Details

Autor(en) / Beteiligte

• Sabot, Manon E. B.
• De Kauwe, Martin G.
• Pitman, Andy J.
• Medlyn, Belinda E.
• Verhoef, Anne
• Ukkola, Anna M.
• Abramowitz, Gab

Titel

Plant profit maximization improves predictions of European forest responses to drought

Ist Teil von

• The New phytologist, 2020-06, Vol.226 (6), p.1638-1655

Ort / Verlag

England: Wiley

Erscheinungsjahr

2020

Quelle

MEDLINE

Beschreibungen/Notizen

• • Knowledge of how water stress impacts the carbon and water cycles is a key uncertainty in terrestrial biosphere models. • We tested a new profit maximization model, where photosynthetic uptake of CO₂ is optimally traded against plant hydraulic function, as an alternative to the empirical functions commonly used in models to regulate gas exchange during periods of water stress. We conducted a multi-site evaluation of this model at the ecosystem scale, before and during major droughts in Europe. Additionally, we asked whether the maximum hydraulic conductance in the soil–plant continuum k max (a key model parameter which is not commonly measured) could be predicted from long-term site climate. • Compared with a control model with an empirical soil moisture function, the profit maximization model improved the simulation of evapotranspiration during the growing season, reducing the normalized mean square error by c. 63%, across mesic and xeric sites. We also showed that k max could be estimated from long-term climate, with improvements in the simulation of evapotranspiration at eight out of the 10 forest sites during drought. • Although the generalization of this approach is contingent upon determining k max, it presents a mechanistic trait-based alternative to regulate canopy gas exchange in global models.