How can decaying trees contribute to atmospheric carbon dioxide after deforestation?

When trees are removed during deforestation, they stop sequestering carbon dioxide from the atmosphere through photosynthesis. However, the contribution of decaying trees to atmospheric carbon dioxide is a distinct process driven by decomposition.123

As trees die—whether left behind after logging or cleared for land use—they become part of the organic matter in the ecosystem, such as litter or soil humus. Microorganisms, primarily bacteria and fungi, break down this organic material. During this process of decomposition, the carbon that the trees sequestered in their tissues throughout their lifetimes is released back into the atmosphere as carbon dioxide.431

This release is a natural part of the carbon cycle, but deforestation accelerates it by increasing the volume of dead biomass and disrupting the balance of carbon storage. While burning trees releases carbon immediately, the slower process of microbial decay also serves as a significant, ongoing source of greenhouse gas emissions following forest clearing.432