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        Charlotte T. Lee  

            Scholar in Residence 
            Biology Department
            Duke University
            Durham NC 27708

            070 Biological Sciences Building
            c.t.lee at duke.edu or
            charlotte.t.lee at duke.edu


               919-613-0995


 

nonlinear dynamics of interacting structured populations

I use mathematical and computer modeling to study the nonlinear dynamics of structured populations. Most biological populations exhibit age, stage, size, or other structure, and most ecological interactions (between individuals, between species, or with the environment) ultimately involve nonlinearity, so very many interesting ecological problems include both. My major research directions are 1) studying feedbacks between consumers and their resources and 2) understanding the interplay between preindustrial human populations and their environments.  Specific projects are listed below. 

        ►competition and consumer-dependent demography

Resource depletion is only one way in which consumers affect resource abundance. Many consumers ingest only portions of resource individuals, or consume products or substances produced by resource individuals. Such partial consumption frequently affects resource survival, growth, and reproductive rates.  Examples include pathogens, parasites, and some parasitoids that do not immediately nor completely consume their hosts; most herbivores, which allow their plant hosts to survive, grow, and reproduce at reduced rates; nonlethal predators; and mutualists, which may collect nectar, food bodies, or pollen from plants while pollinating or protecting them. In addition, even lethal predators frequently affect the behavior and foraging activity of surviving prey. When consumer species differ in their effects on resource demography, the resulting system dynamics can be surprising, including competitive coexistence or exclusion in otherwise unexpected situations.  

Lee, CT, TEX Miller, and BD Inouye.  2011.  Consumer effects on the vital rates of their resource can determine the outcome of competition between consumers.  The American Naturalist 178:452-463.  --  abstract -- Link to article at AmNat


Lee
, CT
, and BD Inouye. 2010.  Mutualism between consumers and their shared resource can promote competitive coexistence.  The American Naturalist 175: 277–288  abstract  --  Link to article at AmNat


        ► demographic dynamics of mutualism

One implication of the dynamics described above is that distinct host demographic responses to different consumer species can enable mutualists to persist in the presence of apparently competitively superior exploiters.  The resulting multi-species assemblage can have fundamentally different dynamics than does a mutualist-host species pair.  This urges a synthetic perspective of mutualism that encompasses demography as well as multiple species.   


nutrient competition in mycorrhizal fungi

Plants frequently need mycorrhizal fungi to obtain soil nutrients; mycorrhizal fungi need carbon from plants.  This nutrient trade has frequently been studied by modeling fungal competition for access to plants and their carbon, but does not inherently alter the identity of a system's limiting nutrient.  Models show that competition for interconverting types of nitrogen could be an important factor structuring fungal communities and suggest measurements that could help determine its importance in the field. 


food-dependent dynamics of human populations

To solve contemporary problems such as ensuring food security for a particular region or for the globe, we need more basic research on the interactions between natural resource dynamics, human population growth, and social factors such as technology, culture, politics, and economics.  I couple ecological, demographic, and social models to examine the interactions between environment, food supply, human demography, and human decision-making.  I have focused on preindustrial agricultural societies, whose dynamics are closely tied to their local environment, but am extending these approaches to hunter-gatherer societies and ultimately to modern industrial societies.  

 

Lee, CT, and S Tuljapurkar. 2011. Quantitative, dynamic models to integrate environment, population, and society. In Kirch, PV, ed. Roots of Conflict: Soils, Agriculture, and Sociopolitical Complexity in Ancient Hawai'i.  School of Advanced Research Press, Santa Fe, New Mexico.first paragraph 

Lee, CT, CO Puleston, and S Tuljapurkar. 2009.  Population and prehistory III: Food-dependent demography in variable environments. Theoretical Population Biology 76: 179-188.abstract  Link to article at TPB 

Lee, CT, and S Tuljapurkar.  2008.  Population and prehistory I: Food-dependent population growth in constant environments.  Theoretical Population Biology 73: 473- 482.abstract  Link to article at TPB

Ladefoged, TN, CT Lee, and MW Graves. 2008.  Modeling life expectancy and surplus production of dynamic pre-contact territories in leeward Kohala, Hawai'i. Journal of Anthropological Archaeology 27(1): 93-110.  abstract    Link to article at JAA  

Tuljapurkar, S, CT Lee, and M Figgs. 2007. Demography and food in early Polynesia. Pages 35-51 in Kirch, PV, and J.-L. Rallu, eds. The Growth and Collapse of Island Societies: Archaeological and Demographic Perspectives from the Pacific. Honolulu: University of Hawai’i Press. – first paragraph 

Lee, CT, S Tuljapurkar, and P Vitousek. 2006. Risky business: spatial and temporal variation in preindustrial dryland agriculture.  Human Ecology 34 (6): 739-763. – abstractLink to article at Human Ecology                                  

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people


Abigail Pastore is a doctoral student in the Miller Lab at Florida State University, and is working with me on fungal competition.

Nick Kortessis earned an MS (2012) in my lab at Florida State University, quantifying the effects of nonlinear functional response on competitive coexistence.  He's currently a Ph.D. student in the Chesson Lab at the University of Arizona.


  
selected publications

Lee, CT, TEX Miller, and BD Inouye. 2011.  Consumer effects on the vital rates of their resource can determine the outcome of competition between consumers. The American Naturalist 178:452-463.  --  abstract -- Link to article at AmNat

Lee, CT, and S Tuljapurkar. 2011. Quantitative, dynamic models to integrate environment, population, and society. Pages 111-133 in Kirch, PV, ed. Roots of Conflict: Soils, Agriculture, and Sociopolitical Complexity in Ancient Hawai'i.  School of Advanced Research Press, Santa Fe, New Mexico.first paragraph 

Lee, CT, and BD Inouye. 2010.  Mutualism between consumers and their shared resource can promote competitive coexistence.  The American Naturalist 175: 277–288  abstract  --  Link to article at AmNat

Lee, CT, CO Puleston, and S Tuljapurkar. 2009.  Population and prehistory III: Food-dependent demography in variable environments. Theoretical Population Biology 76: 179-188.abstract  Link to article at TPB 

Lee, CT, and S Tuljapurkar.  2008.  Population and prehistory I: Food-dependent population growth in constant environments.  Theoretical Population Biology 73: 473- 482.abstract  Link to article at TPB 

Donahue, MJ, and CT Lee. 2008. Colonization.  pp. 672-278 in SE Jorgensen and BD Fath (Editor-in-Chief), General Ecology. Vol. 1 of Encyclopedia of Ecology, 5 vols. Oxford: Elsevier. – abstract   Link to article at ScienceDirect 

Ladefoged, TN, CT Lee, and MW Graves. 2008.  Modeling life expectancy and surplus production of dynamic pre-contact territories in leeward Kohala, Hawai'i. Journal of Anthropological Archaeology 27(1): 93-110.  abstract    Link to article at JAA

Morris, WF, CA Pfister, S Tuljapurkar, CV Haridas, CL Boggs, MS Boyce, EM Bruna, DR Church, T Coulson, DF Doak, S Forsyth, J-M Gaillard, CC Horvitz, S Kalisz, BE Kendall, TM Knight, CT Lee, and ES Menges. 2008. Longevity can buffer plant and animal populations against changing climatic variability. Ecology 89 (1): 19-25. – abstract    Link to article at Ecology

Tuljapurkar, S, CT Lee, and M Figgs. 2007. Demography and food in early Polynesia. Pages 35-51 in Kirch, PV, and J.-L. Rallu, eds. The Growth and Collapse of Island Societies: Archaeological and Demographic Perspectives from the Pacific. Honolulu: University of Hawai’i Press. – first paragraph 

Lee, CT, S Tuljapurkar, and P Vitousek. 2006. Risky business: spatial and temporal variation in preindustrial dryland agriculture.  Human Ecology 34 (6): 739-763. – abstractLink to article at Human Ecology

Boyce, MS, CV Haridas, CT Lee, and the NCEAS Stochastic Demography Working Group. 2006. Demography in an increasingly variable world. Trends in Ecology and Evolution 21: 141-148. – abstract   Link to article at TREE

Lee, CT, and A Hastings.  2006.  Non-equilibrium genetic structure is robust to the shape of the dispersal distribution.  Evolutionary Ecology Research 8: 279-293. – abstract –   Link to article at EER

Chesson, P, and CT Lee.  2005.  Families of discrete kernels for modeling dispersal. Theoretical Population Biology 67 (4): 241-256.  – abstractLink to article at TPB

Lee, CT, MF Hoopes, J Diehl, W Gilliland, G Huxel, EV Leaver, K McCann, J Umbanhowar, and A Mogilner.  2001.  Non-local concepts and models in biology.  Journal of Theoretical Biology 210: 201-219. – abstract –   Link to article at JTB



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