All posts by Greg Wiles

Working Remotely with Youth Groups in Southeast Alaska

We had the good fortune to work (remotely) with four TRAYLS groups in Alaska. The TRAYLS (Training Rural Alaskan Youth Leaders & Students) Groups from Southeast Alaska teamed up with Earth Scientist students  Ricky Papay (’22), Wenshuo Zhao (‘23) and Lucie Fiala (‘23) to investigate tree-rings and climate in Southeast Alaska. Students from the villages of Hoonah, Angoon, Klawock and Kake cored trees in the region, plotted the location of their sites on GIS software Survey 123, sent the cores to the WTRL for processing and analyses, and then the groups met to discuss results. The logistics and implementation of the program was possible through all the great group leaders in Southeast Alaska and Nick Wiesenberg (Wooster) and Ben Gaglioti (University of Alaska – Fairbanks).

The groups had a full summer and the tree-ring work was only one of their projects. They traveled by kayak, boat and floatplane across the region, sampling and taking notes on each tree they cored (various photos of the Kake and Angoon groups)

The Hoonah and Klawock teams shown measuring and coring and filling out the survey data.

The AYLS groups from Kake, Hoonah, Angoon and Klawock sampled an extensive portion of Southeast Alaska in the summer of 2021. The groups entered their data in to Survey 123 and Wooster students could check in each day and see the map populate with the sample sites.

Wooster students (Ricky Papay and Wenshuo Zhao) worked up the tree-ring data in the lab at Wooster and then we met on Zoom to share the results.

Representative samples from the AYLS groups. These are the first Red Cedar (far left) that the Wooster lab has worked with.

One of the tables showing the combined AYLS and Wooster data set. This was for the Prince of Wales group (Klawock). Three of the cedar trees are over 400 years old.

 

Some of the results included the Yellow Cedar tree-ring record above that brings the LIA (Little Ice Age) increase in growth and a recent release that could be related to warming or logging at a site on Prince of Wales Island.

 

A red cedar chronology appears to record reduced ring-width shortly after the 1815 eruption of Tambora (1816 called the year without summer in Europe) – it may be that the volcanic event forces a change in ocean temperatures that then causes the cooling to persist. Further study is needed.

Tree-ring series from Hoonah – these western hemlocks show an interesting suppression of growth in the mid to late 1700s, a change that persists for some decades. Western hemlock here also appear to track the warming well. Again further analysis can test some of the ideas the groups generated about the changes in observed tree growth.

Next summer we hope to visit some of these sites and expand on this work, as well a s continuing our remote collaboration.

A 40-foot spruce dugout canoes carved in Hoonah by master carver Wayne Price, and apprentices Steven Price, Zack James (Tlél Tooch Tláa.aa) and James Hart (Gooch Éesh) arriving Bartlett Cove, Glacier Bay, Alaska. The trip from Hoonah marked the return of the Tlingit to their ancestral homeland in 2016. Image courtesy of the Juneau Empire, the full story is here.

 

This project was funded by the National Science Foundation Paleoclimate Program (Awards: P2C2-2002561 and 2002454).

Wolf Lake and the Surrounding Landscape, Glacier Bay, Alaska

Members of the Wooster Tree Ring Lab had a great opportunity to travel to a seldom-visited part of Glacier Bay National Park and Preserve – a transect from Wolf Lake to Burroughs Glacier. We were there because there is 2500 year-old forest remnant that was overrun by ice. The ice has gone and continues to melt. Our interest is recovering these logs is to fill a gap millennial-scale tree-ring record from the Gulf of Alaska. The recently exposed logs are being lost to science each year as they flush out into the sea and rot away in this hypermaritime climate. Wooster student independent studies (ISs) in the region quite literally have surrounded this Wolf Lake site with their research, and over the last 10 years we have honed into this key location from all directions.

A view of Mount Wright through a gap in drift and bedrock. Tree-ring records from the flanks of Mt. Wright were part of a study led by Stephanie Jarvis and sampled by Sarah Appleton, who did their thesis work in the region.

We flew into the site this year. In previous years we attempted to walk in twice and once we were successful. I recommend the flying

https://woostergeologists.scotblogs.wooster.edu

Wooster Memorial Park – Now Part of the Old Growth Forest Network

On 20 April 2021 Wooster Memorial Park became part of the Old Growth Forest Network.  The founder and director, Joan Maloof, visited Wooster Memorial Park forest to officially induct the park into the Network. The Wooster Tree Ring Lab cored some of the white oaks in the park to determine their age and to see how they are responding to the increasingly wetter climate of Northeast Ohio. Nathan Kreuter (Biology) and Nick Wiesenberg (Earth Sciences Dept. Technician) found the oldest trees and helped work up the tree-ring data.

Joan Maloof with the largest hemlock in the park.

Nathan Kreuter cores one of the oldest oaks as part of his tutorial at the Wooster Tree Ring Lab.

The ring-widths of the Wooster Memorial Park chronology. There was a likely time of early logging in the park about 1815 and again in the 1920s
Tree ring widths are most sensitive to April-August total precipitation. The correlation between the ring-widths and precipitation changes over time with the strongest relationship r = 0.6 for the interval 1945-1975. After 1975 the correlation falls off possibly due to the increase in precipitation and loss of sensitivity at the site with the abundant moisture.

Friends of the trees and Friends of Wooster

https://woostergeologists.scotblogs.wooster.edu

Coring Trees on Chicagof Island, Hoonah, Alaska

We had the good fortune this summer to work remotely with the TRAYLS group out of Hoonah, Alaska.
Figure 1. Google Earth map showing the location of the town of Hoonah and the coring sites. Two tree ring sites were sampled by the group the HN site in the town and the EAR site on Ear Mountain.
Arianna Lapke lead a group of four participants through an ambitious set of projects over much of the summer. Our collaboration with the group centered on meeting virtually with the group to describe the utility and sampling of trees for dendroclimate information. Below are the results of their sampling on EAR Mountain, Chicagof Island and our lab work at the Wooster Tree Ring Lab.
The group shown coring a Sika spruce just outside of town.
More coring – this time in the rain.
The steep climb up the flank of Ear Mountain to find the old Mountain Hemlocks.
Comparisons of the fast growing Sitka Spruce and the slow growth of the higher elevation Mountain Hemlock.
The cores from the hemlock some over 400 years old show lots of stress , clinging to the mountain side and battered by storms. They are also showing a possible drop in ring-width over

https://woostergeologists.scotblogs.wooster.edu

Tree Rings and Climate, Ear Mountain Hoonah, Alaska

We had the good fortune this summer to work remotely with the TRAYLS group out of Hoonah, Alaska.

Figure 1. Google Earth map showing the location of the town of Hoonah and the coring sites. Two tree ring sites were sampled by the group the HN site in the town and the EAR site on Ear Mountain.

Arianna Lapke lead a group of four participants through an ambitious set of projects over much of the summer. Our collaboration with the group centered on meeting virtually with the group to describe the utility and sampling of trees for dendroclimate information. Below are the results of their sampling on EAR Mountain, Chicagof Island and our lab  work at the Wooster Tree Ring Lab.

The group shown coring a Sika spruce just outside of town.
More coring – this time in the rain.

The steep climb up the flank of Ear Mountain to find the old Mountain Hemlocks.

Comparisons of the fast growing Sitka Spruce and the slow growth of the higher elevation Mountain Hemlock.

The cores from the hemlock some over 400 years old show lots of stress , clinging to the mountain side and battered by storms. They are also showing a possible drop in ring-width over time 

So we measured the ring-widths (Nick Wiesenberg and Melita Wiles did) and then we compiled the ring-width data into a chronology aboveThis chronology is the full record going back into the 16th century

This chronology is truncated at 1720 or so when we had at least 4 samples. The most narrow rings follow the 1808 unknown eruption that cooled much of the region – it is unknown as no one knows where the volcano that erupted is located – it is recognized in ice cores.  The other intriguing feature is the relatively recent (last 50 year) drop in ring widths.  It may be due to increased evapotranspiration demands with increasing summer minimum temperatures.  There is a correlation of -0.39 (p<0.04) between tree growth and average April-August minimum temperatures. Other studies have shown that warming night time temperatures lead to increased respiration at night and along with possible greater ET demand or increased cloudiness during the day there may be a decrease in photosynthesis leading to  decreased carbon uptake (Sullivan et al., 2015). This is a promising line of research to further investigate the health of Mt. Hemlock in the region and it is something we plan to pursue with more samples in the future. 

View from Ear Mountain looking north.

Reference cited:
Sullivan, P. F., Mulvey, R. L., Brownlee, A. H., Barrett, T. M., & Pattinson, R. R. (2015). Warm summer nights and the growth decline of shore pine in Southeast Alaska. Environmental Research Letters.

Acknowledgements: We thank Arianna Lapke and the TRAYLS group and look forward to future work with them. This work was supported by the Sherman-Fairchild Foundation, The Luce Funds and the National Science Foundation. NSF Grant AGS 8001184 supported Julia Pearson, Claire Cerne, Ben Gaglioti and Greg Wiles. We also acknowledge the contributions of AMRE participants – Mazvita Chikomo, Srushti Chaudhari and Fred Whenshuo.