@article{hoffmann_sanders_just_wall_hohmann_2020, title={Better lucky than good: How savanna trees escape the fire trap in a variable world}, volume={101}, ISSN={["1939-9170"]}, DOI={10.1002/ecy.2895}, abstractNote={Abstract}, number={1}, journal={ECOLOGY}, author={Hoffmann, William A. and Sanders, R. Wyatt and Just, Michael G. and Wall, Wade A. and Hohmann, Matthew G.}, year={2020}, month={Jan} } @article{wall_douglas_hoffmann_wentworth_gray_xiang_knaus_hohmann_g._2014, title={Evidence of population bottleneck in Astragalus michauxii (Fabaceae), a narrow endemic of the southeastern United States}, volume={15}, ISSN={1566-0621, 1572-9737}, url={http://link.springer.com/10.1007/s10592-013-0527-2}, DOI={10.1007/s10592-013-0527-2}, number={1}, journal={Conservation Genetics}, publisher={Springer Science and Business Media LLC}, author={Wall, W. A. and Douglas, N. A. and Hoffmann, W. A. and Wentworth, T. R. and Gray, J. B. and Xiang, Q. Y. J. and Knaus, B. K. and Hohmann and G., M.}, year={2014}, month={Feb}, pages={153–164} } @article{wall_hoffmann_wentworth_gray_hohmann_2012, title={Demographic effects of fire on two endemic plant species in the longleaf pine-wiregrass ecosystem}, volume={213}, ISSN={["1385-0237"]}, DOI={10.1007/s11258-012-0068-7}, number={7}, journal={PLANT ECOLOGY}, author={Wall, Wade A. and Hoffmann, William A. and Wentworth, Thomas R. and Gray, Janet B. and Hohmann, Matthew G.}, year={2012}, month={Jul}, pages={1093–1104} } @article{wall_wentworth_shelingoski_stucky_leblond_hoffmann_2011, title={Lost and Found: Remnants of the Big Savannah and Their Relationship to Wet Savannas in North Carolina}, volume={76}, ISSN={["1938-4386"]}, DOI={10.2179/10-046.1}, abstractNote={Abstract Conversion to agriculture and plantations, development, and fire suppression have reduced the extent of savannas in the southeastern United States, and there is a need to catalog and classify the remaining savannas for both restoration and resource management purposes. The Big Savannah was a wet savanna in North Carolina that was destroyed in the 1950s, and subsequent vegetation classifications have generally not accommodated well the unique natural plant community of the Big Savannah. Vegetation reminiscent of that described for the Big Savannah was discovered north of the original site and designated as Wells Savannah. To evaluate the uniqueness of the savanna vegetation at Wells Savannah, we compiled a data set from permanent quadrats with information on vegetation and environmental variables from other Outer Coastal Plain savannas to compare with similar data from the natural community at Wells Savannah. We also inventoried an additional 26 quadrats on a tract adjacent to Wells Savannah that had experienced fire suppression. Results from multivariate analyses demonstrated clear differences between the Wells Savannah quadrats and other regional wet savanna quadrats based on both vegetation and soils. A number of species and several soil characteristics (higher clay percentage, and higher available iron and boron) distinguish Wells Savannah from other wet savannas. Although the fire suppressed quadrats near Wells Savannah had lower species richness, typical savanna species such as Ctenium aromaticum and Calamovilfa brevipilis were still present. Further exploration of fire-suppressed tracts in the area may yield more wet savanna inclusions similar to the former Big Savannah.}, number={4}, journal={CASTANEA}, author={Wall, W. A. and Wentworth, T. R. and Shelingoski, S. and Stucky, J. M. and LeBlond, R. J. and Hoffmann, W. A.}, year={2011}, month={Dec}, pages={348–363} } @article{douglas_wall_xiang_hoffmann_wentworth_gray_hohmann_2011, title={Recent vicariance and the origin of the rare, edaphically specialized Sandhills lily, Lilium pyrophilum (Liliaceae): evidence from phylogenetic and coalescent analyses}, volume={20}, ISSN={["0962-1083"]}, DOI={10.1111/j.1365-294x.2011.05151.x}, abstractNote={Abstract}, number={14}, journal={MOLECULAR ECOLOGY}, author={Douglas, Norman A. and Wall, Wade A. and Xiang, Qiu-Yun and Hoffmann, William A. and Wentworth, Thomas R. and Gray, Janet B. and Hohmann, Matthew G.}, year={2011}, month={Jul}, pages={2901–2915} } @article{wall_hilton_wentworth_gray_hohmann_hoffmann_2010, title={Effects of light and temperature on germination of Pyxidanthera brevifolia Wells (Diapensiaceae)}, volume={137}, ISSN={["1940-0616"]}, DOI={10.3159/10-ra-023.1}, abstractNote={Abstract Pyxidanthera brevifolia is an evergreen semi-woody cushion plant endemic to the Sandhills of North and South Carolina, with the majority of populations occurring on Fort Bragg Military Reservation in North Carolina. Currently the species is listed as Endangered in North Carolina and is designated as a Species at Risk (SAR) by the US Department of Defense. Previous studies have suggested that seeds may not be viable because they failed to germinate under controlled conditions. Our objectives in this study were to attempt germination of Pyxidanthera brevifolia seeds, determine the best temperature conditions for germination, and understand more about germination requirements to aid in future restoration efforts. Using seeds that had been stored at room temperature for six months, we performed a germination experiment at the NCSU Phytotron with six treatments, all combinations of three temperature regimes (low (18 °C day / 14 °C night), medium (22/18 °C), and high (26/22 °C)) and two light conditions (light and dark). We monitored the experiment for 13 weeks, recording the number of seeds germinating per dish and the number of days to germination for seeds in each treatment. We found that Pxyidanthera brevifolia produces germinable seeds and that there are significant effects of light and temperature on germination. Highest germination occurred under low temperature and high light conditions (78%); the combination of high temperature and no light produced the lowest germination (6%). Seeds exposed to light germinated significantly earlier at the coolest temperature, compared to medium and high temperatures. These results indicate that it is possible to germinate seeds of this rare plant and suggest that germination of Pyxidanthera brevifolia likely occurs in late fall and is dependent on adequate light availability.}, number={4}, journal={JOURNAL OF THE TORREY BOTANICAL SOCIETY}, author={Wall, Wade A. and Hilton, Jacob L. and Wentworth, Thomas R. and Gray, Janet B. and Hohmann, Matthew G. and Hoffmann, William A.}, year={2010}, pages={348–354} } @article{wall_douglas_xiang_hoffmann_wentworth_hohmann_2010, title={Evidence for range stasis during the latter Pleistocene for the Atlantic Coastal Plain endemic genus, Pyxidanthera Michaux}, volume={19}, ISSN={["1365-294X"]}, DOI={10.1111/j.1365-294x.2010.04793.x}, abstractNote={The general phylogeographical paradigm for eastern North America (ENA) is that many plant and animal species retreated into southern refugia during the last glacial period, then expanded northward after the last glacial maximum (LGM). However, some taxa of the Gulf and Atlantic Coastal Plain (GACP) demonstrate complex yet recurrent distributional patterns that cannot be explained by this model. For example, eight co‐occurring endemic plant taxa with ranges from New York to South Carolina exhibit a large disjunction separating northern and southern populations by >300 km. Pyxidanthera (Diapensiaceae), a plant genus that exhibits this pattern, consists of two taxa recognized as either species or varieties. We investigated the taxonomy and phylogeography of Pyxidanthera using morphological data, cpDNA sequences, and amplified fragment length polymorphism markers. Morphological characters thought to be important in distinguishing Pyxidanthera barbulata and P. brevifolia demonstrate substantial overlap with no clear discontinuities. Genetic differentiation is minimal and diversity estimates for northern and southern populations of Pxyidanthera are similar, with no decrease in rare alleles in northern populations. In addition, the northern populations harbour several unique cpDNA haplotypes. Pyxidanthera appears to consist of one morphologically variable species that persisted in or near its present range at least through the latter Pleistocene, while the vicariance of the northern and southern populations may be comparatively recent. This work demonstrates that the refugial paradigm is not always appropriate and GACP endemic plants, in particular, may exhibit phylogeographical patterns qualitatively different from those of other ENA plant species.}, number={19}, journal={MOLECULAR ECOLOGY}, author={Wall, Wade A. and Douglas, Norman A. and Xiang, Qiu-Yun and Hoffmann, William A. and Wentworth, Thomas R. and Hohmann, Matthew G.}, year={2010}, month={Oct}, pages={4302–4314} }