Shoot dimorphism enables Sequoia sempervirens to separate requirements for foliar water uptake and photosynthesis.

Autor: Chin ARO; Plant Sciences Department, University of California Davis, Davis, CA, 95616, USA., Guzmán-Delgado P; Plant Sciences Department, University of California Davis, Davis, CA, 95616, USA., Sillett SC; Department of Forestry and Wildland Resources, Humboldt State University, Arcata, CA, 95521, USA., Orozco J; Plant Sciences Department, University of California Davis, Davis, CA, 95616, USA., Kramer RD; Dipper and Spruce LLC, White Salmon, WA, 98672, USA., Kerhoulas LP; Department of Forestry and Wildland Resources, Humboldt State University, Arcata, CA, 95521, USA., Moore ZJ; Plant Sciences Department, University of California Davis, Davis, CA, 95616, USA., Reed M; Department of Biological Sciences, Humboldt State University, Arcata, CA, 95521, USA., Zwieniecki MA; Plant Sciences Department, University of California Davis, Davis, CA, 95616, USA.
Jazyk: angličtina
Zdroj: American journal of botany [Am J Bot] 2022 Apr; Vol. 109 (4), pp. 564-579. Date of Electronic Publication: 2022 Apr 12.
DOI: 10.1002/ajb2.1841
Abstrakt: Premise: Trees in wet forests often have features that prevent water films from covering stomata and inhibiting gas exchange, while many trees in drier environments use foliar water uptake to reduce water stress. In forests with both wet and dry seasons, evergreen trees would benefit from producing leaves capable of balancing rainy-season photosynthesis with summertime water absorption.
Methods: Using samples collected from across the vertical gradient in tall redwood (Sequoia sempervirens) crowns, we estimated tree-level foliar water uptake and employed physics-based causative modeling to identify key functional traits that determine uptake potential by setting hydraulic resistance.
Results: We showed that Sequoia has two functionally distinct shoot morphotypes. While most shoots specialize in photosynthesis, the axial shoot type is capable of much greater foliar water uptake, and its within-crown distribution varies with latitude. A suite of leaf surface traits cause hydraulic resistance, leading to variation in uptake capacity among samples.
Conclusions: Shoot dimorphism gives tall Sequoia trees the capacity to absorb up to 48 kg H 2 O h -1 during the first hour of leaf wetting, ameliorating water stress while presumably maintaining high photosynthetic capacity year round. Geographic variation in shoot dimorphism suggests that plasticity in shoot-type distribution and leaf surface traits helps Sequoia maintain a dominate presence in both wet and dry forests.
(© 2022 The Authors. American Journal of Botany published by Wiley Periodicals LLC on behalf of Botanical Society of America.)
Databáze: MEDLINE
Externí odkaz: