Abstract Detail

Systematics

Melton, Anthony [1], Folk, Ryan [1], Grady, CJ [2], Stewart, Aimee [2], Beach, James (Jim) [2], Soltis, Pamela [1], Soltis, Douglas [1].

Do Macroecological or Biogeographic Processes Better Explain the Patterns of the Eastern Asia – Eastern North America Floristic Disjunction?

Species richness anomalies are often found along environmental or latitudinal gradients. One species richness anomaly of great interest is that of the eastern Asia - eastern North America (EA-ENA) floristic disjunction. In addition to over 60 genera of seed plants, many other groups of organisms, from rodents to lichens, exhibit this disjunction. Many of the seed plant clades that occur across the disjunction are more species-rich in EA than ENA, with EA having approximately 1.6 times as many species of seed plants as ENA. The EA and ENA clades typically occupy similar habitats, although the topography and climate of EA are much more heterogeneous than in ENA. This study aims to test the alternative hypotheses that either macroecology or biogeographic processes have contributed to the EA-ENA species richness anomaly. Analyses were conducted for eight species pairs and seven larger genera. Occurrence data and climate data were downloaded from public databases for Ecological Niche Model (ENM) development. Maximum likelihood phylogenies were reconstructed using public data from GenBank. Age-overlap correlation tests were conducted for larger genera and included occurrence, distribution, and ecological data using ENMTools. Results suggest that these clades exhibit phylogenetic niche conservatism and that speciation has occurred largely in allopatry. The BiotaPhy platform was used to test for correlations between speciation events and environmental variables or biogeographic features across phylogenies. Many nodes connecting EA and ENA clades were highly correlated with biogeographic features. Within these clades, some nodes were correlated with environmental variables. These results suggest that patterns of the disjunction largely associated with biogeographic processes, followed by macroecological processes. This work will help elucidate whether macroecological or biogeographic processes have contributed to the species richness patterns we see today.

1 - Florida Museum of Natural History, University of Florida, 1659 Museum Road, Gainesville, Florida, 32611, USA
2 - University of Kansas, Biodiversity Institute & Natural History Museum, 1345 Jayhawk Blvd., Lawrence, KS, 66045

Keywords:
ecological niche modelling
Niche Conservatism
biogeography.

Presentation Type: Oral Paper
Session: SYS1, Systematics I: Land plants, Gymnosperms to Rosids part 1
Location: Tucson H/Starr Pass
Date: Monday, July 29th, 2019
Time: 1:30 PM
Number: SYS1001
Abstract ID:714
Candidate for Awards:None