Brenda Casper

Professor of Biology and Department Chair
330A Leidy Laboratories
bcasper@sas.upenn.edu
215-898-8569
Ecology and Biodiversity
Evolution
Plant Biology
Education: 

Ph.D., University of Utah, 1982

Research Interests: 

Research in my plant ecology lab is wide-ranging, with recent projects focusing, broadly, on the responses of plants and soil microbes to various stresses: including climate change, soil contaminants, and the inhospitable environment of coastal sand dunes.  We work at the level of individuals, populations, and communities.

Climate Change

We pursue various questions with data from a four-year climate change experiment in the steppe of Mongolia, including how temperature increases will interact with changing precipitation patterns and land use to affect the structure of plant communities, flower production, and flowering phenology.  Replicating the experiment at two locations in the landscape enabled us to incorporate existing spatial variation in the microenvironment and steppe vegetation.  We are particularly interested in whether functional leaf traits, e.g. N and C content and specific leaf area, can explain climate-induced changes in the abundance of individual species and responses by the plant community as a whole.  We consider both interspecific variation in leaf traits and the plasticity of the traits under different climate scenarios.

Soil Contaminants and Remediation

The Anthropocene has produced significant and widespread environmental pollution.  We seek to understand the effects of soil contaminants on the structure of plant communities, their development over time, and their associated arbuscular mycorrhizal fungi.  Conversely, we investigate the utility of plants and the role of these fungi in the remediation of polluted sites.  We work with soils polluted with heavy metals and sites with high levels of asbestos.  We consider locations where asbestos occurs naturally, including serpentine outcrops in Eastern Pennsylvania, and an industrial waste site.

Coastal Dune Ecology

Coastal sand dunes are the first line of defense against tidal surges produced during storms, and storm severity is expected to increase with climate change.  Plants are key in building dunes and essential in stabilizing them.  We investigate factors that govern the colonization of bare dunes by vegetation, including mycorrhizal fungi, and the plant traits that best explain variation among species in their ability to serve as dune-building engineers.

Selected Publications: 

Dietterich, L.H., C. Gonneau, and B.B. Casper.  2017.  Arbuscular mycorrhizal colonization has little consequence for plant heavy metal uptake in contaminated field soils.  Ecological Applications (in press)

Gonneau, C., S.K. Monhanty, L.H. Dietterich, W.-T. Hwang, J.W. Willenbring, and B.B. Casper.  2017.  Differential elemental uptake in three pseudo-metallophyte C4 grasses in situ in the Eastern U.S.A.  Plant and Soil 416:149-163.  DOI 10.1007/s11104-017-3198-9

Dietterich, L. H. and B. B. Casper.  2017.  Initial soil amendments still affect plant community composition after nine years of succession on a heavy metal contaminated mountainside.  Restoration Ecology 25:201-210.  DOI 10.1111/rec.12423

Wiley, E., B. B. Casper, and B. R. Helliker.  2017.  Recovery following defoliation involves shifts in allocation that favor storage and reproduction over radial growth.  Journal of Ecology 105:412-424. DOI 10.1111/1365-2745.12672

Spence, L.A., P. Liancourt, B. Boldgiv, P.S. Petraitis, and B.B. Casper.  2016.  Short-term manipulation of the amount and timing of precipitation affects forbs but not graminoids in the Mongolian steppe.  Journal of Vegetation Science 27:249-258. DOI 10.1111/jvs.12349.

Liancourt, P., B. Boldgiv, D.S. Song, L.A. Spence, B.R. Helliker, P.S. Petraitis, and B.B. Casper.  2015.  Leaf-trait plasticity predicts vulnerability to climate change in a Mongolian steppe.  Global Change Biology 21:3489-98. DOI 10.1111/gcb.12934

Jones, O. R., A. Scheuerlein, R. Salguero-Gómez, C. Giovanni Camarda, R. Schaible, B. B. Casper, J. P. Dahlgren, J. Ehrlén, M. B. García, E. Menges, P. F. Quintana-Ascencio, H. Caswell, A. Baudisch, and J. W. Vaupel.  2014.  Varieties of ageing across the tree of life.  Nature 55:169-173.  DOI 10.1038/nature12789

Spence, L.A., P. Liancourt, B. Boldgiv, P.S. Petraitis, and B.B. Casper.  2014. Climate change and grazing interact to alter flower production in the Mongolian steppe.  Oecologia 175:251-260.  DOI 10.1007/s00442-014-2884-z

Salguero-Gómez, R., H. Kempenich, I. Forseth, and B.B. Casper.  2014.  Long-term demography of a desert perennial species.  Ecology 95:577.  DOI 10.1890/13-1256.1

Courses Taught: 
  • BIOL 101, Introductory Biology A
  • BIOL 240, Ecology and Population Biology
  • BIOL 423, Plant Ecology
  • BIOL 444, Advanced Ecology and Population Biology