Published online by Cambridge University Press: 20 January 2017
A radiocarbon-dated pollen record near the Boylston Street Fishweir site in Boston; Massachusetts, provides a regional and local record of vegetation changes from the middle Holocene to present. The stratigraphy begins about 5630 ± 90 yr B.P. with a marine transgression and is continuous up to the historic backfilling of the Back Bay area about 100 yr B.P. When pollen began accumulating at the site, the immediate area resembled the swamp forests growing today in southern New England. Fresh- and brackish-water vegetation was present before the area near the site was submerged. While these vegetation changes occurred locally, oak forest grew in the region. Correlation of this stratigraphy with archaeological data collected from 500 Boylston Street indicates that between 4700 and 3700 yr B.P., a number of fence-like alignments ("weirs"), were probably placed within existing channels and/or along shorelines to capture fish and other marine animals as they moved with the tidal flow.