Old forests as carbon sinks

Scientists break forest carbon into five major “pools”:

• Aboveground biomass (trunks, branches, leaves)

• Belowground biomass (roots)

• Deadwood

• Forest litter

• Soil organic carbon

Soil alone can account for 50–75% of a forest’s total carbon storage, often more than the trees themselves. But when forests are logged or fragmented, carbon is lost from both above and below ground, and forest soils can continue releasing CO₂ for up to 20 years after cutting. Even so-called “ecological thinning” can degrade soil carbon if mismanaged.

Contrary to popular belief, older forests and large trees store more carbon, and continue to sequester carbon at high rates.

A single 120-year-old white pine can sequester 182 lbs of carbon in a year, the same as 152 saplings.

A 200-year-old pine can hold 25,000 lbs of biomass, even accounting for decay.

The highest total carbon accumulation happens between ages 40 to 140 years, peaking between 80 and 120.

Younger trees grow quickly in percentage terms, but their total carbon gains are small. It’s the older forests that do the real work.

The Wabanaki Forest is a globally significant ecosystem—rich in carbon, biodiversity, and cultural history. It’s home to species at risk like the Canada Warbler, Olive-sided Flycatcher, Black Ash, and countless rare lichens, mosses, and fungi. Its wetlands, bogs, and mature woodlands are massive carbon sinks that cannot be replaced by plantations or young regrowth.

But the forest is being lost rapidly. Across the Maritimes:

• Clearcutting continues in proposed protected areas

• Logging roads fragment carbon-rich soils

• Older stands are being harvested just as they reach their peak climate value

• In Nova Scotia alone, less than 14% of land is currently protected, and in places like Kings County, that number is under 5%.