Invasive, non-native organisms, climate change, and habitat fragmentation have been identified as the three greatest threats to biodiversity globally. Research in my lab focuses on plant and community responses to these factors, and on the mechanisms that regulate responses to these factors. As an example, we are examining the broad impacts of urbanization on plants and communities. Research sites include the Calder Center, Central Park, Black Rock Forest, the New York Botanical Garden, and other preserves and parks in southern New York.

A related project is examining the mechanisms regulating plant responses to environmental factors such as climate change and urbanization. These projects include research on the relative contributions of developmental and physiological processes to plant responses to the environment. A key area of research is disentangling effects of plant age and plant developmental stage on responses to the environment. Much of this work has been funded by the NSF.

Other projects we are collaborating on include research on forest responsesto loss of eastern hemlock (Tsuga canadensis) due to the hemlock woolly adelgid (HWA), an invasive non-native insect. The HWA generally causes extensive hemlock mortality at the stand level within five years of initial invasion. Decline of eastern hemlock may have far-reaching effects because of the unique suite of environmental characteristics associated with hemlock-dominated forests. Some objectives of our research are to examine how forest composition regulates the effects of the HWA on species diversity and productivity, and to examine the effects of changes in productivity on resource transfer between trophic levels. Much of this work has been funded by the USDA competitive grants program.

Current research opportunities in the Lewis Lab

We have research opportunities for graduate, undergraduate, and high school students broadly interested in plant or forest ecology. While much of our research focuses on the impacts of invasive species, climate change, and urbanization on plants, and on the interactive effects of physiology and development in regulating plant responses to the environment, student projects also addresses a variety of other topics, reflecting the various interests of the students in my lab.

If you are interested in pursuing a graduate degree in our program, please feel free to contact me directly (jdlewis@fordham.edu) to find out more about our program.

I am also the assistant director of the Calder Summer Undergraduate Research (CSUR) program, an NSF-funded REU Site program. If you are interested in participating in this program, please feel free to contact me directly (jdlewis@fordham.edu), or check out our webpage for more information.

Recent Abstracts

Gary, G. and J.D. Lewis. 2007. Changes in plant growth, reproduction and offspring vigor with increasing distance from an urban center. Annual Meeting of the Ecological Society of America.

Gordon, E.P., J. Lewis and D.T. Tissue. 2007. Potential regulatory mechanisms that control photosynthetic responses to developmental processes in Xanthium strumarium. Annual Meeting of the American Society of Plant Biologists.

Lewis, J.D., J. Licitra, A.R. Tuininga, A. Sirulnik and J. Johnson. 2006. Indirect effects of the hemlock woolly adelgid on oak seedling growth through effects on mycorrhizal richness and abundance. IUFRO (International Union of Forest Research Organizations) Canopy Processes Traveling Workshop.

Rubino, L., S. Charles, J.D. Lewis, A. Sirulnik and A.R. Tuininga. 2006. Hemlock woolly adelgid density affects net photosynthetic rates but not respiration rates or needle biochemistry in eastern hemlock. IUFRO Canopy Processes Traveling Workshop.

Sirulnik, A., J.D. Lewis, A.R. Tuininga and J. Johnson. 2006. Infestations of hemlock woolly adelgid are associated with changes in eastern hemlock ectomycorrhizal fungal communities and soil conditions. IUFRO Canopy Processes Traveling Workshop.

Johnson, J., A. Sirulnik, A.R. Tuininga and J.D. Lewis. 2006. Molecular and morphological analyses of ectomycorrhizal fungal communities across hemlock defoliation and composition gradients. Annual Meeting of the Mycological Society of America.

Avolio, M., A.R. Tuininga, J.D. Lewis and M. Marchese. 2005. Nitrogen form affects ectomycorrhizal fungal colonization and growth. Annual Meeting of the Ecological Society of America.

Lewis, J.D., L. Rubino, K.L. Griffin and D.T. Tissue. 2005. Phosphorus and nitrogen supply affect growth but not development rates in Xanthium strumarium. Annual Meeting of the Ecological Society of America.

Martin, A.P., W.F. Harden and J.D. Lewis. 2005. Effects of copper supply on growth and photosynthesis of Xanthium strumarium, a native, invasive annual plant. Annual Meeting of the Ecological Society of America.

Rubino, L., J.D. Lewis, K.L. Griffin and D.T. Tissue. 2005. Nitrogen supply and leaf position but not phosphorus supply affect net photosynthetic rates in Xanthium strumarium. Annual Meeting of the Ecological Society of America.

Tirpak, J.M., W.M. Giuliano and J.D. Lewis. 2005. Sex and age status affects estimates of Ruffed grouse habitat suitability in the Central and Southern Appalachians. Annual Meeting of the Ecological Society of America.

Turner, G., J.D. Lewis and W.S.F. Schuster. 2005. Effects of nitrogen on ectomycorrhizal abundance and diversity from red oak seedlings grown in contrasting soils. Annual Meeting of the Ecological Society of America.

Sirulnik, A., J.D. Lewis, A.R. Tuininga and J. Johnson. 2005. Soil conditions, host community, and infestations of the hemlock wooly adelgid (Adelges tsugae) affect ectomycorrhizal diversity in eastern temperate forests. Annual Meeting of the Ecological Society of America.

Sirulnik, A., J.D. Lewis, A.R. Tuininga and J. Johnson. 2005. Hemlock woolly adelgid (Adelges tsugae) infestation reduces ectomycorrhizal diversity and accelerates N cycling in eastern hemlock (Tsuga canadensis) stands. 10th Biennial International Conference of the Soil Ecology Society, Argonne, Illinois.