Auburn researchers innovate with downed timber harvest, uses

Forest landowners in the Southeast were reeling from the devastation of Hurricane Michael when faculty in Auburn University's College of Forestry, Wildlife and Environment (CFWE) sought methods to recover and utilize downed timber. 

With the recent devastation of Hurricanes Helene and Milton and the increased frequency and severity of such weather events, the importance of this work is more paramount than ever. 

In Georgia alone, Helene impacted 8.9 million acres, with the timber resource impact estimated at $1.28 billion, per the Georgia Forestry Commission. And damage to western North Carolina’s abundant hardwood forests will impact that state in other significant ways.  

These numbers make the downed timber research of five CFWE professors even more invaluable to sustainable recovery efforts and support for landowners and the environment. Their ongoing research is funded by a $1.05 million federal appropriation to the U.S. Forest Service, an agency of the United States Department of Agriculture. 

The need for downed timber innovation  

From the perspective of a landowner, Assistant Professor and Extension Specialist Richard Cristan considered the need for innovation in harvesting and utilizing downed timber.  

“Financial losses from timber damage are high for landowners,” said Cristan. “Recovering downed timber from events like hurricanes is challenging. Landowners must harvest within two to three months due to pine bark beetles, other woodborers and fungi impacting timber quality.”  

He adds that financial return for salvaging downed timber is lower than harvesting undamaged timber, and following a weather event, timber markets are flooded, limiting how much timber mills can accept.  

“This ultimately impacts how much timber can be recovered, leaving landowners looking for other options,” said Cristan.  

Assessing impact of catastrophic events 

The need to develop a faster, safer, more efficient and accurate approach to assessing and mapping storm-damaged timberland is the driving force behind Cristan’s research on the use of unmanned aerial vehicle (UAV) technology to understand the pattern, nature and severity of damage following windstorms.  

“This research showed the feasibility and advantages of using UAV LiDAR with UAV-derived RGB imagery in evaluating the impact on storm-damaged forests,” said Cristan.  

Cristan believes the research will enable foresters and other forestry professionals to quickly make informed decisions on salvaging timber and reforestation efforts, providing societal, environmental and economic benefits for landowners and hopes they adopt the UAV technologies for this purpose.  

Efficient, affordable harvesting  

Tom Gallagher, professor emeritus and former Regions Professor of forest operations, focused his research on harvesting downed timber more efficiently and thus utilizing more of the downed timber in a functional way.  

“Current feller-bunchers used in the Southeast are very efficient for harvesting standing trees,” said Gallagher. “But if the trees are already on the ground, they are challenging to harvest. Our idea was to develop a felling head with a small boom able to reach and gather the downed trees.” 

Gallagher also strived for this new felling head to be able to attach to existing machinery, which is cheaper than purchasing new machinery, creating “a safer and more efficient way to recover timber that is easier for the logger and more cost-effective for the landowner.”  

Classifying downed timber uses   

While Gallagher focuses on harvesting downed timber, Brian Via, the Regions Professor of forest products, researches the characterization of the downed timber quality before going to the lumber mill. 

Via’s research seeks to provide efficient methods of classifying which timber can be used for high-value applications, like cross-laminated timber, and which can be used for lower value products, like wood composites.  

“We hope that rapid assessment tools like acoustics and near-infrared spectroscopy can be used in the field to determine the ‘health’ of the tree for different product streams,” said Via.  

This research will benefit landowners by allowing them to affordably assess the most feasible use of downed timber before beginning recovery efforts after major weather events.  

Considering value-added products  

Following the assessment of downed timber health, researchers must next consider how downed timber can be used in the manufacture of value-added products. Yucheng Peng, assistant professor of sustainable packaging and bioproducts, focuses his research on exploring this issue.  

Peng’s research seeks “to understand the behaviors of wood polymer composites using wood materials generated from downed timber with different tree maturities and environmental exposure periods.”  

By studying this, Peng hopes to determine the downed timber collection time window for its utilization in manufacturing wood polymer composites — in other words, how quickly the downed timber needs to be harvested for optimal performance in later product uses.  

Impacts of this research clearly benefit forest landowners by finding new markets for the use of downed timber, minimizing the economic losses caused by hurricanes and tornadoes.  

“The environmental benefit is to promote the use of downed timber in products with longer life spans to sequester the carbon stored in forests for applications in construction, automobile and packaging industries,” said Peng.  

Developing new downed timber markets    

Soledad Peresin, associate professor of forest biomaterials, addresses two major environmental challenges with her research: developing new markets for hurricane-downed timber and reducing the growing frequency of annual wildfires, often fueled by downed trees.  

Like Peng, Peresin contributes research that seeks innovative approaches to repurpose downed timber, converting it to valuable products.  

Most specifically, Peresin seeks to create efficient, scalable and cost-effective methods to convert downed timber into micro/nano materials (CNMs) and to consider if integrating CNMs can improve performance characteristics of food packaging materials.  

“This research could create a more sustainable and economically viable approach to forest resource utilization and food packaging,” said Peresin. “It addresses critical environmental concerns while potentially opening new economic opportunities and improving food safety standards.” 

Enhancing timber industry’s resilience 

At the core of all this research is the desire to enhance the timber industry’s resilience and sustainability, particularly in hurricane-prone areas. These researchers seek to give new life to downed timber, supporting forest landowners and innovating value-add products in the process.  

“This research project is highly relevant to sustainable forest management in the state and region,” said Daowei Zhang, CFWE associate dean of research and the George W. Peake Professor of forest economics.  

“It has all the components — assessment, recovery, classification and new products and markets — for quickly salvaging downed timber and enhancing landowner income. Its social and environmental impacts are largely positive, and its economic impact could reach hundreds of millions of dollars.”