Extreme drought triggers parallel shifts in wood anatomical and physiological traits in upper treeline of the Mediterranean Andes
Por:
Santini L., Jr., Craven D., Rodriguez D.R.O., Quintilhan M.T., Gibson-Carpintero S., Torres C.A., Roig F.A., Muñoz A.A., Venegas-Gonzalez A.
Publicada:
1 ene 2024
Resumen:
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 physiology 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 treeline environments of the Mediterranean Andes, although it is not clear whether these adaptations will be sufficient to persist in scenarios that predict intensification of climate stress. Finally, our results provide empirical evidence that integrating wood anatomical and physiological traits facilitates the understanding of resilience mechanisms that treeline forests develop in the face of increasing drought stress. © The Author(s) 2024.
Filiaciones:
Santini L.:
Hémera Centro de Observación de la Tierra, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile
Jr.:
Hémera Centro de Observación de la Tierra, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile
Craven D.:
GEMA Center for Genomics, Ecology and Environment, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile
Data Observatory Foundation, ANID Technology Center, Eliodoro Yáñez 2990, Santiago, Providencia, 7510277, Chile
Rodriguez D.R.O.:
Department of Forest Sciences, ESALQ-University of Sao Paulo, Pádua Dias Avenue 11, Piracicaba, Brazil
Quintilhan M.T.:
Department of Plant Biology, Institute of Biology, University of Campinas, Monteiro Lobato, 255, Cidade Universitária, Campinas, Brazil
Gibson-Carpintero S.:
Instituto de Geografía, Universidad Nacional Autónoma de México (UNAM), Circuito de la, Investigación Científica, Ciudad de Mexico, 04510, Mexico
Torres C.A.:
Hémera Centro de Observación de la Tierra, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile
Roig F.A.:
Hémera Centro de Observación de la Tierra, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile
Argentine Institute of Nivology, Glaciology and Environmental Sciences (IANIGLA CONICET), Dr. Ruiz Leal S/N-Parque General San Martín, Mendoza, M5500, Argentina
Muñoz A.A.:
Institute of Geography, Pontificia Universidad Católica de Valparaíso, Brasil Avenue 2241, Valparaíso, 2362807, Chile
Venegas-Gonzalez A.:
Hémera Centro de Observación de la Tierra, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile
Instituto de Ciencias Agroalimentarias, Animales y Ambientales (ICA3), Universidad de O’Higgins, Ruta 90 Km 3, San Fernando 90, Chile
gold, All Open Access; Gold Open Access
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