Why protect old forests? People often mention recreation and health, natural beauty, biodiversity, and wildlife habitat as reasons to preserve forests. Less often mentioned is what is arguably the most important reason to protect old forests at this critical time: Protecting large trees is crucial to combat climate change.
Drastically reducing emissions of carbon dioxide and methane is essential to halt the increase in global temperature, but reducing future emissions is not enough. We also must remove some of the carbon already released into the atmosphere, and forests play an essential role in doing this. They are the largest CO2 sink on land.
Large trees store more carbon than smaller ones. As environmental scientist Bill Moomaw points out, the largest 1% of trees in a forest store about half the forest’s carbon. And research documents that trees continue adding carbon throughout their lives, contrary to the earlier assertion that carbon storage decreases as a tree ages. A single big tree can add the same amount of carbon in just one year as is contained in an entire mid-sized tree.
One of the most important things we can do, in addition to reducing carbon emissions, is preserve existing forests intact to allow trees to grow large. Coined proforestation, the term distinguishes this strategy from both reforestation and afforestation (planting trees on land that has historically not been forested, which can also have negative impacts, if natural ecosystems and groundwater quantities are compromised by the effort). Planting trees can help combat climate change, but protecting existing forest and allowing it to develop into old growth is far more effective, given the magnitude of carbon removal we now require in a very short time frame and the slow rate of carbon absorption by small trees.
Proforestation is a major benefit of Athens Conservancy’s activities. The forests in our preserves are permanently protected from logging and development. So in addition to the many other benefits of land preservation, protecting large, mature trees and allowing them to grow old helps draw down atmospheric carbon and combat climate change.
— Heather and Phil Cantino