Looking back on the impacts of low-impact forestry principles and practice
By Tim Libby, Low-Impact Forestry Steering Committee Chair
I started working in the forest as a low-impact forestry (LIF) practitioner over 10 years ago. In that time, though very small on the timescale of a forest, I have seen exciting changes as a result of careful and conscious management, or as I like to describe it, “responsible stewardship.”
When I first started working in the MOFGA woodlot in the winter of 2012, the LIF crews were just finishing up a crop tree release project in the Pine Lot, just outside the Pine Gate entrance to the Common Ground Country Fair fairgrounds. It’s the same stand of pines that tens of thousands of fairgoers walk through each year to access the south gate. I was with one of the older LIF loggers out there one day when he commented that after the work we had done thinning the pine we could see through the understory (some 600 feet) all the way to the woods road where his trailer was clearly visible. Apparently when they started their work in that area the forest was so thick you couldn’t see through it. I can believe it: The MOFGA Pine Lot is an abandoned pasture that regenerated to basically pure pine. That pine grew in so thick that the trees were competing with each other for space: Many had already lost that race to the sky, many were actively loosing, and there was essentially no other tree species living there. This condition is a monoculture, an ugly term in organics. On a resiliency scale, monoculture ranks pretty poor whereas diversity ranks quite high.
A decade later, in that same area of the Pine Lot where we could see all the way to the road though the understory, we can no longer see that far. The thinning project removed some of the at-risk trees and left the healthier, more vigorous pines to continue growing. Commonly these thinning projects only remove up to 30% of the canopy. To an untrained eye it might not even be noticeable. In my work at the Hidden Valley Nature Center, I can compare one side of a road to the other, one side treated, the other not, and it’s still hard to tell that we had done a thinning just that winter because so many trees were left — even if the thinning resulted in 4 cords to the acre in product removal. The gaps created by thinning the overstory allow direct light to penetrate to the forest floor, which encourages a number of other species to grow.
Pine saw logs and pulp were extracted during these thinning operations. While overstory removal on a harvest scale (when compared to natural disturbance such as single tree mortality or windthrow) is highly impactful, the equipment needed to remove the tree parts that we want can also be highly impactful. There is, I think, a very unique feature to the MOFGA Pine Lot though, in that the extraction of logs was done with draft animals. Horses and oxen step over the ground, they do not roll or crawl like wheels or tracks touching every inch of ground in their paths. And even when set in pairs and thus requiring more space to maneuver, the animals still take up less space than all but the very smallest (and more obscure) modern harvest machinery.
Another important contribution to the current condition of the MOFGA forest is that only useable pine logs were removed. This means that tree tops and logs that were not of useable value were left in the woods. Commonly in today’s harvests entire trees are removed, tops and all. Ten years ago in the MOFGA woods the practice for dealing with those residual tree parts was to chop it up with our saws at least until it was on the ground.
Looking through the forest today we don’t just see pine stems and slash (those un-used tree parts left over from the thinning); we see maple, oak, larch, cherry, dogwood, fir and spruce (among others), as well as pine trees making their way from the understory into a mid-story. In the understory there are numerous kinds of ferns, bunchberries, raspberries, jack-in-the-pulpits and more. If you step off of any of the trails you might immediately notice the squish and/or crunch as you sink into a surprisingly thick layer of organic matter on the forest floor that has been accumulating since the trees began regenerating from grassland. I think it is worthy of note that this organic matter was not burned up during the thinning and harvest operation; it is there because it was barely disturbed by the hooves of draft animals that trod on frozen ground, and it was added to by leaving the tops of trees (woody debris) to break down on the forest floor slowly (it wasn’t smushed into the floor, which would cause it to break down quickly). The majority of all seedlings and other dwellers of the forest floor were left unharmed by the operation, which allowed them to recover and respond to the thinning almost immediately.
What had been an even-aged (the older pines are essentially all the same age since they grew from pasture together) monoculture with low potential for resiliency over a decade ago has now become a multiple-canopy, mixed-age forest hosting a diversity of species. It is not only trees who take advantage of these conditions though. These characteristics help to maximize the value as habitat for many woodland species through the entire profile from deep into the soil right up though the canopy of the tallest trees.
To me, one of the most exciting results of the management in the Pine Lot is the low-impact benefit to the soil. When I started poking around one day five or so years ago looking for a place to do a felling demo at the Fair, I almost couldn’t believe what I was stepping through. My feet were crunching through piles of branches that were obscured by needle falls, and I could feel the spongy organic matter as I stepped. Growing up around forests that had been cut over so many times I hadn’t really been used to this condition. And this organic material could only be the age of the pines themselves (quite young for a tree, at about 70 years of age) since pasture culture doesn’t tend to accumulate much of an organic layer comparatively.
Today I am a forest manager for Midcoast Conservancy, and my charge includes the forest operations at the 1,000-acre Hidden Valley Nature Center where I get to implement the principles and techniques that I’ve learned from low-impact forestry. I strive very carefully to mimic the management style that we use at MOFGA. It’s not in the cards for me to use animal draft power like has been done at MOFGA, but I am able to reduce the disturbance to the soil by using smaller machinery and reaching far off of temporary trails with a cable. It helps of course to have a forester who has the same management goals and a cost-share program to help reduce the cost (in my case it’s the same as MOFGA’s — the forester being Mid-Maine Forestry and the Natural Resources Conservation Service crop tree release cost-share program). I am very pleased with the results of my work there, owing great thanks to the principles and practices of LIF.
This article was originally published in the spring 2024 issue of The Maine Organic Farmer & Gardener.