Fluctuating Resources

Resource supply in nature is often highly dynamic. Resource fluctuations may change community composition and species diversity. Light is a major resource for phytoplankton that fluctuates on a wide range of temporal and spatial scales. During my Ph.D. I (E. Litchman) started looking at how fluctuating light affects phytoplankton competitive interactions. Light fluctuations can alter growth rates of phytoplankton in a species-specific way: some taxa are depressed and some are stimulated by light fluctuations, compared to constant light. Consequently, community structure changes depending on the temporal regime of light supply. Light fluctuations may switch competitive outcomes and promote species coexistence, as was shown for other fluctuating resources. Light fluctuations also mediate phytoplankton competition for nutrients by altering patterns of nutrient utilization.

We are continuing looking at how seasonal patterns of resource fluctuations structure phytoplankton communities and drive seasonal succession.

Personnel

Lab Members

Elena Litchman, Christopher Klausmeier

Collaborators

Peter Bossard (EAWAG, Switzerland)

Publications

Litchman, E. 1998. Population and community responses of phytoplankton to fluctuating light. Oecologia, 117: 247–257.

Reprint (606KB PDF)

Litchman, E. 2000. Growth rates of phytoplankton under fluctuating light. Freshwater Biology, 44: 223–235.

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Litchman, E. and C.A. Klausmeier. 2001. Competition of phytoplankton under fluctuating light. American Naturalist, 157: 170–187.

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Litchman, E., D. Steiner and P. Bossard. 2003. Photosynthetic and growth responses of three freshwater algae to phosphorus limitation and daylength. Freshwater Biology, 48: 2141-2148.

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Litchman, E. 2003. Competition and coexistence of phytoplankton under fluctuating light: experiments with two cyanobacteria. Aquatic Microbial Ecology, 31: 241-248.

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Litchman, E., C.A. Klausmeier and P. Bossard. 2004. Phytoplankton nutrient competition under dynamic light regimes. Limnology and Oceanography, 49: 1457-1462.

Reprint (125KB PDF)

Last updated: December 19, 2006