Abstract Detail

Ecophysiology

Mozzi, Giacomo [1], Hultine, Kevin [2], Crivellaro, Alan [3].

Leaf traits in succulent and non-succulent plants show both similar constraints and divergent strategies in water storage and resources use.

Economic spectrum theory dictates that plant traits evolve to optimize carbon gain given a set of environmental constraints. Among environmental constraints, drought-related stress is of key importance in determining plants survival and natural distribution. Moreover, in a predicted changing climate, to understand the mechanism underlying drought stress resistance in plants is becoming even more relevant. In our study, we tested the relationships between three leaf traits which describe leaves water storage capacity, an important parameter in determining plants drought resistance, and resources use strategies. We included 133 different species classified in three leaf types: sclerophyllous, fast return and succulent and, for each species, we computed the specific leaf area (SLA), the water mass per area (WMA) and the saturated water content (SWC). We tested the interplay between SWC and WMA to investigate if different leaf types, including succulent leaves, are similarly constrained in terms of water storage capacity and resources use. Thus, we tested if, unlike non-succulent leaves, SWC and WMA of succulent-leaf bearing taxa scale independently of SLA. Finally, we supposed that the degree of succulence, in a wide range of succulent leaves morphologies, would vary with the climatic conditions while the SLA remains largely invariant of climate in succulent-leaf taxa. We show that succulent and non-succulent species are similarly constrained in terms of water storage capacity. We also show that the different water storage indices bear different information regarding water storage and resources acquisition strategies in different leaves morphologies. Finally, we show that for the species we considered in this study the SLA is invariant of aridity in leaf succulent taxa as supposed. SWC is independent of climate variables too, but we found a significant relationship between WMA and rain precipitation data. The results of this study add to our understanding of the constraints that drive plant evolution over broad taxonomic scales and in response to climate variability with a special focus on succulent leaves.

1 - University of Padova, TESAF, Viale dell Universitá 16, Legnaro, Padova, 35020, Italy
2 - 1201 N Galvin Parkway, Phoenix, AZ, 85008, United States
3 - University of Cambridge, Department of Geography, Downing Place, CB2 3EN, Cambridge, UK

Keywords:
Succulence
Leaf traits
Leaves economic spectrum.

Presentation Type: Oral Paper
Session: ECOPH1, Ecophysiology I
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 11:45 AM
Number: ECOPH1004
Abstract ID:680
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize,Physiological Section Best Paper Presentation