Tree Rings May Reveal Hidden Clues About Water History

Key TakeawaysTree rings can reveal past floods and droughtsUsing several tree species gives better water dataFindings may help protect future water supplies.TUESDAY, Dec. 23, 2025 (HealthDay News) — Trees don’t just clean the air, they also keep a quiet record of the past.New research suggests that tree rings may help scientists uncover missing pieces of environmental history, especially when it comes to water in the midwest. By studying how different tree species respond to wet and dry conditions, researchers say they can better understand how watersheds have changed over time, and how they may change in the future.Watersheds are areas of land that drain water into nearby streams, rivers and lakes. Healthy watersheds help protect drinking water, support wildlife and keep ecosystems balanced, according to the U.S. Environmental Protection Agency. But climate change can put a big strain on these systems, especially when historical data is limited.“One human lifespan is not going to show us the big picture,” study leader Alessandra Bertucci, a graduate student at Ohio State University in Columbus, said in a news release."So using trees to address these gaps of understanding is really important for managing water resources, even in intensively managed watersheds," Bertucci added.Trees typically grow a new ring each year and the size and density of those rings can reflect weather conditions such as droughts, floods and long periods of rain. But not all trees record these events the same way. That’s why the research team found that using multiple tree species gives a clearer picture than relying on just one.The study focused on riparian trees, which grow near rivers and streams in the Midwest. Researchers found that many of these trees are especially good at recording past wet and dry periods, making them useful for understanding regional water patterns.The work was recently presented at a meeting of the American Geophysical Union in New Orleans.To gather their data, researchers collected tree core samples from areas where long-term watershed records are scarce, including Ohio’s Old Woman Creek State Nature Preserve near Lake Erie. They studied three common tree species and compared ring width and density with recorded climate data.Because much of the Midwest is heavily farmed, accurate water data is critical. Bertucci said limited historical records can lead to poor estimates of past floods or droughts, which may affect decisions about water use and conservation.With the updated tree ring data, the team hopes to build models that can help predict how weather patterns and water flow may change in the coming 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,” Bertucci said.Researchers plan to expand their work by sampling more tree species and studying additional watersheds. The findings could help farmers, water managers and communities make smarter decisions about water conservation.“Water is life,” Bertucci said. “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.”Research presented at meetings should be considered preliminary, until published in a peer-reviewed journal.More informationThe Arbor Day Foundation has more on trees and water.SOURCE: Ohio State University, news release, Dec. 19, 2025.What This Means For YouStudying tree rings could help communities plan for flooding and climate change by learning from past data..Sign up for our weekly HealthDay newsletter