Carol C. Horvitz
University of Miami
P. O. Box 249118
Coral Gables, FL 33124
Phone: 305 284-5364; Fax: 305 284-3039
Ph.D. Northwestern University, Evanston, Illinois. June, 1980
B.A. Antioch College, Yellow Springs, Ohio. June 1972
CURRENT PROFESSIONAL APPOINTMENTS:
Professor, Biology Department, University of Miami. 1999 - present.
Director, John C. Gifford Arboretum, University of Miami. 1999 – present
(Chair of the John C. Gifford Arboretum Committee, 1991-1998)
Current Research Activities: Research in my lab concerns demographic analysis of tropical plants and of their interactions with animals (mutualists and enemies) and with non-native species (including plants). Geographic foci have been tropical and subtropical hardwood forests of Mexico, Central America and Florida. Taxa of special interest include tropical understory herbs in the family Marantaceae (e.g., Horvitz and Schemske 1995, Horvitz et al. 2000, Johnson, in press.) and understory shrubs in the genus Ardisia (Myrsinaceae) (e. g. Pascarella and Horvitz 1998, Koop and Horvitz, in prep.). The focal issues are how interactions impact particular life history events and how different events during the life cycle influence population growth rate. This parameter not only predicts the fate of a population in a particular place (extinction, growth or stasis), but also links ecology to evolution. For selection to act on a trait, trait values must be associated differentially with fitness; fitness in structured populations is measured by population growth rate. Field experiments combined with matrix modeling of population dynamics constitute our main analytical approach. A major problem is modeling long run population growth rate (and the effects of interactions on it) in the context of spatial and temporal variation (Tuljapurkar, Horvitz and Pascarella, 2003). Spatiotemporal heterogeneity created by natural disturbances (such as treefalls, hurricanes and river meanders) has received considerable attention (e.g., Horvitz and Sternberg 1999). In studying the effects of non-natives in post-hurricane forest regeneration, the particular role of vines and lianas has emerged as a very important topic (Horvitz et al. 1998, Horvitz and Koop 2001).
A central concern of my current work is stochastic temporal variation in demography. This work is at the center of my collaboration with S. Tuljapurkar on a variety of ecological and evolutionary issues. In this context, we have recently been funded to work on the evolution of lifespan with a grant from NIA (NIH). Also, we are involved in a new NCEAS (National Center for Ecological Analysis and Synthesis) working group on stochastic demography which will begin meeting in spring, 2004.
The interface between dispersal and demography has long been a focal theme in my work and I was involved in an NCEAS working group during 2000-2001 that developed new models of wave speed for structured populations in which only one or a subset of stages disperses. Wave speed measures the rate of spread of a population across a landscape and new elasticity analyses address the importance of life history transitions to this rate of spread. In my lab, we have developed applications of the new model in several contexts, e.g. (1) seed dispersal of Marantaceae by ants and by birds, (2) invasion of a non-native shrub in Florida, (3) migration rates of a specialist beetle in a landscape of patchily distributed host plants.
Some representative publications:
Tuljapurkar, S., Horvitz, C.C. and J. Pascarella, 2003. The many growth rates and elasticities of populations in random environments. American Naturalist. 162: 489-502.
.Horvitz, C.C., M. A. Pizo, B. Bello y Bello, J. LeCorff and R. Dirzo. 2002. Are plant species that need gaps for recruitment more attractive to seed-dispersing birds and ants than other species? In. D.J. Levey, W. R. Silva and M. Galetti (eds.) Seed dispersal and frugivory: ecology, evolution and conservation. CAB International Press. Oxon, UK.
Horvitz, C. C. and A. Koop. 2001. Removal of non-native vines and post-hurricane recruitment in tropical hardwood forests of Florida. Biotropica 33: 268-281
Slocum, M. G. and C. C. Horvitz. 2000. Seed arrival under different genera of trees in a neotropical pasture. Plant Ecology 149: 51-62.
Horvitz, C.C. and L. Sternberg. 1999. 14C dating of treefalls on Barro Colorado Island (Panama): a new method to study tropical rain forest gap dynamics. Journal of Tropical Ecology 15: 723-735.
Horvitz, C. C., J. B. Pascarella, S. McMann, A. Freedman, and R. H. Hofstetter. 1998. Functional roles of invasive non-indigenous plants in hurricane-affected subtropical hardwood forests. Ecological Applications: 8: 947-974.
Pascarella, J. B. and C. C. Horvitz. 1998. Hurricane disturbance and the population dynamics of a tropical understory shrub: megamatrix elasticity analysis: Ecology 79: 547-563.
Horvitz, C.C. and D.W. Schemske. 1995. Spatiotemporal variation in demographic transitions for a tropical understory herb: projection matrix analysis. Ecological Monographs 65: 155-192.
If you're interested in experiencing ecology up close and personal, be sure to register for Field Ecology. Dr. Horvitz is one of the instructors.
Dr Horvitz's CV
Dr. Horvitz also serves as chair of the John C. Gifford Arboretum Committee.
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