Forests and the Carbon Cycle
Forests–through photosynthesis–store (sequester) carbon from the atmosphere with carbon becoming part of plant mass or eventual wood products. When trees die, carbon continues to remain in the forest ecosystem and cycle through dead trees (or wood products), downed dead wood, forest floor, soil organic carbon, and/or eventually to the atmosphere through decay or combustion.
Plants are the lungs of the Earth, shaping the atmosphere which sustains us today. Every natural process and human activity eventually results in gases being added to or removed from the atmosphere. A century of fossil fuel burning has raised international concern over levels of carbon dioxide that could substantially alter Earth’s climate. Forests remove carbon dioxide from the atmosphere and store it in long-lived pools (like trees and soils) and products (like furniture and building materials), so forests may play a critical role in climate change mitigation. The cycle of carbon atoms from the atmosphere through forest ecosystems and back to the atmosphere is highly complex and varies over both time and spatial scales.
Across highly productive forests (for example, the central hardwoods of the Eastern US), large quantities of carbon are sequestered on an annual basis. Forest products, like the pages of a book, offer an alternative approach to storing carbon over longer time periods. By contrast, disturbance events like wildfires and hurricanes may be important for forest health, but they also release large quantities of carbon dioxide. Forest carbon currently stored in trees and soils dwarfs annual fossil fuel emissions, and there are concerns about the stability of these pools under a changing climate.