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Eastern Hemlock

Latin name:
Tsuga canadensis

Extracted from a waterfront pier near Wilmington, Delaware, the tree used to make this portion of the pier
actually came from a forest located in central Pennsylvania. The outermost tree ring dates to the late 1830s.

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Giant Sequoia

Latin name:
Sequoiadendron giganteum

A close up of numerous fire scars on a giant sequoia cross section from Sequoia National Park in California, dating back well prior to A.D. 1000. Look closely! Can you find the sad bearded face cradled by his hands, as if he was crying?

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Douglas-fir

Latin name:
Pseudotsuga menziesii

This photo shows the tree rings from a beam extracted many years ago from a pueblo in northeastern Arizona. The section shows many false rings and many micro-rings, suggesting this tree may have been growing in a marginal environment.

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Ponderosa Pine

Latin name:
Pinus ponderosa

Close up of tree rings of a ponderosa pine collected at El Malpais National Monument in New Mexico, USA, showing tree rings centered around A.D. 1400. Notice the variability in ring widths indicative of sensitivity to year-to-year variation in precipitation.

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Douglas-fir

Latin name:
Pseudotsuga menziesii

Perhaps my most requested image of tree rings, obtained from a small Douglas-fir growing in the Zuni Mountains of west-central New Mexico by my colleagues Rex Adams and Chris Baisan. Not very old, but has some of the most beautiful rings of all my displays!

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White Oak

Latin name:
Quercus alba

Oak cores from the Hoskins House in Greensboro, North Carolina, site of a famous battle during the Revolutionary War. The house was built from trees cut in 1811 to 1813, not cut and built in the 1780s as the historical agency had hoped.

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Ponderosa Pine

Latin name:
Pinus ponderosa

This ponderosa pine once grew at El Morro National Monument in New Mexico, USA, and was cut many years ago. Once you get up close to the stump, you can see a very old scar from a fire many hundreds of years ago that scarred the tree when it only about 12 years old!

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Bahamian Pine

Latin name:
Pinus caribaea var. bahamensis

We collected many cross sections of Bahamian pines that had been cut for an industrial park on the island of Abaco, but the rings are very difficult to date! Many false rings, and the pine appears to terminate tree growth during the dry season.

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Longleaf Pine

Latin name:
Pinus palustris

This cross section was one of many that came from an old crib dam across a creek that was exposed after a modern dam broke in Hope Mills, North Carolina in 2003. Such sections from old-growth longleaf pines are very rare and provide information on climate back to AD 1500!

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White Oak

Latin name:
Quercus alba

Sometimes you don't have to look far to find beauty in wood, and sometimes it may not be a living tree! After an oak tree was cut a year or two before this section was obtained, decay fungi had already set in, beginning to break the wood down to its basic elements.

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Southwestern White Pine

Latin name:
Pinus strobiformis

I collected this fire-scarred pine on Mt. Graham in southern Arizona in fall 1991, and it remains one of the best examples of how we can determine the season of fire by looking at the position of the scar within the ring.

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Bristlecone Pine

Latin name:
Pinus longaeva

Bristlecone pines have become one of the best proxy records for those who study the history of volcanic eruptions because the cool temperatures caused by these eruptions create "frost rings" that form when the cells implode from the cold.

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Eastern Redcedar

Latin name:
Juniperus virginiana

Many well-preserved eastern redcedar sections have been recovered from prehistoric sites in eastern Tennessee, and they have more than enough rings to date, but we don't have a long enough living-tree reference chronology to overlap with them!

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Red Oak

Latin name:
Quercus rubra

Oak is by far the most common genus we find in the many historic structures we date using tree rings in the Southeastern U.S. The genus has good ring variability and rarely has problem rings. This section came from a historic tavern in Lexington, Virginia.

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Sugar Maple

Latin name:
Acer saccharum

Maple, birch, beech, and basswood are all examples of hardwood species that form diffuse porous wood, meaning that the ring contains many small-diameter vessels all through the ring. Identifying the ring boundary on this wood type is a challenge to tree-ring scientists.

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Live Oak

Latin name:
Quercus virginiana

Live oak is an example of an evergreen oak, which is not common within this genus. As such, the wood is semi-ring porous and the rings are very difficult to see and date. Ring growth is also very erratic, not forming the concentric around the tree that we require.

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Douglas-fir

Latin name:
Pseudotsuga menziesii

These cores were collected on Mt. Graham in southern Arizona and show a major suppression event beginning in 1685 when missing rings became evident, followed by many micro-rings. This suppression was caused by a major wildfire in 1685!

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Gallery of Tree Rings 1

Tree Ring Gallery 1	Tree Ring Gallery 2	Spectacular Trees
Beautiful Landscapes	Taking Samples	Historic Structures
Bristlecone Pines

	My most requested image. A spectacular view of a Douglas-fir (Pseudotsuga menziesii) cross section obtained from the Zuni Mountains of New Mexico by my friends Chris Baisan and Rex Adams (photo © H.D. Grissino-Mayer). Note how very sensitive the ring widths are of this species, despite its young age. indicating it is ideal for reconstructing climate. This picture has appeared in over 100 publications.
	This picture shows a row of disrupted cells in a tree ring from a bristlecone pine (Pinus longaeva) growing in the White Mountains of California (photo © R.K. Adams and H.D. Grissino-Mayer). This is no ordinary frost ring. This one was formed in the year 1627 B.C., and is connected with the eruption of Thera in the Mediterranean Sea.
	A Table Mountain Pine (Pinus pungens) from Kelly Mountain in the George Washington National Forest of Virginia, U.S.A., showing multiple fire scars (photo © H.D. Grissino-Mayer).
	The famous Douglas-fir (Pseudotsuga menziesii) tree-ring specimen from Broken Flute Cave in northeastern Arizona, with the year AD 550 marked (photo © LTRR). Note the marker rings for the years AD 536 and 543. This tree was not 1,500 years old when it died, but was dated absolutely against a nearby reference chronology for northwestern New Mexico.
	This simple image shows the tree rings of the famous Pemberton white oak (Quercus alba) tree that fell down due to old age on August 2, 2002, near Bristol, Tennessee (photo © H.D. Grissino-Mayer). The tertiary limbs on this tree dated to the 1760s. Who knows what the trunk would have dated to had it not been so decayed.
	Beautiful swirls of tree rings on a giant sequoia (Sequoiadendron giganteum) caused by repeated low-severity fire events on the western slopes of the Sierra Nevada of California, U.S.A. (photo © H.D. Grissino-Mayer). Can you see the face?
	The "Bannister Tree," a Douglas-fir (Pseudotsuga menziesii) collected at El Malpais National Monument in New Mexico, with a continuous sequence of rings that date from 200 B.C. to A.D. 550. This was the first tree found at the site that broke the B.C. barrier (photo © H.D. Grissino-Mayer).
	The curious swirls seen in tree rings on some stinking cedar trees (Torreya taxifolia) that formerly grew in Torreya State Park, Florida, near the Appalachicola River (photo © H.D. Grissino-Mayer). The entire species is facing possible extinction from as-yet unknown reasons.
	Increment cores taken from Douglas-fir (Pseudotsuga menziesii) trees growing on Mt. Graham in southeastern Arizona (photo © H.D. Grissino-Mayer). Note the suppression in tree growth around 1685 due to a forest fire that caused damage to the trees.
	Here's a close-up of tree rings of a bristlecone pine (Pinus longaeva) (photo © H.D. Grissino-Mayer). Notice the very good marker ring (the narrowest ring seen towards the right of the photograph).
	I've had many requests to provide digital pictures of charcoal samples that show tree rings (photo © H.D. Grissino-Mayer). This one shows tree rings in a charcoal sample of pinyon (Pinus edulis) collected from southwestern New Mexico.
	An incredible set of tree rings on a longleaf pine (Pinus palustris) section from Lake Louise in southern Georgia (photo © H.D. Grissino-Mayer). Notice how tight the ring growth is here. Longleaf pines are very slow-growing and ideal for reconstructing climate in the coastal plain region of the Southeastern U.S.
	A very curious section of fossil wood that I bought online (genus and species unknown). The wood appears to belong to the hardwood group, possibly a ring porous species. But notice the internal scar over which the tree rings have grown (photo © H.D. Grissino-Mayer)!
	A cross section from a white spruce (Picea glauca) that was struck by a snow avalanche (impact scar on the top of the picture) in the Canadian Rocky Mountains near Alberta, Canada (photo © H.D. Grissino-Mayer and R.K. Adams).
	One of the coolest sections I'd ever seen. Collected at Apex Mountain, British Columbia, Canada in 2008, this subalpine fir (Abies lasiocarpa) is undergoing decay, which causes the unusual and most beautiful pattern seen in the wood (photo © H.D. Grissino-Mayer). But, notice the rings are still visible and datable!
	Who knows what patterns you'll see in the wood? Here's a shortleaf pine (Pinus echinata) collected from a historic house being renovated in Forsyth County, Georgia, U.S.A. showing a beautiful star like pattern emanating from an internal branch node (photo © H.D. Grissino-Mayer).
	On diffuse porous tree species, such as mesquite (Prosopis juliflora), the rings are very faint (photo © H.D. Grissino-Mayer). So, try this. Rub some chalk or talcum powder across the sanded surface and blow off the remaining dust.
	Some pine species are just very hard to work with, such as the very erratic rings found on West Indies pine (Pinus occidentalis) growing at the highest elevations in the Dominican Republic, about 3,000 meters (photo © H.D. Grissino-Mayer).
	Dr. Charles Aiken of my department brought this oak (Quercus spp.) section to me for a workshop he was hosting, and I was struck by the beautiful patterns caused by decay fungi (photo © H.D. Grissino-Mayer).
	A series of fire scars on a ponderosa pine (Pinus ponderosa) tree found growing on a kipuka in El Malpais National Monument in New Mexico (photo © H.D. Grissino-Mayer). This image clearly shows how a tree can record multiple low-severity fire scars.
	This section of longleaf pine (Pinus palustris) came from an 1830s crib dam that was exposed after a river flooded and broke the modern dam in Hope Mills, North Carolina, U.S.A. (photo © H.D. Grissino-Mayer).
	A section of eastern red cedar (Juniperus virginiana) that had been excavated from an archaeological site in southeastern Tennessee in the 1930s (photo © H.D. Grissino-Mayer). It remains undated but likely dates to pre-1300. The sample shows the excellent tree rings that can be preserved in ancient wood.
	A cross section of a giant sequoia (Sequoiadendron giganteum) showing a remarkable release in growth (notice the wider rings that start in the middle of the photo) following a widespread and intense fire in A.D. 1297 (photo © T.W. Swetnam and A.C. Caprio).
	Tree rings seen in a stinking cedar (Torreya taxifolia) from Torreya State Park in the panhandle of Florida (photo © H.D. Grissino-Mayer). They are very faint for a conifer, but still show enough variability to be crossdated!
	Tree rings on a lodgepole pine (Pinus contorta) collected on Morrell Mountain in the Lolo National Forest of western Montana (photo © H.D. Grissino-Mayer). The scars were once thought to be caused by fire, but we believe these to be caused instead by bark beetles.
	Tree rings on a live oak (Quercus virginiana) from Ft. Sumter National Monument in South Carolina, U.S.A. showing the erratic and very indistinct ring patterns associated with this evergreen oak (photo © H.D. Grissino-Mayer).
	This ponderosa pine (Pinus ponderosa) was growing alongside a stream in Pine Canyon in the Chiricahua Mountains of southeastern Arizona (photo © H.D. Grissino-Mayer). The impact scar on the right was from a flood. Notice the resin behind the scar and how the tree leaned to its left after it was struck by the flood water.
	This photo shows a fire scar on a red spruce (Picea rubens) collected from Mt. Rogers in the southern Appalachians in southern Virginia (photo © A. Krustchinsky). This must have been a low-intensity fire to have scarred the tree when it was so young, dispelling the myth that fires do not occur in such mesic, high-elevation locations of the eastern U.S.
	I found this subalpine fir (Abies lasiocarpa) log in a pile of logs on Mt. Graham, southeastern Arizona, in late 1990 (photo © H.D. Grissino-Mayer). The scar was caused by a bear peeling away most of the bark, yet a small portion of the tree remained living, causing this unique formation.
	Tree rings from a red oak (Quercus rubra) extracted from a squared beam from a historic structure in Lexington, Virginia (photo © H.D. Grissino-Mayer). This sample helped us date when the structure was likely built.
	This Rocky Mountain juniper tree (Juniperus scopulorum) is the oldest tree yet found in New Mexico (photo © H.D. Grissino-Mayer). It grew in the lava fields of El Malpais National Monument for 1,889 years!
	Tree rings on American basswood (Tilia americana) are very difficult to see because it is a diffuse porous type of wood (photo © H.D. Grissino-Mayer). I tried enhancing the rings using image analysis software and got this beautiful pattern.
	A fairly close-up image of tree rings from a ponderosa pine tree (Pinus ponderosa) growing in El Malpais National Monument, New Mexico (photo © H.D. Grissino-Mayer).
	Fire scars can be found in oak species (Quercus spp.) growing in mesic locations in the eastern U.S. (photo © H.D. Grissino-Mayer). This tree was growing in a drainage bottom in the Jefferson National Forest, of southwestern Virginia.
	Sometimes you find a tree so unique, it has its own story, one that lasts 700 years as did the one from this western juniper (Juniperus occidentalis) growing near Frederick Butte in central Oregon (photo © H.D. Grissino-Mayer). It had been long-dead already when we sampled it.
	Close-up of CRE340, a ponderosa pine (Pinus ponderosa) tree from El Malpais National Monument, New Mexico (photo © H.D. Grissino-Mayer). Notice the pinpricks for the year AD 1400 (three dots) and for AD 1390 (one dot below). Also notice the narrow rings for the years AD 1399, 1405 and 1407, a classic "signature" pattern.
	Close-up of boxwood (Buxus sempervirens) shrub rings, from a sample collected at President Thomas Jefferson's Poplar Forest Plantation near Lynchburg, Virginia (photo © H.D. Grissino-Mayer).
	A section from eastern hemlock (Tsuga canadensis) cut from a log used in a pier in Dover, Delaware (photo © H.D. Grissino-Mayer). We were able to date this log as having come from central Pennsylvania.
	A section from an Engelmann spruce (Picea engelmannii) that was logged during construction of an observatory on Mt. Graham in southeastern Arizona, U.S.A. (photo © H.D. Grissino-Mayer). Although small, the tree was quite old, having spent much of its life in the understory.
	A section from a Douglas-fir (Pseudotsuga menziesii) that was cut from a beam located in a pueblo in northeastern Arizona (photo © H.D. Grissino-Mayer). The opposite side contains axe cut marks.
	Close-up of tree rings from a section from a Douglas-fir (Pseudotsuga menziesii) that was cut from a beam located in a pueblo in northeastern Arizona (photo © H.D. Grissino-Mayer). Notice the numerous false rings and very tight narrow rings to the left.
	A section from a Table Mountain pine (Pinus pungens) sapling collected on Brush Mountain in southwestern Virginia in 1993 (photo © H.D. Grissino-Mayer). We were surprised to find a buried scar on such a small (5 cm diameter) sapling. The sapling was no more than 10 years old when first scarred.
	A close-up of a fire scar that was dated to 1842, as captured on this southwestern white pine (Pinus strobiformis) from Mt. Graham in southern Arizona (photo © H.D. Grissino-Mayer). The scar position indicates this fire occurred early in the growing season (May or June) of 1842.
	Palo verde (Cercidium microphyllum), a diffuse porous wood species commonly found in the southwestern U.S., has indistinct growth rings and therefore can not be dated using dendrochronology (photo © H.D. Grissino-Mayer).
	Sugar maple (Acer saccharum) is common throughout the eastern U.S. (photo © H.D. Grissino-Mayer). Even though this species also contains diffuse porous wood, the tree rings can be distinguished and dated using dendrochronology.
	Wood from Norway spruce (Picea abies) is commonly used to make musical instruments (photo © H.D. Grissino-Mayer). In this photo, one can see the "side grain" view of tree rings running longitudinally down the trunk of tree. These can also be dated when viewed in this position.
	A cross-section from a longleaf pine (Pinus palustris) that was excavated from the Fountain of Youth State Park archaeological site in St. Augustine, Florida, U.S.A. (photo © H.D. Grissino-Mayer). The sample was dated to the mid-1600s.
	This section of a longleaf pine (Pinus palustris) was cut from a very eroded stump on the edge of Lake Louise in southern Georgia, U.S.A. (photo © H.D. Grissino-Mayer). The tree rings date back to A.D. 1421!