Profile: Claus Holzapfel

Associate Professor

Department of Biological Sciences

Fusion Ecology

As a plant ecologist I am fascinated by the intriguing ways of how species interact with each other. Within that topic I address questions spanning community ecology, evolutionary ecology and ecophysiology. The list of keywords describing my past and present work is long: disturbance, breeding systems, diversity, invasion, seed ecology, root interactions, clonal plant biology, species interaction. So far I conducted field research in a wide range of systems ranging from Old World and New World deserts, through Mediterranean-type ecosystems to temperate forests. Significant parts of my research take place also in the greenhouse and the lab: sometimes nature is simply too complex to pursue specific questions.

Community ecology of plants - the theme of my research - is the examination of ecological and evolutionary processes and their outcome in plant populations and communities. These processes can be detected at a variety of ecological and temporal scales; accordingly, my research includes studies of individuals (ecophysiology), populations, communities and higher levels (flora).

I am pursuing two main goals: (1) to predict the ecological consequences and evolutionary trajectories of interactions between plants. Ecological interactions are understood to have the potential to lead to intricate co-evolution among interacting species. I am interested to find out whether coexisting species are coevolved and affect each other in non-random ways. The leading question is whether communities are much more than simple chance assemblies. Perturbed systems - systems that are altered from their pristine state - are ideal study objects to address such a question, since here coevolved interactions are likely disrupted. Good examples are plant communities that are invaded by alien organisms or systems otherwise heavily impacted by human activity. Needless to say, such systems are increasingly common throughout the East Coast Region. (2) to detect the mechanisms by which plants adapt to varying environments. Real environments are never constant and organisms are likely to encounter new abiotic factors and/or new neighbors. Evolutionary and ecological plant responses to stochastic environments often differ strongly from responses to predictable environmental change.

  • Education

    Ph.D., University of Göttingen, 1993.   

  • Publications

    Schafer, J.L., Mudrak, E.L., Haines, C.E., Parag, H.A., Moloney, M.A., Holzapfel, C.  (2012).  The association of native and non-native annual plants with Larrea tridentata (creosote bush) in the Mojave and Sonoran Deserts.  Journal of Arid Environments 87:  129-135.

    Gallagher, F.J., Pechmann, I., Holzapfel, C., Grabosky, J.  (2011).  Altered vegetative assemblage trajectories within an urban brownfield.  Environmental Pollution 159: 1159-1166.

    Harel, D., Holzapfel, C., Sternberg, M.  (2011).  Seed mass and dormancy of annual plant populations and communities decreases with aridity and rainfall predictability.  Basic and Applied Ecology 12: 674-684.

    Sternberg, M., Holzapfel, C., Tielbörger, K. Sarah, P., Kigel, J., Lavee, H., Fleischer, A., Jeltsch, F.& Köchy, M. (2011). The use and misuse of climatic gradients for evaluating climate impact on dryland ecosystems - an example for the solution of conceptual problems. In: J. Blanco & H. Kheradmand (Eds.), Climate Change - Geophysical Foundations and Ecological Effects, pp. 361-374.

    Gallagher, F.J., Pechman, I., Holzapfel, C.,  Grabosky, J. (2011).  Altered vegetative assemblage trajectories within an urban brownfield. Environmental Pollution 159:1159-66.

    Holzapfel, C., Shahrokh, P., Kafkewitz, D. (2010). Polyphenol oxidase activity in the roots of Seedlings of Bromus and other grass genera. American Journal of Botany 97: 1-5.

    Hofer, C., Gallagher, F.J., Holzapfel, C. (2010). Metal accumulation and performance of nestlings of passerine bird species at an urban brownfield site. Environmental Pollution 158: 1207–1213.

    Holzapfel, C., Parag, H.A., Shmida, A. (2009). Resilience of Mediterranean and desert vegetation after disturbance. Forstarchiv 90:297-304.

    Moloney, K.A., Holzapfel, C., Tielbörger, K., Jeltsch, F., Schurr, F. (2009) Rethinking the common garden in invasion research. Perspectives in Plant Ecology, Evolution and Systematics 11:311-320.

    Cincotta, C., Adams, J.M., Holzapfel, C. (2009): Testing the enemy release hypothesis: A comparison of foliar insect herbivory of the exotic Norway maple (Acer platanoides L.) and the native sugar maple (A. saccharum L.). Biological Invasions Biological Invasions 11:2, 379-388.

    Holzapfel, C. (2008) Deserts. In S.E. Jørgensen & B.D. Fath (eds.), Vol.2 of Encyclopedia of Ecology, pp. 879-898. Oxford: Elsevier.

    Sapir, Y., Mazer, S.J., & Holzapfel, C. (2008) Sex Ratio. In S.E. Jørgensen & B.D. Fath (Eds.),. Vol. 4 of Encyclopedia of Ecology, pp. 3243-3248. Oxford: Elsevier.

    Holzapfel, C., Tielbörger, K., Parag, H.A., Kigel, J., and Sternberg, M. (2006). Annual plant-shrub interactions along an aridity gradient in Israel. Basic and Applied Ecology 7: 268-279.

    Alpert, P., Holzapfel, C., & Slominski, C. (2003).  Differences in performance between genotypes with different degrees of resource sharing in Fragaria chiloensis. Journal of Ecology 91: 27-35.

    Schenk, H.J., Holzapfel, C., Hamilton, J.G., & Mahal, B.E. (2003): Spatial ecology of a small desert shrub on adjacent geological substrates. Journal of Ecology 91: 383-395.

    Holzapfel, C. & Alpert, P. (2003): Root cooperation between plants of the same clone. Oecologia 134: 72-77.

    Alpert, P., Bone, E., & Holzapfel, C. (2000): Invasiveness and invasibility: the possible role of environmental stress in preventing biological invasions by plants. Perspectives in Plant Ecology, Evolution and Systematics 3: 52-66

    Hamilton, J.G., Holzapfel, C., & Mahall, B.E. (1999): Coexistence and interference between a native perennial grass and non-native annual grasses in California. Oecologia 121: 518- 526.

    Holzapfel, C. & Mahall, B.E. (1999): Bidirectional facilitation and interference between shrubs and annuals in the Mojave Desert. Ecology 80: 1747-1761.