A pollen profile by scanning electron microscopy bracketing the mid-Holocene Tsuga canadensis decline at Poutwater Pond Bog, Holden, Massachusetts

Pollen profiles have routinely been prepared by identification by light microscopy (LM). This report presents a pollen profile from the mid-Holocene counted exclusively by scanning electron microscopy (SEM) targeting the Tsuga canadensis (hemlock) decline at the site and four published profiles counted by LM. While pollen profiles have routinely been counted by LM, counting by SEM provided more detailed pollen images, improved pollen identification, decreased the sample preparation time, and limited the use and disposal of hazardous chemicals. The SEM pollen profile revealed a three phased decline at the Poutwater Pond site. The most recent decline is in agreement with three of the four sites which show the decline occurring between 5700 and 4700 calibrated years before present (cal bp). This report is, to our knowledge, the first SEM pollen profile highlighting the T. canadensis decline in North America and supports previous datings of terminal hemlock decline as reported using LM methods.