Large, older trees have been found to grow faster and absorb carbon dioxide more rapidly than younger, smaller trees, despite the previous view that trees’ growth slowed as they developed. Research published in the journal Nature shows that in 97% of tropical and temperate tree species, growth rate increases with size. This suggests that older trees play a vital role in absorbing carbon dioxide from the atmosphere.
Prior to the study, the common assumption was that as trees aged, their growth rate and carbon absorption decreased because the leaves of older trees are less efficient at photosynthesising than the leaves of younger trees. But the new study led by authors from the US Geological Survey, re-examined carbon storage in individual trees. The findings highlight the value of large, older trees as important carbon sinks. They are not only storing lots of carbon but they are also sequestering more carbon and faster than smaller trees.
This study reinforces the importance of large, older trees for absorbing carbon and reducing the mega-effects that are going to arise from massive climate change. This study also highlights flaws in forest policy where old-growth forest is often cleared for pulp and timber purposes.
[Based on the article published at The Conversation.]