Plantation restoration

Forest restoration with conifer plantations

Since the early 1900s, tens of millions of trees have been planted in southern Ontario to increase forest cover. This was initiated in response to environmental problems caused by the low forest cover levels of the late 1800s. These problems included severe soil erosion, extreme flooding and low summer river flows and an overall loss of biodiversity.

Historically, large areas were often planted with only one or two species of conifer trees - especially white and red pine, spruce, and cedar. These hardy species provided an inexpensive and reliable way to quickly re-establish forests. Over 40 per cent of the 11,500 hectares of forest owned by the GRCA are conifer plantations.

Plantation management

Establishing these large blocks of conifer trees is only the first step in the restoration of a healthy, diverse forest. Plantation thinning is a management practice used to diversify these plantation forests, and is the next step in the forest restoration process. 

Thinning means removing some of the planted trees. This allows more light to reach the forest floor, so that young trees and shrubs can germinate. It also provides room for the larger trees to grow. The ultimate goal is to establish a forest with a diversity of tree, shrub and plant species of various ages and sizes.

Usually a plantation is ready for its first thinning at around 30 years of age. The first thinning typically includes the removal of full rows of trees to allow large forestry equipment access into the area. Scattered individual trees are also removed in adjacent rows. Most of the trees are used for timber products. Small logs and branches are left on the forest floor, where they provide habitat and eventually decompose, enriching the forest soil.

Follow-up thinnings take place every 10 to 15 years. Scattered trees are removed so that a diversity of younger trees have enough sunlight and space to grow into the forest canopy. Over time, a forest with a variety of trees species, sizes and ages is established.

Benefits of plantation thinning:

• Increases forest species and structural diversity
• Increases forest resilience
• Improves and protects wildlife habitat
• Produces useful timber products - sequestering carbon
• Provides revenue from renewable, sustainable forest products (The GRCA uses this revenue for additional forest improvements.)

How we protect and improve wildlife habitat:

• By promoting trees and shrubs that provide food for wildlife
• By protecting raptor stick nests and trees with nest cavities
• By increasing the number of logs and branches on the forest floor
• By protecting streams and wetlands
• By not harvesting during bird breeding (March 15 - July 31)

Learn more about plantation thinning:

Managing Regeneration in Conifer Plantations to Restore a Mixed Hardwood Forest (on the Landowner Resource Centre website)