Biomass Availability in Managed Northern Hardwoods Forests

How are landowners in upper Michigan currently managing trees on their land, and what does this mean for forest re-growth?

The Research Question

How are landowners in upper Michigan currently managing trees on their land, and what does this mean for forest re-growth? Answering questions like these is critical for understanding how much forest-based biomass may be available within a 150 mile radius of the proposed biofuel refinery in Kinross, Michigan. Management practices on state-owned forest land may be different from practices in privately owned corporate forests or family forests. This study aims to understand current forest management practices under each of these ownership types and how this might affect forest biomass availability in the area. Ultimately, this will help to determine what practices might contribute to a sustainable supply of feedstock for the Kinross biofuel refinery, now and into the future.

 

The Research Approach

To compare current forestry practices across different ownerships in upper Michigan, several study sites were located in forests under three different ownerships. Sites are either in State Forests managed by the Department of Natural Resources and Environment (DNRE), on privately owned family forest land, or corporately owned forest land. This study included over 60 forest stands within 150 miles of the Kinross refinery that are at least 20 acres in size and have undergone a harvest within the last 6 years. All of the sites were in northern hardwood forests, which are composed of sugar maple, hemlock, white ash, yellow birch and several other species.

In this study, the process for determining available biomass involved a series of steps. First, researchers looked at the forest conditions for each site to determine how much biomass was there and what type of harvest practices were taking place. Next, researchers determined how much biomass was removed in the latest harvest by looking at data from before that harvest. Using these measurements from the past and present, they predicted how much biomass may be available in the future by looking at projected tree growth. Finally, they can looked at whether there were differences in these measurements between forests under different ownership types.

 

Progress and Results

Final Project Report:

Northern Hardwood Management in Michigan