Trait coordination, mechanical behaviour and growth form plasticity of Amborella trichopoda under variation in canopy openness
Por:
Trueba, Santiago, Isnard, Sandrine, Barthelemy, Daniel, Olson, Mark E.
Publicada:
1 ene 2016
Categoría:
Plant Science
Resumen:
Understanding the distribution of traits across the angiosperm phylogeny
helps map the nested hierarchy of features that characterize key nodes.
Finding that Amborella is sister to the rest of the angiosperms has
raised the question of whether it shares certain key functional trait
characteristics, and plastic responses apparently widespread within the
angiosperms at large. With this in mind, we test the hypothesis that
local canopy openness induces plastic responses. We used this variation
in morphological and functional traits to estimate the pervasiveness of
trait scaling and leaf and stem economics. We studied the architecture
of Amborella and how it varies under different degrees of canopy
openness. We analyzed the coordination of 12 leaf and stem structural
and functional traits, and the association of this covariation with
differing morphologies. The Amborella habit is made up of a series of
sympodial modules that vary in size and branching pattern under
different canopy openness. Amborella stems vary from self-supporting to
semi-scandent. Changes in stem elongation and leaf size in Amborella
produce distinct morphologies under different light environments.
Correlations were found between most leaf and stem functional traits.
Stem tissue rigidity decreased with increasing canopy openness. Despite
substantial modulation of leaf size and leaf mass per area by light
availability, branches in different light environments had similar leaf
area-stem size scaling. The sympodial growth observed in Amborella could
point to an angiosperm synapomorphy. Our study provides evidence of
intraspecific coordination between leaf and stem economic spectra. Trait
variation along these spectra is likely adaptive under different light
environments and is consistent with these plastic responses having been
present in the angiosperm common ancestor.
Filiaciones:
Trueba, Santiago:
IRD, UMR AMAP, Lab Bot & Ecol Vegetale Appl, BPA5, Noumea 98800, New Caledonia
Isnard, Sandrine:
IRD, UMR AMAP, Lab Bot & Ecol Vegetale Appl, BPA5, Noumea 98800, New Caledonia
Barthelemy, Daniel:
CIRAD, BIOS Direct, F-34398 Montpellier, France
INRA, UMR AMAP, F-34398 Montpellier, France
Olson, Mark E.:
Univ Nacl Autonoma Mexico, Inst Biol, Tercer Circuito S-N Ciudad Univ Mexico, Mexico City 04510, DF, Mexico
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