Nature & Science

The Science and Practice of Winter Logging

Over the years, Hiawatha National Forest staff have worked closely with local loggers to refine techniques that allow over-snow winter access to forested wetlands while protecting the soils beneath.  

"Hiawatha National Forest is often referred to as 'the Great Lakes National Forest,' primarily because the forest lies adjacent to three of the Great Lakes," said US Forest Service forester Martha Sjogren. "But the nickname is also appropriate because over 40% of the Forest’s land mass is classified as wetland.”

She explained that the term "wetland" is a broad description covering a range of habitat types from “somewhat poorly drained” soils to marshes and lakes. Some of those wetland acres don’t grow trees and aren’t managed for timber but many of the forested wetlands are managed for a combination of timber and wildlife habitat reasons. These areas are only accessible to loggers during winter.  The Eastern Upper Peninsula has a long tradition of successfully managing these forested wetlands by accessing the areas in the winter.

In order to protect national forest resources, over the years the US Forest Service has worked closely with the UP timber industry and researchers to test and improve techniques. For instance, in the story below, you'll learn about a winter logging research project conducted in 2008 and 2009. In 2018, Hiawatha National Forest foresters Martha Sjogren and Eric Raikko arranged a field demonstration during which US Forest Service employees and loggers visited four sites where winter logging is being utilized to see the effectiveness, impacts, and challenges of these kinds of logging operations. In 2019, the Forest made a short video to highlight a few techniques used in "winter ground".

“In order to protect soil and water quality, prescriptions for vegetation treatments in areas with somewhat poorly drained soils include an operating requirement of 6 inches of frost or 12 inches of compacted snow (or a combination of the two),” said Sjogren, who is the Timber Management Assistant for the Hiawatha National Forest’s East Zone. 

This combination of frost, snow, and the use of slash, actually supports the logging equipment so that, for the most part, they are able to stay out of the muck, "floating" on a layer of snow an brush while harvesting trees.

According to Eric Raikko, Forest Service Representative for the Hiawatha’s East Zone, “Monitoring data shows that we have really good results in terms of revegetation, even when some soil disturbance was evident.”

When there is adequate snow cover and the ground is frozen, soil disturbance from logging equipment can be greatly reduced. 

“We think it's helpful for people to understand the steps logging operators take to work lightly on the land during winter operations. Without their efforts, it would be harder for us to manage the national forest,” said Raikko.

 

Hiawatha & USFS Technology Center Conduct Winter Logging Study 2008-2009

Currently, a variety of methods are used to protect soil resources during management operations. One recommended method is for use when logging during winter conditions, particularly for wet sites.

In a joint project with the San Dimas Technology Development Center, a pilot study is being conducted on the Hiawatha National Forest (UP-Michigan) to identify suitable winter logging guidelines that can extend the treatment while minimizing impacts to soil resources.

The objectives of the study were to:

1. Identify and test robust indicators of soil conditions including frozen ground, and/or snow conditions by measuring soil temperature, soil moisture, air temperature, and snow depth;

2. Correlate the above and below ground indicators with the mechanical operations used during the treatment; and

3. Develop low-cost, science-based guidelines that can be easily identified in the field by the sale administrator and logger.

A variety of methods were used to collect information on site conditions. First, in fall of 2008, pre-harvest monitoring was conducted to assess site condition and bulk density. During harvest, frost tubes and data loggers were used to collect on-going information regarding the air and soil temperature and moisture status. Also during harvest, data was collected on compacted and uncompacted snow depth, and depth of frost in soils on and off skid trails. The stands will be evaluated again in the 2009 field season to assess post harvest disturbance and compare it to the data collected during harvest operation.

Like all successes, many people worked together to make this project happen, including personnel from the Hiawatha National Forest Soils/Watershed and Timber Programs, the San Dimas Technology and Development Center, Rocky Mountain Research Station, and Michigan Technological University. Furthermore, during the field assessment, two Soil Scientists from the Chequamegon-Nicolet National Forest helped evaluate the data sheets and field conditions.

It is proposed to extend the study to other Forest Service units in the coming years to assess conditions on a wider range of sites and climatic conditions.





https://www.fs.usda.gov/detailfull/hiawatha/learning/nature-science/?cid=STELPRDB5106478&width=full