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Past Projects

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Dendrochronological Dating of the Warner House and Barn (20LV334), Livingston County, Michigan, U.S.A

Maegen L. Rochner, Hudson W. Kelley, Christopher S. Wilson, Tim Bennett, and Henri D. Grissino-Mayer

An oak section from the Warner House in Livingston County, Michigan.

We were contacted recently about the possibility of our assisting with the dating of timbers from a house and barn located on a historic farmstead in Livingston County in southeastern Michigan. Very few such dendroarchaeological studies have been conducted in the upper Midwesst, so we were unsure about the probability of success for this project. Luckily, a nearby oak chronology already existed in the ITRDB and we successfully dated several timbers from the house and barn from this farmstead. The house dated to 1855, corroborated by historical accounts, while the barn dated to 1876. The date of construction for the barn was not previously known.

The Historical Dendroarchaeology of Two Historic Structures, Bear Paw State Natural Area, Valle Crucis, North Carolina

Maegen L. Rochner, Saskia van de Gevel, and Henri D. Grissino-Mayer

Maegen Rochner cores the Big Cabin at Bear Paw State Natural Area, North Carolina, U.S.A.

This project represents a collaboration between the Laboratory of Tree-Ring Science and the Department of Geography and Planning at Appalachian State University. Former LTRS graduate student Dr. Saskia van de Gevel developed this project as a teaching tool for students in her introductory geography classes to demonstrate techniques used by scientists for experiential learning. We hope to learn when exactly both log structures were built prior to their being relocated in their present locations sometime in the early 1900s. The Big Cabin has extremely large logs made from tulip poplar (shown above) and we believe the Small Cabin may have logs hewn from chestnut trees before their demise!

The Historical Dendroarchaeology of Sabine Hill, Elizabethton, Tennessee, Home of General Nathaniel Taylor

Henri D. Grissino-Mayer, Elizabeth A. Schneider, Maegen L. Rochner, Meagan E. Dennison, and Lauren A. Stachowiak

Lauren and Liz core a wall crace in the Sabine Hill historic house in Elizabethton, Tennessee.

General Nathaniel Taylor was a major historical figure, having served in the War of 1812 to protect General Jackson's forces during the siege of New Orleans. After a long and distinguished career as a politician and local business leader, Taylor supposedly began to build Sabine Hill in Elizabethton, Tennessee, but died in 1816 likely before the impressive two-story structure was completed. Today, the Tennessee Historical Commission is mounting a major effort to restore Sabine Hill to its original early 19th century grandeur as a classic example of Federal architecture. Our project is to determine when exactly Sabine Hill was constructed.

Environmental Modeling of the Spatiotemporal Dynamics of Past Wildfires, Lower Florida Keys, U.S.A.

Lauren A. Stachowiak and Henri D. Grissino-Mayer

Liz and Lauren pose with a fire-scarred slash pine, Big Pine Key, Florida.

Ph.D. student Lauren Stachowiak (right) initiated her dissertation research on Big Pine Key in the Key Deer National Refuge in Florida, assisted by Liz Schneider (left). Lauren hopes to enhance our knowledge of the spatial and temporal behavior of past wildfires on the key by using advanced GIS and environmental modeling techniques, coupled with a grid-based sample design, focusing on the Blue Hole Burn that occured in September 2011. This fire burned at various intensities and had differential effects on the flora of the 100 acre burn site, and Lauren hopes to learn more about environmental factors that affected the ability of fire to spread.

Temporal Stability in the Climate Response of Two Tree Species, Norris Dam State Park, Tennessee

Allison E. Ingram and Henri D. Grissino-Mayer

Kyle Landolt assists in coring oak trees for the thesis research of Allison Ingram.

We've noted that some tree species here in the southeastern U.S. demonstrate a changing response to climate over the 20th century, which would hinder our ability to reconstruct climate. For her master's project, Allison will be collecting cores from one hardwood species (white oak, Quercus alba) and one conifer species (shortleaf pine, Pinus echinata) at Norris Dam State Park in eastern Tennessee to test how stable the climate signal is in these two common species. The area has gone unlogged for many decades and has beautiful examples of old-growth forest.

Tree-Ring Dating of Timbers from the Seal Cove Shipwreck, Acadia National Park, Maine

Henri D. Grissino-Mayer, Grant L. Harley, Savannah A. Collins, Meghan Foard, and Paul J. Krusic

Grant Harley surveys the Seal Cove shipwreck in Acadia National Park, Maine.

This was a very welcome surprise! While visiting the Visitor Center at Acadia National Park, I noticed a display about an archaeological project conducted a few years ago on a shipwreck in Seal Cove on the Maine coast. The ship is only exposed at low tide but is very accessible after a short hike through some dense understory. We were allowed to take only a few core samples and it turned out that Haglof increment borers were far better at extracting cores than our dry wood borers. We hope to learn when the timbers were fashioned that eventually went into the construciton of this schooner sometime in the late 1800s.

Long-Term Cimate Drivers of Wildfire Activity in the Magdalena Mountains,
New Mexico, U.S.A.

Elizabeth A. Schneider and Henri D. Grissino-Mayer

Liz kneels in front of her extensive collection of samples from the Magdalenas.

The Magdalena Mountains in west-central New Mexico have long been overlooked in fire history analyses, and no wonder why. The slopes are very steep, the terrain is very rugged, no accommodations for 50 miles, and the weather is unpredictable! For Liz's M.S. project, she developed a detailed fire history from over 75 fire-scarred southwestern white and ponderosa pines collected at three sites above 9000 feet elevation, and investigated both short-term and long-term climate mechanisms that could have contributed to fire activity in the past. The photo above shows the results from our collecting at just the first of the three sites.

Dendrogeomorphic Dating of Debris Flow Events in Great Smoky Mountains National Park, Tennessee, U.S.A.

Maegen L. Rochner and Henri D. Grissino-Mayer

A debris slide on the Alum Cave Trail on the way up to Mt. Le Conte.

The steep slopes of Great Smoky Mountains National Park are prone to debris flows and slides, especially during heavy rain events. This particular slide shown above is very recent, likely having occurred sometime between March and June of 2013. Maegen's master's research conclusively demonstrated that tree-ring data can be used to date the years such events occurred in the past. While common in Europe, no such study has even been conducted in the eastern U.S.! The initial scouting along several trails in the park revealed several potential debris flows to test this strategy, including the one above, which did indeed leave several scars on trees along the perimeter of the slide.

Dendrochronological Dating the Year of Construction for the Samuel Harned Cabin, Parrottsville, Tennessee, U.S.A.

Maegen L. Rochner, Elizabeth A. Schneider, and Henri D. Grissino-Mayer

The Samuel Harned Cabin in Norris, Tennessee, made from eastern hemlock logs!

This historic cabin was originally built in Parrottsville, Tennessee in Cocke County and later relocated and preserved in Norris, Tennessee. Historical documents suggest a construction date around 1860, but could tree-ring dating prove when exactly this cabin was built? When we sampled this, we were surprised to see that this structure may be built from eastern hemlock trees, the first time we've ever seen this species used in log cabin construction! The downside to this is that we have few eastern hemlock reference chronologies in eastern Tenneessee, so dating when this two-story cabin was built could be challenging!

Dendroarchaeology of the Harding Cabins at the Belle Meade Plantation, Belle Meade, Tennessee

Lauren A. Stachowiak, Elizabeth A. Schneider, Savannah A. Collins, Maegen L. Rochner, and Henri D. Grissino-Mayer

The Harding Cabin at Belle Meade Plantation was indeed built in 1807!

The Harding Cabin is considered the first structure ever built at the plantation that would later become the most productive breeders of thoroughbred horses in the United States in the early to late 1800s. Colonel John Harding himself was reportedly born here in 1809. This unique structure is actually two separate cabins separated by a central dogtrot, but the workmanship on the two cabins clearly indicates one was built after the other. The question is: which one is the original Harding Cabin? The one with half-dovetail notches on the right or the one with diamond notches on the left? We'll soon find out!

Dendrochronological Dating of the Historic McKenzie Home,
Meigs County, Tennessee, U.S.A.

Lauren A. Stachowiak, Elizabeth A. Schneider, Maegen L. Rochner, Savannah A. Collins, Chaney P. Swiney, Henri D. Grissino-Mayer, and Thomas G. McKenzie

The McKenzie Home ca. 1895. We found that it was built in the year 1876.

We were sent five sections from this historic cabin, located in Meigs County in southeastern Tennessee, to determine if we could date the exact year the oaks were harvested to construct this structure. We learned that all five oaks were felled somtime beginning in spring of 1876 to the dormant season of 1876. This proves that the structure was built by E.G. McKenzie Sr., shown with the beard in the left of the photo! He had bought the land on which the structure originally sat in February 1876 from his brother J.M. McKenzie and soon began cutting oak trees to build the structure for his growing family, shown here about 1895.

Dendroarchaeology of the Spencer's Cabin and Bledsoe's Cabin, Wynnewood State Historic Site, Castalian Spring, Tennessee

Elizabeth A. Schneider, Lauren A. Stachowiak, and Henri D. Grissino-Mayer

Bledsoe's Cabin at the Wynnewood State Historic Site, which dated to 1806.

Bledsoe's Cabin shown above is considered the earliest structure at the Wynnewood State Historic Site, located just behind the massive log structure created by Colonel Wynne beginning in 1828. Would Bledsoe's Cabin pre-date the the main structure? And what about Spencer's Cabin, located a few hundred meters away, which was supposedly built by the longhunter Richard Spencer in the late 1780s? This is one of the most intriguing projects yet undertaken by the Laboratory of Tree-Ring Science!

Evaluating the Age Structure of Trees for Restoration Efforts at the
Cumberland Homesteads Historic Area, Crossville, Tennessee

Lauren A. Stachowiak, Elizabeth A. Schneider, Maegen L. Rochner, Savannah A. Collins, Chaney P. Swiney, and Henri D. Grissino-Mayer

Sampling Oak Trees at Cumberland Towers Historic District in Crossville, Tennessee.

The Cumberland Towers Historical Association contacted our lab about testing the ages of nearly 20 trees in their historic district in Crossville, Tennessee to help inform them and the Tennessee Department of Transportation about the need to preserve trees that were original to the homesteads built in the mid-1930s. The oak tree above had nearly 190 rings, dating back to the 1820s, meaning that it was already extremely old (over 100 years old) when the historic district was established!

Fire History and Stand Dynamics on Rainy Mountain, Chattahoochee National Forest, Georgia, U.S.A.

Alex W. Dye and Henri D. Grissino-Mayer

Alex Dye takes notes at his study site on Rainy Mountain in northeastern Georgia.

The north Georgia mountains are one of the few areas in the U.S. where no tree-ring research has been conducted. For his master's project, Alex hopes to develop a 300-year long chronology from old-growth shortleaf pines and investigate the fire history and stand dynamics of forests on Rainy Mountain in extreme northeastern Georgia. The area does have abundant fire-scarred pine stumps that we hope to develop the first fire history for Georgia.

Stand Dynamics of the Pygmy Forests on the McCarty's Lava Flow, El Malpais National Monument, New Mexico, U.S.A.

Sarah J. Jones and Henri D. Grissino-Mayer

Getting ready to sample a plot on the pygmy forest in El Malpais National Monument.

One of the great mysteries of the malpais region is the existence and perpetuation of the so-called pygmy forest found only on McCarty's Lava Flow in the malpais region. Why do these ponderosa pine, pinyon pine, and juniper trees only grow to be no more than 20 feet tall yet live to be hundreds of years old? Sarah's master's research seeks to answer those questions by conducting an extensive analysis of the ages and disturbance history of these rare and endangered forests.

Did the 2008 TVA Coal Ash Spill Have an Effect on Growth of Surviving Trees?

Niki A. Garland and Henri D. Grissino-Mayer

Niki getting ready to sample for the TVA Project on an island that was impacted by the coal ash spill of 2008.

In December 2008, one of the nation's worst environmental diasters occurred when an impoundment dam at the TVA Fossil Plant in Harriman Tennessee failed, spilled millions of cubic meters of coal ash into the pristine environment. Once the area was safe enough for researchers, Niki Garland, for her master's project, initiated a project to evaluate whether or not the survising trees on two islands in the Emory River showed any adverse effects of this disaster. She found that the surviving trees showed no reduction in tree growth rates post-spill, although many trees had already succumbed to the effects of the coal ash.

Stand Dynamics of Ponderosa Pine Forests in Relation to Past Wildfire Activity,
El Malpais National Monument, New Mexico, U.S.A.

Alex J. Pilote and Henri D. Grissino-Mayer

Alex Pilote (right) samples pondoera pines and Douglas-firs in on eplot for his master's research at El Malpais National Monument.

For Alex Pilote's master's research, we initiated a project that complements the extensive fire-scar based fire history at El Malpais in New Mexico. To better understand the possible influence of moderate to high severity fires, we collected cores from over 600 trees at three sites in the area to evaluate the age structure and successional patterns of the ponderosa pine forests where we had previously reconstructed fire history. Possible pulses of establishment could indicate higher severity fires in the past.

The Historical Dendroarchaeology of Four Log Structures at the
Anderson-Doosing Farm, Catawba Valley, Virginia, U.S.A.

Henri D. Grissino-Mayer and the NADEF 2011 Archaeology Group

Sampling an old double-crib bark in the Catawba Valley of southwestern Virginia.

Perhaps one of the greatest achievements on research on log structures, members of the NADEF 2011 Archaeology Group intensely sampled four log structures at a historic farm complex just north of Blacksburg, Virginia. We found that a dilapidated cabin nearby was built in 1809-1810, the double pen cantilever barn (above) was built in 1830-1831, and the standing cabin and smokehouse were built simultaneously in 1838-1839. This research was subsequently published in the Journal of Archaeological Science in 2013.

Evaluating the Dendrochronological Potential of Shortleaf Pine Logs
from a Timber Crib Dam in Fredericksburg, Virginia, U.S.A.

Henri D. Grissino-Mayer, Grant L. Harley, and Alex Dye

A pile of logs rescued from a crib dam that was dismantled near Fredericksburg, Virginia.

We were very fortunate to be contacted by a wood worker in Fredericksburg, Virginia about some logs he had salvaged from a dismantled crib dam that was built across the Rhappahannock River in 1855. We collected over 40 cross sections from these logs and hope to build a long floating chronology spanning back to the 1500s from these samples to help shed light on past climate in a region virtually devoid of long pine chronologies.

Climate History from Old-Growth Ponderosa Pines,
El Morro National Monument, New Mexico, U.S.A.

Niki A. Garland, Grant L. Harley, Sarah J. Jones, and Henri D. Grissino-Mayer

Niki Garland surveys the landscape at El Morro National Monument.

This project focused on the extensive stands of old-growth ponderosa pine trees that exist in the sheltered environs of Inscription Rock at El Morro National Monument. These immense pines grow within the Box Canyon surrounded by the north and south mesa tops. Niki and Sarah analyzed the climate response of these trees and reconstruct climate using this climate signal, in the hope that these trees provide additional climate information than that gathered at nearby El Malpais.

Tree-Ring Dating of Timbers Extracted from a Spanish Mission Era Church,
Fountain of Youth Historic Park, St. Augustine, Florida, U.S.A.

Niki A. Garland and Henri D. Grissino-Mayer

Niki Garland crossdates a pine sample for the Fountain of Youth project.

We were quite surprised when contacted by the Florida Museum of Natural History who asked if we could attempt tree-ring dating on two timbers extracted from the original site of a Spanish Mission church constructed in the earliest decades of settlement by Pedro Menendez in St. Augustine, Florida. We found that one pine timber had conclusive dating with a reference chronology from Lake Louise and dated to the late 17th century.

Fire History and Vegetation Dynamics in the Lower Florida Keys, U.S.A.

Grant L. Harley, Henri D. Grissino-Mayer, and Sally P. Horn

Grant Harley cuts into a slash pine on No Name Key in the lower Florida Keys.

Grant Harley collected fire-scarred samples on Big Pine Key to learn about the disturbance history of endangered pine rocklands so that the U.S. Fish and Wildlife Service can learn more about the forest dynamics on the Key Deer National Wildlife Refuge. We collected over 100 fire-scarred samples and cored numerous slash pines for this project, and learned that fire was a recurring phenomenon on the key for nearly 200 years.

The Impact of Oceanic-Atmospheric Oscillation Change in the Southeastern United States Abstracted from Tree-Ring Network Data

Nancy Li and Henri D. Grissino-Mayer

Nancy Li cores into a large Table Mountain pine for her master's project.

For this project, Nancy investigated the climate response of trees along an east to west gradient here in the Southeastern U.S., across the southern Appalachian Mountains. She focused primarily on the longer-term decadal oscillations, such as the Atlantic Multidecadal Oscillation, the North Atlantic Oscillation, and the El Nino-Southern Oscillation. Here, Here, Nancy is coring a Table Mountain pine at her Linville Gorge site in North Carolina.

Fire-Climate Relationships in Ponderosa Pine Forests
of the Zuni Mountains, New Mexico, U.S.A.

Monica T. Rother and Henri D. Grissino-Mayer

Monica Rother flags a fantastic fire-scarred pine at Paxton Springs, New Mexico.

An extension to our research on fire history in the malpais region of New Mexico, this project investigated the spatial dynamics of past wildfires from tree-ring data to better understand the influence of topography and fuel loadings in the Zuni Mountains on fire regimes immediately to the south in El Malpais National Monument. Monica also investigated climate drivers of wildfire activity by evaluating relationships between these past fires and longer-term climate oscillations.

Fire History of Xeric Mixed Pine-Oak Hardwood Forests in Great Smoky Mountains National Park, Tennessee, U.S.A.

Lisa B. LaForest, Henri D. Grissino-Mayer, and Charles W. Lafon

Dr. Grissino-Mayer inspects a fire-scarred cavity in a shortleaf pine at Goldmine Trail.

In 2006, we initiated a project in Great Smoky Mountains National Park to reconstruct the history of wildfires using the fire-scar record as well as the age structure and stand dynamics of xeric mixed pine-oak forests found exclusively in the western end of the park. Led by Ph.D. student (now Dr.) Lisa LaForest, we found that fire was quite frequent at three sites, aveaging about one fire every 5 to 7 years. Equally important, we found that fire-dependent yellow pines are not regenerating because of changes in fire regimes caused by human activities in the last 70 years. Forests in the future will likely consist of fire-intolerant tree species as fire continues to be less a factor in forest development.

The Historical Dendroarchaeology of the Ximénez-Fatio House,
St. Augustine, Florida, U.S.A.

Henri D. Grissino-Mayer and Leda N. Kobziar

The beautiful Ximenez-Fatio House in St. Augustine, Florida.

The Ximénez-Fatio House is one of the oldest standing structures in St. Augustine, Florida, the first city established by Europeans in the U.S. in 1565. During renovations, we were able to extract numerous cores from beams in this house, and our data do corroborate the 1798-1799 construction date. In addition, our results indicate that the wing to the right was actually built when owned by Louisa Fatio, around 1855-1858.

Fire History at Two Sites near Cades Cove,
Great Smoky Mountains National Park, U.S.A.

Ian C. Feathers and Henri D. Grissino-Mayer

Ian Feathers finds a fire-scarred snag at the Cooper Road site in Great Smoky Mountains National Park.

A central question we have about the fire regimes in Great Smoky Mountains National Park concerns how variable fire activity is in such a topographically diverse area. Ian collected fire-scarred samples and stand inventory data from two sites, one nearly bordering Cades Cove and the other about 3 miles down Cooper Road trail away from the cove. He found that the two fire histories were very distinct and found that fire activity at the interior site may have been impacted more by human activities.

Fire History In Idaho: Does Fire Affect the Climate Signal in Ponderosa Pine Trees?

Jessica D. Slayton and Henri D. Grissino-Mayer

Maggie, Jessica, and Lisa take a break from scouting, Payette National Forest, Idaho.

A central question concerns whether or not fire activity has an effect on the climate signal found in ponderosa pine trees, one of the most heavily sampled species in the western U.S. This master's project by Jessica Slayton (center) evaluated the climate signal of pines in areas with frequent fire activity as well as areas with little fire activity, and she found little effect of fire on tree growth patterns.

The Dendroarchaeology of Two Log Structures at the Marble Springs Historic Site, Knox County, Tennessee, U.S.A.

Jessica D. Slayton and Henri Grissino-Mayer

The Walker Springs Cabin, Knox County, Tennessee, at the Marble Springs State Historic Site.

We were asked by the Tennessee Historical Commission to determine if a cabin at the Marble Springs Historic Site in Knox County, Tennessee could have been constructed by the State's first governor, General John Sevier in the late 18th century. We additionally sampled the Walker Springs cabin, shown above, which had been relocated to the site from west Knoxville. We found that the cabin above was built in 1829, while the John Sevier cabin was constructed in the early 1830s, long after his death.

Stand Dynamics and Fire History in Whitebark Pine Communities of Western Montana

Evan R. Larson, Saskia van de Gevel, David F. Mann, and Henri Grissino-Mayer

Spectacular views from on top of Mineral Peak, Lolo National Forest, Montana.

We conducted a comprehensive study of the complex stand dynamics, disturbance regimes, and the effects of climate change on the whitebark pine ecosystem in western Montana. Dendroecological techniques and analyses were used to provide high-quality, temporally precise information on the ecological status of this declining keystone species. Evan Larson focused on stand dynamics of three whitebark pine stands, Saskia van de Gevel analyzed whitebark pine forests in relation to the blister rust, and David Mann analyzed whitebark pines growing at upper treeline.

Fire Regimes of Forested Kipukas in El Malpais National Monument, New Mexico

Daniel B. Lewis and Henri D. Grissino-Mayer

Michael, Daniel, and Beth pose with one of the best fire-scarred stumps ever found at El Malpais National Monument.

Daniel's thesis research gathered information on the fire history of relict areas where human disturbances have been minimal. Daniel found that fire was very frequent on these isolated kipukas and saw little change in fire frequency into the 20th century. Daniel also conducted a comprehensive age structure analysis on two of these kipukas and found that the ages nonetheless indicated major disturbances during the 20th century. No evidence was found that high-severity wildfires occurred in these sites.

Fire Regimes of Pinus pungens Lamb. in Great Smoky Mountains National Park, Tennessee, USA

Michael R. Armbrister and Henri D. Grissino-Mayer

Michael Armbrister poses with one of his fire-scarred pines on Bote Mountain, Great Smoky Mountains National Park.

The status of Table Mountain pine as a component of forests in the southern Appalachian Mountains is unknown because the species is largely dependent on fire (notice the fire scar on the snag). Fire has been nearly non-existent in this park since about 1934. Table Mountain pine, however, largely depends on recurrent wildfires for its very existence. Michael was able to find out that fires had occurred with regular frequency prior to the park's establishment, about once every 7-10 years. More importantly, Michael found out that the maximum length of time the park could go without fire was about 80 years, and the park is fast approaching this critical fire-free interval.

Oxygen Isotope Ratios of Longleaf Pines as a Proxy of Past Hurricane Activity along the Atlantic Seaboard

Whitney L. Nelson, Henri D. Grissino-Mayer, and Claudia I. Mora

Tom Harlan and Whitney Nelson take a break after lessons on crossdating.

Here, Whitney confers with the late Tom Harlan of the tree-ring lab in Tucson. Whitney's project was an extension of the project begun by Dana Miller, and involved isolating a hurricane signal from tree rings of longleaf pines growing in South Carolina. Whitney provided higher resolution information on hurricane activity by further subdividing the tree-ring data into smaller portions for isotopic analysis.

Past Trends in Decadal-Scale Climate Inferred from Old-Growth Longleaf Pine Stands in the Southeastern U.S.

Joseph P. Henderson and Henri D. Grissino-Mayer

Joe Henderson poses with a section cut from a pine stump, Eglin Air Force Base, Florida

Lieutenant Colonel Joseph P. Henderson completed his Ph.D. at the Laboratory of Tree-Ring Science, shown here kneeling next to a section cut from a longleaf pine stump that had been logged sometime in the past 10 years in Eglin Air Force Base near Pensacola, Florida. This one tree goes back to the early 1500s, and Joe collected over 100 similar samples from the area. Joe has also collected extraordinary samples from remnant longleaf pine trees in Texas and South Carolina. In his dissertation, Joe demonstrated how these pines revealed past trends in climate phenomena such as the El Nino-Southern Oscillation, the Atlantic Multidecadal Oscillation, and even the Pacific Decadal Oscillation.

A Millennial-Length Reconstruction of Spring Rainfall
from Western Juniper in South Central Oregon, USA

Christopher A. Underwood and Henri D. Grissino-Mayer

Daniel takes notes after we extracted a section from this incredibly old western juniper, Frederick Butte, Oregon.

In 2001, Daniel Lewis and I collected over 100 cross sections from dead and downed juniper logs from trees that once had grown at Frederick Butte in southern-central Oregon. This site contains some of the most remarkable long-lived trees and dead wood anywhere in the U.S. Some of these trees are over 1000 years old, and the region around the butte is full of dead and downed remnant wood. Sadly, most of this wood makes its way to fireplaces in campsites. Chris has already dated some of these samples back to about AD 800.

Assessing the Dendrochronological Potential of Pinus occidentalis in the Cordillera Central of the Dominican Republic

James H. Speer, Kenneth H. Orvis, Henri D. Grissino-Mayer, and Sally P. Horn

Henri cutd into a pine snag at the Conuco del Diablo, Cordillera Central, Domincan Republic.

Here, Henri cuts a small cross section from a standing snag of West Indian pine with a chain saw in the Conuco del Diablo ("Cornfield of the Devil") at approximately 3000 meters on the northern slope of Loma La Pelona. Our initial study investigated the potential of this species to yield past climatic information for a subtropical location. The block field contains hundreds of remnant pieces of well-preserved wood that should push the record back several more centuries. We've also sampled nearly 100 trees (mostly dead and downed) that contain a very clear record of past wildfires, and eventually we hope to push the fire history back for several centuries.

A 600-Year Reconstruction of Spring Precipitation from Longleaf Pines in South-Central Georgia, U.S.A.

Henri D. Grissino-Mayer

Henru cuts a section from a longleaf pine stump, Lake Louise, Georgia.

We found an incredible area of relict longleaf pine stumps and remnants at Lake Louise, a research site owned by Valdosta State University in southern Georgia. We were surprised to find stumps that had remained intact since logging occurred around the turn of the 20th century. One reason these were so intact is because these trees had been turpentined previously, and the stumps were impregnated with resin. These samples have already provided a continuous well-replicated chronology back to AD 1421!

Alfred's Cabin at The Hermitage: Slave Cabin or Freedman's Cabin?

Daniel B. Lewis, Whitney L. Nelson, Henri D. Grissino-Mayer, and Edward R. Cook

Alfred's Cabin at the Hermiate, just outside Nashville Tennessee, and home of President Andrew Jackson.

Alfred was born on Andrew Jackson's Hermitage Plantation about 1815 and lived there until his death in 1901. The staff at The Hermitage would like to furnish the cabin for interpretive programs but needs to know if the double-pen, saddlebag cabin was built by Alfred while he was a slave or later when he was a freedman. The cabin is rare, constructed exclusively with eastern redcedar logs, the first such structure we've encountered in Tennessee. We extracted about 90 cores from the cabin and successfully dated the construction of this cabin to the year 1843.

Tree-Ring Dating the Joseph Hoskins' Log House, Tannenbaum State Park, Greensboro, North Carolina

Joseph P. Henderson and Henri D. Grissino-Mayer

The Hoskins House at Tannenbaum State Park in Greensboro, North Carolina.

This two-story, clapboard-sided structure is the main feature at Tannenbaum State Park in Greensboro, North Carolina, believed to have been built around 1780 by Joseph Hoskins. The state park now occupies the location where the highly significant battle of the Guilford County Courthouse was fought in 1781 during the Revolutionary War. We extracted about 60 half-inch wide cores from most logs on both floors of this structure and should eventually be able to date its year of construction.

Tree-Ring Dating of Abraham Lincoln's Birthplace Log Cabin, Hodgenville, Kentucky

Henri D. Grissino-Mayer and Dwight T. Pitcaithley

Henri poses with a core just extracted from a log at President Abraham Lincoln's Birthplace log cabin.

This cabin is housed in a beautiful memorial building, but some believe the cabin may not contain a single log associated with Abraham Lincoln. The tree rings in these logs could provide information on when the logs were cut. Eventually, we found several logs that dated to the 1840s and 1850s, but none that dated to the early 1800s. It's likely that not a single log in this cabin dates to the birth year of Abraham Lincoln (1809).

Dendrochronological Dating of Musical Instruments made by Antonio Stradivari

Henri D. Grissino-Mayer, Paul R. Sheppard, and Malcolm K. Cleaveland

Henri poses with the Messiah violin, which we found out was indeed contemporary with Antonius Stradivarius.

One of the most exciting projects I've ever been involved with. Some contend the "Messiah" violin could not have been made by Stradivari based on stylistic grounds. Funded by the Violin Society of America, we took our instruments to England to find out. Are the tree-ring dates contemporary with Stradivari? We found that indeed the tree rings dated to Stradivari's time (1577-1687) and therefore could not have been made by a copyist at a later time.

Analysis of Wood Samples from a Crime Scene using Laser-Induced Breakdown Spectroscopy (LIBS)

Henri D. Grissino-Mayer and Madhavi Z. Martin

Logs that were collected from a homicide site in Collin County, Texas in 2004.

In April 2004, we were contacted to help solve a homicide in Collin County, Texas. The victim's body had been burned under a pile of mesquite logs (upper left of photo) in an attempt to conceal evidence. Soon after, the sheriff's office found similar mesquite wood in a fireplace (lower right in photo) and people who attended the gathering around the fireplace knew from whom the wood came. If we could connect the two sets of wood, then the prosecutor's office would have convincing evidence that could help convict the suspect. To do so would require a relatively new technique called Laser-Induced Breakdown Spectroscopy.

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