While some new forests are inefficient carbon sinks, because they are made up of young trees with little biomass, the key consideration in the case of methane is not how mature a forest is but how much bark it has to interact with the atmosphere. “It doesn’t matter if the trees are young; as long as there are plenty of them, there will be a lot of exposed trunk surface and the potential for capturing methane from the atmosphere will be high.”
This article published by CREAF is definitely an eye-opener and a very worthwhile read: