Abstract Detail

The evolution of functional traits in plants: is the giant still sleeping?

Soh, Wuu Kuang [1], Murray, Michelle [2], McElwain, Jennifer [1].

Trends in plant functional traits under elevated atmospheric carbon dioxide.

Climate change will likely alter the ecological functioning of future ecosystems; however, the magnitude and direction of such changes are unpredictable and difficult to quantify. We evaluate the impact of increased atmospheric CO₂ concentration [CO₂] on plant ecological functioning on two contrasting case scenarios linked to leaf mass per area (LMA); firstly, on the long-term impact of a natural CO₂-induced global warming event in the geological past and, secondly, on the short-term impact of anthropogenic-induced global warming. LMA is a key trait used in the measurement and categorization of plant ecological strategies because it is tightly correlated with important functional attributes of the leaf. Our first case study was set in the Late Triassic to Early Jurassic, c. 208–199 Ma (c. 9 million years) with a ~1000-1800 ppm increase in atmospheric [CO₂]. Our second case study was set in the late 1980s–2015 (c. 25 years) with a ~45 ppm increase in [CO₂]. In the first case study, we applied a new paleo-LMA proxy to fossil gymnosperm leaves and showed a significant shift in LMA from low-LMA-dominated taxa in the Late Triassic to high-LMA taxa in Early Jurassic. We demonstrated that extreme CO₂-induced global warming selected for taxa with high LMA which was associated with a stress-tolerant strategy and that post-warming ecological success may be attributed to adaptive plasticity in leaf functional traits such as LMA. In the second case study, we evaluated carbon isotope composition and LMA trends for 264 modern woody angiosperm species across seven biomes, and showed that water-use efficiency in evergreen species had increased more rapidly than in deciduous species. The observed differential physiological response is strongly associated with LMA, which is higher in evergreen than deciduous plants. Our studies highlight that leaf functional traits such as LMA can provide an insight into plant responses to rising [CO₂] in both geological and contemporary time scales.

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1 - Trinity College Dublin, the University of Dublin, Botany Department, College Green, Dublin 2, Dublin, Ireland
2 - Trinity College Dublin, the University of Dublin, Botany Department, College Green, Dublin 2, Dublin, Dublin 2, Ireland

Keywords:
Functional traits
Leaf mass per area
Leaf habit
Elevated CO2
Global warming
Ecological strategy
Physiology.

Presentation Type: Colloquium Presentations
Session: CO04, The Evolution of Functional Traits in Plant: Is the Giant Still Sleeping?
Location: Tucson J/Starr Pass
Date: Monday, July 29th, 2019
Time: 4:30 PM
Number: CO04012
Abstract ID:650
Candidate for Awards:None