Extreme drought triggers parallel shifts in wood anatomical and physiological traits in upper treeline of the Mediterranean Andes  

作　　者：Luiz Santini Jr. Dylan Craven Daigard Ricardo Ortega Rodriguez Manolo Trindade Quintilhan Stephanie Gibson‑Carpintero Cristina Aravena Torres Fidel A.Roig Ariel A.Muñoz Alejandro Venegas‑Gonzalez 

机构地区：[1] Hémera Centro de Observación de la Tierra,Universidad Mayor,Camino La Pirámide 5750,Huechuraba,Santiago,Chile [2] GEMA Center for Genomics,Ecology and Environment,Universidad Mayor,Camino La Pirámide 5750,Huechuraba,Santiago,Chile [3] Data Observatory Foundation,ANID Technology Center,Eliodoro Yáñez 2990,7510277 Providencia,Santiago,Chile [4] Department of Forest Sciences,ESALQ-University of Sao Paulo,Pádua Dias Avenue 11,Piracicaba,Brazil [5] Department of Plant Biology,Institute of Biology,University of Campinas,Monteiro Lobato,255,Cidade Universitária,Campinas,Brazil [6] Instituto de Geografía,Universidad Nacional Autónoma de México(UNAM),Circuito de la,Investigación Científica,04510 Ciudad de Mexico,México [7] Argentine Institute of Nivology,Glaciology and Environmental Sciences(IANIGLA CONICET),Dr.Ruiz Leal S/N-Parque General San Martín,M5500 Mendoza,Argentina [8] Institute of Geography,Pontificia Universidad Católica de Valparaíso,Brasil Avenue 2241,2362807 Valparaíso,Chile [9] Instituto de Ciencias Agroalimentarias,Animales y Ambientales(ICA3),Universidad de O’Higgins,Ruta 90 Km 3,San Fernando 90,Chile

出　　处：《Ecological Processes》2024年第1期132-143,共12页生态过程(英文)

基　　金：FONDECYT Postdoctorado 3200765;AVG to Fondecyt Regular 1221701;DC to FONDECYT Project 1201347;supported by a fellowship from the Fundacao de AmparoàPesquisa do Estado do Sao Paulo(FAPESP,grants 2023/07753-6)

摘　　要：Background Treeline ecotones of Mediterranean ecoregions have been affected by the increasing intensity and severity of droughts.Even though the effect of droughts on forest dynamics has been widely documented,knowledge is relatively scarce of how extreme climate episodes affect the hydraulic structure and,therefore,the phys-iology of woody plants.The Mediterranean Andes have experienced an uninterrupted period of drought since 2010,including an extremely dry year in 2019 with approximately 80%rainfall deficit.Here,we investigated shifts in wood anatomical and physiological traits of Kageneckia angustifolia,an endemic treeline species,in response to this drought period.Methods We evaluated the xylem plasticity of three K.angustifolia populations across their natural distribution(31–35°SL)based on anatomical(vessel structure and distribution)and physiological(intrinsic water-use efficiency)variables in the tree rings.We focused on the period 2000–2020 that corresponds to before the megadrought(2000–2007),(ii)megadrought(2008–2018)and(iii)hyperdrought(2019–2020).The variables were annualized and analyzed by linear mixed-effects models.Results Our results provide insights to the anatomical and physiological mechanisms underlying the resilience of treeline forests to persistent droughts in central Chile.We found that the extreme drought in 2019–2020 triggered shifts in vessel size and frequency that increased hydraulic safety.These significant shifts in vessel traits occurred in parallel with a decrease in pit aperture area and an increase in water-use efficiency,further increasing the resilience of K.angustifolia to extreme drought stress.Conclusions Our results revealed coordinated shifts in vessel size and frequency and water-use efficiency in response to the megadrought,thereby reducing vulnerability to hydraulic failure.The apparent resilience of K.angustifolia to extreme droughts suggests that this adaptation to drought stress may increase its ability to tolerate novel climatic conditions of treeli

关 键 词：Dendro-anatomy Kageneckia angustifolia Xylem vulnerability Drought Climate change 

分 类 号：S781[农业科学—木材科学与技术]