Fungal disease fight gets airborne
While an emerging fungal disease continues to chip away at the forestry industry in the southern United States, remote sensing researcher Hamdi Zurqani is developing artificial intelligence models to seek answers from the skies.
“My job is to identify different stages of mortality,” said Zurqani, assistant professor for the College of Forestry, Agriculture and Natural Resources at the University of Arkansas at Monticello.
Using aerial imagery obtained from drones, Zurqani said he is developing tools that give landowners and other stakeholders the information they need to manage this growing threat to the forestry industry.
By applying geospatial artificial intelligence techniques, Zurqani said he can assess how many trees have been affected by the disease.
“How many trees have already died? How many trees may be in the early stage that are going to get worse? How many trees are still green?” he said.
Since summer 2022, foresters and researchers have been fielding calls about pine decline in Arkansas. Pine decline is a convergence of environmental and genetic issues that cause tree health problems in pine forests. Results from diagnostic tests in July 2023 confirmed that a fungal disease called brown spot needle blight is at least partially to blame.
“It’s kind of nipping away at pine forests,” said Michael Blazier, director of the Arkansas Forest Resources Center and dean of the College of Forestry, Agriculture and Natural Resources. “Although there are pockets of dying trees within affected forests, a bigger issue could be slower growth of infected forests.”
Blazier said that when trees lose their foliage, as often happens with the needle blight disease, they have less energy to invest in growing their trunk diameter. Less trunk growth means less wood production and delayed harvest.
Understanding the how and why of brown spot needle blight
remains the primary focus for researchers in Arkansas and the wider region, Blazier said. That’s where Zurqani’s work comes in.
“If we were able to identify the early stages of the disease, we can somehow get a clue about what’s going to happen in the future,” Zurqani said.
In Arkansas, Blazier said the fight against pine decline has been highly collaborative. The Forestry Division of the Arkansas Department of Agriculture and the Arkansas Forestry Association have been working closely with the Arkansas Forest Resources Center, which conducts research and extension activities through the Arkansas Agricultural Experiment Station and the Cooperative Extension Service, the University of Arkansas System Division of Agriculture’s research and outreach arms.
“We have a tight working relationship between all of those agencies,” Blazier said. “There’s been excellent communication between the university, extension service, forestry association and the state’s forestry division.”
REGIONAL CHALLENGE
In August 2023, Blazier attended a meeting at Auburn University to discuss the needle blight phenomenon with researchers and industry stakeholders from across the southern U.S.
According to information from the U.S. Department of Agriculture’s Forest Service, brown spot needle blight has been confirmed in nine states, including Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, South Carolina, Tennessee and Texas. Severe damage, however, has so far been limited to Alabama, Arkansas, Louisiana and Mississippi.
The meeting was organized by Lori Eckhardt, professor and director of Auburn University’s Forest Health Cooperative.
“I organized this meeting to bring together industry, government, academia and private landowners to create a space in which attendees can discuss questions, brainstorm ideas, identify problems and make decisions and develop solutions pertaining to brown spot needle blight,” Eckhardt said.
“Collaboration is important between the researchers and the landowners,” she said. “The day-to-day managers in the field can share knowledge that assists us as researchers in asking good questions to design studies that better help us understand and manage the disease. Working together will help us find answers sooner.”
COLLABORATION LEADS TO CLUES
Blazier said the Auburn meeting provided an opportunity for participants to share what actions each affected state is taking on the research side to understand what’s causing the problem.
“One of the things that was shared at the Auburn meeting was some anecdotal evidence from the forest industry showing that there may be a soil nutrient facet to this,” Blazier said. “And that’s actually something that we are looking into further within the Arkansas Forest Resources Center.”
Researchers have been collecting samples this winter from stands of trees affected by pine decline and analyzing nutrient levels. If a nutrient deficiency is found to contribute to pine decline, Blazier said that targeted soil fertilization might be a way to fight the disease.
“And that would actually give us another tool,” he said.
LOOKING TO THE FUTURE
As the winter dormant season ends and the life cycles of fungal diseases pick up again, Blazier said that testing for pine decline will continue next month.
“We’re going to resume testing on a monthly basis as a group in February, and we’ll continue that all the way through the growing season,” he said.
That information will continue to feed into Zurqani’s research efforts using geospatial AI. Blazier sees hope for spatial analysis and machine learning tools to help researchers identify patterns in the data and get to the bottom of pine decline.
“We’re really optimistic,” he said.
To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https:// aaes.uada.edu/.