For Jack Pine Type
Article #105, March 2006
By Bill Cook
Forest management practices vary considerably across forest types, site conditions, market availability, and many other factors. There simply is not any single way or best way to manage all forests, or even a particular kind of forest. While nature is a dynamic system that defies simple categorization, there remains a body of knowledge and experience that can be very effectively applied.
Jack pine is one
of our more common northern forest types, especially on sandy, well-drained
soils. It's also one of our more interesting types, especially because of its
adaptation to wildfire. Like many Lake States forest types, jack pine regeneration
requires full sunlight to grow. This is true throughout the life of jack pine.
Even moderate shade will significantly reduce tree vigor, adding to stress and
increasing vulnerability to insects and diseases.
were the primary agent of jack pine reproduction. A major jack pine conflagration
is an awesome sight to behold, and frightening. As stands would burn, the heat
would cause sealed cones to open up over the subsequent few days. The seed would
fall on mineral soil, laid mostly bare by the fire. These are the ideal conditions
to secure jack pine regeneration. With full sunlight, jack pine grows very rapidly.
Today, forest managers
work to prevent jack pine fires, which tend to run hot and fast. They are usually
very difficult to control. However, most jack pine cones still need heat in
order to release the protected seeds. Forest management uses clearcutting to
create the needed environmental conditions.
within a few inches of the sandy soils get high enough to cause jack pine cones
to open. So, following a clearcut, leftover tops, called slash, are chopped
to get the cones close to the ground. In this way, most jack pine stands regenerate
naturally. When this sort of technique fails, a landowner can resort to planting.
Not all jack pine
cones are "glued" shut. In mature trees, about 25 percent may open
without the aid of high temperatures. In younger trees, this percentage is higher.
Not all jack pine stands burned regularly, so the species employed a back-up
strategy where some cones open without heat. Jack pine also produces cones at
a young age, just in case that fire returned sooner than the average.
Jack pine budworm
is another neatly fitting piece of jack pine ecology. When trees reach ages
around 50 years, budworm populations begin to build. Given the right conditions,
populations will reach epidemic proportions and will eventually feed even on
the younger trees. Large portions of stands can be killed. The dead and dying
timber create a very flammable situation. Of course, this feeds right into the
regeneration strategy of the species.
and wildfire do not fit well with human habitation. Natural is not always desirable.
People who live in or near jack pine forests should be aware of the natural
hazards. Dead trees should be removed. The forest should be set-back at least
100 feet from any structures. The "Firewise" program has suggestions
to help reduce the risk of fire damage to homes.
to create a patchwork of age classes across a jack pine landscape is a good
strategy to minimize the risk of fire and insect outbreaks. Even if a fire does
happen, when it reaches younger trees, then firefighters have a chance to control
the fire. In larger timber, if crowns begin to burn, there is little that humans
can do except get out of the way.
The mix of age classes
is also the recovery strategy for one of the finest success stories of bringing
an endangered species back from the brink of extinction. The Kirtland's warbler
breeds in Michigan jack pine, and has fairly exacting requirements. The bulk
of the Kirtland warbler management has been in the northern Lower Peninsula.
Warbler populations have reached their recovery goals and breeding pairs have
recently been sighted in Upper Peninsula jack pine stands.
Jack pine is an excellent
example of where forest management has helped maintain a valuable forest type,
reduced risks to people, and has played a critical wildlife recovery role. Jack
pine timber is valued in making high quality paper, oriented-strand board, and
new technologies that produce dimensional lumber. Together, these benefits serve
to illustrate the advantages of managing a renewable and sustainable natural
resource. Forest management, in many ways, is a key to our future.
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Bill Cook is an MSU Extension forester providing educational programming for the entire Upper Peninsula. His office is located at the MSU Upper Peninsula Tree Improvement Center near Escanaba. The Center is the headquarters for three MSU Forestry properties in the U.P., with a combined area of about 8,000 acres. He can be reached at email@example.com or 906-786-1575.
by Bill Cook, Forester/Biologist, Michigan State University Extension, 6005
J Road, Escanaba, MI 49829
906-786-1575 (voice), 906-786-9370 (fax), e-mail: firstname.lastname@example.org
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Last update of this page was 2 March, 2006
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