Invasive Plants: An Endpoint?

As the Chittenden County Forester for the Vermont Department of Forests, Parks and Recreation, my job can be broadly described as negotiating the relationship between humans and the forested ecosystems of Chittenden County. To this end, I serve as a resource for landowners, communities, and individuals interested in forests, forest management, and land stewardship. Through my work I have the opportunity to observe the ‘big picture,’ the trends and forces that influence our forested ecosystems over time. One of the most disturbing of these trends is the threat posed by invasive exotic plants, which present a disturbing vision of the future of our forests. In my view, the presence of these species represents a theoretical ‘endpoint’ in the growth and development of our forested ecosystems.

In the remarkably diverse forested ecosystems of the northeastern United States, we are blessed with a suite of native species that regenerate readily following disturbance events. Our forests utilize a simple scheme to do this: when some trees die, others capitalize on the opportunity to establish and grow. While this may seem obvious, in many parts of North America the regeneration of native trees is no easy thing, and it is the exceptional diversity and richness of our forested ecosystems that make this possible. We humans benefit from this capacity by having new trees constantly establishing and growing, ready for us to tend, harvest, and enjoy.

In the midst of this abundance, it is easy to ignore invasive plants as they establish and slowly spread through the understory of a forest. We put off their removal, saying that we will address the issue when these species become a problem. However, when trees in the overstory of a woodlot succumb to natural mortality, become mature, or start to decline, we are forced to encounter these species head-on.  I have seen many cases where the loss of an overstory, which is normally rewarded with a diverse crop of native seedlings, is met only by a sea of invasives. Unless they are removed, these invasive plants will occupy these areas, inhibiting the forest’s natural regeneration process, indefinitely. This is the ‘endpoint’ to which I refer, a moment at which the cycle of life in a forested ecosystem is arrested into the indefinite future.

Taken broadly, I see this trend applying to many of our forests, given enough time and inactivity. So, what do we do? The days may be gone when any disturbance will automatically trigger an abundance of native regeneration, but this doesn’t mean that our forests’ days are numbered. These days, when I see a single invasive plant on a landowner’s property, I tell them that they have an invasive plant problem. The truth is that all of us, even those who have never seen one of these plants, have an invasive plant problem. My dream is to see concentrated, community-wide efforts in the removal of these species, in recognition of the fact that these species don’t stop at property lines, and neither do our forests. I hope that we can use these actions as a springboard to talk about how to make the forests in our region, and all those reliant on them, healthy into the indefinite future.

Article by Ethan Tapper, Chittenden County Forester, VT Department of Forests, Parks and Recreation.

Photo credit: Lee Krohn, UCF Council