Eastern white cedars (Thuja occidentalis) found along Escarpment cliffs have defied the notion that bigger trees are older trees. Their discovery also redefines what constitutes a “forest.” The Niagara Escarpment Ancient Tree Atlas Project, started in 1998, is a comprehensive search for the oldest trees that populate cliff faces of the Escarpment between Grimsby and the Bruce Peninsula.
Researchers have since discovered trees that are over 500 years old, with some over 700 years old, on sites across the Niagara Peninsula, Hamilton-Wentworth and Halton Regions, and Grey and Bruce Counties.
The ancient trees are part of an undisturbed forest ecosystem that occupies cliff faces. Kelso Conservation Area, Mount Nemo Conservation Area, Inglis Falls Conservation Area, Metcalfe Rock, Old Baldy, Flowerpot Island and Lion’s Head Provincial Nature Reserve are among the cliff sites where several trees discovered were over 700 years old.
The discovery of these old cedars occurred in part because of previous research on dendrochronology, or tree-ring analysis, and on the impacts of rock-climbing, and through the specific focus of the Niagara Escarpment Ancient Tree Atlas Project.
What habitat variables are responsible for promoting the longevity of these cedars?
In A Review of the Niagara Escarpment Ancient Tree Atlas Project; 1998-2001, researchers noted that despite cliff faces in the Niagara Region being short and unstable, various tree species including eastern white cedar, eastern hemlocks (Tsuga canadensis), and eastern red cedar (Juniperus virginiana), surpassed the 200 year mark.
Comparatively, in the Hamilton region, cedar trees were found to be over 200 and 300 years old and were rooted on cliffs associated with waterfalls. Two 500 year old cedars were found at Webster’s Falls. The high dolostone cliff faces, some as high as 31 m in the Halton region, are home to a large number of eastern white cedars between over 400 years and over 800 years old.
Along a former glacial meltwater channel known as the Nassagaweya Canyon, researchers found trees that were over 400 years old, with a 588 year old tree found at Rattlesnake Point that was only 3.2 m in height. In Grey County, researchers found cedars that ranged from 300 to 700 years old.
Various sampled sites in Bruce County proved to be a hotspot, with a number of trees between 500 and 700 years. At Lion’s Head, the oldest tree was reported to be a cedar that germinated 1050 years ago in 952 A.D., which would make it the oldest tree in Canada east of coastal British Columbia!
Remarkably, cliff-dwelling trees were rooted in shallow soil of cracks and crevices on the face of the Escarpment facing a harsh growing environment with high winds, low nutrients, varying temperature and moisture fluctuations.
The eastern white cedar is a slow-growing and hardy tree, and the trees found along the Escarpment cliffs are indeed smaller and appear almost shrub like, twisted and gnarled due to the growing conditions. The harsh environment has impacted their growth and size, implying that a tree could be hundreds of years old with a circumference of a few centimeters. Activities such as recreational rock climbing can disturb germination sites by removing dirt from ledges that may be used as holds, and by damaging remaining trees in the process.
The discovery of these ancient trees on cliff faces from the Niagara region to Flowerpot Island is significant in terms of natural heritage. Remarkably, these trees survive in an internationally recognized area, the Escarpment, which is also located in a densely populated region of Ontario.