Schumacher, Brian , Willyard, Ann .
Species Delimitation of Pinus arizonica and Pinus arizonica var. stormiae Using Molecular, Morphological, and Environmental Criteria.
Unclear evolutionary relationships in the genus Pinus present a unique challenge to researchers, especially in pine species spanning the Mexico-U.S.A. border. We focus on two taxa, P. arizonica (Arizona pine) and P. arizonica var. stormiae (stormiae pine). Until recently, these were considered varieties of P. ponderosa (ponderosa pine), but may be more closely related to Mexican pines treated as P. cooperi. Our research is the first to use population-level molecular evidence (i.e. allele frequency for about 25 individuals per site) to help clarify the status of stormiae pine. We sampled stormiae pine at four sites in Texas, U.S.A. (representing most of its known distribution in Big Bend National Park, the Guadalupe Mountains, and Mt. Livermore) and included samples of seven sites representing Arizona pine and ponderosa pine. The three criteria examined in this study were 1) the presence/absence of genetic intermediates using multi-locus molecular markers (Simple Sequence Repeats from the nuclear genome (nSSRs) and the plastid genome (cpSSRs)); 2) diagnosability using morphological characters observed on one herbarium collection for each population; and 3) analyses of climatic data for the geographic distributions of putative pine taxa assessing whether the habitats of stormiae and Arizona pine represent environmentally unique niches.We used the results from these measures to assess the hypothesis that the four populations of stormiae pine we examined are more closely related to each other than they are to Arizona pine or to ponderosa pine. We also discuss future plans to include samples from P. arizonica and P. cooperi sites in Mexico in these analyses.
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1 - Hendrix College, Biology Dept, 1600 Washington Ave, Conway, AR, 72032, USA
ecological niche models
Presentation Type: Poster:Posters for Sections
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM