Reforestation is an important part of tackling climate change, but it seems we need to think carefully about where we do it.
Research led by the University of Cambridge, UK, shows that river flow is reduced in areas where forests have been planted and does not recover over time. In some regions it can disappear within a decade.
And that can alter the local cost-benefit mix of tree-planting programs, says plant scientist Laura Bentley, first author of a paper in the journal Global Change Biology.
The bottom line, the researchers say, is that reduced river flow can “constitute a notable ecosystem disservice” in areas where it has value for economic activity and welfare, but in other parts of the world can be an “effective environmental restoration program to achieve historic conditions”.
“Rather than assert whether changes in river flow resulting from forestation would constitute an ecosystem service or disservice overall,” they write, “we emphasise the potential importance of accounting for these changes in future forestation programs so that forests may be accurately valued, to the benefit of local communities.”