Researchers find trees could spruce up future water conservation efforts

NEW ORLEANS – Trees contain valuable information about Earth’s past, so much so that studying their rings may help fill in hidden gaps in Ohio’s environmental history. 

Trees are the planet’s living lungs; they remove carbon from the atmosphere to clean the air, and filter our water. Yet depending on their species, not all record long-term environmental changes, such as fires, floods and droughts, in the same way. 

By analyzing how various types of tree rings grow in response to these distinct weather-related events, researchers discovered that some can act as useful tools in managing local watersheds, that drain water into nearby streams and rivers. 

Specifically, they found that trees in the Midwest are extremely apt at recalling past wet and dry conditions, noting that using more than one type of tree’s rings to reconstruct previous environmental periods can paint a much more accurate picture of the region’s current water ecosystem.

“One human lifespan is not going to show us the big picture,” said Alessandra Bertucci, lead author of the study and a graduate student in food, agricultural and biological engineering at The Ohio State University. “So using trees to address these gaps of understanding is really important for managing water resources, even in intensively managed watersheds.“

According to the U.S. Environmental Protection Agency, healthy watersheds serve nature by helping to ensure water quality, connecting aquatic habitats and ecosystems, and shaping diverse biological communities. But when left unprotected, they eventually degrade, leading to issues like less productive fisheries and polluted drinking water.

Consequently, as the planet continues to warm and water resources are impacted, learning new ways to manage altered watersheds is an urgent priority, said Bertucci. The research was presented this week at the annual meeting of the American Geophysical Union.

While tree ring chronologies are often used to understand long-term climate changes in the western United States, the tool is often left out of similar studies of the Midwest, where large-scale agricultural production relies heavily on the health of local watersheds. Additionally, already scarce instrumental data in some areas can make it difficult for researchers to grasp historical trends in the region, resulting in misleading estimates about past events, said Bertucci. 

These hurdles motivated Bertucci’s team to retrieve tree cores from places where watershed data reporting is sorely lacking, such the Old Woman Creek State Nature Preserve near Lake Erie in northern Ohio. There, they took samples from three species of common riparian trees and will plan to compare aspects like ring width and density to real recorded climate data.

Now, with updated measurements, the team expects to be able to build models that could predict how weather and local water flow will change over the next few decades. 

“If we can round out that historical data and understand what to expect, we can better plan for how to manage our water resources in the future,” said Bertucci. These improved solutions might include helping local resource managers determine which environmental conditions to focus on accounting for when coming up with smart water-saving strategies. 

In the future, the team will work to increase the range of tree species they sample and utilize the expanded data they gather to create better reconstruction models of other important watersheds. These models may be especially helpful to farmers in the Midwest, and later on, the United States as a whole. 

“Water is life,” said Bertucci. “We literally cannot live without it, so it’s important to protect and make sure that we are taking care of it, because that is our lifeline.”

Bertucci conducted the research with Lorrayne Miralha, assistant professor of food, agricultural and biological engineering at Ohio State. 

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Contact: Lorrayne Miralha, Miralha.1@osu.edu

Written by: Tatyana Woodall, Woodall.52@osu.edu