1CCR contribution no: 982.
Indirect vegetation–soil moisture feedback with application to Holocene North Africa climate1
Article first published online: 25 SEP 2009
© 2009 Blackwell Publishing Ltd
Global Change Biology
Volume 16, Issue 6, pages 1733–1743, June 2010
How to Cite
LIU, Z., NOTARO, M. and GALLIMORE, R. (2010), Indirect vegetation–soil moisture feedback with application to Holocene North Africa climate. Global Change Biology, 16: 1733–1743. doi: 10.1111/j.1365-2486.2009.02087.x
- Issue published online: 4 MAY 2010
- Article first published online: 25 SEP 2009
- Received 3 June 2009 and accepted 16 September 2009
- indirect feedback;
- soil moisture feedback;
- vegetation feedback
Using a fully coupled climate–terrestrial ecosystem model, we demonstrate explicitly that an initial perturbation on vegetation induces not only a direct positive vegetation feedback, but also a significant indirect vegetation–soil moisture feedback. The indirect feedback is generated through either fractional cover change or soil moisture depletion. Both indirect feedback mechanisms are triggered by a vegetation perturbation, but involve subsequent effects of soil moisture and evaporation, indirectly. An increase in vegetation tends to reduce bare-ground evaporation through either the area reduction in bare ground or the depletion of soil moisture; the reduced evaporation may then counter the initial plant transpiration, favoring a negative net vegetation feedback. Furthermore, grasses are more effective in inducing the indirect vegetation–soil feedbacks, because of their limited plant evapotranspiration and shallower roots that tend to change surface soil moisture, and, in turn, evaporation, effectively. In comparison, trees favor a direct positive vegetation feedback due to their strong plant transpiration on subsurface soil moisture as well as a lower albedo.