The Gifts of Old Growth Forest in the Ottawa Valley

When you step into an old-growth forest, you enter a very special place. Some of the trees you encounter may be several hundred years old and tower above the forest floor. These trees have been alive through many human generations. They are connected to one other in an intricate living web under the forest floor through which they communicate and share nutrients.

There is a sweet rich earthy smell in an old growth forest that comes in part from volatile compounds given off by trees and from the thick layer of decaying organic matter on the forest floor. There is also often a deep silence.

The majestic height of old growth tree canopies has prompted many people to liken these forests to living cathedrals. Often a spontaneous feeling of awe arises when we visit them. Perhaps something deep inside us recognizes that this old, intelligent, intact ecosystem is not only beautiful, but is of great value.

Standing dead trees and fallen giants decaying on the forest floor are common in old growth forests and provide habitats for many different birds, small mammals, amphibians, insects, ferns, fungi, mosses and lichens thus greatly increasing biodiversity. Gaps in the tree canopy and the presence of many tree species of varying ages are also typical of these forests. The rich biodiversity and complex web of life in old growth forests makes them living laboratories with enormous potential for scientific discoveries.

While there is no hard and fast definition of old growth forests, in essence they are forests that have been largely free of human disturbance for 150 years or more.

Research has documented many benefits to human health of spending time in the woods. Forest visits lower our pulse rate and blood pressure, reduce stress and anxiety, boost our immune system and increase creativity. These effects are measurable in all types of forests but older, more pristine forests provide the greatest benefits.

Old growth forests also provide benefits to human communities including air and water purification, flood prevention, oxygen production and carbon storage. All forests provide these services but old growth forests are better at doing all of these things than younger forests. Big old trees are especially good at storing carbon and the soil in old growth forests also is much better at taking up and storing carbon than soil in younger forests.

Magnificent forests covered the landscape of the Ottawa Valley before the arrival of European settlers. On both sides of the Ottawa River, for as far as the eye could see were mature forests of red and white pine, spruce, balsam, and hemlock; with smaller quantities of hardwoods like poplar, maple, oak, and basswood. Sadly, only small fragments of these forests remain today.

To our great good fortune, a few foresighted folks saw fit to set aside some of these old growth forests for future generations to enjoy. And some fragments escaped the saw by being in remote areas.

Perhaps the most famous old growth forest in the Ottawa Valley is the Gillies Grove in the Town of Arnprior, northwest of Ottawa. This is a hardwood-hemlock dominated forest with stands of tall white pines up to 47 meters high and 250 years in age. Two other old growth forests in Renfrew County are open to the public, the Shaw Woods, near Eganville Ontario and the Reilly Bird Nature Reserve operated by Nature Ontario and situated along the upper Ottawa River, just northwest of the town of Deep River.

Algonquin Provincial Park contains remnants of old growth forest totaling thousands of hectares. For details see the webpage Old Growth Forest in Algonquin Park. Unfortunately, logging is still allowed in Algonquin Park and much of the old growth forest there remains unprotected. Hopefully this will change soon, with mounting evidence of the benefits of leaving these valuable resources undisturbed.

The Province of Quebec has put considerable effort into identifying and protecting old growth forests. Detailed information and maps are provided on the “exceptional forest ecosystems” page of the Ministry of Natural Resources and Forests website. (Click on the Outaouais tab). An interactive map provides a wealth of information on exceptional forests and biodiversity reserves. Many of these forests are in remote areas and not easy to visit however.

More accessible are some old growth forest remnants in and around the City of Ottawa. You can access information on these places by visiting the Trees Canadensis website.

If you’d like to help preserve old growth forests for future generations to enjoy, consider supporting organizations like the Nature Conservancy of Canada that work to purchase and protect special forests and other natural places in perpetuity.

For more information check out the book Ontario’s Old Growth Forests, available in many libraries. Another excellent resource is the US based Old-Growth Forest Network which offers a How to Save a Forest Toolkit on its website. A publication on the website of the Eastern Ontario Model Forest can help you find and nurture old growth in your woodlot.

It’s good to know that younger forests, left undisturbed, will develop old growth characteristics such as increased biodiversity and carbon storage. If you are in a position to do so as a private landowner or elected representative, consider setting aside younger forests now so that they can become old growth forests for our descendants to enjoy.

Lynn Jones is a founding member of the Ottawa River Institute, a non-profit, charitable organization based in the Ottawa Valley. ORI’s mission is to foster sustainable communities and ecological integrity in the Ottawa River watershed.