Fernández-Molano Ginna Esperanza, Méndez-Alonzo Rodrigo, Alvarez-Añorve Mariana, Terrazas Teresa, Tinoco-Ojanguren Clara
Instituto de Ecología, Departamento de Ecología de la Biodiversidad, Universidad Nacional Autónoma de México, Campus Hermosillo, Luis Donaldo Colosio s/n, Los Arcos, Hermosillo, Sonora CP 83250, México.
Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Unidad de Posgrado, Edificio D, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán CP 04510, Ciudad de México, México.
AoB Plants. 2025 Aug 19;17(5):plaf041. doi: 10.1093/aobpla/plaf041. eCollection 2025 Oct.
To cope with heat and water stress, evergreen and deciduous species from hot and arid deserts should adjust their stomatal conductance ( ) and leaf water potential (Ψ) regulation in response to changes in soil water availability, high temperatures, and vapour pressure deficits (VPDs). To test whether phenology induces changes in -Ψ coordination, we tested for associations between 14 leaf traits involved in leaf economics, hydraulics, and stomatal regulation, including minimum seasonal water potential (Ψ) and maximum ( ), turgor loss point (Ψ), osmotic potential (Ψ), leaf area (LA), and specific leaf area (SLA), across 12 tree species from the Sonoran Desert with contrasting phenology. We found that foliar phenology, leaf hydraulics, and leaf economic traits are coordinated across species and organized along the axis of physiological efficiency and safety in response to temperature and VPD. Evergreens were more drought-tolerant and more restrictive in water use than deciduous species, maintaining lower during the rainy season and lower Ψ, Ψ, and Ψ. In contrast, deciduous species were less drought-tolerant, shedding their leaves during the dry season. During the rainy season, they exhibit higher than evergreens, enhancing water transpiration. Moreover, deciduous species, as isohydric plants, showed stricter control over and finer regulation of leaf water potential (Ψ). Due to their remarkable physiological diversity, desert trees can endure extreme environmental conditions by employing contrasting hydrological strategies.
为了应对高温和水分胁迫，来自炎热干旱沙漠的常绿和落叶树种应根据土壤水分有效性、高温和水汽压差（VPD）的变化来调整其气孔导度（ ）和叶片水势（Ψ）调节。为了测试物候是否会引起 -Ψ协调的变化，我们测试了索诺兰沙漠中12种物候不同的树种的14个与叶片经济学、水力学和气孔调节有关的叶片性状之间的关联，这些性状包括最小季节性水势（Ψ）、最大 （ ）、膨压损失点（Ψ）、渗透势（Ψ）、叶面积（LA）和比叶面积（SLA）。我们发现，叶物候、叶片水力学和叶片经济性状在物种间是协调的，并沿着生理效率和安全性的轴进行组织，以响应温度和VPD。常绿树种比落叶树种更耐旱，水分利用更具限制性，在雨季保持较低的 以及较低的Ψ、Ψ和Ψ。相比之下，落叶树种耐旱性较差，在旱季落叶。在雨季，它们的 高于常绿树种，从而增强水分蒸腾。此外，落叶树种作为等水植物，对 的控制更严格，对叶片水势（Ψ）的调节更精细。由于其显著的生理多样性，沙漠树木可以通过采用不同的水文策略来忍受极端环境条件。
