Worst-First and Femelschlag
Ecological Forestry with the Foundation for Sustainable Forests
Editor’s Note: I first heard of Troy Firth years ago, in an essay by Wendell Berry. It sounded too good to be true: a horse logger who never cut a healthy tree, but only slowly removed those that, to his eye, were beginning to lose vigor. Then I had a chance to visit with Troy and his colleagues Guy Dunkle and Annie Socci Maloney, to take a walk in some of those woodlots, and to see the results of this patient approach. This is impressive “worst-first” forestry at its furthest reach. - Brian Donahue
Troy Firth in the forest. Photo © Richard Deiss
The Foundation for Sustainable Forests (FSF) is a 501 (c)(3) organization in northwestern Pennsylvania. FSF was founded 20 years ago to conserve forested land as carefully managed working forest, and promote sustainable forestry practices for the benefit of the land. Today, we manage nearly 4,000 acres using an approach developed by our President and Founder, Troy Firth. We seek a balance between stewarding the forest for resources and cultivating ecosystem health and resilience.
Troy has been a forester and maple syrup producer for most of his 77 years. Not formally trained, he takes an approach to forest management that is born of a lifetime of observation, practice, and study of the land ethic and stewardship. When asked to describe FSF’s approach to ecological forestry, Troy will often quote Aldo Leopold, saying: “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.”
Building upon this tone, and wary of mapping a forestry approach that is too narrow and rigid to adapt to inevitable change, FSF follows a set of guiding principles:
Be reactive in our assessment yet proactive in our approach. Let conditions recommend the management rather than dictating conditions through management.
Maximize options. To accommodate future variables, management should create diversity and opportunity.
Emphasize art, informed by science. Our scientific understanding is limited to a single generation of trees. Therefore, personal experience, humility, and a certain degree of restraint must also play a role.
Our region’s woodlands are primarily the product of multiple high-grade harvest cycles, selectively removing many of the “best” trees. As a result, today’s prevailing condition is a mature, closed-canopy forest with a lack of regeneration in the understory, thanks also to the spread of invasive plants and heavy browsing by deer. To improve the overall vigor of these forests, we use “worst-first” single-tree selection, removing trees that have reached the end of their healthy growth cycle due to disease, competition, or other factors that make them the “weakest” in a particular stand.
“Over time, our scattered forest lands will serve as beacons, brightening the region’s overall forest condition.”
In order to overcome the lack of diversity in stand age and structure, we also use group selections, creating small gaps (generally a half acre to two acres) to introduce light where there is desirable, advanced regeneration present on the forest floor. Side light to the closed forest surrounding the gaps fosters additional growth, creating opportunities to strategically expand the gaps over time, an approach known as “femelschlag”—a concept introduced to American forestry by German forester Carl Schenck. The results of this long-term, comprehensive approach are impressive: a shifting mosaic of forest age and diverse structure that supports wildlife and overall ecosystem resilience. Careful directional tree felling further protects and promotes healthy regeneration.
Small overstory removals within an even-aged, closed canopy stand diversify the light environment in the forest and promote diverse, vigorous tree regeneration and structure. Photo © Annie Socci Maloney
Side light under the closed canopy that surrounds the gaps further promotes forest regeneration and structural diversity that plays host to a variety of wildlife. Photo © Annie Socci Maloney
The recent findings of a three-year study of forest bird activity in FSF’s forests provide insights into the benefits of this approach to wildlife. Dr. Steve Latta, Director of Conservation at the National Aviary, concluded that even very small gaps (less than half an acre) support a diverse array of birds; early successional species utilize the gaps for nesting, while species that nest in the forest interior also use the gaps during post-fledging and molting periods. These findings underscore the importance of managing forests for both early- and late-successional habitat within a stand, not just to foster the future forest but also to support a greater diversity of wildlife.
National Aviary researcher Dr. Steven Latta and a member of his team stand in a gap surrounded by mature forest in Erie County, Pennsylvania. His team recently completed a three-year study of how different groupings of forest birds utilize these gaps throughout the nesting and post-fledging season. Photo © Annie Socci Maloney
A fledgling rose-breasted grosbeak following banding and release. The small gaps created by FSF have been found to be important sites for a wide variety of species during nesting, fledging, and molting. Photo © Nancy Ransom
For our management system to be successful, worst-first harvests must be profitable and the work appealing. We have developed a strong market for low-grade logs and polewood, primarily for pallet stock and railroad ties. We also benefit from robust demand for higher-quality logs, including local grade lumber mills and export buyers. Our system of high-frequency, low-intensity harvests only works because of the relatively low cost to mobilize horse logging crews and administer the process. Most local governments and highway departments we work with require only minimal permitting and paperwork. And, when the horses load into the trailer each morning, there isn’t much difference in cost, whether traveling to an old established logging job or a new one. This nimbleness enables us to respond to small wind events, disease outbreaks, or other low-volume harvest opportunities, and to craft silvicultural disturbances that are precise and tailored to each situation.
Long-term stewardship requires consistent, long-tenured forest ownership. FSF’s management of conserved lands is designed to be perpetual; thus, our foresters and loggers will come to know our properties better and better and will make sound decisions through experience. The result is a mosaic of properties under our care that buoys the resilience of forests on a landscape scale. We will not own or manage all of the forest in our region. But, if you picture our healthy forests as stars in the night sky, each year as FSF grows there are more stars appearing. Over time, our scattered forest lands will serve as beacons, brightening the region’s overall forest condition.
“Emphasize art, informed by science. Our scientific understanding is limited to a single generation of trees. Therefore, personal experience, humility, and a certain degree of restraint must also play a role.”
While FSF’s team has crafted a system that routinely yields positive forest outcomes, we do face a number of headwinds. Our ecosystems, practitioners, and markets are not immune from change. As invasive plants become more abundant, we are rapidly approaching the point where treatment will routinely preclude most timber harvests because the introduction of additional sunlight can be counterproductive. On a few sites, where we have fostered the forest understory through decades of stewardship, the native plant community remains vigorous and abundant. However, high deer browse pressure and the tenacious spread of invasives are constantly pushing against our forests’ resilience. The cost of addressing invasive plants across so many acres will significantly impact our ability to financially sustain the organization from its land base.
Climate change is a genuine threat to our model as well. Like other regions, we are experiencing longer “mud seasons” and fewer weeks of frozen ground for logging. Our diversity of soil types and the reduced impact of horse skidding provides a bit of a cushion against these impacts. Furthermore, even with the growing Amish community in our area, the number of horse loggers is declining. Horse logging is very much a way of life, and it requires a commitment to husbandry that extends beyond an eight-hour workday.
Horses complement our “high-frequency, low-intensity” system nicely, minimizing damage to the forest floor. They are also relatively easy to mobilize, thus enhancing a forester’s agility when responding to changing conditions. Photo © Guy Dunkle
Our silvicultural process has been developed through trial and error, observation and intuition, and will continue to be honed constantly. It is incredibly rewarding to walk through forests that have been under FSF’s style of management for decades, and to feel the momentum of multi-aged regeneration and larger, older trees with exceptionally high vigor. Our working woodlands offer an inspiring model of how to provide for people while respecting the ecological community. However, our role as stewards will never be complete. Disturbance is inevitable. That fact is both the greatest vulnerability—and the lifeblood—of forest ecosystems.
Guy Dunkle has spent the last 20 years practicing conservation-minded forestry in the same region of western Pennsylvania where he grew up. Guy partners with industrial, NGO, and public and private forest landowners to create vibrant, uneven-aged forests using a unique silvicultural system of low-intensity, high-frequency thinnings, group selection openings, and horse logging.
Annie Socci Maloney joined the Foundation for Sustainable Forests team in 2016. Annie holds a PhD in forest ecology from Boston University and a BS in natural resources from Cornell University. She spent 15 years in wilderness education and leadership development with the Voyageur Outward Bound School in northern Minnesota. Annie and her family live on a farm in northwestern Pennsylvania, where they raise sheep and make maple syrup.