What Intensive Forest Management Looks Like
The first step is to assess the trees and the site. What’s the species
composition? Are the trees of good quality? How rapidly are they
growing? How old are they? Are the soils capable of growing quality
trees? Is the area accessible and amenable to harvesting? Only
then is it possible to know if the best of the current trees are worth
growing or if it is time to plan for regeneration. If there are enough
trees worth growing, then thinning, crop-tree release, or individual
tree selection methods can be used. If it is time to start over again
and regenerate the stand, then patch cuts, shelterwood, seed tree,
and clearcutting are options.
In my work, I’ve found that if we intercede early enough, we can
change the species composition in a forest stand. For example, white
pine usually out-competes hardwoods only in abandoned fields or
on excessively well-drained soils. Since pine seedlings spend their
first few years growing slowly, they are easily overtopped by hardwoods on most soils. Once they become well established, however, the pines can grow three or more feet in height per year and
compete well with hardwoods. Therefore, where nature has planted
a mix of white pine and hardwoods, we can keep much more pine
for the future if we release the pine seedlings.
We can also improve the quality of the trees for future forest
products with early intervention. Most of the value of a tree is in the
first log – the first 16 feet. By choosing to retain straight seedlings
and saplings that don’t have forks, we can dramatically increase the
value of the future logs. Pruning the best of the trees at an early age
will yield the most prized logs.
And we can dramatically increase the growth rate of the young
trees by releasing them from competition. Instead of letting spindly
trees grow in “dog-hair” stands, we can have robust seedlings and
saplings, which gain significant girth as they reach for the sky.
I’ve learned that it makes sense to do the first thinning of dense
regeneration when the tallest seedlings are knee-high to chest-high.
At this height, I can look down on the trees and quickly determine
which ones are of the most desirable species and form. With a clearing
saw – essentially a heavy duty weed-whacker equipped with a saw
blade – I can generally selectively thin an acre or more per day, with
the cut seedlings easily falling to the ground. I also evaluate stump
sprouts, keeping one per stump if they are of a desired species and
I take a cue from prescribed planting rates in determining the
spacing for these little seedlings. When planting, foresters often
specify around 500 trees per acre, or a spacing of something like
8 feet by 10 feet. I hedge my bets, generally spacing the seedlings
about five feet apart. This is far enough apart that they will readily
fall when I come back to thin again in two to four years, and I will
have many options to choose from at the next entry.
If I wait until the seedlings are taller – say saplings 10 to 15 feet
in height – the work becomes harder and it takes days rather than
hours per acre to thin if the saplings are dense. For spacing, my cue
is that if the saplings won’t readily fall when cut, I need to space the
save trees farther apart. Note that at a growth rate of three feet per
year, it takes but two or three years for the job to go from fast, easy
work to difficult, time-consuming work. And if I wait until the trees
Clockwise from top left:
This tree was about 35 years old when it was released. It promptly
doubled its size in the next 10 years.
This five-inch-diameter tree was putting on about an inch of girth a year.
A good brush saw is a must in this type of work.
Note the fine form of the mature trees and layers of vertical diversity in