Oecologia

, Volume 170, Issue 3, pp 835–845

Phylogenetic niche conservatism in C4 grasses

  • Hui Liu
  • Erika J. Edwards
  • Robert P. Freckleton
  • Colin P. Osborne
Global change ecology - Original research

DOI: 10.1007/s00442-012-2337-5

Cite this article as:
Liu, H., Edwards, E.J., Freckleton, R.P. et al. Oecologia (2012) 170: 835. doi:10.1007/s00442-012-2337-5

Abstract

Photosynthetic pathway is used widely to discriminate plant functional types in studies of global change. However, independent evolutionary lineages of C4 grasses with different variants of C4 photosynthesis show different biogeographical relationships with mean annual precipitation, suggesting phylogenetic niche conservatism (PNC). To investigate how phylogeny and photosynthetic type differentiate C4 grasses, we compiled a dataset of morphological and habitat information of 185 genera belonging to two monophyletic subfamilies, Chloridoideae and Panicoideae, which together account for 90 % of the world’s C4 grass species. We evaluated evolutionary variance and covariance of morphological and habitat traits. Strong phylogenetic signals were found in both morphological and habitat traits, arising mainly from the divergence of the two subfamilies. Genera in Chloridoideae had significantly smaller culm heights, leaf widths, 1,000-seed weights and stomata; they also appeared more in dry, open or saline habitats than those of Panicoideae. Controlling for phylogenetic structure showed significant covariation among morphological traits, supporting the hypothesis of phylogenetically independent scaling effects. However, associations between morphological and habitat traits showed limited phylogenetic covariance. Subfamily was a better explanation than photosynthetic type for the variance in most morphological traits. Morphology, habitat water availability, shading, and productivity are therefore all involved in the PNC of C4 grass lineages. This study emphasized the importance of phylogenetic history in the ecology and biogeography of C4 grasses, suggesting that divergent lineages need to be considered to fully understand the impacts of global change on plant distributions.

Keywords

Phylogenetic niche conservatismC3/C4 photosynthesisPoaceaeMorphologyHabitat

Supplementary material

442_2012_2337_MOESM1_ESM.pdf (595 kb)
Supplementary material 1 (PDF 570 kb)

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Hui Liu
    • 1
  • Erika J. Edwards
    • 2
  • Robert P. Freckleton
    • 1
  • Colin P. Osborne
    • 1
  1. 1.Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
  2. 2.Department of Ecology and Evolutionary BiologyBrown UniversityProvidenceUSA