Tag Archives: dendroclimatology

Climate Change, Drought, Ohio, Projects

AMRE at Brown’s Lake Bog

Brown’s Lake Bog, located near Shreve in Wayne County, Ohio, is a nature preserve and National Natural Landmark that was established in the 1960’s. College of Wooster students have been involved in several past projects at Browns Lake Bog including sediment coring and ice drilling. Last week, the 2018 AMRE students ventured to this local spot to collect tree cores from some red and white oaks in order to perform some climate analysis for the Nature Conservancy and the Friends of Brown’s Lake Bog.

Brown’s Lake Bog is one of a few remaining peatland sites across Ohio that contains an open kettle lake surrounded by a floating sphagnum moss mat. These features are glacial relicts and the knolls surrounding the bog are glacially-formed hills called kames.

This field site is known for its diverse and rare plant community which thrives in the bog’s special acidic and nutrient-poor environment. More than twenty rare plant species can be found here.  The carnivorous Northern Pitcher Plant (Sarracenia purpurea) is one of the rare species that attracts bog visitors.

After checking out the kettle lake, the tree ring lab group hiked the short trail to reach the trees sitting on top of the kames. The AMRE students sampled 6 of the oldest white and red oak trees.

AMRE students with a sampled tree (Left to right: Alexis Lanier ’20, Juwan Shabazz ’19, and Kendra Devereux ’21)
The carnivorous Northern Pitcher Plant (Sarracenia purpurea) receives nutrients by trapping insects in its fluid-filled cavities.
The AMRE students getting coring tips from Nick.
Extracting a fresh oak core on top of the kame at Brown’s Lake Bog.
Juwan, Kendra, and Arrow sitting on a fallen oak.

Upon returning to the lab, the group mounted up the fresh cores and prepared them for counting and measuring ring widths. This week, Kendra and Alexis are working to update the local chronology and perform various correlations with the data. The final product will be an official climate analysis report.

The map below displays a positive correlation between ring width and precipitation during the months of June and July in the local Wooster area. These months displayed the highest p values and correlations (as shown in the bar graph), which is why these months were selected while creating the map using Climate Explorer. A positive correlation suggests that the more it rained, the better the trees grew (this is expressed in wider ring widths).

Stay tuned for more of their results!

Correlation between ring width at Brown’s Lake Bog and precipitation records.

 

One of Kendra’s initial correlation maps created with Climate Explorer. 

Read our complete dendroclimatological report here.

Dating Historical Structures, Ohio

Summer Researchers Start on New Project: Gingery Barn

Summer researchers in the CoW Tree Ring Lab have started a new project!

Early Wednesday morning, the group met with a new client, Don Gingery, who is interested in learning the age of his barn located in the Wooster area.

He brought in a few pieces of wood for us to check out and determine if they were good enough for processing. The oak samples did pass the test and qualified for sampling.

Some things we consider:

  • How many rings can we see with the naked eye? If there are only around 30 rings, that would not be a good sample for dating and comparing to the Ohio master chronology.
  • Is the sample whole? We look for the presence of both the outermost and inner rings to ensure we can obtain the most data. It is difficult to date structures if the outer rings are missing because we do not know exactly when that particular tree was felled.
  • Variation in ring width? The more variation between rings, the more interesting the data will be for us when looking at the tree’s relationship to precipitation records.
Oak beam sample.
The second oak sample.
Close-up prior to sanding in the lab.

To prepare the samples, Josh sanded the oak slice on the belt sander to polish its surface while Juwan and Dr. Wiles worked on obtaining a core from the other oak beam. This was done with a drill and special hollow drill bit. Two cores were extracted and immediately mounted.

Drill used for coring the beam.
Dr. Wiles aligning the drill bit prior to drilling in order to hit the heartwood and center of the rings.
Obtaining the first core.
Juwan drilling for the second core.
Obtaining the second core from the oak beam.

This drill bit is different from the hand borers used at the Holden Arboretum because it provides us with a core of a larger diameter. This is beneficial in studying the rings under the scope because we can look at a larger area of each annual ring. This drill is often used by the Tree Ring Lab when coring beams of structures rather than living trees.

The two cores extracted from the oak beam brought in by the client.
Juwan preparing the mount with wood glue.

One of the mounted cores to be left to dry.

When we returned this morning, Juwan, Victoria, and Kendra sanded and polished the two cores. Kendra is now working on measuring the ring widths under the microscope. Next steps include cross-dating and comparing these measured series to other Ohio records. We hope to then be able to provide our client with a report of our findings including a calendar date for the Gingery structure.

Stay tuned for updates!!

Our final report can be found here.