Category Archives: Climate Change

Concluding 2018 summer of research

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.

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).

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.

AMRE students with Nick Wiesenberg collecting samples from historical structures at Sonnenberg Village in Kidron, Ohio.
Alexis and Kendra visiting one of the historical structures at Sonnenberg Village.

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.

Stebbin’s Gulch at the Holden Arboretum (Left to right: Josh Charlton ’19, Juwan Shabazz ’19, Alexis Lanier ’20, Kendra Devereux ’21, and Dr. Wiles).
Juwan with the machete, ready to clear a path for the rest of the team at Brown’s Lake Bog.
Lining up to cross the moat at Brown’s Lake Bog after a weekend of strong thunderstorms.
Kendra Devereux with the sample bag at Barnes Preserve in Wayne County.
Josh Charlton ’19 coring a tree at Stebbin’s Gulch in the Holden Arboretum.

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!

AMRE students with Victoria Race ’19 and Arrow at Brown’s Lake Bog.

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!

 

An Update on Stebbin’s Gulch at the Holden Arboretum

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.

Our views of the canopy.
Team members recording measurements and extracting a core from this living chestnut oak.
Kendra and Victoria looking at a giant burl on one of the sampled trees.
Team members coring an old chestnut oak along the gulch reaching high into the canopy.

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.

AMRE at Barnes Preserve and The Wilderness Center

Last week, AMRE students, Kendra Devereux and Alexis Lanier, ventured out to Barnes Preserve in Wooster and The Wilderness Center located in Wilmot, Ohio.

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.

AMRE students Kendra Devereux (left) and Alexis Lanier (right) coring an oak at Barnes Preserve.
Nick Wiesenberg coring a nearby tree.
A honeysuckle bush along the trail.
The team coring a fallen oak deep in the brush at Barnes Preserve.

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.

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.

A New Publication on the Russian Fareast

Two alumni of the Wooster Tree Ring Lab and Wooster Geology, Clara Deck (’17, now at the University of Maine studying ice sheets) and Sarah Frederick (’15, now at The University of Arizona studying drought and streamflow) together with Greg and Nick, and colleagues in the US and Russia published a new study on tree growth and climate in Kamchatka, Fareast Russia. This is part of a special edition of the Journal Forests. The group has donated the data in to the International Tree Ring Databank.

Photo below shows some of the coauthors at the base of Tobalchik Volcano on the Kamchatka Peninsula.Image result for deck tree rings and kamchatka

Dating the Tracy House (Apple Creek, OH)

Climate Change 2017 is pleased to have been asked to date the Tracy House, Apple Creek Ohio. The log house/cabin is now stored in the soon to be Apple Creek Community Center and Library will be reassembled this coming summer. The date is unambiguous and most of the timber was cut after the growing season of 1826 and it is likely that the house was originally constructed in 1827, one of the first to be built in the East Union Township. A copy of our report can be found here.

Maddie cores an old growth living tree to help assemble a calendar dated tree ring chronology.
Dean extracts a core from a beam of the Tracy House under the watchful eye of Annette – the TA, as Conner looks on.
Extracting a core being careful to preserve the outer ring of the core (don’t bend the extractor John).
Another successful core extracted.

Originally posted to the Wooster Geologists blog.

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.