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Tree-Ring Dates from the Navajo Land Claim IV. The Eastern Sector
No full textThe Eastern Sector of the Navajo Land Claim is located in the state of New Mexico, and is comprised of areas located across or adjacent to the Continental Divide. Of the 724 specimens processed in the Laboratory, 346 yield tree-ring dates.This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. It was digitized from a physical copy provided by the Laboratory of Tree-Ring research at The University of Arizona. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]
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Tree-Ring Evidence for Great Plains Drought
No full textA new collection of tree-ring chronologies developed from trees and remnant material located in the western and central Great Plains makes an important contribution to the spatial coverage of the US tree- ring chronology network. Samples from 24 sites were collected from the west-central Great Plains, and to date, ten chronologies have been produced. When correlated with a set of 47 single-station PDSI records, the chronologies display relationships with regional spring and summer drought. The reconstruction of spring PDSI for eastern Colorado generated in this study suggests that the inclusion of Great Plains trees can improve the quality of Great Plains drought reconstructions. The eastern Colorado drought reconstruction explains 62% of the variance in the instrumental record and extends to 1552. This reconstruction provides information about the regional character of major droughts over the past four and a half centuries. Major eastern Colorado droughts include events in the 1580s, 1630s, 1660s, 1730s, and the 1930s. The late 16th century drought, noted as an especially severe drought in the southwestern US, appears in this reconstruction as only slightly more severe than other major droughts in this region.This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. It was digitized from a physical copy provided by the Laboratory of Tree-Ring Research at The University of Arizona. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]
Exploratory temperature and precipitation reconstructions from the Qinling Mountains, north-central China
No full textFebruary-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.This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. It was digitized from a physical copy provided by the Laboratory of Tree-Ring Research at The University of Arizona. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]
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Drought History and Reconstructions from Tree Rings
No full text"Chapter 1"This item is part of the Natural History Reports collection. It was digitized from a physical copy provided by the Laboratory of Tree-Ring Research at The University of Arizona. For more information about items in this collection, please contact the Lab's Curator, (520) 621-1608 or see http://ltrr.arizona.edu/collection
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A Modified Increment Borer Handle For Coring In Locations With Obstruction
No full textA simple modification to a standard increment borer handle is described that enhances use of the borer in situations where obstructions to the rotation of a normal handle prevents utilization of the full length of the borer. The modification, informally called the ‘‘Quad-B’’ (Brown’s bent boomerang borer handle), involves bending both sides of the handle to ~35–40° angles. Some potential uses of the modified handle are described.This item is part of the Tree-Ring Research (formerly Tree-Ring Bulletin) archive. For more information about this peer-reviewed scholarly journal, please email the Editor of Tree-Ring Research at [email protected]
Unicorn (Rowan Tree Church) 5, no. 8 (Harvest Home, 1982)
No full text1 Electronic record(s) and derivatives. 8058846 bytes. 13 pages.Dear Friends / Andrius -- Sun Dancing / by Rain Wolf -- Fall Equinox / Poem by Tisunná -- [Goddess of the Crescent Moon] / Art by Prairie Jackson -- Our Flesh Feeds Stars / Poem by M [Mari Jackson] -- Harvest Recipes: Apple Pie / by Lady Judyth -- Proud & Faithful / art by Angel -- Some Thoughts on Initiation At the Time of Harvest / Nell Morningstar -- Night Song / Poem by Noel-Anne Brennan -- Wild Angel / Poem by Elwing -- Notes from an Herbal: [Simple Balms] / Paul -- News from the Rowan Tree / Paul -- Book Review -- [Relationship] / Anonymous -- The Readers' Forum / Paul -- Good Evening Starshine / Poem by Kaloulu -- [Two men] / art by Crow -- Letter from Ale
Looking at the Wood, Seeing the Trees and More: Australia-New Zealand Tree-Ring Science Conference, January 2025
No full textThe Australia-New Zealand Tree-Ring Conference was held January 21–23, 2025, at Waipapa Taumata Rau/University of Auckland, in Aotearoa/New Zealand. It was intended to provide an opportunity for the Australian and New Zealand dendrochronological researchers to meet, present current research, and discuss the challenges and opportunities in working with Southern Hemisphere tree species, but it was open to others outside of Australasia, including some keynote speakers. The meeting brought together many researchers from within and outside academia for the first time since the pandemic, and in addition to providing a look at current interesting and ongoing dendrochronology projects, it promoted camaraderie for this regional tree-ring community
The Future of Systematics: Tree-Thinking Without the Tree
No full textPhylogenetic trees are meant to represent the genealogical history of life and apparently derive their justification from the existence of the tree of life and the fact that evolutionary processes are tree-like. However, there are a number of problems for these assumptions. Here it is argued that once we understand the important role that phylogenetic trees play as models which contain idealizations, we can accept these criticisms and deny the reality of the tree while justifying the continued use of trees in phylogenetic theory and preserving nearly all of what defenders of trees have called “the importance of tree-thinking.
Investigating Evaluation Measures in Ant Colony Algorithms for Learning Decision Tree Classifiers
No full textAnt-Tree-Miner is a decision tree induction algorithm that is based on the Ant Colony Optimization (ACO) meta- heuristic. Ant-Tree-Miner-M is a recently introduced extension of Ant-Tree-Miner that learns multi-tree classification models. A multi-tree model consists of multiple decision trees, one for each class value, where each class-based decision tree is responsible for discriminating between its class value and all other values present in the class domain (one vs. all). In this paper, we investigate the use of 10 different classification quality evaluation measures in Ant-Tree-Miner-M, which are used for both candidate model evaluation and model pruning. Our experimental results, using 40 popular benchmark datasets, identify several quality functions that substantially improve on the simple Accuracy quality function that was previously used in Ant-Tree-Miner-M
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