Healthy Young Forests Work Hard to Sequester Carbon

By Peter Kuitenbrouwer

Over 83 per cent of trees planted under Forests Ontario’s 50 Million Tree Program (50 MTP) are thriving on the landscape and, over time, will sequester significant amounts of carbon, says a new study published in the Forestry Chronicle.

These young forests across Ontario are proof that carefully-planned and well-executed tree planting programs, like those of Forests Ontario, offer long-term help to fight climate change, the authors conclude.

The Canadian Forest Service at Natural Resource Canada conducted a study, Growing Our Future: Assessing the Outcome of Afforestation Programs in Ontario, Canada, using satellite imagery and remote sensing tools, in conjunction with Forests Ontario data, to see how many trees survived on about 12,500 hectares planted through Forests Ontario’s 50 MTP from 2007 to 2016. Elizabeth Celanowicz, Forests Ontario’s chief operating officer, co-authored the paper.

Provided these forests grow undisturbed, the study concludes, over 54 years the forests will remove about 2.24 megatons of carbon dioxide from the atmosphere. The trees will sequester roughly as much carbon as a million cars would produce by driving from Montreal to Vancouver -- and back.

“Trees planted today,” write the authors, “will not result in a carbon sink immediately, but the sink strength will increase over time. Tree planting in Canada is not an immediate solution, but a proactive one; if we hope to see benefits in the long-term, we must start to plant trees today.”

The study also validates Forests Ontario’s data collection methods. “Forests Ontario’s tree planting database is a reliable baseline for afforestation tracking,” reads the report.

But one can’t just plant trees, walk away, and expect to see new forests. The study authors draw from their analysis of Forests Ontario data to make recommendations to the government of Canada on how to implement a pledge to plant two billion trees over the next decade.

Those suggestions include educating landowners on how to look after and monitor new forests, once planted. Here, too, Forests Ontario does good work, “hosting tree planting and forest management workshops for landowners.”

To make sure young forests succeed, the authors write, the forests must be monitored and managed. Quality control of planting should check that trees are properly spaced, roots are covered, and trees go in at the correct depth.

“Newly planted trees are most vulnerable during the first couple of years of establishment and should be assessed to determine survival, growth, and if refill or tending is required,” reads the study. The assessment should check for weed competition, browsing by deer or other wildlife, and pest or rodent damage. If needed, landowners could mow, apply herbicide to control competition, plant refill trees where trees failed, and later thin the stand. These activities “can improve an afforested site's ability to reach free-growing status,” the authors note.

Financial incentives, long-term funding, and landowner outreach are key components that will allow afforestation projects to succeed, the report says.

The study also notes the importance of the Ontario government’s Managed Forest Tax Incentive Program (MFTIP) in enhancing forest cover. MFTIP encourages landowners to maintain and manage existing woodlots, as well as plant more trees, in order to qualify for a property tax reduction.

The results of the research show that Forests Ontario’s database is useful to estimate changes in carbon stocks. Canada can use this data, the authors write, to compile annual carbon inventory reports, which Canada has committed to reporting each year under the United Nations Framework Convention on Climate Change.

Carefully planted forests become carbon sinks that will help Canada hit emissions targets.

“Afforestation in Canada (slow growing trees) is always a long-term strategy, the benefits of which will increase substantially over time,” the authors write. “Therefore, if Canada wants afforested areas to contribute to net zero emission targets by 2050, additional tree planting initiatives have to start as soon as possible.”