College of Agriculture & Natural Resources Department of Forestry

A grant from the United States Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) will allow Michigan State University (MSU) researchers to understand why oak species – whose regeneration is a major challenge in hardwood forests -- regenerate well under red pine plantations. Furthermore, the research will develop silvicultural best practices for oak management and evaluate the potential benefits of gradually converting red pine plantations into oak-dominated forests across the Lake States as the regional climate warms.

Akihiro Koyama, Ph.D., and Andy Vander Yacht, Ph.D., of the Department of Forestry received the grant for $499,501 through the USDA NIFA Agriculture and Food Research Initiative – Foundational and Applied Science Program.

“The aim is not to eliminate profitable red pine plantations but demonstrate how they create perfect conditions for promoting oaks – a group of ecologically and economically important tree species expected to perform better regionally under predicted changes in climate,” said Vander Yacht.

The four-year project, in collaboration with Michigan Department of Natural Resources, and partly carried out at MSU’s W.K. Kellogg Experimental Forest and Tree Research Center, has three major goals. An immediate goal is to use field and greenhouse experiments to better understand why oak regeneration is often more successful under red pine than under oak overstories.

Young oak trees rarely survive to adulthood under mature oaks that dominate forests across the Lake States, but often thrive in the understories of red pine plantations. Several potential mechanisms may explain the differential success of oaks under red pine and oak canopies, including light availability, frost protection, and symbiotic and antagonistic soil microbes. Definitively assessing how each of these mechanisms contribute could help develop new silvicultural techniques for regenerating oak forests. 

“Despite our difficulty in regenerating them on all but low-quality sites, oaks are an important regional resource,” said Koyama. “They provide habitat and mast (acorns) to wildlife, support more insect diversity than any other group of tree species and contribute substantially to Michigan’s timber products industry, which has an economic impact of more than $21 billion.”

The second goal of the grant is evaluate the potential economic and ecological advantages of gradually converting red pine plantations to oak-dominated stands as the climate warms.

Michigan currently occupies the southernmost distribution of red pine and the northernmost distribution of many oak species. As the climate warms, these native ranges will likely shift northward and oak species could outperform red pine across much of Michigan. Computer simulations using collected data will model resource inputs, economic outputs, forest productivity, and carbon sequestration under three management (no planting, underplanting red pine and underplanting oak) and three future climate scenarios (no warming, conservative warming, high warming). Model comparisons will allow researchers to chart the most sustainable path forward for regional forest management.

“Imagine our region’s forests as a patchwork quilt. Right now, making all the patches red pine plantations is tempting – they grow fast and generate high economic return – but the quilt needs to be passed to future generations. Patches where red pine currently grows may be the best places to promote the oak patches that will better sustain the future ecological and economic integrity of the quilt,” said Vander Yacht.

The final and long-term goal of this research is to synthesize all results into silvicultural guidelines capable of optimizing oak establishment in red pine plantations and the associated benefits of such action as the climate warms. This information should be extremely valuable to land managers and owners as they plan for the future of forests and related industry across the Lake States region.