A paleoecological record in a day (PLE day 13)

Analyzing plant macrofossils from a peat core.

Analyzing plant macrofossils from a peat core.

One afternoon. Nine students. Approximately 8500 years of history.

The Pymatuning wetlanders spent the morning learning about wetland development and the roles that wetlands play in the broader earth system. In the afternoon, we examined the sediment core that we collected from Titus Bog yesterday – all 8.5 meters of it! The students sieved samples from along the core, and identified and tallied plant macrofossils (e.g., leaves, seeds). By applying age-depth information from previous work on the bog (Ireland et al., 2011), we estimated the age of the samples along the length of the core.

Carefully examining peat from Titus Bog.

Carefully examining a sediment core from Titus Bog.

The diagram below shows our paleoecological results, and clearly shows that the site started as a deep kettle lake (the lower samples lacked macrofossils) some 8500-10,000 years ago, and  was occupied by a shallow lake with abundant submerged aquatics like nodding waternymph (Najas flexilis) and pondweed (Potamogeton sp.) throughout much of the mid Holocene. In the later Holocene the area was shallower, supporting a mix of submerged aquatic plants like nodding waternymph, along with floating leaved plants like white water lilies (Nymphaea odorata).  About 800-900 years ago a floating peatland established at the site, with various sedges, Sphagnum, cranberries (Vaccinium oxycoccos), and leatherleaf shrubs (Chamaedaphne calculata) characterizing the surface vegetation. We will discuss the record in the context of peatland developmental models tomorrow…

Plant macro fossil diagram from Titus Bog put together by the 2014 Pymatuning wetlanders. All values are numbers per 30cm3 of peat, except for Sphagnum and Cyperaceae which represent coverage estimates in cm2 for 30cm3 samples. Estimated age and depth are shown to the left.

Plant macrofossil diagram from Titus Bog put together by the 2014 Pymatuning wetlanders. All values are numbers per 30cm3 of peat, except for Sphagnum and Cyperaceae which represent coverage estimates in cm2 for 30cm3 samples. Estimated age and depth are shown to the left.

 

About these ads

Posted on June 18, 2014, in Teaching, Wetland Ecology & Management (PLE) and tagged , , , , . Bookmark the permalink. Leave a comment.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 108 other followers

%d bloggers like this: