Tag Archives: alaska

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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.

 

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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

Alaska, Uncategorized

The Northern Pacific Coastal Temperate Rainforest (PCTR)

The high rainfall and high coastal ranges nourish the icefields of southern Alaska along and with the extensive carbon-rich forests and ecosystems of the Northern Pacific Coastal Temperate Rainforest (PCTR).

Chris surveys the North Pacific noting the extensive moisture source and ocean pasture that is just offshore of the terrestrial ecosystems we are studying.

Malisse sits atop a shore pine, another slow growing coastal species that is experiencing potential decline.

Kerensa sites atop an obducted ophiolite – we were 71% sure that there were pillows in the basalt.

Josh cores another Alaska Yellow cedar – we were able to sample three sites in the Juneau area. These cedars are in decline due to warming and loss of snowpack, which makes their fine roots vulnerable to frost. Our objective is to work up the tree-ring record of the sites to contribute to our understanding of the decline.

Alora takes a break from taking notes and GPS coordinates for each tree.

Ice caves fund to explore and act as a conduit to meltwater and warm air accelerating the melt.

Blue the dog – takes a break from pursuing porcupines in the muskeg.

Nick of the Ophiolite.

Kerensa wades through the deep texture of coastal carbon.

Buried forests emerge from the wasting margin of……..

https://woostergeologists.scotblogs.wooster.edu

Dating Historical Structures, Ohio, Projects

Summer research in the COW Tree Ring Lab

This summer, several students will be working in the COW Tree Ring Lab on several different projects. Josh Charlton, Eduardo Luna, and Emily Randall have already been hard at work conducting research on Alaska Yellow Cedar trees. Emily has been looking at ring widths and correlating them with climate variables at Tlingit Point, Alaska, while Josh has been measuring their blue intensity. Both are working on a Keck Gateway project on tree dating.

Josh (left) and Emily (right) in the lab annex.

Until today, Eduardo Luna was also in the lab, working with cores from Kamchatka and Alaska. He has also been our resident expert in Adobe Illustrator for producing figures to explain our research — which is very important work.

The final member of our lab right now is me, Brandon Bell. I’ve been working to design this new website for the Tree Ring Lab, with the help of Dr. Breitenbucher, who is the director of Educational Technology at the College. My work station is actually in the center of the photo above.

Yesterday, however, we all went out to do what the Tree Ring Lab does best — core and date trees. We went to the Wayne County Historical Society on Bowman Ave. in order to core two bald cypress trees in front of the Beall House. We were asked to find their date for the Historical Society and for the City of Wooster — the latter is preparing a publication on old or significant trees in the city.

Seeing them for the first time, we were impressed at just how large they were in diameter — although only the tree rings themselves can tell us the tree’s actual age.

The two bald cypress trees in front of the Beall House, with Josh Charlton to the left.

The trees themselves were quite difficult to core. We had to use our longer, blue-colored cores due to the larger diameter of these trees. At one point, we even had to climb on a ladder to get cores from higher on the tree. As it turns out, these particular trees had rot near the base, which made it hard to find a core we could use to date the trees.

Eduardo Luna coring near the base of the of the bald cypress trees, with Brandon Bell (L) and Emily Randall (R) behind him.

Overall, though, it was nice to get out of the lab and core. The lab will examine the cores we collected yesterday in the near future.

All of us standing in front of the Beall House — (L to R) Josh Charlton, Brandon Bell, Emily Randall, Nick Wiesenberg, and Eduardo Luna.

In the coming weeks, all of us are going on research trips for Geology — In fact, Eduardo just left for Utah. Emily will also be going to Utah in a couple of weeks, and Josh will join Dr. Wiles and Nick Wiesenberg for research in Alaska. I’ll leave next Tuesday for San Francisco, California for my Independent Study research.

Despite this, it looks like it will be a full summer of research for the Tree Ring Lab. I’ve heard that, after we are gone in late June, another crew of students will come to the Tree Ring Lab to take our places in July. Stay tuned for the next updates on this research, and the launch of our new website.