- Ph.D., Ecology, Evolution, and Behavior, University of Texas at Austin, 2008
- Postdoctoral research: Yale University and the University of Notre Dame
My research integrates population, community, and ecosystem-level processes across multiple spatial scales to understand determinants of species and genetic diversity, and ecosystem properties in aquatic systems. Recently, the importance of space in mediating population connectivity and local species interactions has become increasingly recognized by ecologists and evolutionary biologists. This interest in spatial ecology has largely arisen from the urgent need to understand how fragmented landscapes alter dispersal and gene flow of threatened species, and how species invasions affect species richness and ecosystem functioning. Over the past decade, the metapopulation and metacommunity concepts have emerged as powerful frameworks in which to place population demography, community interactions, and ecosystem properties in a spatially explicit context. My research employs experimental and observational approaches to extend metapopulation and metacommunity theory to diverse freshwater species and landscapes. To date, I have conducted field research in the temperate ponds of Michigan, the coastal lakes of New England, and the arid wetlands of the Cuatro Ciénegas Biosphere Reserve in Mexico. Research in my laboratory addresses both basic and applied ecology and currently follows two main themes:
Species diversity and ecosystem properties in multi-trophic metacommunities
The metacommunity concept provides a framework that describes and forecasts effects of community connectivity (species dispersal rates) on species diversity and ecosystem properties across hierarchical spatial scales in a landscape. My research in metacommunities is situated at the interface of local and regional spatial scales, and integrates food web interactions and evolutionary biology to understand processes affecting multi-scale diversity and trophic structure. Most of this work uses experimental and observational studies of freshwater plankton communities to test and extend metacommunity theory. My previous research in pond and lake plankton metacommunities addressed the influence of spatially and temporally heterogeneous predation (invertebrate, fish) on metacommunity structure, and the effect of intraspecific variation in a fish predator on multi-scale diversity. Current research uses non-native species to take a mechanistic and trait-based approach towards understanding the process of invasion in metacommunities.
Trait-based invasive species risk assessment
A new, collaborative research effort develops trait-based invasive species risk assessments for non-native fishes in North America. The research focuses on identifying traits of non-native fish which are associated with different stages of invasion. Comparative studies of non-native fish communities in multiple regions of North America that differ in spatial extent, environment, and regional native species pool will elucidate region-independent patterns of important and shared traits associated with invasion. Additionally, this research aims to identify non-native fish species in international trade (e.g., aquarium, live-food) which pose a threat to freshwater ecosystems across North America. This integrative science has strong implications for community ecology theory, management practices, and environmental policy.
Howeth, J. G., Weis, J. J., Brodersen, J. , Hatton, E.C. and D. M. Post. 2013. Intraspecific phenotypic variation in a fish predator affects multi-trophic lake metacommunity structure. Ecology and Evolution 3: 5031-5044.
Howeth, J. G. and M. A. Leibold. 2013. Predation inhibits the positive effect of dispersal on intraspecific and interspecific synchrony in pond metacommunities. Ecology 94: 2220-2228.
Howeth, J. G. and W. S. Brown. 2011. Terrapene coahuila – Coahuilan box turtle. In: Rhodin, A. G. J., Pritchard, P.C.H., van Dijk, P. P., Saumure, R. A., and Iverson, J. B. [eds]. Conservation Biology of Freshwater Turtles and Tortoises: A Project of the IUCN/ SSC Tortoise and Freshwater Turtle Specialist Group. Chelonian Research Monographs 5: 49.1-49.13.
Howeth, J. G. and M. A. Leibold. 2010. Species dispersal rates alter diversity and ecosystem stability in pond metacommunities. Ecology 91: 2727-2741.
Howeth, J. G. and M. A. Leibold. 2010. Prey dispersal rate affects prey species composition and trait diversity in response to multiple predators in metacommunities. Journal of Animal Ecology 79: 1000-1011.
Howeth, J. G., Derry A. M. and A. M. Reitzel. 2010. Metacommunity biology as an eco-evolutionary framework for understanding exotic invasion in aquatic ecosystems. p. 93-109. In: P.F. Kemp [ed.], Eco-DAS VIII Symposium Proceedings, American Society of Limnology and Oceanography.
Howeth, J. G. and M. A. Leibold. 2008. Planktonic dispersal dampens temporal trophic cascades in pond metacommunities. Ecology Letters 11: 245-257.
Howeth, J. G., McGaugh, S. E. and D. A. Hendrickson. 2008. Contrasting demographic and genetic estimates of dispersal in the endangered Coahuilan box turtle: A contemporary approach to conservation. Molecular Ecology 17: 4209-4221.