2017-12-07 / Outdoors

From the Forester

Bill Cook

Michigan forests are growing older, with larger trees, and covering more acres. Inventory statistics reveal a dynamic and ever-changing resource.

The forestry community continually monitors and inventories the forests of Michigan. The federal inventory units collect data across the entire State. The DNR constantly updates the state forest land inventory and status. Other tools are used by different public and private forest holdings on their respective woodlands. A lot of tree counting is going on “out there”.

Sometimes, we think that forests are static resources, the same from year to year. In the short-term, in some ways, this may seem true. Yet, by reading the forest, most anyone will see constant change. Trees grow, die, reproduce, and are harvested. In some places, woodlands are converted to other land uses, while in other places nonforest, once again, grows trees.

Michigan has about 20 million acres of forest, more than at any time over the past few decades. The many characteristics vary widely across Michigan. The sets of changes in the western U.P. are quite different than the changes that most people see in the southern Lower Peninsula.

The amount of data and definitions is rather mind-boggling and can be challenging to sort through. Definite discernible trends can be winnowed-out. However, for every trend there are exceptions, especially when drawn from the statewide pool of data. These trends and rankings change over time, as the forests change. With that in mind, here are a few highlights, mostly from the 2017 U.S. Forest Service publication “Michigan Forests 2014” (NRS-110), which focuses primarily on the changes from 2009-2014.

• Michigan has the 12th largest forest among U.S. States, 20.3 million acres, covering about 54 percent of the State.

• The southern LP has the least amount of forest but is experiencing the most amount of change.

• Michigan is growing about 14 billion trees (over one inch in diameter).

• Most tree species volumes are increasing. Notable exceptions are paper birch, jack pine, quaking aspen, balsam poplar, and balsam fir.

• Considering growth, natural mortality, timber harvest, and other forest removals, Michigan’s forest inventory is increasing every year. Using the average volume per acre, the equivalent volume of over 330,000 “acres” were added each year.

• Almost two-thirds of Michigan forest is privately-owned, with 45 percent of the total forest area owned by families and individuals. About 190,000 family parcels are at least ten acres in size.

• Most family / individual ownerships have not participated in forestry programs over the five-year period (2006-2010) and less than 10 percent have management plans.

• Over half of the primary owners of family / individual ownerships are at least 65 years old.

• Forests are growing older, with larger diameters, and composed predominantly of hardwoods (broad-leaved trees).

• Northern hardwood (sugar maple forests) and aspen forest types cover about a third of the forest. Northern hardwoods are increasing, aspen is declining.

• The most common tree by volume is sugar maple, by tree count is balsam fir (at least one inch in diameter).

• The least fragmented forests are in the U.P., especially the western U.P.

• Two-thirds of the forest carbon resides in the organic components of soils. Wood in standing trees accounts for about a quarter of forest carbon.

• Forest industries directly employ nearly 35,000 people, with a direct product value of $10.2 billion per year. Indirectly and directly, the numbers are nearly 100,000 people and $20 billion dollars.

Wood, water, habitat, and recreation are key values of Michigan forests. Forest ecology is highly variable and increasingly complicated. Managing forests will provide more of all the characteristics we value and offers the best alternatives for forest health and protection.

— — —

Bill Cook is an MSU Extension forester. His office is located at the MSU Forest Biomass Innovation Center near Escanaba.

Return to top