Not All Savannas Should be Forests
A misinterpretation of what Asian savannas are and have been may be driving some ecological efforts in the wrong direction. In this article at Anthropocene, two recent studies on savannas are discussed, which question the dominant policy of afforestation in such regions.1
There are a number of issues to disentangle. One issue is the question of whether afforestation efforts are going to be useful — there are indications that these efforts are less useful than earlier supposed:
They highlight recent research suggesting that the Bonn Challenge’s 3.5 million square kilometers would, if covered by natural forests, sequester 42 gigatons of carbon, but that figure falls to a mere 1 gigaton if the forests are the pine and eucalyptus plantations expected in much of Africa. Forests may also absorb more solar radiation than do grasslands, thus offsetting the extra carbon they store. And when eucalyptus and pine plantations, which are particularly vulnerable to high-severity fires, burn, most of the carbon they store is released back into the atmosphere.
This feeds into another issue, which is whether the benefits of afforestation of savannas would outweigh the costs of that effort. One such cost would be the destruction of such habitats that have “never been forests” for millions of years:
Bond’s team stresses that truly degraded forests ought to be restored and existing forests protected. But large-scale afforestation “is based on the wrong assumptions,” they argue. “Far from being deforested and degraded, Africa’s savannas and grasslands existed, alongside forests, for millions of years.”
This debate reveals a tension between two principles that can drive ecological efforts. One principle is the restorative principle, which seeks to restore the environment to what it was before — in this context, it would mean understanding the savannas as they have existed for the past few million years, and trying to restore the balance of the environment so that only degraded forests are restored. Another principle could be termed the creative principle, which might seek instead to alter the present environment to meet current needs.
The former is conservative, seeking to restore a past situation, the latter is progressive (for lack of a better word), seeking to create a new situation for some goals to be achieved. We clearly need both principles to operate together, qualifying each other and ensuring that excesses are avoided. The above debate is an interesting one when seen as the working out of a tension between these two principles.