PARENT SESSION
Poster Session #22: Paleoecology.
Wednesday, August 8, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall

Peatland Development in North-Central Wisconsin.

Callis, Mona¹, McGee, Amber¹, Brugam, Richard¹, ¹

ABSTRACT- One 6 meter sediment core was taken from Schulz bog, a Sphagnum peatland, located in north central Wisconsin. Because of its location outside the lake effects snow belt of Lake Superior, Schulz bog provides a climatic contrast with better understood sites in the Upper peninsula of Michigan. Six local pollen assemblage zones were recognized from Schulz bog. These are: (1) a basal Picea - herb zone (12,000 - 10,000 bp). (2) a Pinus banksiana - Betula- Ulmus zone (10,000 - 8,000 bp). (3) a Pinus strobus zone (8,000 - 5,000 bp). (4) a Sphagnum zone (5,000 - 3,000 bp). (5) a Tsuga zone (3,000 - 100 bp). (6) an Ambrosia zone (100 - present). Percent ash weights are low (<20%) throughout the core until 400 cm depth, suggesting Schulz bog may have been a wetland since 9,000 bp. Pollen analysis indicates an increase in Sphagnum beginning at 5,000 bp. Colorimetric measurements of humic acids in the core indicate an increase in humic matter at the same time. Comparisons with a 1,700 site data set of modern pollen samples show that the core is most similar to modern Tsuga zone samples from the Upper Peninsula of Michigan. The Pinus banksiana zone has only poor modern analogues. The Picea - herb zone is similar to modern samples from Quebec.

KEY WORDS: Paleoecology, Central Wisconsin, Peatland, Tsuga