By Ethan Tapper
Forestry is the practice of managing forested ecosystems. However, forests seem to be able to take care of themselves — do we really need to manage them at all?
In theory, forested systems don’t need human intervention to be healthy. If left alone, a forest will grow, change and develop, be periodically disturbed by natural events and recover. However, “leaving forests alone” as a management strategy is more complicated than it seems, largely due to problems created by humans.
Nearly all Vermont’s forests are recovering from being cleared for agriculture in the 1800’s. While most fields were abandoned and regrew into forests, these areas are now generally less diverse, less healthy, less resilient to disturbance and feature lower-quality wildlife habitat than the forests that existed prior to clearing.
Invasive pests, nearly all introduced by humans in the past 100 years, have also fundamentally altered our forests. Exotic pathogens have ravaged or removed American Chestnut, American elm, Butternut, and American beech from Vermont’s forests, with ash trees soon to follow due to the recent discovery of emerald ash borer (EAB) in Vermont. Invasive exotic plants such as honeysuckle, common and glossy buckthorn, Japanese barberry and multi-flora rose outcompete native species in our forests’ understories and inhibit their ability to regenerate and respond to disturbance.
An additional problem apparent across much of Vermont is over-browsing by white-tailed deer. Deer have become an impediment to forest regeneration in Vermont due to habitat changes and decreased hunting and predation. In the wintertime, deer browse heavily on tree seedlings, and can effectively steer the future forest towards tree species that they find less palatable, such as invasives and beech. This over-browsing challenges our forests’ ability to regenerate a diversity of tree species, and to respond to disturbance with vigor.
To add to these problems, forests must cope with habitat loss, fragmentation, climate change, pollution, many other changes in environmental conditions. Forests adapt to change over time; these are the same adaptations that allow species native to our forests to form a functional community. However, at some point we must consider how much change a forest can tolerate over a short period of time, and wonder if we can give our forests a helping hand. By engaging in active management we have the opportunity to help forests remain resilient and to mitigate the effects of these drastic changes.
So, what can we do? One of the most important things is to be active in removing invasive exotic plants and controlling their spread. Our forests rely on natural regeneration to respond to disturbance and changing environmental conditions. Invasive plants outcompete native regeneration and only increase in intensity without our intervention. Cutting and hand-pulling these plants is a step in the right direction, but for more established populations of invasives, using herbicide is often the only realistic way to control them. You can find more information on invasive exotic plants and their treatment at VTInvasives.org.
Secondly, we can employ smart harvesting techniques that increase the health of our trees and the diversity of tree species, sizes and ages in our forests. Using harvesting to remove unhealthy trees and favor our highest quality, healthiest stems will increase vigor and decrease stress in our forest, and creating pockets of regeneration will increase diversity, improve wildlife habitat and ultimately make our forests more resilient. Leaving the tops and limbs of trees in the woods and un-lopped during and after logging, while it looks messy, provides great wildlife habitat and protects regeneration from deer browse. Being active in creating regeneration also gives us a chance to overwhelm the browsing ability of our local deer herd.
Finally, I would argue that harvesting timber is important in and of itself; it supports our working lands economy and the loggers, truckers, mills and timber processors in our communities, and provides a local source of heat, building materials, paper, electricity and more. It also provides income to forest landowners, helping them pay taxes, fund non-commercial stewardship activities (such as invasive species treatment) and incentives keeping our forested land intact and forested. As I often say to people: we can harvest a local, renewable resource while improving the health of our forest and producing awesome wildlife habitat … Why wouldn’t you want to do that?
Ethan Tapper is the Chittenden County forester. He can be reached at 585-9099, firstname.lastname@example.org, or at his office at 111 West St., Essex Jct. For more information about timber harvesting, please visit VTCutWithConfidence.com.