Abstract Detail

Systematics Section/ASPT

Spalink, Daniel [1], MacKay, Ron [2], Sytsma, Kenneth J. [3].

When you can’t run and you can’t hide: biological and climatic threats to a globally imperiled bulrush (Scirpus) revealed by genotyping-by-sequencing and ecological niche modeling.

Long’s bulrush (Scirpus longii, Cyperaceae) is a globally imperiled species with scattered populations ranging from southern New Jersey to Nova Scotia. A pyrophyte, Long’s bulrush typically only flowers following massive disturbance events such as fire; otherwise, reproduction is exclusively vegetative. This presents a challenge to conservation efforts, as the ability of Scirpus longii to migrate in concert with climate change is potentially limited. Furthermore, populations in Nova Scotia are possibly experiencing introgressive invasion by the weedy Scirpus cyperinus. Thus, this already rare species may be under threat of extinction in both the southern and northern extremes of its range. We seek to characterize the distribution of genetic diversity among populations, to determine if southern populations are genetically distinct and under threat of climatically induced extirpation, and to measure the extent of hybridization in northern populations. We present data obtained through genotyping-by-sequencing (GBS), a restriction site associated DNA next-generation sequencing approach, on samples collected throughout the entire range of Scirpus longii. We reconstruct the historical distribution of this species using ecological niche modeling and phylogeographic methodologies from the Last Glacial Maximum to the present, and project its potential distribution under future climate scenarios. We determine that populations in Maine and Nova Scotia are genetically distinct, that populations south of Massachusetts will be outside of Scirpus longii’s current climatic envelope by 2070, and that introgressive hybridization is abundant in Nova Scotia, Maine, and Massachusetts.

1 - University Of Wisconsin-Madison, Department Of Botany, 430 Lincoln Drive, Madison, WI, 53706, USA
2 - Mount Saint Vincent University, Biology, 166 Bedford Highway, , Halifax, NS, B3M2J6, Canada
3 - University Of Wisconsin, Department Of Botany, Birge Hall, 430 Lincoln Drive, Madison, WI, 53706, USA

Keywords:
Cyperaceae
Scirpus
genotyping by sequencing
Population Genomics
Phylogeography
ecological niche modeling
climate change
hybridization
introgression
extinction.

Presentation Type: Oral Paper:Papers for Sections
Session: 31
Location: Salon 4/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 9:15 AM
Number: 31006
Abstract ID:1144
Candidate for Awards:George R. Cooley Award