Tag Archives: dendrochronology

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.

Alaska, Dating Historical Structures, Ohio, Projects

Summer 2018 Research in the CoW Tree Ring Lab

This summer, students through the AMRE program will be working in the lab doing historical dating. Kendra Devereux, Alexis Lanier, and Juwan Shabazz will be working with clients to date local barns, update chronologies, and study past climate.

Two additional students are working in the lab with data collected from Columbia Glacier in Prince William Sound, Alaska. Josh Charlton and Victoria Race will be helping out the AMRE students and also spending time with data collected from Columbia Glacier. Josh is working on constructing a model of the rapidly retreating Columbia Glacier and Victoria will be looking more closely at Blue Intensity data obtained from tree cores collected in Columbia Bay.

Work started earlier this week and the group went out in the field yesterday for the first time together. We headed up North to the Holden Arboretum to collect core samples from living Chestnut Oak trees in Stebbins Gulch.

2018 “Tree Huggers” From left to right: Victoria Race, Kendra Devereux, Alexis Lanier, Josh Charleton, and Juwan Shabazz
Alexis removing tree borer after extracting core from this chestnut oak.
Taking some measurements along with a few cores from this living chestnut oak.
Juwan and Kendra showing off their extracted cores.
Dr. Wiles checking the budding leaves of a chestnut oak.
One of our freshly extracted cores.

Today we finished mounting the cores and will begin dating them after they have been sanded. These samples will be used to update the chronology from the Holden Arboretum which has not been updated in several decades. We plan on looking specifically at precipitation data extracted from these cores and then writing an official report of our findings for the researchers at Holden.

Chestnut oak cores collected from Stebbins Gulch before mounting process.
Close-up of a damp core before mounting.

In the coming weeks, the group will be working on various projects including the Holden chronology, barn dating, and Columbia Glacier data. Stay tuned for updates!!

You can also follow the Geology Club instagram for more information and photos along with the departmental Facebook page.

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The Cooper Plots – Ecological Succession in Glacier Bay National Park and Preserve, Alaska

I recently had the pleasure to work with a team of ecologists for eight days in Glacier Bay National Park and Preserve. The point of the trip was to reoccupy and expand investigations of the Cooper Plots established over 100 years ago in the wake of the retreating ice in the West Arm. A nice rundown of this ecological succession work is presented here on Glacier Hub. The ecology team recently published on their rediscovery of the plots, which was heroic considering the immense lands, intense brush and  sometimes cryptic description of the plot locations.

The accommodations and views in the West Arm of Glacier Bay were spectacular. Logistics of the project were supported by the National Park Service, who we gratefully acknowledge.

The team of ecologists included (left to right) Drs. Allison Bidlack (Director, Alaska Coastal Rainforest Center, University of Alaska Southeast), Sarah Bisbing (University of Nevada – Reno) and Brian Buma (University of Alaska Southeast). I was along to core trees at the sites (Wooster Tree Ring Lab) and to measure the size of alders.

Sarah and Brian cordon off one of Cooper’s 1-meter plots with string so we don’t trample the vegetation. Sarah reals out a 15-meter tape with Allison on……

https://woostergeologists.scotblogs.wooster.edu

Climate Change, Ohio, Projects

Coring Brown’s Lake Bog

Two class projects kick off the Climate Change 2017 course. The first deals with tree-ring dating (dendrochronology, blog post coming soon) of historical structures and then analyzing the tree-rings for their climate significance. The second is is shown below and it concerned with analyzing sediment cores from Browns Lake Bog that document climate variability since the last Ice Age. Below are some photos of the bog coring – great thanks to Dr. Tom Lowell and his Glacial Geology class from the University of Cincinnati – the folks who did most of the work.

Setting up the coring rig at Browns Lake – early in the day snow covered the ground by 4 pm it was gone (albedo feedback in play).
The core boss (Dr. Tom Lowell) oversees the extraction of another meter of mud from the bog.
Extracting peat – the upper 5 meters or so are peat (significant amount of sphagnum moss and carbon). Note the trees, it is not a sphagnum bog now here.
Setting up the production line and assigning teams and tasks.

 

Coring a tree to determine the recruitment time – the hypothesis is that these trees moved into the bog recently (past 200 years) – the first trees here since the Ice Age. This nutrient limited bog was fertilized by wind blown dust during European Settlement allowing these vascular plants to obtain a foothold in the previously sphagnum moss dominated bog.

 

Hey there is a Wooster student – good job Ben. This white oak is growing on the top of a kame and it has witnessed the changes in the climate and land use for the last 300 years.

 

Nick samples the bog water for its isotopic composition. This is work done in collaboration with isotope geologists at the University of Cincinnati.

Post originally published on the Wooster Geologists blog.