larger patterns of drought sensitivity observed through remote sensing."

Geospatial analysis and remote sensing make up the third element of the project. Because agencies like NASA have conducted global satellite observation for more than 30 years, Felton said, historical data on drought and forage cover in large areas like the Northern Great Plains are easily accessible. He hopes that comparing the chemical analysis of the forage samples with historic data about rain, snow and forage growth will provide a more nuanced look at the response of important forage crops to changes in precipitation patterns.

The study will also see whether plants experiencing drought stress can adapt and use other water sources instead of the ones they are used to. That flexibility in accessing water in a time of stress could help to identify which forage crops are best for Montana's increasingly variable climate and precipitation patterns. If a particular plant is less adaptable, it may not be a good option for producers.

Felton plans for this initial NIFA funding to establish a long-term research program at MSU involving graduate and undergraduate researchers, potentially leading to the creation of resources and recommendations for Montana producers who rely on forage crops to feed their livestock.

"The information this will produce could be of use to folks who are managing their systems within unpredictable and variable weather patterns," he said. "Summers are expected to get drier, and if you know the types of vegetation that are most flexible and the types of water they use, you can select for using that vegetation when you're grazing on forage."

While the funding is new and Felton himself is a recent addition to MSU's faculty – he arrived in fall 2022 – he can already see the potential for a far-reaching project to benefit students, scientists and agricultural producers around the state and region.

"The investment of the USDA in this grant will hopefully return dividends not only in the research but also in the training of new young scientists," he said. "What I really like about the project is that it's very integrative. It combines field, lab and remote sensing approaches. It's facilitating these collaborations across the western U.S. and it'll help me build my lab here at MSU. I'm really excited about the idea, and I think it will help facilitate a lot of wider success."


Reader Comments(0)