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| OFRI summer experience student Tianna Burke sets up for a hemispherical photo to assess light available to regenerating white cedar. |
They grow just about everywhere in Ontario, but not in great numbers. They grow where little else does, but not quickly or well. They are important not only to Ontario’s forest industry but also as a spiritual and cultural species for Canada’s First Nations people. Those growing on cliffs in southern Ontario are the oldest trees in eastern North America (up to 1,100 years old!). The species? Eastern white cedar.
Until recently, eastern white cedar was not a major crop species in Ontario. But demand for it has always been steady, as cedar is rot resistant, making it popular for docks, decks, posts, fences, shingles, and cabin logs. However, due to its relative sparseness, its slow growth, and a shortage of quality wood, the forest industry has generally viewed it as a secondary species.
Eastern white cedar has other important uses: It is one of the primary medicinal plants of the Ojibway people, who have used it to treat scurvy and other ailments. It is also a source of food and habitat for white-tailed deer, small mammals, and several bird species, as well as a popular landscaping tree and mulch ingredient.
Several years ago, OFRI research scientist Rongzhou Man became interested in white cedar when he noticed entire stands being clearcut and realized that information about managing this species is sparse. MNR now has a series of studies underway to address the lack of information about white cedar (see list at the bottom of the page), and Man has been part of the research since the planning began. His work focuses on how residual cedars respond to harvesting. It is unclear, for example, whether harvesting methods ensure the survival and growth of cedar advance regeneration (young trees left after harvest to become the next forest) in lowlands where understory cedar is generally abundant. Also unknown: whether partial harvest leaves residual overstory trees in uplands healthy enough to provide seed sources and shelter for natural regeneration.
Studying white cedar is challenging because it grows slowly, Man says. “While other species take four or five years to regenerate, white cedar takes up to 20. Slow growth and high stress tolerance mean that it takes longer for researchers to determine cedar’s response to harvesting.”
Researchers will assess the study plots every five years as the trees continue to grow, but conclusive results will likely take 20 years.
If you’d like to learn more about OFRI’s white cedar work, contact Rongzhou Man, rongzhou.man@ontario.ca, (705)946-7484.
Who else in MNR is studying eastern white cedar?
Rongzhou Man’s eastern white cedar study is part of a larger framework of MNR research designed to fill information gaps related to this species. Other studies include:
- Developing a monitoring protocol to assess regeneration success - Gordon Kayahara, Northeast Science and Information Section
- Measuring cedar stand attributes, tree form patterns, and individual tree characteristics as they relate to ecological relationships - Dan Corbett, Northwest Science and Information Section
- Assessing planted stock perfomance on competitive upland sites and evaluating seed dispersal from residual trees and/or edges - Nick Buda and Doug Reid, Centre for Northern Forest Ecosystem Research (CNFER)
- Conducting screening trials to determine which forest herbicides eastern white cedar can tolerate - Tom Noland and Rongzhou Man, OFRI, and Michael Irvine, Forest Health and Silviculture Section
Researchers hope that their efforts will help maintain healthy productive cedar stands, supporting the needs of forest industry as well as protecting ecological and cultural heritage values.
