Abstract Detail



Biogeography

Henzler-Lhasawa, Jampa [1], Douglas, Norman [2], Flores Olvera, Hilda [3], Ochoterena, Helga [4], Moore, Michael J. [5].

Are gypsum plant communities stable during periods of climate change? A phylogeographic case study in Acleisanthes (Nyctaginaceae).

Acleisanthes (Nyctaginaceae) is a small genus of arid-adapted annual to perennial herbs and shrubs, pollinated by crepuscular or nocturnal insects. A clade of six species in the genus are endemic to gypsum outcrops throughout the Chihuahuan Desert region. During full glacial periods of the Late Pleistocene, the climate in the Chihuahuan and Sonoran Deserts became colder and wetter, reducing population sizes within most desert plant species. However, we hypothesize that geographically widespread gypsum endemic species may have experienced less reduction in population size during glacial periods of the Pleistocene, because most plant species do not thrive on gypsum soils under most climate conditions. Hence gypsum endemics may not have experienced increased competition during wetter periods when grassland and savanna invaded the modern region of the Chihuahuan Desert. If true, we would not observe evidence of genetic bottlenecks in widespread gypsum endemic taxa. The gypsum clade of Acleisanthes represents an excellent opportunity to test this hypothesis because it is one of dominant gypsum endemic groups in the Chihuahuan Desert. Specifically, we investigated plastid genetic diversity in populations of three species of gypsum endemic Acleisanthes that occur in the southern half of the Chihuahuan Desert: A. purpusiana, A. palmeri, and A. acatitensis. We sequenced two plastid spacer regions (ndhF/rpl32 and psbD/trnT-GGU) for 120 individuals, and created haplotype networks for all individuals. We found relatively high plastid haplotype diversity and geographic structure, and found no evidence of a range-wide bottleneck. These results are consistent with other recent studies of dominant gypsum endemics in the same region (Fouquieria shrevei, Petalonyx crenatus), suggesting that gypsum environments may experienced little plant community turnover during the Pleistocene.


Related Links:
The Origin and Evolution of Gypsum Endemic Plants


1 - Oberlin College, Department of Biology, 119 Woodland St, Oberlin, OH, 44074, USA
2 - University Of Florida, Biology, PO Box 118525, Gainesville, FL, 32611, United States
3 - Instituto de Biología, UNAM, Departamento de Botánica, Apartado Postal 70-367, Mexico, DF, 04510, Mexico
4 - Instituto de Biología, UNAM, Apartado Postal 70-367, Mexico, DF, 04510, Mexico
5 - Oberlin College, Department Of Biology, 119 Woodland St., Science Center K111, Oberlin, OH, 44074, United States

Keywords:
Acleisanthes
Nyctaginaceae
gypsum
Phylogeography
Mexico
Chihuahuan Desert
Pleistocene.

Presentation Type: Poster
Number: PBG002
Abstract ID:410
Candidate for Awards:None


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