TY - JOUR
T1 - Unravelling the effect of species mixing on water use and drought stress in Mediterranean forests
T2 - A modelling approach
AU - De Cáceres, Miquel
AU - Mencuccini, Maurizio
AU - Martin-StPaul, Nicolas
AU - Limousin, Jean Marc
AU - Coll, Lluís
AU - Poyatos, Rafael
AU - Cabon, Antoine
AU - Granda, Víctor
AU - Forner, Alicia
AU - Valladares, Fernando
AU - Martínez-Vilalta, Jordi
N1 - Funding Information:
The authors would like to thank an anonymous reviewer for his/her constructive suggestions on previous versions of the manuscript. This research was supported by the Spanish Ministry of Economy and Competitiveness through project DRESS (CGL2017–89149-C2–2-R) and a Ramon y Cajal fellowship to MDC (RyC-2012–11109). The Puéchabon and Font-Blanche experimental sites were annually supported by the French research infrastructure AnaEE-France (ANR-11-INBS-0001) through the SOERE F-ORE-T. JMV benefited from an ICREA Academia Award. RP acknowledges support from Spanish grants CGL2014–55883-JIN and RTI2018–095297-J-I00. AF and FV work was supported by the project COMEDIAS (CGL2017–83170), with Spanish and FEDER funds. Authors thank Dr. Ismael Aranda for data contribution from Armallones site.
Publisher Copyright:
© 2020
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2021/1/15
Y1 - 2021/1/15
N2 - Understanding how water use and drought stress in woody plants change in relation to compositional, structural and environmental variability of mixed forests is key to understand their functioning and dynamics. Observational and experimental studies have so far shown a complex array of water use and drought stress responses to species mixing, but progress is hampered by the costs of replicating measurements. A complementary approach consists in using in silico experiments with trait-based forest ecosystem models, which have the advantage of allowing the interpretation of the net mixing effect as the result of specific combinations of trait differences. We explore the potential of such an approach using a novel trait-based forest ecosystem model with a strong focus on plant hydraulics and data from 186 mixed forest inventory plots including holm oak (Quercus ilex L.) and eight co-occurring species. Sensitivity analyses focusing on the effect of differences in individual plant traits indicate that water use and summer drought stress of holm oak trees respond primarily to the variation in competitor's height, root distribution and xylem hydraulic efficiency and safety. Simulations of pure and mixed stands across different combinations of climate aridity and stand leaf area index indicate that differences in traits may compensate for one another, so that the influence of a given trait (e.g. tree height) on water use or drought stress can be decreased or offset by the influence of another one (e.g. hydraulic efficiency). Importantly, we show that species mixing does not always have positive effects at the stand level. Overall, our simulation study shows that the complexity of species- and stand-level mixing effects on water use and drought stress arises primarily as the result of differences in key functional traits of the competitor, although stand structure and climate aridity may modulate mixing effects.
AB - Understanding how water use and drought stress in woody plants change in relation to compositional, structural and environmental variability of mixed forests is key to understand their functioning and dynamics. Observational and experimental studies have so far shown a complex array of water use and drought stress responses to species mixing, but progress is hampered by the costs of replicating measurements. A complementary approach consists in using in silico experiments with trait-based forest ecosystem models, which have the advantage of allowing the interpretation of the net mixing effect as the result of specific combinations of trait differences. We explore the potential of such an approach using a novel trait-based forest ecosystem model with a strong focus on plant hydraulics and data from 186 mixed forest inventory plots including holm oak (Quercus ilex L.) and eight co-occurring species. Sensitivity analyses focusing on the effect of differences in individual plant traits indicate that water use and summer drought stress of holm oak trees respond primarily to the variation in competitor's height, root distribution and xylem hydraulic efficiency and safety. Simulations of pure and mixed stands across different combinations of climate aridity and stand leaf area index indicate that differences in traits may compensate for one another, so that the influence of a given trait (e.g. tree height) on water use or drought stress can be decreased or offset by the influence of another one (e.g. hydraulic efficiency). Importantly, we show that species mixing does not always have positive effects at the stand level. Overall, our simulation study shows that the complexity of species- and stand-level mixing effects on water use and drought stress arises primarily as the result of differences in key functional traits of the competitor, although stand structure and climate aridity may modulate mixing effects.
KW - Drought stress
KW - Functional traits
KW - Holm oak forests
KW - Plant hydraulics
KW - Trait-based model
KW - Water-related interactions
UR - http://www.scopus.com/inward/record.url?scp=85095708400&partnerID=8YFLogxK
U2 - 10.1016/j.agrformet.2020.108233
DO - 10.1016/j.agrformet.2020.108233
M3 - Artículo
AN - SCOPUS:85095708400
VL - 296
JO - Agricultural and Forest Meteorology
JF - Agricultural and Forest Meteorology
SN - 0168-1923
M1 - 108233
ER -