Minnesota Dept. of Natural Resources: Sawbill Hardwoods

Yes
Evaluation

DNR staff from the Divisions of Forestry and Fish and Wildlife worked together on this project idea at a Forest Adaptation Planning and Practices workshop in the summer of 2015. The timber sale was intially designed in 2012. This site has been harvested and planted, and now follow-up monitoring is continuing in partnership with The Nature Conservancy and University of Minnesota-Duluth. This project was one of the stands selected in TNC's "Adaptation Forestry in Minnesota's Northwoods" project, funded through a Wildlife Conservation Society grant.  

Staff from the Minnesota Dept. of Natural Resources (DNR) used the Adaptation Workbook at a 2015 workshop to consider climate change risks and adaptation actions for a 57-acre northern hardwoods stand in northeastern Minnesota. The stand has been harvested and planted with a mix of climate-adapted species, and monitoring continues.

Project Area

The DNR's Sawbill Hardwoods project occurred on a 57-acre stand of northern hardwoods in northeastern Minnesota. This stand is representative of a narrow band of northern hardwoods that parallels Lake Superior in this portion of the state. Prior to the project, this stand was 85-90% sugar maple and was lacking structural and species diversity.

Management Goals

The DNR's management goals for this northern hardwoods stand are similar for their goals in this forest type across the region. The goal is to increase species diversity and structural diversity while maintaining a healthy and productive forest.  Specifically, the management objectives in this stand were to thin the stand down to 80 BA and to install several irregular canopy gaps. The gaps were created by harvesting mature paper birch, with the idea that the gaps will allow for natural regeneration of paper birch and also other shade-intolerant and mid-tolerant species (yellow birch, basswood, northern red oak, white pine, white spruce). 

Climate Change Impacts

For this project, the most important anticipated climate change impacts include:
milder winters and reduced snowpack may increase the deer population in the area, which will increase browse pressure
reduced soil moisture may stress mesic species such as sugar maple and yellow birch

Challenges and Opportunities

DNR staff considered key challenges and opportunities from climate change, including:

Challenges

increased deer browse may make it difficult to regenerate oak on this site
more frequent droughts may stress species like paper birch and sugar maple

Opportunities

a longer growing season could benefit northern hardwoods species in this part of the state
this stand has a mix of southern and northern exposures, so there is opportunity to pick good "micro-sites" that could retain more moisture

Adaptation Actions

Project participants used the Adaptation Workbook to develop several adaptation actions for this project. They found that many of the actions already planned for this stand have great win-win benefits for climate adaptation. After this site was intially harvested, the DNR was contacted by the Nature Conservancy (TNC) and this site was selected for follow-up planting with a mix of climate-adapted tree species: white pine, bur oak, and northern red oak. TNC arranged the planting of 40 seedlings of these species to be planted across the site, including 20 from the local seed zone and 20 from a seed zone further south in Minnesota. This follow-up planting added to a mix of adaptation actions on the site.  

Area/TopicApproachTactics
Northern hardwoods
1.4. Reduce competition for moisture, nutrients, and light.
2.1. Maintain or improve the ability of forests to resist pests and pathogens.
Thinning the stand down to 80 BA
5.1. Promote diverse age classes.
Installing several canopy gaps to encourage natural regeneration.
5.1. Promote diverse age classes.
9.1. Favor or restore native species that are expected to be adapted to future conditions.
Planting seedlings within the canopy gaps and throughout the site, including white pine, bur oak, northern red oak, and basswood.
Match plantings to micro-site characteristics. For example, plant more oaks on south-facing slopes.
8.2. Favor existing genotypes that are better adapted to future conditions.
Plant a portion of each species from seed zones further south in Minnesota and also Michigan.

Monitoring

Project participants identified several monitoring items that could help inform future management. The Nature Conservancy and the University of Minnesota-Duluth are collaborating on this project and designed several of the planting sites as rigorous research plots. Some of their monitoring items include:
Survival and growth of planted seedlings, particularly seedlings from southern seed zones
Phenology of seedlings from local seed zones compared to southern seed zones

Project Photos

Click to enlarge photos

A bud-capped oak seedling at the Sawbill Hardwoods site. Photo credit: Chris Dunham, TNC.

Project Documents

Next Steps

Initial regeneration checks have been completed on this project, as well as 1st-year monitoring of planted seedlings. This monitoring will continue in partnership with TNC and UMD. TNC may also be responsible for follow-up maintenance on the site, such as releasing planted seedlings from competition. One of the take-home lessons from this project for the Minnesota DNR is that is is really helpful to work with external partners like TNC to design and implement complex planting projects. Additionally, in future projects DNR staff will likely prepare two separate planting proposals for a site (one for planting in the gaps, one for planting across the site) in order to reduce confusion.

Learn More

Keywords

Upland hardwoods, Assisted migration, Planting, Research

Last Updated

Thursday, October 27, 2016