Fall 2009: Biology Dept. offers research talk on white spruce

Today, Oct. 9, 3:30-4:45 p.m.
ConocoPhillips Integrated Science Building (CPISB), Room 120

Bjartmar Sveinbjörnsson of the Dept. of Biological Sciences Environmental and Natural Science Institute, will present "White spruce growth above and below the forest boundary across Alaska: Carbohydrate source or sink limitation?"

White spruce branch extension growth has been reported to be lower in the treeline zone above the forest boundary than below it in Alaska. This has been attributed to a shorter growing season and greater needle loss.

There are two main hypotheses regarding carbon limitation affecting tree growth. The carbon source limitation hypothesis states that at the treeline there is less photosynthesis, greater respiration or greater loss of carbon stored from previous season. The carbon sink limitation hypothesis states that there is ample carbon supply in the tree at treeline but instead there are limits on their use, e.g. for biosynthesis, cell division, and growth because of low temperatures. Patterns of variation in needle non-structural carbohydrate concentration and content are examined to evaluate the above hypotheses for white spruce.

Parking is free on Fridays and no-host refreshments are offered.