Restoring old growth forests to benefit future generations

Old growth forests are require fundamentally different care than woodlot management, and it's something family forest owners should talk about and come up with a plan that will span generations.

Many of North America's old growth forests were harvested by European settlers, and because of the length of time it takes for mature forests to grow, there are still plenty of opportunities to allow the land to regenerate.

The Ontario Woodlot Association has written about this topic, giving forest owners advice on restoring old growth forest conditions and allow future generations the chance to experience them again. Here is a rundown on the significance of old growth forestry and why you should consider regenerative practices.

There are quite a few differences between how land owners might typically treat their private forests compared to old growth. Here are a few examples of different kinds of forested land you may have on your property:

Woodlot: Woodlots are typically highly managed and designed for routine harvesting. Trees are typically planted in rows with a plan that allows for optimal height, sunlight and ideal growth conditions according to forest managers.

Woodlots often:

• • Are made up of straight rows of the same species of tree

  • Are regularly harvested according to a woodlot management plan

  • Harvesting is usually done to generate income for the landowner

Private forests: Whereas woodlots are usually planted according to a plan, private forests are more plentiful and less planned. Many property owners will purchase land with pre-existing forested land that may have some old growth characteristics.

Private forests often:

• • Include a greater diversity and tree density of tree species than woodlots

  • Can still be harvested but often are not as closely managed as woodlots

  • Dead trees, sick or injured trees are often harvested in place of healthy trees

Old growth forests: Most of North America's old growth forests are second generation after being harvested in the 1700s. While much of the old growth forests are on federal lands and make up protected public parks and national forests, there are also old growth forests under private ownership. Care must be taken to preserve these lands due to the species which inhabit them.

Old growth forests often:

• • Have the greatest diversity of plant species, though second-generation old growth lacks the stronger diversity of the first generation

  • Old growth forests provide habitats to many different types of species, from forest owls to possums, raccoons and other mammals and insects

  • Include standing dead trees and fallen trees, which create habitats for various species

  • May be protected by environmental laws restricting harvesting

Older forests made up of mature trees create optimal conditions to support various species, and can help ones endangered by a loss of habitats and over-harvesting.

However even these second-generation forests now don't offer as many benefits as the natural forests which have been lost.

"Today’s second-growth forests are less diverse than the original mixed-hardwood forests and provide habitat for fewer and different forms of life," says the Ontario Woodlot Association. "Today’s forests support more deer, but they provide fewer homes for warblers, wood ducks, saw-whet owls, blue spotted salamanders, bats, wolves, grey foxes and many other species. Some species, like elk and woodland caribou, are no longer found in southern Ontario."

That's why restoring old growth is so important, not only to create for a healthier natural environment for people, but also to support species impacted by man-made development and climate change.

"Restoration is a long-term process. It takes several years to begin to see results, but the benefits are immense. By restoring diversity, we can provide habitat for many more species, including 28 birds and 18 mammals in southern Ontario that prefer old-growth habitat. Some of these species are now considered rare or endangered. These include the southern flying squirrel and the silver-haired bat," adds the Ontario Woodlot Association.

As a property owner or land manager, one of the most important things you can do to improve forest resilience and support land conservation is to let the environment take its own path.

"The easiest approach to restoration is to leave the forest alone and let natural processes take their course. Over a century or two, natural succession will transform second growth into old-growth ecosystems," says the Ontario Woodlot Association.

"As trees die, fall and decompose they will create habitat and return nutrients and energy to the soil where they can support new life. As organic matter builds on the forest floor it will retain moisture and transform the drier second-growth forest into a moister, old-growth environment."

Here are some things you may want to consider to promote growth and mature forest and restore old growth characteristics:

While many private land owners try to avoid harvesting healthy trees, they will often target diseased, injured, felled or standing dead trees to harvest.

However doing this can still harm the long term health of your forest. Standing dead trees provide habitats for species like owls and many rodents and mammals use fallen trees for shelter.

The best thing you can do is allow the tree density to naturally develop and allow forest plant life to take its natural course. Lands managed this way will slowly build resilience and create stronger habitats for forest species.

Doing this will take many years and will take decades to see results. If you want a more hands-on approach to old growth management, be sure to consult a forestry expert before affecting your forest's features, says the Ontario Woodlot Association.

"For faster results in a managed forest, you can take a more active approach that involves thinning, cutting holes in the forest canopy, rebuilding a rich layer of decaying organic matter on the forest floor and protecting wildlife trees from harvest," it advises.

While it is possible to aid the forest's canopy in supporting healthy forest conditions, you may want to be cautious about this because it takes a lot of different conditions for the forest's health to bloom.

"Fire, wind, ice storms, disease and insects created openings in the canopy where new growth could occur," says the Ontario Woodlot Association. "Small canopy gaps, created by a falling tree or a group of trees, gave shade-tolerant understorey trees the room and sunlight they needed to grow quickly and capture a place in the canopy. Larger openings gave mid-tolerant and intolerant species the chance to become established. The result was a highly varied forest, with stands in different stages of succession, trees of all sizes and ages, and many different species."

While it is possible to encourage and support a healthy forest canopy, there are a few best-practices you should follow.

"You can mimic natural disturbances and speed the process of natural succession by cutting small and large holes in the canopy. Periodically, make clearings in about half of one to two per cent of the forest. Each hole in the canopy should be greater than six metres from one edge of the canopy to the next."

Different sizes of openings impact different species, and the goal is to maintain an environment that supports a lot of different flora and fauna. Because of this, canopy management should be carefully considered and done in consultation with experts.

If this seems like a lot to manage, you can leave the forest to do its own thing. Disease, insects, storms and other elements will naturally create holes in the forest canopy which support growth, and these do not require human intervention.

A lot of North America's forested land has been at risk, due to changing environmental conditions, forest fires and harvesting. All of this has led to the second generation of old growth forests being less diverse, resilient and supporting fewer species.

But with many generations of careful land management, it's possible to allow these forests to recover and rebuild. If you own old growth land it's advised to:

• Come up with a long term plan, spanning from one year to multiple decades

• If this land is going to be managed by your children or other family in the future, talk with them and get them up to speed on your forest planning

• Consult forestry experts and get the best, up-to-date advice as your forest continues its growth

Following these tips will help to restore old growth and aid in the expansion of forest biodiversity.

The Ontario Woodlot Association is a non-profit organization dedicated to supporting owners of privately owned forests and is committed to sustainability. Its members promote, through education and mentorship, the benefits of a healthy ecosystem thereby increasing the enjoyment of our forests. For more information visit their website. You can also read more on this topic here.