From the ‘Not as bad as we theorised’ department, a paper which finds that models of water cycling in rainforest over-estimated the effect of drought by a big factor. The paper is paywalled, but there’s a write up here which summarises. Worth noting that the paper emphasises this natural resilience operates best in undisturbed forest.
Journal of Climate 2013 ; e-View
doi: http://dx.doi.org/10.1175/JCLI-D-13-00074.1
Impact of evapotranspiration on dry season climate in the Amazon forest
Anna Harper*
College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, Devon, UK, Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
Ian T. Baker, A. Scott Denning, David A. Randall, Donald Dazlich, and Mark Branson
Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
Abstract
Moisture recycling can be an important source of rainfall over the Amazon forest, but this process relies heavily upon the ability of plants to access soil moisture. Evapotranspiration (ET) in the Amazon is often maintained or even enhanced during the dry season, when net radiation is high. However, ecosystem models often over predict the dry season water stress. We removed unrealistic water stress in an ecosystem model (the Simple Biosphere model, SiB3), and examined impacts of enhanced ET on the dry season climate when coupled to a GCM. The “Stressed” model experiences dry season water stress and limitations on ET, while the “Unstressed” model has enhanced root water access and exhibits strong drought tolerance.
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