More intense rainfall could increase woody plant encroachment

Forest encroachment into savannah systems is a phenomenon being observed across Gabon and Central Africa. While it is not clear what environmental factors are driving this vegetation change in Gabon, factors such as fire, grazing and CO2 concentrations have been used elsewhere as explanations.

A new study published online in Nature Climate Change shows that increases in precipitation intensity, but not total precipitation, increased aboveground woody plant growth and decreased aboveground grass growth in a savannah system in Kruger NP, South Africa, by driving soil water deeper into the soil, enabling woody plants to increase their rooting depths. Woody plant encroachment may continue in the future should precipitation intensity increase.

Kulmatiski A, Beard KH (2013) Woody plant encroachment facilitated by increased precipitation intensity. Nature Climate Change advance online publication.