Saskia L. van de Gevel

Forest Dynamics in a Natural Area of the Southern Ridge and Valley, Tennessee

Abstract This study was initiated to document forest development in the oldest natural area in the Ridge and Valley of east Tennessee. The Ijams Nature Reserve was established in 1910 and provided the opportunity to document secondary succession of the oldest upland forest reserve in the region. We established forest inventory plots in the original land holding of the Ijams family to quantify species composition, stand structure, and successional dynamics. We also analyzed the radial growth patterns of trees to document stand age, recruitment, and the disturbance regime of the reserve. The forest was dominated by Quercus alba and Liriodendron tulipifera while Acer saccharum and Fagus grandifolia had high densities in the understory. Liriodendron tulipifera was the most important species in the stand because it colonized the site following agricultural abandonment and subsequently established in small canopy gaps. The stand had a reverse J-shaped diameter structure typical of regenerating forests. The forest experienced one stand-wide disturbance event likely attributed to the decline of Castanea dentata in the 1920s. The return interval of stand-wide disturbances was much longer than what has been reported in other eastern hardwood forests. With the exception of this one stand-wide release, the disturbance regime was characterized by localized, asynchronous events that influenced only neighboring trees. Under the current disturbance regime, composition of the stand is projected to change as shade-tolerant mesophytes in the understory (A. saccharum and F. grandifolia) are recruited to larger size classes. This phenomenon has been widely reported throughout the eastern United States and is most commonly linked to active fire suppression. However, the forest of the Ijams Nature Reserve has not burned during development and still shows a marked change in species composition even with no change in the fire disturbance regime. We propose the composition shift is related to understory facilitation by disturbance oriented canopy species that have created conditions favorable for the establishment of mesophytes and by the loss of C. dentata that resulted in canopy gaps.

CLIMATIC RESPONSE OF OAK SPECIES ACROSS AN ENVIRONMENTAL GRADIENT IN THE SOUTHERN APPALACHIAN MOUNTAINS, USA

Abstract We investigated the climatic sensitivity of oak species across a wide elevation range in the southern Appalachian Mountains, an area where greater knowledge of oak sensitivity is desired. We developed three tree-ring chronologies for climatic analyses from oak cores taken from the Jefferson National Forest, Virginia, and Great Smoky Mountains National Park, Tennessee. We statistically compared the three chronologies with monthly climatic data from 1930 to 2005. The results of our analyses suggest that oak species in the southern Appalachian Mountains require a cool, moist summer for above average-growth to occur. The climate signal increased in duration from high to low elevational and latitudinal gradients, indicating a strong moisture-preconditioning signal during the previous fall at our lowest elevation site. A notable finding of this research was the degree of responsiveness in oaks that are growing in forest interior locations where strong climate sensitivity would not be expected because of the effects of internal stand dynamics. Furthermore, the relationships between evapotranspiration rates and the geographic factors of elevation, latitude, and aspect influence the climate signals at the three sites. Our research suggests that oaks located in a warm and xeric climate experience more physiological stress and put forth a more varied climatic response.

Tell-Tale Trees: Historical Dendroarchaeology of Log Structures at Rocky Mount, Piney Flats, Tennessee

The Rocky Mount site has important historical and cultural significance for the State of Tennessee because it was built by one of its earliest settlers and served as the capital of the territory from 1790 to 1792. Questions arose concerning whether the two main log structures—known as the Cobb House with adjoining dining room—were built by William Cobb between 1770 and 1772. The authors used tree-ring dating to determine the year(s) of construction of these two log structures. Three nearby reference tree-ring chronologies anchored the Rocky Mount tree-ring chronology from 1667 to 1829. Cutting dates obtained from 19 logs revealed that the Cobb House was built beginning in 1827 and finished by 1828, while the dining room was begun in 1829 and finished by 1830. An additional six logs had outermost dates between 1820 and 1825. These 25 logs demonstrate, instead, that Michael Massengill constructed the house and dining room between 1827 and 1830.

THE HISTORICAL DENDROARCHAEOLOGY OF THE HOSKINS HOUSE, TANNENBAUM HISTORIC PARK, GREENSBORO, NORTH CAROLINA, U.S.A.

Abstract The Hoskins House is a two-story, single pen log structure located in Tannenbaum Historic Park, Greensboro, North Carolina. The house is thought to have been built by Joseph Hoskins, who lived in Guilford County from 1778 until his death in 1799. Previous archaeological testing of soil around the house yielded over 1000 artifacts, and the ceramics of these gave a Mean Ceramic Date (MCD) of 1810 as a possible initial year of construction. Our objective was to date the outermost rings on as many logs as were accessible in the Hoskins House to determine the year or range of years when the house was likely built. We compared 37 ring-width measurement series from 28 white oak group logs with a composite reference chronology created from three oak reference chronologies from Virginia. We found that the logs were cut over a 3-year period from 1811 to 1813, lending credence to the initial MCD of 1810. Joseph Hoskins had already passed away in 1799 and the property was deeded to his two sons, Joseph and Ellis. Ellis Hoskins eventually was later deeded sole possession of the property. The two-story log house located at Tannenbaum Historic Park may be more correctly called the “Ellis Hoskins House” rather than the “Joseph Hoskins House.”

TREE-RING DATING OF OLD-GROWTH LONGLEAF PINE (PINUS PALUSTRIS MILL.) LOGS FROM AN EXPOSED TIMBER CRIB DAM, HOPE MILLS, NORTH CAROLINA, U.S.A.

Abstract On 26 May 2003, intense rainfall from a series of thunderstorms in eastern North Carolina caused flooding that eventually destroyed the concrete dam in Hope Mills, draining Hope Mills Lake, and revealing a formerly submerged and buried structure that was identified as a timber crib dam. Inspection revealed these logs to be old-growth longleaf pines, which are now rare on the coastal plain landscape. Our primary objective was to develop a new multi-century longleaf pine tree-ring chronology by crossdating the tree rings from sections extracted from logs in the crib dam with an anchored tree-ring chronology created from nearby living longleaf pine trees. We also examined the climatic response in the longleaf pine trees to evaluate their potential for reconstructing climate. Using tree-ring measurements obtained from old-growth longleaf pines found at a nearby church, we were able to date the rings on 21 series representing 14 logs from the crib dam, spanning the years 1597 to 1825. Distorted sapwood in many of the logs prevented us from finding absolute cutting dates and lessened the strength of correlation during the period of overlap between the church series and crib dam series. Human disturbances, specifically related to the naval stores industry, likely influenced the growth-ring patterns of the crib dam pine samples, as well. Correlation analyses between the longleaf pine chronology and temperature, precipitation, Palmer Drought Severity Indices, and North Atlantic sea surface temperatures showed a significant response to cool and wet spring months.

Variability in Fire Regimes of High-Elevation Whitebark Pine Communities, Western Montana, USA

Abstract: We investigated the stand history of whitebark pine forests on 3 mountains in the Lolo National Forest, Montana, USA to characterize the fire regimes and other disturbance agents that historically operated at these sites and to explore the potential influences of modern fire suppression on these forests. We used hLarsonistorical fire atlas data and dendroecological data to reconstruct the distinct stand. The fire regimes of each site fit within the general definition of mixed-severity fire regimes, but distinct differences in fire frequency anween them. All 3 stands contained at least 1 post-disturbance cohort and had experienced at least 1 widespread fire over their histories. We found no consistent fire—climate relationship at these sites. Mountain pine beetles were the primary mortality agent in the current stands at all 3 sites. Subalpine fir began establishing at each site within 2 decades of the most recent widespread fire and well before fire suppression was effective in this region. Fire suppression may have reduced the occurrence of fire during the late 20th century at all 3 sites, but only the forest on Point Six has exceeded the mean interval between widespread fires. The differences in fire activity and effects of fire suppression that we observed at these sites are likely the result of different biophysical site characteristics and disturbance legacies and hold important implications for the development of site-specific management strategies for whitebark pine restoration. Nomenclature: ITIS, 2008.

RADIAL GROWTH RESPONSES OF THREE CO-OCCURRING SPECIES TO SMALL CANOPY DISTURBANCES IN A SECONDARY HARDWOOD FOREST ON THE CUMBERLAND PLATEAU, TENNESSEE

We analyzed the radial growth patterns of Liriodendron tulipifera, Acer rubrum, and Acer saccharum growing in 39 canopy gaps in a mature secondary hardwood forest on the Cumberland Plateau in Tennessee to compare species-specific growth responses to small canopy disturbances. We tested for differences between mean radial growth increases during the year of release initiation (i.e., first year of discernible growth increase) over the year prior, mean percent growth increases during the year of release initiation over the year prior, mean release durations, and mean lag times between canopy gap formation and radial growth response. At each level of analysis (i.e., by species, canopy position, and gap position) only the radial growth increase during the year of release initiation over the year prior revealed significant differences. In each case where a systematic difference was noted, the growth increase of L. tulipifera was greater than one or both of the Acer species. However, field observation indicated accelerated growth of L. tulipifera was largely negated in the relatively small and short-lived gaps. Our findings provide information on the successional pathway of the forest, the physiological responses of these species to small canopy openings, and the applicability of these species to reconstruct canopy gap formation in secondary stands from tree-ring records.

Legacy of Charcoaling in a Western Highland Rim Forest in Tennessee

ABSTRACT Forests of the Western Highland Rim were heavily influenced by the iron industry during the 19th and 20th centuries. The production of iron required large amounts of charcoal. Timber was cut, burned in hearths to produce charcoal and then the charcoal was transported to local furnaces and forges. The goal of our study was to document the lasting effects of charcoal production on soil characteristics, species composition and stand structure for a forest on the Western Highland Rim in Tennessee. Fires used in hearths to produce charcoal were intense, spatially concentrated events that modified soil characteristics differently than typical surface fires. We hypothesized there would still be a footprint of the charcoal making process evidenced by systematic differences in forest composition and structural attributes that could be related to soil properties. Results show there were significant differences in some soil traits between charcoal hearths and surrounding sites. However, differing soil conditions have not significantly influenced forest development. Although tree density differed between hearths and adjacent areas, there were no systematic differences in tree species richness, diversity (H′), evenness (J) or basal area between charcoal hearth and non-hearth sites. Results of this study indicate the historic land use has minimal influence on modern forest communities in our Tennessee study site.

The Dendroarchaeology Of Cagle Saltpetre Cave: A 19th Century Saltpeter Mining Site In Van Buren County, Tennessee, U.S.A

Abstract During the historic mining episodes at Cagle Saltpetre Cave, wooden leaching vats needed for the lixiviation of calcium nitrate from mined sediments (from which saltpeter was then produced) were constructed and used in the cave. When mining operations ceased, these features were abandoned and preserved in situ, some remaining virtually intact. Their remarkable preservation enabled tree-ring dating of timbers associated with these vats to be accomplished. Tree rings from oak planks used in the construction of the leaching vats were measured to 0.001 mm precision on a Velmex measuring system. Using COFECHA software, we crossdated the measurement series to both the Norris Dam State Park and Piney Creek Pocket Wilderness white oak reference chronologies, spanning the years from 1633 to 1982, obtained from the International Tree-Ring Data Bank. Graphical comparisons via scatter plots were inspected to ensure correct temporal placements. The final chronology developed from 39 dated series correlated very highly with the Norris Dam State Park reference chronology (r  =  0.49, n  =  170 yrs, t  =  7.29, p < 0.0001) and verified that our site chronology extends from 1692 to 1861 The results of our analyses indicate that saltpeter was mined and processed at the site during separate episodes throughout the 19th Century. Additionally, saltpeter-processing technology changed throughout the course of the mining operations.

Using Dendrochronology to Investigate the Historical and Educational Value of two Log Structures at Bear Paw State Natural Area, North Carolina, USA

Abstract During May 2013, the Bear Paw State Natural Area near Boone, North Carolina acquired an 11.5 ha tract of land and two log cabins from David Wray of Blowing Rock, North Carolina. Work was soon underway to determine the historical nature of these two buildings and to evaluate them for consideration for the National Register of Historic Places. A historic structure report, completed as a collaboration between Appalachian State University and the North Carolina Division of Parks and Recreation, was unable to discover much about the history of the two log cabins except that they were both likely moved to their current location in the early 20th Century. To determine when the cabins were built, we extracted core samples from logs in both cabins and compared the tree-ring patterns to region-wide, precisely-dated reference chronologies. We dated the tulip poplar tree-ring chronology from the Big Cabin to the period 1675–1859. Cutting dates on several of the logs revealed tree harvest likely occurred between fall 1859 and spring 1860. Some logs had outermost rings that dated to 1857 and 1858. Still, these logs may have been harvested a few years earlier, or some of the outer rings may have been lost during construction or sampling. We were unable to absolutely date an 81-year long American chestnut chronology from the Small Cabin. Our results confirmed that the Big Cabin was an Antebellum Period structure (pre-American Civil War) and therefore has potential historical significance. Because we still cannot tie this cabin to a historical figure or a historical event, the cabin cannot be nominated yet for inclusion in the National Register of Historic Places, but the identification of an original construction date for the cabin may contribute to further assessment for inclusion on a local or national register. In the meantime, we intend to use this cabin in annual summer workshops for undergraduate students taking courses at Appalachian State University so that more students can be exposed to the hands-on nature of scientific inquiry and can learn the value of dendrochronology for understanding human and environmental history.