Results of fieldwork in Glacier Bay National Park and Preserve by collaborators from Lamont-Doherty Earth Observatory and University of Alaska – Fairbanks are described here in this excellent blog. This narrative is written by scientist, author and collaborator on the project Lauren Oakes. Lauren is also author of a forthcoming book on Alaska Cedar Decline and Climate.
Summer 2018 research in the Tree Ring Lab has come to a close. The group of five students worked on a variety of projects, learning about the climate and history of Ohio and Alaska, and the application of different dendrochronological techniques and statistical analyses. They also gained experience effectively conveying their research to others and writing official reports of their findings.
The summer research team on their last day working together (Left to right: Greg Wiles, Nick Wiesenberg, Victoria Race ’19, Juwan Shabazz ’19, Kendra Devereux ’21, Josh Charlton ’19, and Alexis Lanier ’20).
AMRE students with a sampled oak tree at Brown’s Lake Bog in Wooster, Ohio (Alexis Lanier ’20, Juwan Shabazz ’19, and Kendra Devereux ’21).
The AMRE team accomplished a lot during the eight weeks they were here on campus. Their research started with the principles of dendrochronology, when they learned how to count individual tree rings and measure their widths under the microscopes. From here, the team learned how to run this data in different programs like COFECHA and ARSTAN. This process allowed them to date many historical structures across Northeast Ohio such as Gingery Barn and Miller House and Barn. You can find a full list on the TRL’s reports page.
AMRE students with
Today is the official last day for AMRE researchers here at the Tree Ring Lab. The AMRE team has accomplished many projects these past 8 weeks.
Their research started with the principles of dendrochronology, when they learned how to count individual tree rings and measure their widths under the microscopes. From here, the team learned how to run this data in different programs like COFECHA and ARSTAN. This process allowed them to date many historical structures across Northeast Ohio such as Gingery Barn and Miller House and Barn. You can find a full list on our reports page.
The AMRE students also learned how to take these chronologies and make hypotheses regarding past climate by uploading the data to Climate Explorer and running various correlations with other datasets.
We were fortunate enough to go out in the field and personally collect most of the data that we worked with this summer. These eventful trips included a lot of tree coring and required lots of bug spray. Some of the AMRE group’s favorites trips included Stebbin’s Gulch and Brown’s Lake Bog.
The other two summer researchers working in the Tree Ring Lab this summer, Victoria Race and Josh Charlton, have been working with tree ring data collected from Alaska. Their work focuses on the modeling of Columbia Glacier located in Prince William Sound, Alaska. They are currently working on an abstract to submit to the upcoming GSA conference this fall. Stay tuned for more information regarding their project!
Special thanks to the National Science Foundation, the Sherman Fairchild Foundation and the AMRE program for helping to make this research possible. Enjoy the rest of your summer!
Summer researchers working in the Tree Ring Lab returned to Stebbin’s Gulch in late May to collect more chestnut oak samples. This increased replication helps us to strengthen our various hypotheses made from the interpretation of our findings.
This information is useful in mapping out land use changes in Northeast Ohio. The team identified an abrupt increase in ring width around 1840. They attributed this rise to decreased competition from logging which coincides with the time of most significant settlement in the area.
Read more about their conclusions in the official dendroclimatological report here.
The team collected cores from white and red oak trees at both locations to update their chronologies and analyze land use history of these areas.
Barnes Preserve is a 76-acre park known for its rejuvenating atmosphere, diverse wildlife, and accessible trails. The team focused on collecting samples from mature trees in order to create a new local chronology. The Tree Ring Lab hopes to return to Barnes Preserve and build upon this record in the future.
The Wilderness Center has an old growth forest named Sigrist Woods that the team was interested in sampling. From these cores they hoped to learn more about a recent storm that damaged and felled many trees in the area. They plan to look more closely at the cores to see if ring widths were affected by this event by either storm damage or loss of competition.
Preliminary results are showing that the trees from Sigrist are dating back to the late 1800’s. Stay tuned for more of their results!
Special thanks for Denny Jordan and Herb Broda for helping facilitate this research.
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.
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).
Last Wednesday, the AMRE group met with Ray Leisly at Sonnenberg Village in Kidron, Ohio.
Mr. Leisly brought the group to three different historical structures, including two homes and one barn. The families who own these structures are interested in learning how old their historical buildings are.
The group collected around 15 cores from each structure, using both hand borers and an electric drill with a hollow drill bit. This process is more thoroughly outlined in our Gingery Barn post.
On Thursday, the group returned to the lab to finish preparing the samples. Nick Wiesenberg used the belt sanders while Kendra and Juwan hand-sanded each core. This process helps to expose the ring boundaries so they can be more easily counted and measured under the microscope.
The team is currently analyzing each core by counting the number of rings, measuring ring widths, and comparing this data to a master chronology. Cross-dating will allow us to obtain the date that each tree was cut down, which will then indicate how old each historical structure is. Soon we will be able to report to our clients with details on our findings and a calendar date for when their buildings were constructed.
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.
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.
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.
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.
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.
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.
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.
Weblog authors are solely responsible for the content and accuracy of their weblogs, including opinions they express, and the College of Wooster disclaims any and all liability for that content, its accuracy, and opinions it may contain. Content is made available under the Creative Commons Attribution-Share Alike 3.0 United States License unless specified otherwise. Privacy Statement