Single Tree Selection

An example of single tree selection at work in a forest. Credit: Wisconsin DNR

Single tree selection is a natural regeneration system that was pioneered here in the Lake States. Used primarily in northern hardwood forests, single tree selection is a cutting method designed to regenerate and maintain uneven-aged stands. Single tree selection stands are maintained at each stand entry by establishing or releasing seedlings and saplings, tending trees to enable quality tree development and harvesting mature trees to create growing space for new age classes. To learn more about this regeneration method, check out the Generally Accepted Silvicultural Principles publication.

Seeing the Forest for More Than Just Trees

The following was adapted from a Wisconsin Natural Resources magazine article.

By Colleen Matula, Wisconsin Department of Natural Resources (DNR) Forest Ecologist/Silviculturist and Patricia Alexandre, Former Forest Ecologist/Silviculturist

Wisconsin’s Forest Habitat Type Classification System (FHTCS) is an ecological classification tool developed in 1988 by John Kotar, a former scientist and instructor at UW-Madison. The FHTCS is based on repeatable patterns of forest understory plants present across similar sites.

Plant composition and growth are determined by site factors, including soils, topography, landform, hydrology and disturbance history. Together these factors represent the foundation of each unique habitat type.

Habitat typing helps foresters make decisions on the ground. This science-based tool can confidently predict how the forest will respond to different management treatments such as thinning, harvesting, and prescribed burning.

Each year in June, when understory plants are in bloom and easy to identify, new foresters from the Department of Natural Resources, county forests and other organizations receive two-day training on the habitat classification system. Continue reading “Seeing the Forest for More Than Just Trees”

Planting and Seeding Trials In The Wake Of Ash Decline

Swamp White Oak seedling planted in a black ash replacement trial. Credit: Wisconsin DNR

The emerald ash borer (EAB) is causing widespread mortality of both upland and lowland ash. Black ash (and to a lesser extent green ash) is a forest wetland species that helps prevent sites from swamping through evapotranspiration. With the loss of ash in these systems, forest practitioners are developing silvicultural strategies to minimize the impacts through planting and seeding trials.

Using Forests to Protect Species of Greatest Conservation Need

Some species of greatest conservation need (SGCN) in Wisconsin require a forested landscape diverse in structure, composition, function and complexity. Both young forests with particular habitat characteristics and old forests with more complex structures and species composition are necessary to meet the life cycle and habitat needs of SGCN species. This allows those species to grow and maintain their populations into the future.  Continue reading “Using Forests to Protect Species of Greatest Conservation Need”

Ecological Landscapes of Wisconsin

Wisconsin forests are incredibly diverse in species composition and structure, mainly due to glaciation that occurred until 11,500 years ago across much of the state. Glaciation in Wisconsin reached its maximum extent nearly 21,000 years ago.

To help guide management decisions and considerations, Wisconsin is divided into 16 ecological landscapes defined by the vegetation, climate, geology and hydrology in each ecological unit. Information about each ecological landscape is available on the DNR website in the landscapes topic.

Ecological Landscapes of Wisconsin. Credit: Wisconsin DNR

Wisconsin Silviculture Trials

The Wisconsin Silviculture Trials Directory was created in 2002 for foresters to document silviculture trials and share results and experiences with their peers. It is a way of documenting non-research trials in applied forestry. A trial site often visited during training sessions is the Nebish Lake oak burn. Here a forester established an oak shelterwood in 2008, followed by a prescribed burn in 2011. The results showed that fire could set back competition while creating a favorable seedbed for oak regeneration.

Nebish Oak Shelterwood burn with comparison of the left side that was burned and right side that was not burned. Credit: Wisconsin DNR

Forest Growth, Removal And Mortality

Forest growth, removal and mortality are indicators of forest productivity. Each forest type in Wisconsin differs in productivity based on many factors such as silvics, demand for products and overall management. Recent data from the U.S. Forest Service shows that aspen, being a short-lived species, currently has the highest mortality rate of the top ten species while eastern white pine is increasing in growth and volume.

White pine regeneration under a managed old-growth white pine at Uhrenholdt Demonstration Forest. Credit: Wisconsin DNR

Managing For Old-Growth Forests

Old-growth forests are unique ecosystems that were historically abundant across the forested regions of Wisconsin but have now dwindled to about 1% of their original presence. Realizing the importance of old-growth forest structure and composition, the Wisconsin Department of Natural Resources (DNR) and U.S. Forest Service (USFS) partners initiated a study in 2004 to look at silviculture methods to maintain and enhance old-growth characteristics. The Managed Old Growth Silviculture Study (MOSS)  continues today on public lands in northern Wisconsin including the Flambeau River State Forest, the Northern Highlands – American Legion State Forest and the Argonne Experimental Forest (located within the Chequamegon – Nicolet National Forest). The main goal of this study is to develop forest management techniques that accelerate the development of structural and compositional complexity in second-growth northern hardwoods.

Wisconsin DNR forest research crew collecting old growth data. Credit: Wisconsin DNR

A forester explains the values of old growth in a Hemlock stand near Woodruff. Credit: Wisconsin DNR