Carbon Storage and Sequestration
Trees are carbon sinks, storing carbon dioxide (CO²) absorbed from the atmosphere through photosynthesis. The tree trunk, especially the heartwood, is a major reservoir for carbon:

How It Works:
Trees convert (CO2) into sugars during photosynthesis, using some for energy and storing the rest in the trunk, branches and roots.
The xylem (wood tissue) locks carbon for decades or even centuries in long-lived species like Ontario's red oaks or globally in giant sequoias.

Ontario Example:
Sugar maples (Mh) and Red Oaks (Or) can sequester up to 20-30 kg of CO2 annually, contributing significantly to carbon storage in temperate forests.

Global Context:
Tropical trees store more carbon per unit area due to their faster growth and larger size. However, deforestation in these areas reduces their potential.
Old-growth forests are crucial because their larger trunks store more carbon despite slower growth.