For you native outdoor enthusiasts of the Greater Boston area, the Arnold Arboretum is probably a familiar place. Designed in 1872 by famed landscape architect Frederick Law Olmsted, the mind behind many of Boston’s green spaces, the Arboretum sits on 265 acres of land in Jamaica Plain and Roslindale, and is home to over 10,000 accessions representing almost 4,000 species. It is open to the public year-round and is visited annually by thousands of bikers, birders, hikers, dog-walkers, students, artists and scientists.
Over the summer, I was lucky to become involved with organizing one of the Arboretum’s newest volunteer programs, the Tree Spotters. The Tree Spotters are a group of citizen scientists responsible for collecting data from 55 individual trees representing 11 separate species throughout the Arboretum. Specifically, we are interested in collecting phenological data about the trees, pertaining to the timing of the events in their life history (leaf out, flowering, fruiting, etc.). This data can then be used by scientists worldwide in all kinds of research.
In addition to collecting data, the Tree Spotters have regular meet-ups, training sessions and events. Joining the Tree Spotters is a great way to learn more about botany, meet new people, and spend time enjoying the outdoors. You can learn about the program on the Arboretum website.
But on to the subject of this post! Each month from March through November, we hold a Tree of the Month meeting, during which we visit one of our tree species and discuss its biology, history and lore. This month, we focused on one of my favorite native species, the American beech (Fagus grandifolia).
The Arnold Arboretum has some magnificent beeches, including a large grove of mature trees surrounded by a dense thicket of saplings. These saplings are actually clones of the mature trees, and began their lives as suckers from the roots of these older specimens, sent out in response to some sort of stress. They are genetically identical to their parent trees, and might even be considered part of the parent organism.
During our meeting, the beeches at the Arboretum had reached their peak autumn color of gold and orange. Beeches have marvelous coloring and their leaves can persist on trees well into winter.
A good deal of leaves had already fallen as well, leaving a dense mat of crispy litter on the forest floor.
In addition to leaves, the beeches in the area had also produced a large mast of prickly fruits. The minute seeds of the beech develop inside of a spiky husk, which typically opens upon the first frost. The botanical word for this phenomenon is dehiscence. Both the seeds and husks can be found in abundance, despite being a food source for many native mammals and birds.
During our meeting, we identified the anatomy of the American beech and discussed what phenological events were occurring, including winter bud presence, leaf senescence, and fruiting.
Group members spent time searching for seeds and pods to take with them.
We also discussed Beech Bark Disease, a common affliction of beeches caused by two separate fungi. The fungi is able to colonize the bark after it has been bored by insects or punctured by people who carve into the smooth, gorgeous bark. The infected specimen that I photographed above is from another location, as luckily I could not find any instances of the pathogen at the Arboretum.
Below is an album of beech trunks at the arboretum, some of which have unfortunately been defaced by visitors. These carvings will likely remain in the tree bark for the life of the trees.
Overall, it was a great meeting and I hope that members came away with a couple of interesting facts about this fantastic species!
Check out the Tree Spotters, and stay tuned for posts about future meetings and events.
Thanks for reading,
Below are more images from the meeting.