Abstract Detail

Pteridology

Ng, Molly [1], Heberling, Mason [2].

Using leaf mass per area to understand ecological opportunity across ferns.

The majority of modern ferns arose from the most recent radiation in the early Cenozoic (~55-50 Ma). Cenozoic radiation of ferns is hypothesized as a result of global climatic change or ecological opportunity, where ferns diversified into new habitats created by angiosperms. The ecological opportunist hypothesis has been tested and supported using functional traits within five fern families from Order Polypodiales. Extending sampling and increasing analysis to include more lineages, especially older lineages, is extremely important in understanding whether ecological opportunity is only seen in Order Polypodiales or throughout multiple taxonomic units. Using leaf mass per area (LMA), we expand on a previous study by including members from different lineages to test whether traits are more similar between closely related species and whether LMA have evolved differently in new ferns than old ferns. We downloaded digitized herbarium specimens of 350 fern species (n = 5–15 specimens/species depending on availability) and measured leaf area and petiole width to estimated LMA based on the fern-specific biomechanical model. Then, we averaged samples for each species and conducted a phylogenetic signal analysis using previously published phylogenies. Our data show a wide range of LMA across lineages, with Bloomberg’s K and Pagels λ (phylogenetic signal indices) showing statistically significant (p<0.05) moderate to high phylogenetic signal (0.6 – 0.8), indicating that traits are more similar between closely related species than by random. Expanding analyses of LMA across all fern lineages has not only shown broad functional diversity across ferns but insights into ferns as ecological opportunists.

1 - Carnegie Museum of Natural History, Section of Botany, 4400 Forbes Ave, Pittsburgh, PA, 15213, USA
2 - Carnegie Museum Of Natural, Section Of Botany, 4400 Forbes Ave, Pittsburgh, PA, 15213, United States

Keywords:
phylogenetic signal
Ferns
leaf mass per area
functional trait.

Presentation Type: Oral Paper
Number: PTR1003
Abstract ID:809
Candidate for Awards:Edgar T. Wherry award