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Heather Sahli

Associate Professor
Office Location FSC 139
Phone Number: (717) 477-1580 


PhD, Michigan State University
BS, College of William and Mary


My primary research interests are at the interface of ecology and evolutionary biology as I strive to understand adaptive evolution in plants, the forces driving plant population differentiation, and variation in plant-insect interactions across populations. To address these questions I use a combination of field studies, greenhouse experiments, and molecular techniques.

For my Ph.D. I measured natural selection by different pollinator species on floral traits of wild radish and examined the influence of genetic drift versus natural selection in driving divergence in floral morphology across different populations of this widespread agricultural weed.  As a postdoctoral researcher at the University of Hawaii, my research was more ecological in nature.  I examined how plant-pollinator interactions changed along an elevation gradient on the Mauna Loa volcano on Hawaii Island.  I also quantified the impact of invasive Argentine ants on populations of endemic Hawaiian bees and how this altered flower visitation rates to endemic Hawaiian plant species in Haleakala National Park on the island of Maui. 

Since joining the Shippensburg Biology Department in 2009, I have worked with undergraduate students on several projects including the effects of logging on pollinator diversity and plant reproduction in nearby Michaux State Forest and the role that eastern box turtles play in seed dispersal in Pennsylvania.  My recent research has focused on the evolution of tolerance to salt spray in plants in the genus Monarda and the reproductive and conservation biology of a Pennsylvania endangered iris, Iris verna.  My master’s students at Shippensburg have addressed topics such as the effectiveness of different pollinator species at pollinating fruit trees as well as the role that the Enemy Release Hypothesis plays in explaining invasiveness of several exotic plant species in Pennsylvania, the reproductive biology of Iris verna, the role that native and exotic species play in promoting bee diversity, and detecting eDNA of an endangered bat at flowering Agave.  

Another interest of mine is sustainable agriculture and increasing environmental initiatives on our campus.  As part of this interest I helped start Shippensburg University’s very own campus farm in 2012!   We are devoted to providing students with a chance to take part in hands-on sustainable agriculture, in providing agricultural research opportunities for students, and in providing fresh, local produce to community members in need.  I also serve on the Environmental Steering Committee on campus to help increase environmental initiatives and environmental awareness on campus.

In addition to the teaching, service, and research that I take part in on campus, I also serve on the PA Vascular Plants Technical Committee, am one of the representatives for our department to the Commonwealth of Pennsylvania University Biologists (CPUB), and am Vice President for the Conococheague Audubon Society. 

Research Interests
  • Evolutionary Ecology
  • Pollination Biology and Pollinator Diversity
  • Plant-Animal Interactions
  • Plant Conservation
  • Sustainable Agriculture
Courses Taught
  • Bio 100 Basic Biology
  • Bio 145 Environmental Biology
  • Bio 162 Principles of Biology: Organismal Diversity
  • Bio 230 Botany
  • Bio 448 Field Botany and Plant Taxonomy
  • Bio 559 Evolutionary Ecology (graduate)
Undergraduate Student Research Projects
  • Manasiben Patel (2021-2022), Leslie Taylor (2021-2022), Tara Feltman (2021-2022), Robert Markey (2022), Hannah Raines (2021), Jessica Zheng (2020), Aron Fitzgerald (2019), Taylor Kolish (2019), Bailey Bzdak (2019), Olivia Pieklo (2019). Local adaptation to salt spray in Monarda punctata (horsemint).
  • Elaina Long (2020), Kimberley Fogelsanger (2020), Olivia Turner(2017-2018), and Megan Conway (2018). Natural selection and pollination biology of the Pennsylvania endangered dwarf iris, Iris verna.
  • Virginia Masland and Josh Levitsky (2014). Impact of invasive Ficaria verna on native plant diversity and soil quality
  • Sean Cooney (2013), Alicia Helfrick (2010), Nathan Weber (2011), and Jaclyn Braund (2011). The Impact of Timber Harvest on Pollinator Visitation, Understory Plant Reproduction, and the Pollinator Community,
  • Lindsey Wayland, Sarah Komisar, and Paige Williams (2012-2013). Organismal Exclusionary Research on Crops.
  •  Josh Levitsky (2012-2013). Different Methods of Crop Covering Used to Extend the Growing Season in South Central Pennsylvania. 
  •  Neal Ryder (2012), Pam Simons (2011-2012) and Danielle Hunsinger (2011). Habitat, Diet, and Seed Dispersal Potential of the Eastern Box Turtle in South Central Pennsylvania.
  • Terrence Topping-Brown (2012). Determination of Microalgal Species as a Potential Biodiesel Feedstock
  • Rhiannon Kerr and Caitlynn Brig (2010). Quantifying pollen loads of pollinators in a Hawaiian coastal habitat.
MS Student Research Projects
  • Julie Zeyzus (2021-2022). eDNA detection and visitation of Leptonycteris nivalis at flowering Agave.
  • Jaci Braund (2015-2017). Conservation biology of the PA endangered Iris verna.
  • Edy Cheremond  (2015-2017). Does the percent of non-native cover affect pollinator abundance and diversity?
  • Brandon Hang (2013). Relative Salt Tolerance of Monarda punctata (Lamiaceae) from Marine and Lacustrine Shores.
  • Varma-Rose Williams (2011-2013). Does the Enemy Release Hypothesis Explain the Success of Invasive Species in Pennsylvania?
  • Amanda Ritz (2010-2012) Quantifying the Efficacy of Native Pollinators for Fruit Tree Production Using Crab Apples.
Selected Publications
  • Braund, J.E.* and F. Sahli. 2021. Mating system, pollination, and seed dispersal in the Pennsylvania endangered Iris verna. Journal of the Torrey Botanical Society 149: 8-16.
  • Sapir, Y., K. Karoly, V. Koelling, H.F. Sahli, F.N. Knapczyk, and J.F. Conner. 2017. Effect of expanded variation in anther position on pollinator visitation to wild radish, Raphanus raphanistrum. Annals of Botany. 120: 665-672.

  • Shay, K., D.R. Drake, A.D. Taylor, H.F. Sahli, M. Euaparadorn, M. Akamine, M., J. Imamura, D. Powless, and P. Aldrich. 2016. Alien insects dominate the plant-pollinator network of a Hawaiian coastal ecosystem. Pacific Science 70: 409-429.
  • Sahli, H. F., P.D. Krushelnycky, D.R. Drake, and A.D. Taylor. 2016. Patterns of floral visitation to native Hawaiian plants in presence and absence of invasive Argentine ants. Pacific Science 70: 309-322.
  • Williams, V. R. J.* and H.F. Sahli. 2016. A comparison of herbivore damage on three invasive plants and their native congeners: implications for the enemy release hypothesis. Castanea 81:128-137.
  • Koch, J.B.* and H.F. Sahli. 2013. Shifts in foraging dynamics of floral visitors across elevation and successional gradients in Hawai¹i. Pacific Science  67: 253-266.
  • Conner, J.K., K. Karoly, C. Stewart, V. Koelling, H.F. Sahli, A. Monfils, L. Prather, and F.H. Shaw. 2011. Rapid independent trait evolution despite a strong pleiotropic genetic correlation. American Naturalist 178: 429-441.
  • Sahli, H.F. and J.K. Conner. 2011. Testing for conflicting and non-additive selection: floral adaptation to multiple pollinators through male and female fitness. Evolution 65: 1457-1473.
  • Conner, J.K., H.F. Sahli, and K. Karoly. 2009. Tests of adaptation: functional studies of pollen removal and estimates of natural selection on anther position in wild radish. Annals of Botany 103: 1547-1556.
  • Sahli, H.F., J.K. Conner, F.H. Shaw, S. Howe*, and A. Lale*. 2008. Adaptive differentiation of quantitative traits in the globally distributed weed, wild radish (Raphanus raphanistrum). Genetics 180: 945-955
  • Crawford, N.G., C. Hagen, H.F. Sahli, E. Stacy, and T. C. Glenn. 2008. Fifteen polymorphic microsatellite loci from Metrosideros polymorpha (Myrtaceae: Myrtales), a model species for ecology and evolution. Molecular Ecology Notes 8: 308-310.
  • Sahli, H.F. and J.K. Conner. 2007. Visitation, effectiveness, and efficiency of 15 genera of visitors to wild radish, Raphanus raphanistrum (Brassicaceae). American Journal of Botany 94: 203-209
  • Sahli, H.F. and J.K. Conner. 2006. Characterizing ecological generalization in plant-pollination systems.  Oecologia 148:  365-372
  • Strauss, S. Y., H. Sahli, and J.K. Conner. 2005. Toward a more trait-centered approach to diffuse (co)evolution. New Phytologist 165:  81-90.
  •  Sahli, H.F. and S. Ware. 2000. Oviposition sites and emergence habitats of 13-year periodical cicadas (Brood XIX) in Eastern Virginia. 2000. Virginia Journal of Science 51: 187-194

* denotes undergraduate or graduate student

Contact the Department of Biology 142 Franklin Science Center 1871 Old Main Drive Shippensburg, PA 17257 Phone: 717-477-1401