Migratory Tree Update
As a part of our effort to preserve and protect climate change resilient ecosystems and communities of flora and fauna, we have been in the process of establishing a migratory tree nursery at Parkman Hill Farm!
So what is a migratory tree?
As observed by the USDA Forest Service, MOFGA, and countless other reputable scientific sources, migratory trees are native to the Eastern United States, but their natural habitats/ranges are shifting as a result of climate change. The selected tree species are all native to Maine or other states within New England, but are currently migrating towards northwestern Maine as climate change makes the southern end of their ranges uninhabitable and causes the expansion of their northern boundaries. Many of these trees actually naturally occur in this region of Maine at extremely low rates, but as their boundaries expand, so will their ability to thrive here, inevitably leading to an increase in their densities.
Why plant migratory trees if they’re already moving here naturally?
With so many of the native trees under attack by invasive pests and pathogens, such as the American Beech, which is currently being decimated by two diseases (Beech Bark Disease and Beech Leaf Disease), Emerald Ash Borers attacking three different species of Ash and countless others, coupled with cold-climate trees, such as spruce, fir, and paper birch, who are likely to decline precipitously as the climate warms, we are seeing a major change in the ecology of Maine's woods. This shift is highlighted by reductions in biodiversity not just among plant species but also among wildlife. Species like Hemlock, which are vulnerable both to climate change and the invasive pest called the hemlock woolly adelgid, are experiencing huge reductions in population, but since these trees also provide habitat for over 400 species of native wildlife, the negative impacts of their loss are multiplied. As native species near extripation, they are replaced by highly competitive invasive species, which don’t fit the ecological niches of their predecessors. While they outcompete surrounding vegetation, they don’t provide nearly the same habitat or resources that their native counterparts do.
By preparing stocks of native trees that would naturally migrate to these areas if not interrupted by human infrastructure, we have the chance to prevent ecologically unhelpful invasive species from degrading our woods even more than they are currently being degraded, and to introduce higher levels of biodiversity if and when the time comes that our woodlands need it. In the meantime, planting these trees in an observable and, to some extent, controllable setting allows us to better understand how these trees might fit into our changing woods; what ecological niches they might fit, what interactions they may have with other species of flora, what habitat, food, and other resources they offer for wildlife, and how they might change our ecosystems for the better or the worse. Additionally, by developing a stock of tree species native to the eastern United States, SWT is given the opportunity to add to our future stocks of native plants as a part of our annual native plant sale.
What are the trees that just got planted at Parkman Hill Farm, and what's the plan for them?
The trees that have been planted this summer at PHF so far include Scarlett Oak, Northern Red Oak, Tulip Poplar, Black Walnut, Silver Maple, Musclewood, Grey Birch, and Sweet Birch. As mentioned, these trees are all native to southern Maine. As they develop, they will be replanted from their current nurseries into ideal locations for their long-term growth. Once they are ready to be transplanted, we have the option of planting them where native tree species are or have died out, and their presence will keep invasives out as well as fill a niche in the community and increase native biodiversity. Additionally, as we plant these trees, we can monitor how well they grow and reproduce, which will allow us to better understand how trees will migrate in the future and which species have a good chance of making Somerset County their home.
