Abstract Detail

Biodiversity synthesis: Linking large phylogenies with species traits and ecologies.

Nogales da Costa Vasconcelos, Thais [1], O'Meara, Brian [2], Beaulieu, Jeremy [3].

Historical drivers leading to spatial gradients of diversity in flowering plants.

Species richness is not homogeneously distributed in space. For instance, there is a general trend for species richness to decrease towards the poles producing a latitudinal diversity gradient (‘LDG’). Several different hypotheses have been put forward to explain this pattern, including tropical zones favoring higher speciation rates leading to species accumulation over time. However, recent efforts in linking the LDG to spatial differences in speciation rates have resulted in a counter-intuitive arrangement where speciation rates actually increase towards the poles. Although these results are based on large, comprehensive datasets, how an inverse LDG for speciation rates would lead to higher species-richness in the tropics requires further investigation. Here we re-evaluate the inverse LDG in speciation rates for a selected group of major flowering plants clades using a different methodological approach than previous recent studies. We use trait-independent, hidden-rates-only, diversification models to estimate turnover and extinction fraction, orthogonal transformations of the original speciation and extinction  rate parameters that may better provide insights into the diversity generating processes. We also used fine-scale environmental variables to test the effect of temperature, precipitation, altitude and freezing tolerance, as well as latitude, on diversification. Our results lead to novel insights into the historical drivers leading to spatial gradients of diversity in flowering plants, including how habitat heterogeneity, extinction, and speciation may have shaped these patterns over time.

1 - University of Arkansas
2 - 8424 Mecklenburg Ct., Knoxville, TN, 37923, United States
3 - University Of Arkansas, Department Of Biological Sciences, 601 SCEN, Fayetteville, AR, 72702, United States

latitudinal diversity gradient.

Presentation Type: Colloquium Presentations
Session: COL01, Biodiversity synthesis: Linking large phylogenies with species traits and ecologies
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 11:00 AM
Number: COL01005
Abstract ID:326
Candidate for Awards:None

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