I had never spent much time thinking about trees until recently. I’ve always been drawn to the less charismatic, mosses, ferns, grasses, and other flora under the canopy. Like any nature lover, I’ve always appreciated trees, but as a part of the larger forest rather than a community in and of themselves. I knew very little about each tree as an individual, only being able to identify a few species with certainty.
Today I stood in Mayor Baxter Woods, a 29-acre open space in Portland. As a Community Tree Steward with Maine Audubon, I now spend great quantities of time thinking about, identifying, caring for, and, more than anything, worrying about trees. This forest is dominated by Eastern Hemlocks, grand trees with branches hanging down to touch a passing hand, brushing their soft needles. Some of the hemlocks in this forest are so large that I couldn’t help but gawk at them. However, even these trees that seem to rival time itself are rife with bare branches, an uncommon occurrence for a healthy evergreen in winter. Hemlock woolly adelgid (Adelges tsugae), an invasive aphid-like insect that is wreaking havoc on hemlock populations throughout southern and coastal Maine, is the cause of this hemlock decline. The insect attaches itself to the base of the needles of hemlock trees and feeds on stored nutrients. When large numbers of the insect are present it can kill the tree.
As I gazed around Mayor Baxter Woods, I couldn’t help but wonder what will become of this forest in 10, 20, 50, 100 years from now when many of the hemlocks are gone. It isn’t just the Hemlocks. Below these conifer stands are young beech trees already showing signs of beech bark disease. Beech trees are known for their large size, unique smooth bark, beech nuts, and dominance in many New England forests. Many of these beeches are now covered in puckering cankers. These cankers are the result of the invasive beech bark scale making the trees vulnerable to fungi that infect the trees and eventually kill them. The Beech Scale (Cryptococcus fagisuga) feeds on the sap of beech trees creating wounds that can then be invaded by two different native fungi: Neonectria coccinea var. Faginta and Neonectria galligena. These fungi block the flow of sap and kill the wood of the tree eventually leading to mortality.
I have always felt a connection to beech trees. They remind me of going to ecology summer camp as a child in Lincolnville, Maine, surrounded by a beech-filled forest. Beech brings up memories of my college plant systematics class, which solidified my growing interest in plants. In that class I learned how to identify many different species native to northeast Ohio, one of which was the American Beech. Even as many scientific names of plants have left my mind since then, Fagus grandifolia is one I will always remember. I grieve knowing many of these trees will soon just be a memory decomposing on the forest floor.
Between threats to hemlock, beech, ash, and butternut, I’m left wondering what will be left of the forests that raised me to be a conservationist and nurtured my love for plants. Death is natural for all living things, even trees which feel almost immortal. But this kind of death of a tree feels unnatural and leaves me feeling helpless. To combat this feeling, I take pictures of the trees I love, I dream of city streets lined with street trees in every neighborhood, I remind myself of disease-resistant trees being studied by scientists, I think of the treatments being invested in to save individual trees, and I find solace in the knowledge of seeds being collected to preserve genetic diversity.
Beech and hemlock are not the first trees to be threatened in this way; the American Chestnut and American Elm, once dominant in North American forests, experienced similar population loss due to pathogens and pests. Yet, we have not lost these species altogether. Thanks to disease resistant cultivars, hybrids, and proper management we can still grow and appreciate these trees and perhaps one day find ways to repopulate these species on larger scales. Similar efforts have been made to address new threats to native trees. The City of Portland has used biocontrol and chemical treatments in Mayor Baxter Woods to help preserve the hemlock population. Baxter Woods is also home to an unaffected stand of beech trees, providing hope for the future of the species here.
I am one of many conservationists and nature lovers around the country and world working to preserve the flora and fauna we and many others hold dear. Standing in a forest looking up at the trees I can feel so solitary, but I’m surrounded by a fraternity of living things. It is not just what is living that is important in our forest. Standing dead wood creates nesting sites for wildlife and places for fungus and moss to grow, and decomposition feeds what is still living in the forest. Much like the trees that came before them, the decomposing beech and hemlock will create opportunities for new life. Knowing the young trees in the understory—which are waiting for the opportunity provided by gaps in the canopy to grow tall—will one day reach the same heights as the hemlocks in Mayor Baxter Woods gives me hope.
