Possibly from logging upstream? The Use of Dendrochronology to Date Pinus strobus Stumps and Examine the Influence of Climate on Radial Tree Growth Douglas Manning Project Advisor: Dr. Margot Kaye Study Objectives Determine when exposed stumps were cut Compare the radial growth rates of the stumps and living trees to climate data to see how temperature and precipitation influenced tree growth over several centuries References The Longfellow data set was downloaded from the International Tree-Ring Database ( and the topographic image was from USA PhotoMaps. The climate data was obtained from: Suppression Conclusions Analysis of tree-ring data from the stumps and adjacent sites (Longfellow Trail) allowed us to determined that the stumps were cut in Results The tree-ring dating shows good correlations between the chronologies. The trees were cut in 1876 and dated back as far as Climate data and tree growth comparisons are not yet completed Further Areas of Study Growth suppression of 1971 and 1972 Climate data correlations Looking at climate data for tree growing months rather than annually Comparison of mesic and xeric growth patterns in P. strobus How is tree-ring data collected? An increment borer is a tool used to collect cores from trees that can then be analyzed for tree rings. The example to the right (labeled “Increment Borer”), displays the parts of an increment borer. The handle (A) is both the casing for the increment borer and the area that the borer shaft (B) locks into. The borer bit (C) is located at the tip of the shaft and is used to essentially screw into the tree. The extractor (D) is used to pull out the core to be used for its specified purpose. Skeleton Plotting In order to cross-date tree-rings graph paper can be used to record the very small and very large years of growth. By doing this you can figure out when a tree established and, if it is dead, when it died. Methods: Dendrochronology Dendrochronology is the study of tree-rings to gain information about the past. Tree-rings can be used to date wood structures, predict historical climate patterns and a lot of other historical data. Increment Borer Pulling a core from a white pine Longfellow trail No trees old enough to data the stumps could be found in the surrounding forests. Therefore, we used an existing chronology from Cook State Forest in Stumps In 2004 flooding from hurricane Ivan caused a small splash dam on Mosquito Creek in the Moshannon Forest to breach, exposing over a dozen eastern white pine (Pinus strobus) stumps that had been buried in river sediment. The majority of white pines in Pennsylvania were cut before the turn of the 20th century and little to no physical evidence from the trees remain on the landscape. The exposed large stumps had the potential to extend our reconstruction of forest history back in time. Therefore, we undertook a project combining tree-ring samples from the stumps and two sites with relict living white pine trees (Longfellow and JHR). Longfellow Stumps JHR Study sites JHR Johnsons Run in Elk State Forest was sampled in an effort to date the stumps. There were too few trees old enough to date the stumps, but the data shows a good correlation to the Longfellow Trail data. Growth Suppression of 1971 and 1972 The early part of the 1970’s (1971 and 1972) showed a significantly low radial growth rate. This trend may correlate to precipitation data from nearby climate stations (Cooksburg and Ridgeway),but it does not correlate with a regional drought index. An alternate hypothesis is that a major gypsy moth (Lymantria dispar) defoliation could have occurred. This hypothesis is not supported because according to US Forest Service gypsy moths were not reported in the area until Analysis of other tree species of the same areas may be able to show if and what other species also were affected during these years.