This study investigated the composition, age-and size-structure, and tree-ring relationships for an old-growth, warm-temperate, mixed-evergreen forest at the University of Tokyo Chiba Forest, Japan. A total of 32 tree species were recorded, which was dominated by Abies firma and Quercus acuta. Tsuga sieboldii dominated the recruitment after 1850, followed by Abies firma. After 1920, many individuals of Castanopsis, Cinnamomum, Cleyera and Quercus became established. The temporal pattern of conifer recruitment did not correspond to the record of strong wind events. Basal area increment in Abies firma and Castanopsis sieboldii trees increased throughout their lives, a trend not seen in the ring width index. Mean annual temperature was below the 100-year mean between 1920 and 1940 and 1960-1980, but increased rather abruptly after 1980. Mean annual precipitation decreased after 1960. Tree-ring releases are very common at the study forest, which are indicative of frequent small to moderate-sized disturbances. At least one release was recorded in every decade from 1890 to the present day, which is likely the primary causal factor promoting tree growth and recruitment. Our results suggest that early logging activities coupled with natural disturbances had a great influence on the developmental process and current structure of the study stand and that tree growth is varying in a manner consistent with forest dynamics. © 2017 by The Tree-Ring Society.

Pinus edulis is one of the most ubiquitous tree species in the US Southwest. It accounts for over a fifth of the total number of trees in New Mexico alone. Its prevalence and relatively long-lived nature makes it an ideal candidate for dendroclimatological studies of the North American Monsoon. The problem occurs with delineating the boundary of the earlywood and latewood for sub-annual reconstructions. In this study, we present a novel method ("the resin duct method") for delineating the latewood boundary using resin ducts of P. edulis from three sites in New Mexico. The climate sensitivity of partial ring widths of P. edulis is then explored and compared to co-occurring Pinus ponderosa, which has a clear latewood boundary. The method of using resin ducts for delineating latewood in P. edulis resulted in a statistically significant relationship when compared to the latewood widths of co-occurring P. ponderosa. Although we found a similar climate response of P. edulis when compared to P. ponderosa, P. edulis latewood was a poor predictor of North American Monsoon precipitation unlike P. ponderosa. However, P. edulis earlywood has a statistically significant correlation with cool-season precipitation, making it useful for cool-season climate reconstructions in the Southwest. © 2017 by The Tree-Ring Society.

We reconstruct pandora moth (Coloradia pandora Blake) outbreaks and climate from a 1572-year (435-2006 CE) ponderosa pine (Pinus ponderosa Dougl. ex Laws.) chronology from a lava flow in central Oregon. We took samples from 128 living trees and remnant logs and crossdated the samples using skeleton plots and COFECHA for quality control. After cutting out and removing those time periods from the chronology during which insects become the main limiting factor to growth, we examine the response of tree rings to climate. Evidence of species longevity (up to 877 years), presence of periodic pandora moth defoliations (13 total), and a significant relationship with the Palmer Drought Severity Index were observed (R2 = 0.34, p < 0.001). Suppressions related to pandora moth outbreaks were recorded back to 618 CE, with a mean return interval of 104 years. Previous-fall to current-spring PDSI was reconstructed over 1376 years (630-2006 CE), where the most prolonged drought periods were 1136-1166 CE and the Dust Bowl 1924-1941. Our research documents longevity of ponderosa pine, resilience in the presence of multiple disturbances, and demonstrates a technique to separate insect outbreak signals from climate reconstructions in long chronologies while embracing the entire signal available in tree rings. © 2017 by The Tree-Ring Society.

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. © 2017 by The Tree-Ring Society.