PARENT SESSION
Oral Session #44: Global Change and Climate Change.
Presiding: C. Wessman
Tuesday, August 6. 1:00 PM to 4:45 PM. Grand Ballroom West, Radisson.

UV Radiation and ephemeral pool ecosystems: The dynamic role of canopy cover.

Clauser, Aaron^*,1, Williamson, Craig¹, ¹ Lehigh University, Bethlehem, PA, aac2@lehigh.edu

ABSTRACT- Ephemeral pool inhabitants vary greatly in their tolerance to UVR. The vertebrates that we have tested to date are more UV tolerant than their invertebrate prey. Thirty-nine pools were sampled from ice-out until desiccation. Attenuation in the water column primarily by dissolved organic carbon (DOC) and particulates was the principle regulator of UV before leaf-out. After leaf-out, direct shading of incident UV by deciduous canopy cover played the largest role. Depth refugia from UV varied strongly among pools as well as seasonally within pools, with UV 1% attenuation depths exceeding maximum pool depth in some cases. In some systems, seasonal variation in UVR may adversely affect zooplankton and thus indirectly alter the available niches for herbivorous versus carnivorous amphibians.

KEY WORDS: uvr, ephemeral, zooplankton, amphibian