Blazes-- as in paint marks found on trees. Those who venture into the state forests of our region [editor's note: this article was written for Michigan, make applications in other states with due caution] often find out that someone has been leaving colorful marks, bright splashes of color on tree trunks that catch the eye.

To those new to such encounters, a question about what these marks mean is understandable.

These marks are placed there by foresters, and they are a sign of active forestry management being practiced.

Craig Allen, an assistant area forest manager for the DNR, says making these blaze marks is just a part of his work, establishing the boundaries of timber sales, wildlife management units, recreational projects, and special use permits.

His marks create visible signs to guide forest harvesters to where they may remove timber-- or in some case, which trees to leave for special purposes.

On a recent tour of an ongoing timber sale site, Allen took the time to explain these timber cruising marks and removed some of the mystery behind such forest grafitti.

At one point, Allen stopped his vehicle to point out a jack pine next to the two-track road, a tree with three horizontal sprays of bright blue paint.

"That is a corner mark-- it gives the logging contractor a definite corner where the sale boundary begins."

From the corner marks, Allen then runs his boundaries with other paint marks which outline the area of each sale.

At this site, a line of single blue paint blazes showed the perimeters of the sale area extending from the corner mark, a bright visible line that followed the cruise line made earlier by the forester as he worked on what ehy call a "compartment"-- an area of forest that is ready to be harvested at this time.

Annual compartment examinations are made to determine what the management goals will be for the year.

Allen explained that it is not just foresters who take part in these annual compartment examinations.

"In many areas we find forest species which are valuable for wildlife and we work closely with the biologists to make sure that wildlife needs are given consideration or attention.

An example might be an area with aspen within oak or jack pine, an important species to maintain for grouse or deer," he said. Areas close to water, streams or lakes are often marked to leave a forested buffer to protect the water resources and fisheries.

Superior trees, good seed sources, are also marked to be saved.

In this particular area, scheduled as a jack pine clear cut, Allen had marked some "islands" of oak trees to be saved as mast trees. Mast trees produce seeds or nuts that are very important for wildlife. Special attention is made to save enough healthy producing mast trees where they are found within a sale area.

Also marked are den trees and nest trees to be saved to provide shelter for other species. Every harvest area is marked so these valuable wildlife trees will remain to shelter various cavity-dwelling species.

Not all areas are clear cut-- just those areas where clear cutting is best for species regeneration. Other areas may be marked for selective cutting-- harvesting individual trees rather than a whole stand.

Periodic selective harvesting in northern hardwoods will improve the stand, benefit reproduction of new trees, put revenue into the state coffers while allowing remaining trees to gain growth and value.

Allen notes that some species, aspen, jack pine, and oak, need a lot of sunlight to regenerate. Clear cutting is necessary on those sites. Aspen and jack pine especailly need direct sunlight on the mineral soil bed to create regeneration.

Aspen is a rapid growing species. New trees are regenerated from clones sprouting from the root system once sunlight reaches the forest floor. Some aspen areas cut just a few years ago are, today, thickly stocked with new trees that may already reach 10 to 15 feet in height and are very important to many wildlife species, both game and non-game animals and many species of birds.

Colors used in marking may vary from site to site. At this site, blue was being used, but in other areas, the foresters may mark with red or orange. Green paint marks are generally made on trees to be saved and left uncut.

Trees that are corner markers will have triple blazes, and corners that adjoin other sales or management areas may have more than one color as a mark.

As you hike through the state forests this year, and encounter bright paint blazes on trees, it means that some forester has left his mark-- a sure sign of forest conservation at work.