FOOD CHAIN LENGTH IN STREAMS

Effects of Flow Regime Shifts, Anticendent Hydrology, Nitrogen Pulses and Resource Quantity and Quality on Food Chain Length in Rivers

The temporal pattern of water flow in a river can affect the abundance of plants and animals and the food web that supports fisheries. Severe floods that scour the riverbed can potentially displace or kill plants and animals, and droughts contribute directly to mortality. Previous work by Sabo et al. suggests that floods and droughts are stronger predictors of food chain length in streams than the supply of energy at the base of the food web, but the mechanisms underlying this pattern remain unclear. Studying streams across Arizona that span a gradient from dominant annual precipitation input during winter frontal storms to summer monsoons, we will examine the role of hydrologic regimes in altering nitrogen supply, energy supply, and food web structure in desert streams.

Funded by Division of Environmental Biology, National Science Foundation

Collaborators: John Sabo (Arizona State University), Albert Ruhí (University of California Berkeley)