IU's data-gathering tower in Morgan-Monroe State Forest earns future funding
BLOOMINGTON, Ind. -- Scientists around the world have never been more interested in understanding and monitoring carbon dioxide exchange between the atmosphere and forest ecosystems, given the role of forests in storing carbon and reducing climate warming. An important tool in that process -- a 150-foot tower in Morgan Monroe State Forest owned by Indiana University -- has been recognized as one of the most important sites for gathering that data.
Since 1998, what IU scientists call the MMSF Flux Tower has been providing data on the things everyday weather-watchers are interested in, like relative humidity and air temperature. But it also provides highly refined information like carbon dioxide flux and photosynthetically active radiation that are of interest to some of the world’s leading climate and ecosystem scientists.
The tower is one of nearly 1,000 similar towers operating around the world as part of the Fluxnet network, and among more than 120 operating across North, Central and South America as part of the AmeriFlux network. Now, IU’s MMSF tower, the second-longest-running carbon dioxide flux monitoring site in the world, has been identified as one of just 11 core data-gathering sites by the AmeriFlux network. The MMSF tower was chosen based on the quality and longevity of data collected from the site, and on how representative its ecosystem processes are compared to other tower sites.
The new designation will ensure support for the maintenance of the tower and processing of data through September 2015, and likely well into the future. The funding comes from the AmeriFlux Management Project, funded by the U.S. Department of Energy. Research activities of IU scientists currently working at the site are supported through the Department of Energy’s Terrestrial Ecosystem Science program, the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration and the National Science Foundation.
It will also mean the spotlight will increase on the scientists, the data and the resulting research produced from a monitoring location that has already helped researchers produce more than 60 different research papers over the past decade, which collectively have been cited more than 1,500 times.
Kim Novick, an assistant professor in the IU School of Public and Environmental Affairs, said that understanding how forests like Morgan Monroe remove carbon dioxide from the atmosphere is important because that information will be used to inform present-day carbon budgets on regional to global scales. As a core site in the AmeriFlux system, the MMSF tower will also become a leader in developing new measurements and techniques for use across those larger networks.
“This designation is a reflection of the foresight researchers at Indiana University had to establish a tower site early on for the study of ecosystem and atmospheric interaction,” Novick said. “It also goes directly to not only the quantity but also the quality of the data and the research that has since been produced from the site.”
The tower was constructed in the late 1990s. In its early years, operations were managed by IU Department of Geography faculty members Hans Peter Schmid, Danilo Dragoni, Sue Grimmond and Sara Pryor, and SPEA professor J.C. Randolph. The tower is collaboratively operated by faculty, post-doctoral scientists, technicians and students in SPEA and the IU Bloomington College of Arts and Sciences’ departments of geography and biology.
Instrumentation on the tower that measures the balance between how much carbon dioxide is taken up by trees through photosynthesis or released by the forest through the respiration of trees and soil microbes is recorded in timescales of less than a second.
“That type of refined data, gathered over years and even decades, can lead to findings of interest not only to scientists but to landowners, the forest industry and to Indiana citizens in general,” said Faiz Rahman, an associate professor in IU’s Department of Geography.
Some of those key findings include:
- Warmer temperatures from 2000 to 2012 have led to longer growing seasons (or when the trees have green leaves).
- At the same time, the forest has been getting drier, with less water in the soil and drier air.
- From 2000 to 2008, longer growing seasons meant more carbon uptake. As the forest has gotten drier and drier, there have been declines in carbon uptake despite having some of the longest growing seasons on record.
- The 2012 drought was exceptional in two ways: timing and severity. Arriving earlier and more severe than typical droughts, it led to the third lowest annual carbon uptake even though it had the longest growing season by about 20 days.
- A drier forest has led to trees stopping their growth earlier in the growing season and producing less wood overall.
IU assistant professor of biology Rich Phillips said that measuring carbon dioxide exchange in ecosystems through the eddy flux measurement -- the continued short-term measurement of flux densities based on vertical transport of mass, momentum and energy per unit area and time -- has become the standard for identifying ecosystem productivity. He also said there has never been a more opportune time to have access to one of the most comprehensive data-gathering systems for carbon exchange available.
“Flux towers have become an integral part in how we measure carbon dioxide, methane and carbon monoxide, and data from these sites are being applied in ecology, weather forecasting and climate studies,” Phillips said. “It’s quite an honor to be recognized for having a key site that is playing a critical role in the analysis of terrestrial water and carbon dynamics, and that our top-down look at forest growth is being used to understand the general principles of ecosystem behaviors around the world.”