Has Anyone Checked the Trees Lately?
by Paul Donahue
I grew up in Winchester, Massachusetts, a suburb of Boston. Fortunately for me, my family lived only a block or two from the boundary of the Middlesex Fells Reservation, and it was there, in the 1960's, where I first began roaming the woods in search of birds. Throughout my early birding years, up through high school and for several years afterward, I spent thousands of hours walking the reservation's many miles of trails in search of birds. During spring and fall migration periods I would be in the Fells birding before school, after school, and on weekends and holidays. I came to know the woods, ponds, swamps, streams and trails of the Middlesex Fells better than I've known any area since.
As, I suppose, is normal, since moving to Maine in the mid 1970's I had spent much time reminiscing about my early birding experiences in the Fells. Finally, this past May, after a hiatus of twenty years or so, I returned to the Middlesex Fells to see how the area had changed in my absence. It is always dangerous to return to places of one's youth, with changes for the worst being almost inevitable. However, I figured I would be safe in visiting the Fells. It was still a state reservation, and I knew it would not have been converted into a housing development or shopping plaza, the fate of so many of my past birding haunts in Massachusetts and southern Maine.
The area I chose to visit used to be covered with some of the tallest and richest woods in the reservation. I remembered the woods here as looking very good twenty years ago, with many large trees, and was looking forward to seeing how much better they looked after twenty years more of undisturbed growth. But as I walked down the woods road, I was struck by the large number of dead and dying trees. The area didn't look better than it did twenty years ago, it looked worse - much worse. Everywhere I looked were completely dead trees, trees with dead limbs sticking out of the crown, or trees with sparse and scraggly vegetation on their uppermost branches. All around were openings where trees had apparently fallen. Most of the dead and dying trees were Green Ash, which are known to be having problems throughout the region. When I reached up for a small leafy branch of a young Ash for a closer look, it broke off easily in my hand, as brittle as an icicle. Many of the large Black Oaks looked less than healthy, as well, and some of the large White Pines in the area had broken off two thirds of the way up their trunks. The scene reminded me of recent photographs I have seen of the once great forests of eastern Europe.
If Green Ash was the only species of tree suffering a decline in eastern North America, maybe it would be acceptable to simply blame the cause on some pathogen and dismiss the problem as unfortunate but unavoidable. But, regrettably, Green Ash is far from the only species at risk. Do you remember back when Sugar Maples would first began to turn orange in September? Now the first orange leaves regularly begin to appear on the trees in the latter half of August. As I sit here writing, in Machias, I can look out over the tops of numerous dying Sugar Maples, their crowns enveloped at the moment in acid fog. In the last eight years or so, at least three large Sugar Maples have come down just in sight of my residence. All along the Maine coast, virtually every Sugar Maple shows signs of slowly dying from the top down. As you travel around the area, look for the dead or sparsely-leaved branches sticking out of the crowns. Some people blame this decline of Sugar Maples on road salt and this is certainly a factor, but trees away from the roads look almost as bad as those along the roads. And the species is doing poorly in northeastern North America as a whole, with some sugarbushes in Ontario having suffered an 80% tree mortality.
Along with Green Ash and Sugar Maple, the thinning crown symptom of slow death can be seen in a number of other hardwood species in Maine, as well. The list includes Red, Silver, and Mountain Maples, Quaking and Big-toothed Aspens, Lombardy Poplar, Paper Birch, Red Oak, American Beech, Apple, and Choke Cherry.
Conifers in New England are also far from immune. Have you noticed how every time a strong wind blows around here now, it seems that several more large White Pines snap off? In southern New England, Eastern Hemlocks have been badly damaged by the Hemlock Woolly Adelgid. And at higher elevations in the mountains across northern New England, Red and Black Spruce and Balsam Fir have been hard hit, especially so in the Green Mountains of Vermont.
Even woody shrubs are not immune. On islands I know well in Casco Bay, islands frequently encased in fog, the same top down death can be seen in Bayberry, Staghorn Sumac, Raspberry, and Steeplebush. All in all, the list of affected species of trees and shrubs represents a hefty percentage of the common species of woody plants found in northern New England.
Moving south and west from New England, other examples of tree death and disease are easy to find. Carolina Hemlocks in the central Appalachians have been badly damaged by the Hemlock Woolly Adelgid, Flowering Dogwood is suffering as the result of anthracose fungus and Butternut as the result of a canker. American Beech in the Adirondacks is being heavily attacked by a scale insect. Fraser Fir in the Great Smoky Mountains of North Carolina are suffering heavy mortality due to the Balsam Woolly Adelgid. White Oaks, Black Locust, and Hickories in West Virginia are dying of unknown causes. And these are only some of the examples.
We can choose to view all these examples of dying trees as isolated cases, each caused by a specific insect or fungus or bacteria or virus or whatever. Or, more accurately, we can look on these pathogens as representing only the proximate causes of death, and consider forest decline and tree death across eastern North America for the pandemic that it is. Our industrial society with its attendant air pollution is slowly killing our forests, as it has the forests of eastern Europe.
We have all read about the effects of ozone, acid rain and other pollutants on our forests. But it is important to remember that these problems are no longer limited to the peaks of the Green Mountains or the Great Smoky Mountains. The rain in our area is now three times as acidic as it was in pre-industrial times, and our area's abundant fog can be 10 times as acidic as the rain. This acidic rain and fog are like a toxic stew, also carrying dioxins and heavy metals like lead, mercury, cadmium and copper. These pollutants have acted in concert in ways we are still far from fully understanding, weakening and stressing trees throughout the eastern half of the continent and making them more susceptible to attack by pathogens.
Trees along the Maine coast, particularly those on exposed, outlying islands, show some of the worst damage in the state. When I recently visited Eagle Island, a state historic site in Casco Bay, it seemed that every tree on the island was either dead or showing signs of damage. Like trees on mountain tops, the trees on offshore islands are already exposed to heavy environmental stresses. On mountain tops the trees have to deal with strong winds and very cold temperatures while on the islands they have to deal with strong winds and salt spray. They are already living at their limits and any additional stress, such as atmospheric pollutants, can be enough to tip the scales against them. And also like mountain tops, the offshore islands are frequently bathed in acid fog.
Once we begin to recognize the damage, we then have to decide how long we are going to accept this transformation of our forests before we make changes in our own lifestyles and speak up to demand that the necessary changes be made in our society? In Germany the term waldsterben - or forest death - is now a household word. Is that what we want here? Is this trend of slow forest death what we want for our children's future, or is it time to rise up en masse to let our legislators know what we do want? If nothing is done and business as usual is allowed to continue, what is a young naturalist growing up near the Middlesex Fells Reservation today going to find when he or she returns to the area for a visit another twenty years from now?