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. Above: Shaw Woods. Photo Trees Canadensis website

There is a sweet rich earthy smell in an old growth forest that comes 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 the tree canopy in old growth forests has prompted people to liken these forests to living cathedrals. Often a spontaneous feeling of awe arises when we visit them. 

Looking up into the canopy of an ancient Eastern Hemlock in the Gillies Grove. Photo Lynn Jones

Standing dead trees and fallen giants decaying on the forest floor are common in old growth forests and provide habitats for many different plants and animals. The rich biodiversity that results makes old growth forests living laboratories with enormous potential for scientific discoveries.

Moss covered “coarse woody debris” typical of old growth forests. Photo Lynn Jones
Spotted Salamander in the Reilly Bird Nature Reserve. Photo Noah Cole, Ontario Nature website
“Hemlock Varnish Shelf” in Eastern Algonquin Park. Photo Lynn Jones

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 forests such as  lowered pulse rate and blood pressure, reduced stress and anxiety, boosted immune systems and increased 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. 

Magnificent mature forests covered the Ottawa Valley landscape 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 the Shaw Woods, near Eganville and the Reilly Bird Nature Reserve northwest of the town of Deep River.

Algonquin Provincial Park contains remnants of old growth forest totalling 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.

Information about old growth forests in the Outaouais is provided on the “exceptional forest ecosystems” page of the Quebec Ministry of Natural Resources and Forests website. (Click on the Outaouais tab). Unfortunately many of these forests are in remote areas and not easy to visit.

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.

It’s good to know that younger forests, left undisturbed, will develop old growth characteristics.   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 descendents to enjoy. 

Editor’s Note: Interested in this subject? Click HERE for an earlier article about old growth forests written by Madawaska Valley resident Don WebbValley.

About the author: 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. 


  1. Chris Huggett

    Thank you Lynn Jones for both an insightful and eloquent article on old growth forests in the Ottawa Valley.
    You have my whole hearted support and I only hope that your observations are accepted by the local population without prejudice or deflection. Anthropogenic disturbance, whether directly from industrial activities, or indirectly by the introduction of forest pathogens and global warming are the result of human activity.

  2. Eve-Marie Chamot

    Unfortunately nowadays we need to deal with other unpleasant imported intruders such as spongy moth, woolly adelgid, emerald ash borer, beech scale, etc which will slowly destroy all those lovely surviving old-growth forests. Perhaps all you “tree-huggers” should also build little outhouses to provide overwinter shelter for lady beetles and artificial summer nesting sites for wasps:- the beetles devour scale insects while the wasps devour caterpillars but they need some help since the scarcity of overwintering sites for lady beetles and summer nesting sites for wasps severely limit their summer populations in the forests. Btw, it would help also to maintain suitably designed bird feeders to cater to overwintering chickadees and woodpeckers:- the chickadees devour caterpillars while the woodpeckers devour scale insects but they don’t migrate and we can maximize their summer populations by providing some supplemental food to help them overwinter in larger numbers.

  3. Eve-Marie Chamot

    Unfortunately in the Ottawa Valley, as in Canada generally, Canadians are much better at cutting trees than at managing private forestland for sustained yield and for increasing the commercial quality of private forestland so everywhere you go there is only commercially worthless brush and this puts more harvesting pressure on Crown land and on Algonquin Park. One thing the “tree-huggers” could do is to replace their old fossil-fuel heating systems with modern automated smokeless wood-pellet heating technology from Europe (such as “Fröling” from Austria). This would increase the domestic demand for fuelwood pellets made from green wood chips made from harvested brush and encourage private forest owners to harvest their low-value brush on a regular cycle and leave the high-value trees behind to keep growing even better and take the pressure off Algonquin Park and other Crown nature reserves. They’ve been doing this for centuries in continental Europe and it works quite well. I got quite an “eye-opener” about this after I moved here:- I had an arborist cull ca 20 dead and/or dangerous and/or deformed overmature trees and from this I got ca 4500 bf of very decent saw logs which I gave to a local furniture factory who paid for the haulage plus ca 16 tons of green wood chips which could heat my home for three years plus I left behind all sorts of nice white pine saplings which will eventually grow into a nice “pine park” behind my house. If everyone worked toward this goal then we could revive the local forest industry in a few years while sparing the remaining old-growth forests:- this is not “rocket science” but only commonsense.

  4. Eve-Marie Chamot

    “Research has documented many benefits to human health of spending time in forests such as lowered pulse rate and blood pressure, reduced stress and anxiety, boosted immune systems and increased creativity.”:- hmmm, not quite:- in this area from about May 20 to June 10 each year the black flies and mosquitoes take over until the dragonflies finally arrive to keep them under control:- during that time it’s a good idea to stay out of the forest unless you enjoy being eaten alive! Black flies and mosquitoes breed on top of water which warms up first while dragonflies overwinter and breed on the bottom of swampy ponds and marshes which warm up later. The best time for a walk in the woods is right now after the snow has melted but before the biting insects move in or after the first fall frost when they all die or go into dormancy. It also helps to be philosophical about flying biting insects:- they are all “diehard” relics of the Carboniferous Era ca 350 million mya which just refuse to give up!

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to Top
Comment Rules

  • Please show respect to the opinions of others no matter how seemingly far-fetched.
  • Abusive, foul language, and/or divisive comments may be deleted without notice.
  • In order to avoid confusion in the community, commenters must provide their full name (first and last) and a valid email address.
  • Comments must be limited to the number of words displayed above the comment box.

Verified by MonsterInsights