Abstract Detail

Conservation Biology

Morris, Ashley [1], Visger, Clayton [2].

Conservation implications of geographic disjunction, limited genetic variation, and predicted shifts in niche space in the federally endangered leafy prairie-clover.

Rare species exhibit geographically disjunct populations for a number of reasons, including anthropological disturbance (either recent or historical), disrupted natural disturbance regimes, and responses to past glacial cycles. Identifying the respective roles of these factors in defining modern-day species distributions can be extremely difficult but may prove to be quite important for defining conservation and recovery strategies. Documenting genetic structure within and among populations, as well as inferring current and potential future environmental niche requirements across disjunct regions can provide key insight into establishment of recovery priorities. Leafy prairie clover (Dalea foliosa (A. Gray) Barneby; Fabaceae) is a federally endangered, herbaceous perennial associated with limestone glades in Alabama and Tennessee and dolomite prairies in Illinois. We developed novel nuclear microsatellite loci to survey nearly 600 individuals over 28 populations across the range of the species to assess how genetic structure varies within and among geographic regions and within and among populations within regions. We also used bioclimatic layers and soil characteristics to visualize potential shifts in niche space during the next 50 years. Overall genetic variation was low within and among populations, but lowest in the most geographically isolated sites in the Illinois region. All alleles observed in Illinois were also observed in Tennessee, whereas some private alleles were observed in Alabama. We infer this to mean that the Illinois populations have likely been isolated for some time, and that the combined effects of a past bottleneck and/or founder effect and inbreeding have led to genetic homogenization among sites. Furthermore, geographic proximity of Alabama populations to Tennessee would seem to promote geneflow among regions, but the presence of private alleles in Alabama suggests some level of separation between the two regions. Moderate climate change models predict an overall increase in temperature and precipitation across all D. foliosa sites, regardless of geographic region. Populations in Tennessee and Alabama are expected to experience daily mean temperature increases that, as a species, D. foliosa has not previously experienced. Illinois populations, however, while poised to experience daily mean temperature increases beyond the current local norm, will still be exposed to temperatures within the envelope of the current climatic regime of Tennessee and Alabama populations. We will discuss the implications that these findings have on conservation and recovery efforts across the range of the species.

Related Links:
the Morris Lab webiste

1 - Furman University, Department Of Biology, 3300 Poinsett Highway, Greenville, SC, 29613, United States
2 - California State University Sacramento, Biological Sciences, 6000 J Street, Sacramento, CA, 95819, United States

population genetics.

Presentation Type: Oral Paper
Number: CB1007
Abstract ID:567
Candidate for Awards:None

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