Study To Forecast Ecological ‘Tipping Points’ For US Wetlands

Scientists with Texas A&M AgriLife Research are leading a NASA-backed effort to develop a predictive tool that could transform how the U.S. approaches wetland conservation.

The study is a three-year, $897,000 grant project funded by NASA’s Ocean Biology and Biogeochemistry program, which monitors short- and long-term changes here on Earth. The study also includes collaborators from Pennsylvania State University.

Together, the researchers are analyzing “big data” sets, including satellite imagery and 25 years of weather data, to detect early warning signs of decline in tidal wetlands across the country. The goal: identify ecological “tipping points” before they become irreversible.

“Each year, billions of dollars go toward wetland restoration and protection,” said project lead Rusty Feagin, Ph.D., AgriLife Research professor and ecologist in the Texas A&M College of Agricultural and Life Sciences Department of Ecology and Conservation Biology. “We want to help public agencies and private landowners be more strategic, investing where recovery is possible and pulling back where the damage is already done.”

Feagin, who also holds an adjunct appointment in the Department of Ocean Engineering in the Texas A&M College of Engineering, and his multidisciplinary team, including assistant professor Wenzhe Jiao, Ph.D., will assess 1.45 million coastal sites, from salt marshes and mangrove forests to tidal swamps and freshwater marshes.

‘Big Data’ To Predict Tipping Points In Tidal Wetlands

Feagin compares an ecological tipping point to a boulder lying at the apex of a steep hill, because a single push can send the boulder down either side of the hill. One side could result in conversion to dry land, whereas the other side could turn the wetland into open water.

In tidal wetlands, numerous human-related and natural factors can push wetland systems toward the apex that leads to dry land, which can leave them vulnerable and teetering on the edge of converting into water.

At the tipping point, any small stressor can then push the wetlands over the edge. For example, a long drought might lead to the wetlands slowly weakening and on the edge of survival, and then a hurricane might push them over the edge into death. The combination of these factors over consecutive years can dramatically alter an ecosystem’s vegetative resilience.

Feagin and team will utilize big data to achieve three primary goals:

• Identify when tidal wetlands transition from healthy to degraded states.
• Detect smaller, cumulative stress-signals, or micro-tipping points, that often precede major changes.
• Predict future vulnerabilities to inform timely intervention.

Feagin hopes to give NASA a new tool that identifies and predicts tipping points to help decision-makers invest restoration and remediation funding where it can help the most.

Tidal Wetlands Play An Important Role

Tidal wetlands play an outsized role in global ecology and are considered the most productive and economically valuable ecosystems on Earth, Feagin said. They represent an integral part of the ocean food web, capture more carbon dioxide than rainforests and act as protective buffers for human infrastructure during oceanic storms like hurricanes. 

“These ecosystems are very important and very resilient, and this tool will help public agencies and private landowners prioritize action before they are pushed too far,” he said.