NEW POLLEN EVIDENCE FOR THE POSTGLACIAL VEGETATION HISTORY OF NORTH HAVEN ISLAND, MAINE

The postglacial vegetation history of North Haven Island is important to understanding the environment in which swordfish-hunting paleo-Indians lived on the Maine coast. Previous attempts to evaluate this using sediment cores from the outer coastal salt marsh adjacent to the Turner Farm archeological site have failed due to very poor preservation. A compressed 1-m core from Fresh Pond, 1 km inland, and a new 1.6-m core from the inner salt marsh have yielded better data. Radiocarbon dating of the Fresh Pond core has been problematic, yielding essentially modern ages at the core base. Wood from 103-105 cm deep in the salt marsh has been radiocarbon dated at 2940 ± 30 BP.

The close-interval Fresh Pond pollen record is dominated (typically >50%) by Betula, with Pinus and Picea only becoming major in the near-surface layers; the macrofossil record shows abundant Picea and Tsuga canadensis needles only in the upper 20 cm.

The inner salt marsh core was sampled at 5-cm intervals throughout the 1.4-m organic portion of the sediments for pollen and macrofossils. The pollen record is dominated by Pinus and Picea throughout. Abies is common only below 30 cm depth, while Betula is fairly uniform at 5-10% of the total throughout; Quercus is common throughout the core but particularly above 90 cm depth, though other hardwoods are rare to absent – save Juglans which is almost 6% of the total at the surface. Poaceae are highly variable and likely represent inflora, while Typha latifolia shows three pulses in abundance culminating in the present. Chenopidiineae reach a broad high in adundance from 40-80 cm depth. Ambrosia varies up to 11.2% of the total but doesn’t appear to reflect 18th-century European forest-clearing; similarly, there are no large “spikes” in other agricultural weeds.

The contrasting records suggest that the inland Fresh Pond site may have been slightly more mesic and birch-dominated than the coastal site, where boreal conifers with modest oak dominated with a rich fern understory, including Osmunda and multiple monolete-spore taxa. However, in the absence of precise dating of the Fresh Pond materials, exact correlations are difficult.

Work is continuing on the macrofossil record from the salt marsh cores.