HR: 1330h
AN: C42A-1005    [PDF]
TI: Contrasting Responses of Arctic Tussock Tundra to Early Season Snow Melt: Growth Acceleration Versus Frost Damage
AU: * Oberbauer, S F
EM: oberbaue@fiu.edu
AF: Florida International University, Department of Biological Sciences 11200 SW 8th ST, Miami, FL 33199 United States
AU: Starr, G
EM: gstarr@ufl.edu
AF: Florida International University, Department of Biological Sciences 11200 SW 8th ST, Miami, FL 33199 United States
AU: Pop, E W
EM: epop@sbcglobal.net
AF: Florida International University, Department of Biological Sciences 11200 SW 8th ST, Miami, FL 33199 United States
AU: Ahlquist, L E
EM: Chocbzee@aol.com
AF: Florida International University, Department of Biological Sciences 11200 SW 8th ST, Miami, FL 33199 United States
AU: Parker, I C
EM: ingaparker@hotmail.com
AF: Florida International University, Department of Biological Sciences 11200 SW 8th ST, Miami, FL 33199 United States
AB: Climate warming scenarios for the Arctic include early snow melt marking the beginning of the growing season. From the perspective of the vegetation, early snow melt may have advantageous or disadvantageous effects. With warm weather following snow melt, bud break and flowering will occur early providing a longer period for growth and photosynthesis. However, if very cold weather follows snowmelt, plants will be exposed directly to freezing conditions that plants under the snow would not. Such exposed plants may suffer freeze damage and delayed bud break. We have been experimentally manipulating snow cover at Toolik Lake, Alaska, since 1995. In 9 years of early snow removal treatments, in only two years has the second scenario occurred, in 2001 and 2002. Here we document the effects of very cold conditions following snow removal on green biomass as assessed by NDVI of treatment plots relative to controls. In 2001 evergreens shrubs were killed, bud break was delayed, and NDVI was lower on treatment plots relative to controls. In contrast, in a year with warm spring temperatures following snow melt, 1999, NDVI on treatment plots was significantly greater than that of controls. Cold conditions following snow melt may lead to death of shrubs and delayed budbreak, effects that will carry over throughout the growing season and ultimately, affect community composition and ecosystem function.
DE: 1851 Plant ecology
DE: 1860 Runoff and streamflow
DE: 1863 Snow and ice (1827)
SC: Cryosphere [C]
MN: 2003 Fall Meeting