Presidential Professor of Biology
George Lynn Cross Research Professor
Dr. Kaspari's Web Page
Current Research Interests and Subject Areas Available for Graduate Research
Our lab explores the biogeography of brown food webs—the microbes and invertebrates that use detritus as both home and food, and, in the process, shape the earth’s nutrient cycles. A shared theme through most of our work is a focus on natural history and the principles of organismal biology toward predicting the behavior of communities and ecosystems.
Current ProjectsNSF Collaborative Research (RUI with Adam Kay): Toward a stoichiometric theory of ant ecology--from colony performance through community dynamics($634K total)
Ants, given their ubiquity and ecology diversity, are a model system in ecology. The goal of this grant is to build a functional understanding of ant communities using energetic and stoichiometric theory. We are exploring how traits of ant colonies (e.g., colony size, body size, metabolic rate/velocity, colony growth rate, and aggressiveness) are themselves built from molecules with differing quantities of C, N, P, and other elements. Toward this end we are quantifying the biochemistry and natural history of ca. 70 of the 400 species of ants on Barro Colorado Panama, measuring the abundance of ants across natural gradients in CNP availability, and experimentally manipulating the availability of carbohydrates, proteins, and micronutrients at the landscape scale.
NSF EAGER (PI): Does Na availability regulate tropical decomposers? ($75K). Pending at NSF: Na as a driver of the central Amazon carbon cycle: biogeochemical synergies and feedbacks ($324K). Pending at DOE: Mapping the effects of Na on the global carbon cycle. ($1.2 million). Both pending proposals are with Jennifer Powers.
Life is built from ca. 25 chemical elements. Yet ecologists, in their first forays into biogeochemistry have largely focused on C, N, and P. We have been exploring how gradients of numerous other elements can leave their mark on the performance of individuals, community abundance, and ecosystem function. Of particular interest is sodium, Na, one of the few elements of little use to plants but vital to the decomposers and herbivores that feed on plants. The need for these two trophic groups to find and concentrate environmental sodium has important consequences for the physiological adaptations to find and use Na, the lower population densities and poor consumer performance in Na-poor ecosystems, and the subsequent low rates of decomposition in Na-poor ecosystems. Na also has geography: it is deposited in oceanic aerosols. Using a one-year experiment, we are testing the prediction that inland forests are unexpected carbon sinks, since photosynthesis proceeds unabated but decomposition rates decline as Na inputs diminish. If true, this premise will transform our understanding of how biogeochemistry feeds back on the geography of abundance and nutrient cycling.
NSF: MacroSystems (with co-PIs Jizhong Zhou, Jim Brown, Robert Waide, and Brian Enquist): Experimental Macroecology: the effects of temperature on biodiversity ($4.8 million total)
One of the strongest statistical patterns in biodiversity is the correlation between temperature and species richness, yet the mechanisms underlying this pattern remain elusive. This unique collaboration will develop and test theory in an iterative fashion over four years toward shedding light on the origin and maintenance of biodiversity. We do so by combining studies of the diversity and dynamics of the woody plants, soil invertebrates and soil microbes across six sites in North and Central America. The grant’s primary focus is the development of a first-principles model of decomposition succession in the brown food web—plant detritus, microbes and invertebrates—which will be tested in the field and in growth chambers. A deep understanding of the temperature dependence of this fundamental earth system has clear implications for the cycling of carbon and the maintenance of biodiversity in a warming world.
To learn more about this research, visit Dr. Kaspari's web page.
Ph.D., University of Arizona
M.S., University of Nebraska
B.S., University of Nebraska
Kaspari M, M Yuan, L Alonso. (2003) Spatial grain and gradients of ant species richness. American Naturalist: 161, 459-477.
Kaspari M, T Valone. (2002) Seasonal resource availability and the abundance of ectotherms. Ecology.83: 2991-2996
Kaspari M, J Longino, J Pickering, D Windsor. (2001) The phenology of a Neotropical ant assemblage evidence for continuous and overlapping reproduction. Behavioral Ecology and Sociobiology. 50 (2001) 4, 382-390.
Yanoviak, S and M Kaspari (2000) Community structure and the habitat templet: ants in the tropical forest canopy and litter. Oikos 89:259-266.
Kaspari M, S O Donnell and JR Kercher (2000) Energy, density, and constraints to species richness: studies of ant assemblages along a productivity gradient. American Naturalist 155:280-293
Kaspari M, S. O'Donnell, and L Alonso (2000) Three energy variables predict ant abundance at a geographic scale. Proceedings of the Royal Society B 267:485-490.