The accurate identification of species that are in need of protection is one of the most essential challenges of conservation biology (Lovich and Gibbons, 1997). When deciding if a species needs conservation protection, there are two main scientific concerns that must be addressed: (1) determining if the taxonomic standing of the target species is upheld (i.e., if it is a real, rare species) and (2) deciding where the target species occurs or is likely to occur. In this study we used an integrative approach combining ecological niche modeling and molecular genetics to understand the taxonomy of a federally threatened Hibiscus species, H. dasycalyx, in East Texas. We tested whether the nomenclature of H. dasycalyx and two common and widespread sympatric species, H. laevis and H. moscheutos is supported. Specifically, we used ecological niche modeling methods to test for ecological distinctness among the species, along with equencing the nuclear gene encoding granule-bound starch synthase (GBSSI) to determine if there were ecological and phylogenetic distinctions among the three species that match their nomenclature. The ecological niche models revealed that H. dasycalyx and H. moscheutos were significantly ecologically different from one another, whereas H. dasycalyx and H. laevis were ecologically indistinguishable. When examining the molecular genetics results, the Hibiscus species were divided into two distinct groups: Group I, H. dasycalyx and H. laevis; and Group II, H. moscheutos. Based on these results, the H. dasycalyx type may be part of the morphological variation that occurs within the more widespread H. laevis species. Therefore, I outline areas of future research that would help to answer more definitively whether H. dasycalyx is a distinct entity from H. laevis or is, in fact, subsumable within H. laevis.
Date of publication
Sain, Melody P., "Distinguishing the Neches River Rose Mallow, Hibiscus Dasycalyx, from its Congeners Using DNA Sequence Data and Niche Modeling Methods" (2015). Biology Theses. Paper 26.