Abstract Detail



Ecophysiology

Segovia-Rivas, Alí [1], Olson, Mark [2], Donoghue, Michael [3], Edwards, Erika [4], Rosell, Julieta [5], Anfodillo, Tommaso [6], Moeglein, Morgan [7].

Plant hydraulics and height of Viburnum across climate gradients.

Worldwide, there has been a massive dieback of trees that might be related to climate change and it seems that hydraulics could play a fundamental role. To maintain constant conductance per-unit leaf area as trees grow taller, vessels in the xylem should widen from the stem tip to the base. Wider vessels are more vulnerable to embolism, so taller plants should be more vulnerable. The traditional theory of vessel hydraulic adaptation postulates that vessel diameter is determined by climate, with cold selecting for narrower vessels compared to warmer areas. Recent work suggests that plant height is the main driver of vessel diameter, meaning that the relationship between vessel diameter, climate, and height remains to be explored. Here, we examine the possibility that there could be adaptive variation in the Y-intercept of within-plant tip-to-base vessel widening curves, with plants in dry and cold areas having lower intercepts (narrower vessels for a given height) than in moist-warm places. To examine this issue, we installed climate stations along strong elevational gradients in three states in Mexico and measured vessel diameter along the stems of ten species of Viburnum (Adoxaceae). We find no evidence that climate affects vessel widening, though total plant height and leaf area affect very little the Y-intercept of the vessel widening profile along individual stems.


1 - UNAM, Instituto de Biología, Tercer Circuito s/n Ciudad Universitaria , Delegación Coyoacán, CDMX, 70-233, Mexico
2 - Instituto De Biologa, Universidad Nacional Autnoma De Mxico, Tercer Circuito S/n De Ciudad Universitaria, Tercer Circuito S/n De Ciudad Universitaria, Ciudad De Mxico, 04510, Mexico
3 - Yale University, Department Of Ecology And Evolutionary Biology, 21 Sachem Street, Po Box 208106, New Haven, CT, 06511, United States
4 - Yale University, Department Of Ecology And Evolutionary Biology, 165 Prospect St, New Haven, CT, 06511, United States
5 - Universidad Nacional Autónoma de México, Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510, Mexico
6 - Università degli Studi di Padova, Dipartimento Territorio e Sistemi Agro Forestali, Viale dell’Università 16, Legnaro, Padova, 35020, Italia
7 - 745 Orange Street, New Haven, CT, 06511, United States

Keywords:
vessel widening (conduit taper)
xylem
climate change
wood anatomy
vulnerability to embolism.

Presentation Type: Poster
Session: P, Ecophysiology Posters
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 5:00 PM Time and date to be determined
Number: PPE004
Abstract ID:816
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize


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