Wood density and hydraulic traits influence species’ growth response to drought across biomes

• Published in: Global change biology Vol. 28; no. 12; pp. 3871 - 3882
• Main Authors: Serra‐Maluquer, Xavier, Gazol, Antonio, Anderegg, William R. L., Martínez‐Vilalta, Jordi, Mencuccini, Maurizio, Camarero, Jesús Julio
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.06.2022
• Subjects: Aridity; Capacity; climate; Climate change; Climate effects; Climate models; Density; Drought; Drought index; dry environmental conditions; Ecosystem dynamics; Extreme drought; Forest ecosystems; functional traits; growth; Growth rate; growth rings; Hydraulic properties; hydraulic traits; Hydraulics; Leaves; Low resistance; Plant species; Recovery; Resilience; Species; temperature; Terrestrial ecosystems; tree growth; Tree rings; trees; Water deficit; Water potential; Wood; wood density; growth; drought; hydraulic traits; functional traits; tree rings; wood density
• ISSN: 1354-1013; 1365-2486; 1365-2486
• DOI: 10.1111/gcb.16123

Tree species display a wide variety of water‐use strategies, growth rates and capacity to tolerate drought. However, if we want to forecast species capacity to cope with increasing aridity and drought, we need to identify which measurable traits confer resilience to drought across species. Here, we use a global tree ring network (65 species; 1931 site series of ring‐width indices—RWI) to evaluate the relationship of long‐term growth‐drought sensitivity (RWI‐SPEI drought index relationship) and short‐term growth response to extreme drought episodes (resistance, recovery and resilience indices) with functional traits related to leaf, wood and hydraulic properties. Furthermore, we assess the influence of climate (temperature, precipitation and climatic water deficit) on these trait‐growth relationships. We found a close correspondence between the long‐term relationship between RWI and SPEI and resistance and recovery of tree growth to severe drought episodes. Species displaying a stronger RWI‐SPEI relationship to drought and low resistance and high recovery to extreme drought episodes tended to have a higher wood density (WD) and more negative leaf minimum water potential (Ψmin). Such associations were largely maintained when accounting for direct climate effects. Our results indicate that, at a cross‐species level and global scale, wood and hydraulic functional traits explain species’ growth responses to drought at short‐ and long‐term scales. These trait‐growth response relationships can improve our understanding of the cross‐species capacity to withstand climate change and inform models to better predict drought effects on forest ecosystem dynamics. This study evaluates de covariation between short‐term growth response to drought (resistance, recovery and resilience), long‐term growth drought relationship and functional traits related to leaf, wood and hydraulic properties. We found that species displaying a strong relationship between growth and drought (Ring Width Index ~Standardized Precipitation and Evapotranspiration Index relationship), low resistance and high recovery to extreme drought episodes tend to have higher wood density and more negative leaf minimum water potential. see also the Commentary: https://doi.org/10.1111/gcb.16157.