Spring 2009: Biology Dept. offers talk on carbon balance of tundra landscapes

Today, April 3, 3:30-4:45 p.m,
Social Sciences Building (SSB), Room 119

The Biology Dept. presents speaker Gaius R. Shaver, senior scientist at The Ecosystems Center of the Marine Biology Laboratory in Woods Hole, MA., who will present this talk: "Heterogeneity and change in the carbon balance of tundra landscapes."

The arctic landscape is covered by a mosaic of ecosystems that differ widely in their species composition, stature and biogeochemistry. Superimposed on this mosaic is a nonuniform pattern of climate changes that is already causing major changes in these ecosystems and their properties. Are all arctic ecosystems responding in the same way? Can we use models developed in one part of the Arctic to understand and predict responses in other locations and ecosystem types?

This seminar will present evidence that, at least for the primary production system, simple models can be developed that do not require us to document the unique properties and composition of every kind of arctic vegetation in order to produce an accurate prediction. Examples include rules for arctic vegetation canopy development and photosynthesis, and for the allocation and use of a commonly limiting element, nitrogen, in plant growth and biomass accumulation. These rules work well for relatively stable arctic ecosystems or for systems that are changing relatively slowly.

The next step is to develop models that do a better job at predicting the dynamics of rapid change, including changes in response to secondary impacts of climate change like increased fire or changes in permafrost. Rather than slow changes in response to a changing climate, these secondary impacts may become the principal driver of overall, large-area change in much of the arctic landscape.

Parking is free on the UAA campus on Fridays. No-host refershments will be provided for which your contributions are greatly appreciated.