Adjunct Assistant Professor, Plant Biology and Conservation, Northwestern University
International Union for Conservation of Nature, Orchid Specialist Group
U.S. Fish & Wildlife Service Recovery Team Member: Platanthera praeclara and Lespedeza leptostachya
- Population biology and reproductive ecology of rare plants
- Effects of gender dynamics on population performance
- Plant population viability analysis
- Effects of climate change on rare plant species
- Modeling range shifts of plants under climate change
- Ex situ conservation
- Assisted migration of plant species in response to climate change
My research is focused on the reproductive ecology and population viability of rare and threatened plant species. My approach includes experimental manipulation on the effects of management options to understand patterns of resource allocation and how demographic trade-offs may influence vital rates and population trajectories.
Cirsium pitcheri (pitcher's thistle) — In 2011 we completed work on a five-year grant to study the demography and genetics of Cirsium pitcheri, a threatened species that occurs around Lake Michigan. We found that the species is in decline, and all populations in the study are below replacement rate due to numerous threats including invasive species, predation by goldfinches, and predation by a biocontrol weevil introduced to control weedy thistles. In 2011 we began collecting data on populations that are infested with weevils to elucidate their effects on plant vital rates. We are also collecting data on pollinators and other insect visitors to understand the network of interactions that occur in our study populations and how these interact to influence population viability (Havens-Young, Fant, Vitt and outside collaborators).
Lespedeza leptostachya (prairie bush clover) —This federally threatened gravel-hill prairie species is found at Nachusa Grasslands in Franklin Grove, Illinois, where we completed an experimental demography study to elucidate the role of grass competition on vital rates. Decreasing grass cover increases seedling recruit. In 2014, Nachusa Grasslands will introduce bison, and we will conduct a spatially explicit exclusion study to determine their effects on grass cover, community composition, and vital rates of prairie bush clover. The approach will include remote sensing of the grasslands to correlate patterns of grassland change as a result of bison grazing with on-the-ground changes in population vital rates and vegetation dynamics (Vitt, Havens-Young and outside collaborators).
Ex Situ Conservation
Seed banking both rare and common species is an important aspect of plant conservation. I curate the Dixon National Tallgrass Prairie Seed Bank at the Chicago Botanic Garden, which has a collection focus of native prairie species. We target the tallgrass prairie, because it is the most endangered ecosystem in North America, having lost approximately 96 percent of its former extent to habitat conversion. I am particularly interested in applying Geographic Information System (GIS) tools to create effective seed collection strategies.
Species Range Shifts
Many plant species will experience significant range shift as climate change proceeds over the coming decades. I am currently working with my postdoctoral assistant Shannon Still on a project which examines the impact of global climate change on the species distribution of rare plants in the Great Basin. With this work we are examining the current distributions of rare plants and then making projections as to how these distributions will change between now and the year 2080.
K. Fox, P. Vitt, K. Anderson, G. Fauske, S. Travers, D. Vik and M. Harris. Pollination of a threatened orchid by an introduced hawk moth species in the tallgrass prairie of North America Biological Conservation 167:316-324.
Havens, K., C. Jolls, J. Marik, P. Vitt, A.K. McEachern, and D. Kind. 2012. Effects of an introduced biocontrol weevil, Larinus planus, and other emerging threats on populations of the federally threatened Pitcher’s thistle, Cirsium pitcheri, Biological Conservation 155: 202-211.
Havens, K., P. Vitt and S. Masi. 2012. Citizen Science on a Local Scale: The “Plants of Concern” Program Undertakes Rare Plant Monitoring. Frontiers in Ecology and the Environment 10: 321–323.
Schwartz, M.W.1, Hellmann, J.J.2, McLachlan, J.M. 2, Sax D.F.3, Borevitz, J.O.4. Brennan, J.5 Camacho, A.E. 6, Ceballos, G.7, Doremus, H.8, Early, R.3, Etterson, J.R.9, Gill, J. 10, Gonzalez, P.11, Green, N12, Hannah, L.13 Jamieson, D.W.14, Javeline. D.2, Minteer, B.A.15, Odenbaugh, J.16, Polasky, S17., Richardson, D.M.18, Root, T.L.19, Safford, H.D.1,20, Sala, O.15, Schneider, S.H.21, Thompson, A.R.24, Williams, J.W.10, Vellend, M.23, Vitt, P.24 Zellmer, S.25. 2012. Integrating the scientific, regulatory and ethical challenges posed by managed relocation. BioScience 62(8):732-743.
Knight, T.M., K. Havens and P. Vitt. 2011. Will the use of less fecund cultivars reduce the invasiveness of perennial plants? BioScience 61(10): 816-822.
Fant, J.B., A. Banai and P. Vitt. 2010. Morphological and molecular evidence of hybridization between the federally threatened Lespedeza leptostachya Englem. and its co-occurring congener Lespedeza capitata Michx. Conservation Genetics 11(6): 2195-2205.
Vitt, P. K. Havens, A.T. Kramer, D. Sollenberger, and E. Yates. 2010 Assisted Migration of Plants: Changes in Latitudes, Changes in Attitude. Biological Conservation 143 (1): 18-27.
Vitt, P. K. Havens and O. Hoegh-Guldberg. 2009. Assisted migration: part of an integrated conservation strategy. Trends in Ecology and Evolution 24: 473-474.
Vitt, P., T. Knight, and B.P. Kendall. 2009. Effects of Community Level Management on Agalinis auriculata, a Rare Non-Target Prairie Annual. Biological Conservation 142 (4): 798-805.
Vitt, P. and K. Havens. 2004. Integrating quantitative genetics into ex situ conservation practices. In: Saving the Pieces: The value, limits, and practice of off-site plant conservation, E.O. Guerrant, K. Havens, M. Maunder (eds).
Vitt, P., K.E. Holsinger, and C.S. Jones, 2003. Local differentiation and phenotypic plasticity of size and gender change in Arisaema triphyllum. Am. J. Bot.
Holsinger, K.E. and P. Vitt, 1996. The future of conservation biology: what's a geneticist to do? in Enhancing the Ecological Basis of Conservation: Heterogeneity, Ecosystem Function and Biodiversity. Proceedings from the Carey Conference VI, 1995.