Hung Nguyen
@ntthung.bsky.social
Water, people, tree rings. Dad.
ntthung.github.io
ntthung.github.io
Crowd sourcing from the Bluesky hive mind: what are these patches with what look like ducts inside that I'm seeing on silver maple? They don't occur in every ring, rather sporadically. @yellowbuckeye.bsky.social @l-tulipifera.bsky.social #dendro
November 21, 2025 at 9:46 PM
Crowd sourcing from the Bluesky hive mind: what are these patches with what look like ducts inside that I'm seeing on silver maple? They don't occur in every ring, rather sporadically. @yellowbuckeye.bsky.social @l-tulipifera.bsky.social #dendro
Why are increment borers so expensive? The 20" chainsaw on the left is $419 but the 20" increment borer on the right is $613 😔
July 9, 2025 at 9:27 PM
Why are increment borers so expensive? The 20" chainsaw on the left is $419 but the 20" increment borer on the right is $613 😔
Just how massive are trees in the Pacific Northwest? Here's a stump at Forks Timber Museum!
June 21, 2025 at 4:20 PM
Just how massive are trees in the Pacific Northwest? Here's a stump at Forks Timber Museum!
June 13, 2025 at 5:51 AM
Belated #microscopicMonday. A region of suppressed growth in a hackberry tree from a local forest in Urbana, IL. This is a piece of deadwood so we still only have a floating chronology and can't pinpoint the time yet. #dendro 🧪
May 20, 2025 at 7:12 PM
Belated #microscopicMonday. A region of suppressed growth in a hackberry tree from a local forest in Urbana, IL. This is a piece of deadwood so we still only have a floating chronology and can't pinpoint the time yet. #dendro 🧪
I keep seeing "post-doctoral student" in the news. Dear @nytimes.com, postdocs are full-fledged PhDs, not students. Please refer to them as researchers or scientists. www.nytimes.com/2025/05/16/n...
May 17, 2025 at 3:59 PM
I keep seeing "post-doctoral student" in the news. Dear @nytimes.com, postdocs are full-fledged PhDs, not students. Please refer to them as researchers or scientists. www.nytimes.com/2025/05/16/n...
Finally, we tested whether our color change detection and adjustment preserve the climate signals in BI. We correlated our adjusted EWBI, adjusted LWBI, and the vanilla DBI (calculated from unadjusted EWBI and LWBI), against growing season temperatures. Here are the results:
April 26, 2025 at 3:43 PM
Finally, we tested whether our color change detection and adjustment preserve the climate signals in BI. We correlated our adjusted EWBI, adjusted LWBI, and the vanilla DBI (calculated from unadjusted EWBI and LWBI), against growing season temperatures. Here are the results:
And here's the before and after for all cores.
April 26, 2025 at 3:43 PM
And here's the before and after for all cores.
Once a change point is detected, we can rescale the mean and variance of the sapwood to those of the last 20 years of the heartwood. Here's how that's done on the same example core above.
April 26, 2025 at 3:43 PM
Once a change point is detected, we can rescale the mean and variance of the sapwood to those of the last 20 years of the heartwood. Here's how that's done on the same example core above.
And here's the result on all 41 cores. The vertical gray bars are what we determined the heartwood-sapwood boundary is visually. Note that our visual determination is based almost entirely on EW, and the transition is somewhat gradual, so visual detection is not perfect.
April 26, 2025 at 3:43 PM
And here's the result on all 41 cores. The vertical gray bars are what we determined the heartwood-sapwood boundary is visually. Note that our visual determination is based almost entirely on EW, and the transition is somewhat gradual, so visual detection is not perfect.
Yes! Instead of using DBI, we propose to detect and correct for the color change directly on EWBI and LWBI. We tested 3 different change point detection methods (detailed in the paper) on a site in Tasmania, and found that they all work well. Here's an example on one core showing the change points.
April 26, 2025 at 3:43 PM
Yes! Instead of using DBI, we propose to detect and correct for the color change directly on EWBI and LWBI. We tested 3 different change point detection methods (detailed in the paper) on a site in Tasmania, and found that they all work well. Here's an example on one core showing the change points.
The heartwood-sapwood color change interferes with our use of BI for climate inference. This change is typically mitigated by calculating delta BI (DBI), i.e., the difference between LWBI and EWBI, assuming that the color change affects EW and LW equally. But this is not always true. Counterexample:
April 26, 2025 at 3:43 PM
The heartwood-sapwood color change interferes with our use of BI for climate inference. This change is typically mitigated by calculating delta BI (DBI), i.e., the difference between LWBI and EWBI, assuming that the color change affects EW and LW equally. But this is not always true. Counterexample:
A little bit of background. A tree ring has two parts: earlywood (EW), which grows early in the growing season, and latewood (LW), which grows late in the growing season. The alternation of the light-colored EW and the dark-colored LW gives us the visual impression of rings.
April 26, 2025 at 3:43 PM
A little bit of background. A tree ring has two parts: earlywood (EW), which grows early in the growing season, and latewood (LW), which grows late in the growing season. The alternation of the light-colored EW and the dark-colored LW gives us the visual impression of rings.
During fieldwork last weekend, we encountered the elusive Borus stickerii, commonly known as the borer sticker. Both our borers got stuck and it took 20 minutes, a lot of sweat, and some creativity to eventually get them out. 😂
April 21, 2025 at 10:59 PM
During fieldwork last weekend, we encountered the elusive Borus stickerii, commonly known as the borer sticker. Both our borers got stuck and it took 20 minutes, a lot of sweat, and some creativity to eventually get them out. 😂
Spotted a bison herd on the Yellowstone live cam. Can you see the ones in the trees? Thanks to the National Park Service for bringing the parks closer to home. www.nps.gov/yell/learn/p...
March 18, 2025 at 5:31 PM
Spotted a bison herd on the Yellowstone live cam. Can you see the ones in the trees? Thanks to the National Park Service for bringing the parks closer to home. www.nps.gov/yell/learn/p...
Teambuilding! Isn't it great that there's a bowling alley on campus?
January 17, 2025 at 12:22 AM
Teambuilding! Isn't it great that there's a bowling alley on campus?
The tube carriers are back at the airports 😄
December 14, 2024 at 2:54 PM
The tube carriers are back at the airports 😄
Danny will also help you set up ImageJ (imagej.net/ij/) with MIST (pages.nist.gov/MIST/) for stitching. Everything is open source so you can DIY too. Here's a sample image of a short section. The fully stitched image is too large; I'll do some resizing and share some full cores soon.
November 25, 2024 at 1:40 PM
Danny will also help you set up ImageJ (imagej.net/ij/) with MIST (pages.nist.gov/MIST/) for stitching. Everything is open source so you can DIY too. Here's a sample image of a short section. The fully stitched image is too large; I'll do some resizing and share some full cores soon.
New equipment! We just got the CaptuRING system to take core images. Shout out to Danny King of Dendro Engine Studios for building the rig. The blueprint is detailed in this excellent paper by Garcia-Hidalgo et al. (2022): onlinelibrary.wiley.com/doi/abs/10.1... 🧪
November 25, 2024 at 1:40 PM
New equipment! We just got the CaptuRING system to take core images. Shout out to Danny King of Dendro Engine Studios for building the rig. The blueprint is detailed in this excellent paper by Garcia-Hidalgo et al. (2022): onlinelibrary.wiley.com/doi/abs/10.1... 🧪
Ride to the playground!
November 24, 2024 at 9:01 PM
Ride to the playground!
Photo 8: Here's me collecting a cross section from a log with a Katanaboy saw. They say this thing can replace a chainsaw. It rips through wood extremely well. As a Japanese saw, it cuts on the pull stroke rather than on the push stroke like American saws, so the cut is very stable and smooth.
November 22, 2024 at 5:10 AM
Photo 8: Here's me collecting a cross section from a log with a Katanaboy saw. They say this thing can replace a chainsaw. It rips through wood extremely well. As a Japanese saw, it cuts on the pull stroke rather than on the push stroke like American saws, so the cut is very stable and smooth.
Photo 4: postdoc @rosie-oaks.bsky.social living in her natural habitat 😁 Photo 5: me coring while enjoying the sunset light. Photo 6: pulling a core out of a tree. Photos 7: examining tree cores.
November 22, 2024 at 5:10 AM
Photo 4: postdoc @rosie-oaks.bsky.social living in her natural habitat 😁 Photo 5: me coring while enjoying the sunset light. Photo 6: pulling a core out of a tree. Photos 7: examining tree cores.
Fieldwork! Last week we conducted our first fieldwork as a new research group. Photo 1: our group before we start coring. Photo 2: grad student Katieanne Peterson - this field trip is for her master's thesis work. Photo 3: grad student Aabhash Bhattarai coring a tree for the first time! 🧵
November 22, 2024 at 5:10 AM
Fieldwork! Last week we conducted our first fieldwork as a new research group. Photo 1: our group before we start coring. Photo 2: grad student Katieanne Peterson - this field trip is for her master's thesis work. Photo 3: grad student Aabhash Bhattarai coring a tree for the first time! 🧵
Tree rings of a Cedrus deodara (Himalayan cedar) tree from Pakistan. The ring with the two dots is 1850, and that with the black dot is 1860. 🧪
(Side note: as a tree ring scientist, I'm interested in the past, but with how the future is looking I actually wish to live in the past...)
(Side note: as a tree ring scientist, I'm interested in the past, but with how the future is looking I actually wish to live in the past...)
November 6, 2024 at 6:20 PM
Tree rings of a Cedrus deodara (Himalayan cedar) tree from Pakistan. The ring with the two dots is 1850, and that with the black dot is 1860. 🧪
(Side note: as a tree ring scientist, I'm interested in the past, but with how the future is looking I actually wish to live in the past...)
(Side note: as a tree ring scientist, I'm interested in the past, but with how the future is looking I actually wish to live in the past...)
Just borrowed this old book from the library. The last time someone read it was 1998!
October 23, 2024 at 9:52 PM
Just borrowed this old book from the library. The last time someone read it was 1998!