Browsing Tree-Ring Research, Vol. 61, No. 2 (2005) by Journal
Now showing items 1-4 of 4
Exploratory Temperature and Precipitation Reconstructions from the Qinling Mountains, North-Central ChinaFebruary-April (FMA) temperature at Foping (1879-1989) and July-August (JA) precipitation at Xian (1895–1988) have been reconstructed using total ring width (TRW) and maximum latewood density (MXD) from trees in the Qinling Mountains, at the northern limit of the East Asian monsoon, in central China. The Xian JA precipitation reconstruction, albeit short, represents the first well-replicated, crossdated dendroclimatic reconstruction of summer monsoon precipitation for this region. Reconstructed Xian precipitation shows significant positive relationships with historical evidence from the region. The key feature of the precipitation reconstruction is prolonged summer drought during the late 1920s and early 1930s. The Foping reconstruction displays warmer-than-average FMA temperatures during this time period. These exploratory reconstructions, along with a previous reconstruction from Huashan, demonstrate the complexity of attempting dendroclimatic reconstructions from this region. Our results indicate that further attempts to locate long-lived conifers from here can result in an extended well-calibrated and verified reconstruction of summer monsoon precipitation.
Laser Trimming Tree-Ring Cores for Dendrochemistry of MetalsThis article discusses the application of laser to trim the outer surface from tree-ring increment cores in preparation for dendrochemistry of certain metals. A source of contamination specific to dendrochemistry of metals is metal constituents, such as iron, tungsten, chromium, nickel, and cobalt, coming off tools used to collect and process cores and adhering to the sample surface. One method to eliminate this contamination is to trim off the outer surface of cores using laser. To test this application of laser, three tree-ring increment cores were collected from each of three trees. For each tree, one core was trimmed using a CO2 laser, one core was trimmed using a stainless steel razor blade, and one core was left untrimmed. The resultant cores were measured for metals using acid dissolution inductively coupled plasma mass spectroscopy. Trimmed cores had on average one-third the content of iron, tungsten, and chromium than that of untrimmed cores. Laser-trimmed cores had less of these metals than razor-trimmed cores. Razor-trimmed cores also had measurable nickel, but laser-trimmed cores had no nickel. Laser trimming is an ideal solution to potential contamination of cores with metals from increment borers without imparting other contamination from tools such as razor blades.
Some Geometric Constraints on Ring-Width TrendSimulations of tree rings from trees of undisturbed forest sites are used to describe natural, long-term width trends. Ring-width trends of canopy-sized white oak are simulated from regressions of BAI (ring area) data of real trees. Examples are given of a tree from a typical re-growth forest in Illinois and of a more slowly growing tree from an old-growth forest in Kentucky. The long-term width trend was simulated as being toward constant ring width regardless of growth rate of the tree. Conditions by which either increasing or decreasing ring-width trends could be simulated from the same linear BAI trend are examined. I conclude that curvilinear width trends, either increasing or decreasing, represent width adjustments to changes in growth rate (BAI trend) after which the width trend stabilizes to a near-constant value. Interpretation of ring-width trends of trees from undisturbed stands may be useful in assessing stand disturbance history.
Tree-Ring Dating of the Karr-Koussevitzky Double Bass: A Case Study in DendromusicologySergei Koussevitzky was one of the world’s premier conductors and virtuoso bass players whose favorite instrument was an unusually-shaped bass reportedly made in 1611 by the Amati brothers, Antonio and Girolamo. In 1962, 11 years after Koussevitzky’s death, his widow gave the bass to Gary Karr, currently considered to be the world’s premier double bassist. In 2004, Karr donated the bass to the International Society of Bassists. Close inspection by a team of experts in 2004, however, revealed stylistic inconsistencies that suggested a later construction date. We used four reference tree-ring chronologies developed from treeline species in the European Alpine region to anchor the dates for the tree rings from the double bass absolutely in time. The bass yielded a 317-year long sequence, the longest sequence yet developed from a single musical instrument. Statistical and graphical comparisons revealed that the bass has tree rings that date from 1445 to 1761. Based on the strength of these correlations, the spruce tree harvested to eventually construct the double bass likely came from the treeline Alpine area of western Austria, not too far from Obergurgl at the Italian border. Our results demonstrate that the double bass was not made by the Amati Brothers, but likely by French luthiers in the late 18th Century.