The Passing of a Great Tree: Sweetgum (Liquidambar styraciflua)

If you follow the Arboretum's stream from the lower pond to the Fitness Center, you may notice a large tree on the east bank just prior to the final bridge. This sweetgum was featured last autumn, and at the time appeared mostly healthy. This past month, the specimen began a rapid descent to its death. What leads us to this conclusion? The tree's leaves have died, completely out of season. Examining the crown from a distance, one can see the sorry condition.

At times like these, we ask ourselves, "Is this a natural death? Has this tree, after reaching its maturity, simply gone the way of all flesh?"

Information on the natural lifespan of Sweetgum is not easily available. The US Forest Service reports that Sweetgums should bear abundant crops for 150 years, setting perhaps a reasonable limit on their viability. A search for America's oldest sweetgum did not reveal anything of interest, although France possesses a specimen over 180 years old.

How old is the arboretum's Sweetgum? We don't know. The tree pre-dates the arboretum and may pre-date the campus. Records are unknown, but perhaps an enterprising amateur scholar could examine old photos of the campus and determine, by clever measurement of the tree's size, about how old it might be.

What, besides its age, may have led to the tree's imminent demise as an independent organism? Twice the tree has been struck by lightning and its crown damaged. Further, IFAS reports that Sweetgum has "extreme sensitivity to construction injury to the root system." As we noted in the opening sentence of this post, this tree is very close to the Fitness Center and the large concrete spillway. It may be that the construction of the Fitness Center damaged some roots of the specimen, but not enough to kill it at the time.

Finally, the tree appears to have a type of canker disease, which has led to profuse 'bleeding' in one area. IFAS reports that there is no effective chemical control for canker and that, "[S]everely infected trees will die."

To recapitulate: the tree is dying and we don't know why. Is it due to advanced age, root damage, lightning strikes, infection, or some combination of the foregoing? We don't know and we will likely never know, but it is still important to assess and record the progress of the Aboretum's specimens.

In this photo taken at range, the canker is visible as dark discoloration in a vertical line down the trunk.

Upon approaching the tree, the bleeding is quite obvious and the bark has been stained.