Steve Voelker

@thetreecorener

Aspiring naturalist and plant nerd. I teach about Climate Change & Tree Physiology. Expert in plant ecophysiology, stable isotopes, dendrochronology. I also study fish otoliths. Husband and Dad. Assoc Prof of Forest Ecology & Mgt at Michigan Tech.

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Steve Voelker@thetreecorener· 21d

Yesterday I stopped by a remote reservoir. It is 1200 acres and does not have a single dwelling on the entire shore. There were many intact white pine stumps with 3-5' diameters along the shore. Here is just one primary root that someone cut off for a bonfire years ago. It has about 300 rings.

A picture of my hand (for scale) with a sun-bleached cross-section of a 10 to 12 inch diameter root from a large, tipped-over white pine stump. The surface of the cross section shows a bit of decay and a thin layer of lichen growth indicating it was cut off maybe 20 years ago. There are also shadows on the cross-section from some adjacent willow shrubs.

Steve Voelker@thetreecorener· 24d

Went down a rabbit hole on FB marketplace. I searched "Barn Beams" and made a list of >100 unique locations in WI and another 40 in MI trying to sell beams from mostly 1800's dismantled barns. It seems this could be interesting sociological info and also represent untapped dendro resources...

Example image from FB Marketplace showing large beams from a dismantled barn in Wisconsin.

Steve Voelker@thetreecorener· 29d

Historic travel corridor, in this case, was the overland trail between what is modern Marquette and L'anse. The rugged geography of the Huron Mts to the north pushes East/West overland travel into a narrow area.

Hinsdale (1931) map of Upper Michigan (I love this atlas, and the care that went into drawing out the landscape features) noting historic travel corridors in black. The small red circle, on the north (south-facing) slope of Teal Lake is where I was walking today. It has patchy red pine stands along most of the north shoreline that is undeveloped. The south and East shores are developed.

Steve Voelker@thetreecorener· 29d

It was >95 degrees today but I had some time to check out a red pine site along a historic travel corridor I have wanted to stop at for the past year. It did not disappoint; pictured below is another culturally modified tree -- used for resin harvesting. Only the 4th we have found in the UP.

An old red pine stump that was cut off high (about 3-4 ft height) by loggers with an axe, probably during the late 1800s or early 1900s. There were at least a dozen such stumps within a small area on a terrace above a lake. Sometime beforehand indigenous harvesting of resin took place by blazing the lower portion of the stem as seen clearly here.

A close up of the blaze mark on the stump with two fire scars around the edge that occurred fairly soon after resin harvesting. Then some decades later settlers cut the tree down.

Steve Voelker@thetreecorener· Jun 30

Two ash trees below our house tonight offer a lesson in resistance. Almost all ash died in this area from emerald ash borer but these survived. One is survives only via epicormic sprouts while the other has a fully intact canopy. Hoping they can confer a bit of resistance to the next generation.

A white ash tree with a dead top but a lush new canopy from epicormic sprouts along the main stem about halfway up the tree. The area has been cleared of invasive Norway maple so these native trees have a chance to thrive.

A white ash tree with a normal looking canopy after being attacked by EAB. The area has been cleared of invasive Norway maple so these native trees have a chance to thrive.

Steve Voelker@thetreecorener· Jun 29

Some MTU students in action collecting fire history data in the UP from our most recent data collection trip.

A person in safety gear facing away from the camera using a chainsaw to cut a weathered cat-face red pine stump within a dense forest of red pine, paper birch, and maple.

A second picture of a person in safety gear facing away from the camera using a chainsaw to cut a weathered cat-face red pine stump within a dense forest of red pine, paper birch, and maple. Now there is a cloud of sawdust as he cuts through the stump.

In the foreground is a pink lady slipper orchid. In the background is a student in safety gear holding a chainsaw and getting ready to cut a red pine stump that is low to the ground and cannot be seen because the ground slopes steeply downward into the background.

A student, with safety equipment uses a chainsaw to cut a large and very decayed red pine stump with a chainsaw for a second time to gain a cross-section of the wood. The decayed wood produces a lot of dust all around the student. The ground slopes steeply downward behind the student into a hemlock-dominated ravine.

Steve Voelker@thetreecorener· Jun 18

The field sites for coastal pine research in the UP are up there with the best of possible research locations.

Steve Voelker@thetreecorener· Jun 15

Stopped by our cabin for an evening and got some kayak fishing time in. Lots of takers of all species and sizes on just one spinner buzzed over the emerging large-leafed pondweed (Potamogeton amplexifolius). Here are just two largemouth bass. The bass were not spawning yet but will be soon.

A 3-inch long largemouth mass hooked on a rooster tail spinner that is orange/yellow/green with a gold blade. In the background is a blue sky with puffy white clouds that is reflected in the lake and an undeveloped forested shoreline with emergent pine canopies.

My hand holding a bass by the mouth held out in front of me. It is good sized fish, maybe 15-16 inches long. The inside of a red kayak are shown as are a spinning reel resting on my legs and sandaled feet. The lake and forested shoreline are visible in the background. The bas has an injury on the top of it's gill plate. It is unclear how the injury may have occurred.

Steve Voelker@thetreecorener· Jun 7

Went for a walk along a really rugged part of the UP woods last week and found some cool trees and plants. I also found yet another an unmarked vertical mineshaft that I managed not to fall down. Those things are all over the rocky parts of the UP.

A very old red pine on a rocky outcrop that was fire scarred and fell over when it's stem failed from decay at the top of the fire scar but then it just kept growing with it's remaining lateral branches taking over as leaders.

A nice cluster of fringed polygala or "gaywings". Which are small statured flowering plants in open forested settings with bright pink/white flowers that look somewhat like orchids.

A closer view of the flower structure of fringed polygala that is not entirely in focus, but the best I could do with my phone.

A selfie with me in a bug net and a camo Harris Walz ballcap posing in front of a giant old white pine snag that probably fell down about 20 years ago because most of the bark has sloughed off. The tree rises upslope behind me like with a giant sun-bleached white trunk (Thar she blows!). This is a rocky, low productivity site so I expect this tree was well over 300 years old when it died to get this big.

Steve Voelker@thetreecorener· May 21

Me, two weeks into a summer of fire scar data collection...

"You're Gonna Need A Bigger Boat" meme showing the sheriff after first seeing the shark from the movie Jaws (1975) but with "Lab" replacing "Boat".

A laboratory with tables almost completely filled with red pine cross-sections in various stages of preparation and in the background are shelves and cabinets almost completely filled with cross-sections and cores from previous research.

Steve Voelker@thetreecorener· May 15

After a record or near record for precip over the past winter shallow groundwater levels are very high in the UP (and probably northern lower MI), continuing the 10-15 yr pluvial across the region. These flooded "ghost trees" are not from beaver activity, just groundwater fluctuation.

An upland pond in the UP of Michigan on a sunny spring afternoon. The pond is surrounded by red and white pine trees in the background. In the foreground are many dead sapling-sized pine trees. To be that size and be killed by high water levels the "ghost trees" probably germinated in the late 1990s or early 2000s when drier condition were more regular.

Steve Voelker@thetreecorener· May 9

MS student Isabella Stone and I went scouting a beautiful coastal red pine site today. After meeting with one of the private landowners we now have access to sample all ~200 acres. Here is a "peel scar" on a snag from indigenous resin harvesting practices.

A woman in a red fleece and a cap standing in a mostly red pine forest next to a snag (dead tree) with an oblong scar centered at about 1.5 m height. Around that original scar, which is now charred, so tool marks are not visible, are multiple fire scars. It looks like this tree died 50 or more years ago but because the wood is impregnated with resin it has been more resistant to decay than an average dead red pine tree.

Steve Voelker@thetreecorener· May 8

My favorite local copse of paper birch in the late afternoon today. All the trees in the foreground are growing out of mine rock but the birch trees would not have been in this location without that intense disturbance many decades ago.

In the foreground are sunlit and mostly small diameter (<8 inches) paper birch stems (white and black bark) amidst a background of evergreen foliage (balsam fir, Northern white cedar and white spruce). There is a bit of blue sky in the background and there are no leaves on the deciduous trees yet because it is still too early in spring here.

Steve Voelker@thetreecorener· May 6

Pulled out the main saws for collecting red pine fire history samples. They are all purring like kittens and ready for me to teach chainsaw safety to a crew of four next week. The big saw is nearly brand new and the oldest saw I have had since 2011 or so when I used it on redwood sections.

Steve Voelker@thetreecorener· May 4

The phenology is late here because we have had a Houghton record 360" of snow this winter. The first of the forest-origin trout lilies in this area popped open this weekend. We found this one after going to a known population with a southern aspect and scanning thousands of individuals.

A single nodding yellow flower, barely open, hanging from a pink stalk that extends between two mottled leaves that have alternating lime green and a faded maroon hues. The leaf extending toward the camera, underneath the flower also has yellow pollen on it's surface. The small plant is extending up amidst dry brown leaf litter and twigs.

Steve Voelker@thetreecorener· May 1

Our research on submerged pine logs in the UP includes a story connecting forest demography to historic fire and Indigenous use/mgt (more later). As such I have been mapping historic Indigenous settlements, trails and river travel corridors from multiple sources to understand where people were.

Yellow triangles are Indigenous settlements from the 1600s-1800s CE. Red dots are settlements known from early archeological records. White lines are trails/travel corridors and blue lines are canoe-navigable river systems connecting the Lake Superior region to the Mississippi basin or Lake Michigan with minimal portages between drainages and/or trails.

Steve Voelker@thetreecorener· Apr 22

Here is an example red pine x-section we collected last fall. We should be dating these fire scars within the week and collecting a few hundred more samples over the summer. I just gotta grade 70 more final exams...

A partially decayed red pine cross-section cut from a stump adjacent to Lake Superior showing 5 or 6 fires over about 200 years.

Steve Voelker@thetreecorener· Apr 22

In shady areas we have had 4 months of continuous snow cover. Today I took 4 representative pics under a northern white cedar canopy on the edge of the melting snow approximating litterfall from Dec - April. Life can be rough in the winter for these trees.

Green and orange cedar leaves, cedar cones and seeds as well as cedar twigs on snow.

Steve Voelker@thetreecorener· Apr 15

Yesterday after I entreated students to fill out instructor evaluation surveys I sat down in the front of the class for a student presentation and my chair broke off completely. Yes, I went awkwardly sprawling and there was much laughter. Not sure if my unintentional comedy will earn higher marks.

Me holding the bottom of my broken seat that catastophically failed when I sat down.

Steve Voelker@thetreecorener· Apr 12

It finally felt like spring today and then ~1000 pounds of ice and snow fell off the roof and dented the steel basement door on the right. The work clearing snow and ice is now well into its 5th month here.

A home with an exposed basement with two doors with a pile of ice and snow in front. The background shows snow piled up around some stacked firewood and lumber and some cedar trees.

Steve Voelker@thetreecorener· Mar 26

My first PhD student, Victor Humanes Fuente, will defend his PhD next week Wednesday on the following topics: 1) L Superior lake-effect isoscapes 2) Connecting 800 yrs of pine establishment to fire and indigenous migrations along the shore of L Superior 3) A >500 yr L Superior temp reconstruction

PhD Defense announcement for Victor Humanes Fuente entitled "What can white pine tree rings tell us about the environmental history of the Lake Superior region?" which is overlayed on top of an illustration of a wood cross-section he sampled from a lake. The lower panel shows a picture of Victor in a wetsuit and holding an oar while balancing on top of floating logs lodged in a green wetland area with white pine trees in the background. The detailed text states "Learn about Victor Humanes Fuente’s doctoral research investigating the capacity of Eastern white pines to store environmental information in their tree rings. He will highlight how lake-effect climate has influenced spatial patterns in tree physiology, how fire and humans have historically modulated 800 years of pine establishment patterns in the Central Upper Peninsula of Michigan, and how Lake Superior water temperatures have changed over the past 500 years, as reconstructed from tree rings."

Steve Voelker@thetreecorener· Mar 24

Bobcat track in fresh snow from this morning. The rabbits and chipmunks are increasingly active aboveground so I imagine the leanest days of winter are now over for whomever left this.

A single bobcat track pointed downward toward the camera with a partial view of my left hand for scale. The track is about the size of what would be expected for a very large domestic cat.

Steve Voelker@thetreecorener· Mar 4

Makes me think about this Powerpoint slide from ~seven years ago that I have used in multiple presentations but needs to be updated for climate disasters.

Image show a distribution of Billion-dollar disasters by state on the left broken down by early vs recent time periods and based on "Drought" for the Western US and "Freeze" for the Eastern US. Adjacent is an image of the conterminous US states broken down the middle and highlighted by an image of forest wildfire in the West and snow-covered boreal conifers in the East.

Steve Voelker@thetreecorener· Feb 24

I never took courses in climate science, paleoclimate, geology, etc. So, there is a lot I don't know. Does anyone know why some geoscientists plot their temporal data backwards from conventional left being further back in time? I never know how to explain this to students.

Example ice core data from Antarctica compared to marine sediment core data over the last ~3 million years.

Steve Voelker@thetreecorener· Feb 23

Here is the current snow level in Houghton in our back yard -- to the top of a four ft fence that is supposed to keep our dog in the yard.

Snow piled up to the top of a chain link fence with trees in yhe background.

Steve Voelker@thetreecorener· Feb 13

Ooh, this is very tempting for a dendrochronologist. A big stack of old growth white pine wood only 15 minutes away.

Facebook marketplace ad showing a stack of white pine boards salvaged from a building on Calumet. Most of the old buildings there were built in the late 1800s.

Steve Voelker@thetreecorener· Feb 13

IDK, maybe you need some minks right now? As seen at our cabin in the UP of Michigan last July 4th.

Steve Voelker@thetreecorener· Feb 9

Students successfully completed the Dice Degrees Challenge this morning within a 50 minute class. They had fun and I think this will help them better understand lecture materials where we look at a lot of time-series data for understanding evidence of climate change.

Figure showing dice degrees displayed as 4 sets of colored lines spanning 1900-2026 that students generated by rolling dice. Each of the four colors is a group; the differences represent how variation in inter-annual climate can lead to different rates of warming in different locations despite the same forcing.

A figure show the overall mean trend in dice degrees across groups from 1900-2026, but broken into three time periods to illustrate to students how it is possible to take a narrow section of years and find no detectable warming even though the long-term trend (here = 2.99 degrees/century) is significant.

Steve Voelker@thetreecorener· Feb 6

Prepping an intro to climate change exercise for Monday where groups of students will be creating 5 synthetic temperature time series based on the # of sides of the dice being scaled to atmospheric CO2 concentrations from 1900 to 2026.

Five sets of dice that are multicolored and include 6, 8, 10, 12 and 20-sided dice.

Steve Voelker@thetreecorener· Feb 4

For this #TreeRingTuesday that I got to visit Santa Cruz Island in 2014: This island is off the coast of Southern CA. I led tree-coring efforts to understand forest mortality patterns. The island is home to dwarf foxes that are not afraid of people. Really cool place I was lucky to visit.