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New publication on Alaska Yellow Cedar

The fate of Alaska yellow-cedar (Callitropsis nootkatensis D. Don; Oerst. ex D.P. Little) in a changing climate is a fascinating tale. Our collaborator, Lauren Oakes published a book last year called the Canary Tree which is a story of yellow-cedar (YC) and her research. The crux of the story is that increased temperatures and loss of snow pack make fine roots of the YC more vulnerable to frost damage and, in some instances, this freezing is killing extensive stands of the tree.

Three of the students who helped sample the trees in Juneau during the summer of 2017 (photo credit: Jesse Wiles).

Brian Buma, also a recent collaborator and author on our contribution, has written several articles describing the biogeography of YC decline. His work includes (Buma, 2018) the thought that with rapid enough rates of warming in Southeast Alaska, the population of YC may not be vulnerable if the warming also decreases the frost threat. This work is informed by mapping of the southern limit of the species, which is thriving in  Oregon and Washington where winter temperatures are well above 0 degrees C. The leading edge of the decline is most vulnerable as the mean winter temperatures are in the range of between -2 and +2 degrees C. Our study sites in Juneau are entering this temperature range and thus are/will be impacted by warming winters and the transition from snow to rain.

Location of study sites.

Our new paper titled:Yellow-Cedar Blue Intensity Tree Ring Chronologies as Records of Climate, Juneau, Alaska, USA appeared  in the Canadian Journal of Forestry Research and describes well-replicated tree-ring chronologies made up of ring-width and latewood blue intensity measurements. Where previously YC has not been considered to be a strong candidate for reconstructing past climate, we have found that blue intensity measurements have a strong signal much stronger than ring-widths.

The Abstract of our paper is here: This is the first study to generate and analyze the climate signal in Blue Intensity (BI) tree-ring chronologies from Alaskan yellow-cedar (Callitropsis nootkatensis D. Don; Oerst. ex D.P. Little). The latewood BI chronology shows a much stronger temperature sensitivity than ring-widths (RW), and thus can provide information on past climate. The well-replicated BI chronology exhibits a positive January-August average maximum temperature signal for 1900-1975, after which it loses temperature sensitivity following the 1976/77 shift in northeast Pacific climate. This is a temporary loss of temperature sensitivity from about 1976 to 1999 that is not evident in RW or in a change in forest health but is consistent with prior work linking cedar decline to warming. The positive temperature response of BI after 1999 suggests a recovery, which remains strong for the most recent decades, although the coming years will continue to test this observation. A confounding factor is the uncertain influence of a shift in color variation from the heartwood/sapwood boundary. Future expansion of the yellow-cedar BI network and further investigation of the influence of the heartwood/sapwood transitions in the BI signal will lead to a better understanding of the utility of this species as a climate proxy.

References:
Buma, B. 2018. Transitional climate mortality: slower warming may result in increased climate-induced mortality in some systems. Ecosphere 9: e02170.

Wiles G, Charlton J, Wilson R, D’Arrigo R, Buma B, Krapek J, Gaglioti B, Wiesenberg N, Oelkers R., 2019, Yellow-cedar blue intensity tree ring chronologies as records of climate and forest-climate response, Juneau, Alaska, USA. Canadian Journal of Forest Research, https://doi.org/10.1139/cjfr-2018-0525.

 

Climate Change, Drought, Ohio, Projects

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.

Climate Change, Drought, Ohio

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.

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

Dating Historical Structures of Sonnenberg Village

Summer researchers have started a new project!

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.

AMRE group and Nick Wiesenberg meet with Ray outside of Sonnenberg Church.
An example of one of the original deeds from  Miller House.

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.

Dr. Wiles using the electric drill to extract a core from a beam in Miller Barn.
Nick extracting core from overhead beam with a hand borer in Miller Barn.
Stacked beams from Zuercher house.
Freshly mounted core taken from Zuercher house beam.

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.

Stay tuned for updates!

Follow the links to read our final reports for Zuercher House and Miller House and Barn.