Environmental Education

It’s no secret that Robertson Cliffs, with sheer faces and towering heights, stand as some of the most dramatic landscapes in Algoma. Amidst this rugged terrain lies a world of overlooked ecological complexity, where life has adapted to thrive in seemingly inhospitable conditions.

Among the resilient inhabitants of Robertson Cliffs is the eastern white cedar (Thuja occidentalis). While the ideal habitat for eastern white cedar typically includes moist, loamy soil found in or around swamps on limestone, these trees have developed unique adaptations that allow them to survive in cliff habitats.

The eastern white cedar is one of the limited species that have adapted to survive the harsh conditions of  Robertson Cliffs,  located in Goulais, Ontario.  Photo credits: Dan Weemhoff

From foliage to root, the eastern white cedar pulls out all the stops to survive harsh cliff environments. Its scaly foliage is uniquely designed to absorb moisture and nutrients directly from the air, particularly during morning fog, while the roots possess the ability to anchor into small crevices and fissures, firmly securing the tree to the rocky substrate of cliffs. These strong roots stabilise the surrounding soil, prevent erosion, and contribute to the overall structural integrity of the area. In essence, these trees not only sustain themselves but also actively contribute to the ecological stability of their habitat.

The root system of a mature eastern white cedar.

The eastern white cedars’ roots aren’t just strong – they’re also arranged in a unique system. While other trees have roots that mix and flow throughout the trunk, white cedars feature sectored hydraulic pathways. In simpler terms, this means that groups of roots are dedicated to specific sections of the trunk, which allows the trees to efficiently channel essential resources to areas where they are most needed for survival.

Further, fungi and algae assist the success of white cedars through a symbiotic relationship known as mutualism. The fungi extend the roots' reach so they can soak up even more water and nutrients from the soil. In return, the fungi get sugars from the cedar. Meanwhile, algae in the rocks provide extra nutrients like phosphorus and nitrogen.

Despite all the work that goes into obtaining the appropriate nutrients and moisture, the growth rate of white cedars is very slow due to limited soil availability on cliffs.  This means that size doesn’t necessarily indicate age. A study conducted in the Niagara Escarpment testifies to this matter – it’s not unusual for a highland eastern white cedar with a height of 5 to 6 feet and a 6- to 7-inch-thick trunk to be a whopping 250+ years old. So… that measly cedar you see carving out a niche in the vertical realm? It may have stood long before “Canada” was even created.

Small cedar trees cling to the towering 400 foot face of Robertson Cliffs. Photo credits: Dan Weemhoff.

Eastern white cedars are resilient, stubborn, and sometimes unsightly – but they’re also an integral part of an already fragile ecosystem. It's for this reason (and many more) that Algoma Highlands Conservancy promotes the preservation of fragile cliff ecosystems and all within them. One way we do this is through prohibiting activities such as bouldering and rock climbing to mitigate soil erosion, loss of vegetation, and loss of biodiversity.

Below the cliffs, Roberston Lake road hosts trailheads open for low impact, non-motorized use. Parking available. Photo credits: Dan Weemhoff