The urban stream syndrome describes a set of interacting stressors that define the conditions that control biological function in urbanized streams, particularly those in the Global North. While one well-studied “symptom” of the urban stream syndrome is increased nutrient loading, the relative stoichiometry of these nutrients (e.g., nitrogen (N) and phosphorus (P)) may also be unique in urban streams due to organismal responses to other urban stressors. Urbanization may alter the stoichiometric traits of aquatic organisms by selecting for sets of traits with a common stoichiometric signature, which may in turn alter the relative storage and fluxes of key elements like N and P in urban streams. We hypothesize that unpredictable hydrology, elevated maximum temperatures, and increased concentrations of salts associated with urbanization select for taxa with low body C:P and N:P because these taxa must exhibit rapid growth rates and/or come from marine-derived lineages with greater salt tolerance. Both rapidly growing insects and salt-tolerant crustaceans have relatively low body C:P and body N:P, albeit for different biological reasons. We also suggest that the effects of urbanization on stoichiometric traits should be strongest at high latitudes, where urban heat island effects and use of deicing salts create a strongly differentiated fitness landscape. We use a recently developed stoichiometric diversity framework to analyze benthic invertebrate assemblages across urban gradients in Vermont and Arkansas (USA) to test these hypotheses.

Primary Presenter: Eric Moody, Middlebury College (ekmoody@middlebury.edu)

Authors:

Baker Angstman, Middlebury College  ()

Jessica Corman, University of Nebraska Lincoln  ()

Molly Costanza-Robinson, Middlebury College  ()

Katherine DeFrancesco, Middlebury College  ()

Charles Forbes, Middlebury College  ()

Halvor Halvorson, University of Central Arkansas  ()

Julia Keon, Middlebury College  ()

Erin Larson, University of Alaska Anchorage  ()

Natalie Montano, Middlebury College  ()

Emma Neill, Middlebury College  ()

Elizabeth Peebles, Middlebury College  ()

Anthony Pignatelli, University of Central Arkansas  ()

Kristen Pundyk, Middlebury College  ()

Ella Roelofs, Middlebury College  ()

A.J. Rossbach, Middlebury College  ()

Liza Toll, Middlebury College  ()