|2007 GSA Denver Annual Meeting (28–31 October 2007)|
|Paper No. 144-29|
|Presentation Time: 8:00 AM-12:00 PM|
PRE- AND POST-EUROPEAN FOREST COMPOSITION AND BOG FLORA CHANGES DOCUMENTED BY POLLEN FROM MAINE SPHAGNUM CORES
CLARK, C. Kittinger1, KRUMDIECK, Newton W.1, LITTLEFIELD, Elizabeth F.1, and NELSON, Robert E.2, (1) Department of Geology, Colby College, 5800 Mayflower Hill, Waterville, ME 04901-8858, firstname.lastname@example.org, (2) Dept. of Geology, Colby College, 5804 Mayflower Hill, Waterville, ME 04901-8858|
What is "natural" in the environment is increasingly becoming of concern as efforts to implement ecological restoration are undertaken. Regional lacustrine pollen records have been reported, but detailed local data for Maine are not available.
Short (~1m) cores were extracted from three sphagnum bogs on a transect through three central Maine counties: Kanokolus Bog in Waldo Co. (44°33'28"N, 69°22'22"W), Hamilton Pond Bog in Kennebec Co. (44°27'58"N, 69°50'15"W) and Round Pond Bog in Franklin Co. (44°31'14"N, 70°05'22"W). Dating indicates core bases are up to 2000 14Cybp; European disturbance of the landscape (marked by ragweed pollen increase) is recorded at depths ≤ 80 cm.
Pollen samples from 5-cm intervals yielded good percentage data. Round Pond shows greatest resolution with 2 mm/yr accumulation; Kanokolus sediments accumulated at ~1 mm/yr, and Hamilton Pond ~0.5 mm/yr. Both Round Pond and Kanokolus show abrupt hemlock decline with European settlement, but this occurred ≥750 years earlier at Hamilton Pond, where colonization had no major impact on hemlock. Maple increased in post-European time at Round Pond and Kanokolus, but decreased at Hamilton Pond. Oak is constant across European contact at Round Pond and Kanokolus, but declined at Hamilton Pond; beech was all but absent at Kanokolus but declined at Round Pond and Hamilton Pond. Pine has increased at all sites in the past century, as have fir and spruce at Round Pond and Kanokolus; fir and spruce are unchanged at Kanokolus. Birch increased at Round Pond and Hamilton Pond shortly after reforestation began, but has declined at Kanokolus. Heaths increased at all sites in post-European time, presumably as increased erosion has increased nutrient flux into the basins.
The data indicate that modern central Maine forests are quite different from those that existed prior to colonization. Pine is more abundant, and hemlock less so, than in pre-European forests, although hardwood variations are more complex.
2007 GSA Denver Annual Meeting (28–31 October 2007)
General Information for this Meeting
|Session No. 144--Booth# 112|
Paleontology (Posters) II: Environments, Ecosystems, and Interactions
Colorado Convention Center: Exhibit Hall E/F
8:00 AM-12:00 PM, Tuesday, 30 October 2007
Geological Society of America Abstracts with Programs, Vol. 39, No. 6, p. 401
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