Carmen Chapin, PhD

Carmen (left) and Bernd Blossey in a stand of invasive Phragmites australis

 

Botanist

USDA Agricultural Research Unit

Tower Rd., Cornell University

Ithaca, NY 14853

Phone: 607-255-7744

ctc13@cornell.edu

 

Research interests:

My research focuses on the physio-chemical interactions between a plant and its environment, a mechanistic approach that yields solutions to the problems posed by biological invasions in a wide variety of settings.  More broadly I am interested in invasive species, wetland ecology, and biogeochemistry.

 

Approaches:

Plants, including invasive species, respond to physio-chemical aspects of the environment (e.g., light, nutrient availability, soil texture), and as a result, invader behavior varies among sites.  Further, because plants modify their environments (e.g., by acidifying soil, altering evapo-transpiration), we must understand these changes in relation to the ecological range of an effective biocontrol agent.  Thus, while trial and error approaches can yield successful biocontrol strategies at a limited number of sites, they don’t transfer effectively to different sites containing the same target species.  In the case of invasive plant control, understanding interactions among the target species, plant community, and abiotic environment during and after invasion ranks among the most critical elements of a successful biocontrol program. 

 

Projects:

  1. Determining the chemical and physical links between purple loosestrife and its introduced bio-control agents (Galerucella spp.).  This project is based on the chemical cues that foster host-specificity between introduced biocontrol agents and their host species.  Chemical production and physiological changes in a plant are in part driven by environmental variables.  We will then use those variables to optimize host habitat and increase herbivore damage.
  2. Assessing purple loosestrife carbon storage and partitioning in relation to herbivory.  One of the largest problems in the reduction of purple loosestrife is the plant’s ability to regenerate after herbivore damage.  This project will assess the levels at which damage needs to occur to dramatically reduce regrowth.  At the same time assessment of different fractions of carbohydrates will indicate any changes in structure or vegetative growth that might occur as a response to herbivory.
  3. Understanding the chemical and physiological changes that occur in an ecosystem as a result of purple loosestrife invasion.  The leaves of purple loosestrife have an extremely high tannin concentration.  In general, tannin and polyphenolic compounds can severely impact the functioning of microbial communities.  In addition, they may cause shifts in community structure through modifications of the food web and allelopathic effects on other plant species.  It terms of post-invasion restoration, it is important to understand the implication of these residual effects. 
  4. Documenting differences between decomposition rates and associated invertebrates between native and introduced haplotypes of Phragmites australis.  Phenological and chemical differences in these types may help determine suitable agents for a biocontrol program without negative impacts on native populations.  Furthermore, understanding fundamental differences in ecosystem processes will greatly aid in the re-establishment of native floral and faunal communities.

 

Key References:

         

Katovich, E., J. S., L. Becker Roger, et al. (1998). “Seasonal fluctuations of carbohydrate levels in roots and crowns of purple loosestrife (Lythrum salicaria).” Weed Science. Sept. Oct. 46(5): 540-544.

         

Rauha, J., J. Wolfender, et al. (2001). “Characterization of the polyphenolic composition of purple loosestrife (Lythrum salicaria).” Verlag der Zeitschrift fur Naturforschung Tubingen 56c: 13-20.