• To the Friends of Camille Flammarion

      Henri Tessier (Orléans), 1926-05-20
    • Tree Ring Evidence of a 22-Year Rhythm of Drought Area in Western United States and Its Relationship to the Hale Solar Cycle

      Stockton, Charles W.; Meko, David M.; Mitchell, J. Murray, Jr.; Laboratory of Tree-Ring Research, University of Arizona; National Oceanic and Atmospheric Administration, Environmental Data and Information Service, Silver Spring, MD (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1978-09)
    • Tree Ring Research Shows Benefits of Natural Forest Fires

      Graduate College, University of Arizona (Tucson, AZ), 1982-12
    • Tree Rings and Forest Mensuration: How Can They Document Trends in Forest Health and Productivity?

      University of Arizona. Laboratory of Tree-Ring Research.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1986-04)
    • Tree Rings in the Western Great Basin

      Ferguson, C. W.; Wright, R. A.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Nevada State Museum (Carson City, Nevada), 1963-01)
      Introduction: The success of tree-ring dating in the Southwest has not been duplicated in the Great Basin area. Studies of modern tree-ring material in the western Great Basin have been relatively limited, but substantial work has been done by Douglass (1928), Hardman and Reil (1936), Keen (1937), Antevs (1938), Schulman (1956), Schulman and Ferguson (1956), Ferguson and Wright (1962), and Ferguson (1963) . In terms of tree-ring dating in the Great Basin, as elsewhere, there are two major aspects: the modern, dealing with both chronology building and interpretation in terms of environment, and the archaeological. Archaeological dating is dependent upon the finding of tree -ring material of suitable sensitivity and length preserved in archaeological context. There has been no dating of archaeological tree -ring material in the Great Basin due to a combination of the paucity of excavated wood and charcoal and to the difficulty in dating any such material. Conditions for the dating of both modern and archaeological material, however, are met in the western Great Basin, and it remains for time and the active participation of research workers to establish the framework for more extensive dating in the area.
    • Tree-Ring Chronologies of Western North America: California, Eastern Oregon and Northern Great Basin with Procedures Used in the Chronology Development Work Including Users Manuals for Computer Programs COFECHA and ARSTAN

      Holmes, Richard L.; Adams, Rex K.; Fritts, Harold C.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1986)
      Well replicated tree-ring samples were collected, dated and measured for California west of the Sierra Nevada, eastern Oregon and the northern Great Basin. A computer program was developed and used to check crossdating quality. Another computer program to generate and analyze tree-ring chronologies was evaluated, further developed cooperatively and used to produce chronologies for the dated site collections. This report contains these site chronologies in three versions along with site descriptions and chronology statistics. Users manuals are included for the two computer programs. The effect on a chronology of poor crossdating is discussed, and a study of standardization of tree-ring measurement series is reported. Some new techniques are described for processing tree-ring samples.
    • Tree-Ring Evidence for Climatic Changes in Western North America

      Fritts, Harold C.; Laboratory of Tree-Ring Research, University of Arizona (American Meteorological Society (Boston, MA), 1965-07)
      The relationships between climatic factors and fluctuations in dated tree-ring widths are statistically evaluated. A wide ring indicates that the year's climate was moist and cool, and a narrow ring dry and warm. In general, ring width relates to a 14-month period from June through July but most tree-ring chronologies exhibit a closer relationship with autumn, winter, and spring moisture than with summer moisture. The climatic relationships for evergreen trees are attributed largely to the influence of environmental factors on photosynthesis and the accumulation of food reserves. Under abnormally dry and warm conditions, especially during the autumn, winter, and spring, little food is accumulated, new cells are formed more slowly during the growing period, and the resulting ring is narrow. Relative 10 -yr. departures are calculated for the entire length of 26 tree -ring chronologies from western North America. Those portions after 1500 are used to map areas of high and low moisture. Periods of widespread drought are noted in 1576-1590, 1626-1635, 1776-1785,1841-1850, 1871-1880, 1931-1940. Periods of widespread and above average moisture occurred during 1611-1625,1641-1650, 1741-1755, 1826-1840, 1906-1920. The moist periods of 1611-1625, and 1906-1920 were most widespread and markedly above average.
    • Tree-Ring Evidence for Climatic Changes in Western North America From 1500 A.D. to 1940 A.D.

      Fritts, Harold C.; Smith, David G.; Holmes, Richard L.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1964-12-31)
      Introduction: The details of the climatic history of the United States during recent centuries are not known. In this period, as in more ancient times, there is much indirect evidence of significant changes of climate. Dendroclimatic analysis represents an especially promising source of information on the chronology and character of such climatic changes, especially those in the semiarid regions of western North America. It is the purpose of this report to present: (1) some recent analyses of the climatic factors influencing ring growth; (2) a brief discussion of the current theory concerning the model of tree growth and climate and (3) a first approximation of synoptic dendroclimatological patterns from 1500 A.D. to 1940 A.D. using 26 selected tree-ring chronologies from western North America. This material is being circulated to professionals in related fields in hopes that they may compare these results with their own findings and make appropriate criticisms. The authors welcome any suggestions, especially those pertaining to correlation or lack of correlation of the maps with other lines of evidence. The paper is to be presented at the VII International Congress of the International Association for Quaternary Research which meets at Boulder, Colorado, during August of 1965. The analyses of the tree growth relationships were sponsored in part by the National Geographic Society and the U. S. Department of Interior, National Park Service, through the Wetherill Mesa Archeological Project. The authors are indebted to past and present staff at the Laboratory of Tree-Ring Research for the development of the regional tree-ring chronologies, and to the Numerical Analysis Laboratory, The University of Arizona, for free computing time and services. They are also indebted to James A. Erdman, Maurice E. Cooley, Nicholas Matelas, and Julie McMahan, who assisted in various phases of the project.
    • Tree-Ring Evidence for Long-Term Climatic Change: Yosemite National Park

      Graumlich, Lisa J.; Laboratory of Tree-Ring Research, University of Arizona (1990-12-15)
      Tree -ring data were collected from two sites within Yosemite National Park: a western juniper stand near Juniper Ridge and a lodgepole pine stand near Gaylor Lakes. Analyses of standardized and prewhitened tree-ring indices from the two sites indicate that at both sites winter (January through March) precipitation is the factor most limiting to tree growth. Using regression analysis a model predicting winter precipitation as a function of tree growth was developed and tested. The model explains 32% of the variance of the precipitation data. While the model is statistically significant, the explanatory (and hence predictive) power of the model could be enhanced by further core collection. When the model is applied to the early portion of the tree -ring record, a reconstruction of precipitation extending back to AD 1620 is obtained. Extended droughts are common in the record and include the following periods: 1650 -1648, 1700 -1720, 1749 -1758, 1807 -1824, 1842- 1851, 1885 -1893, and 1911 -1934. Further funding is being sought to expand the tree-ring data base allowing for more accurate climatic reconstruction and a longer temporal extent of the reconstruction.
    • Tree-ring Variation in Western Larch (Larix occidentalis) Exposed to Sulfur Dioxide Emissions

      Fox, C. A.; Kincaid, W. B.; Nash, T. H., III; Young, D. L.; Fritts, H. C.; Southern California Edison Company; Department of Botany and Microbiology, Arizona State University; Department of Botany and Microbiology, Arizona State University; Department of Mathematics, Arizona State University; Laboratory of Tree-Ring Research, University of Arizona (NRC Research Press, 1986)
      A Tree-ring analysis was conducted to determine the relationship of sulfur emissions from the lead /zinc smelter at Trail, B.C. to radial growth in western larch (Larix occidentalis Nutt.). Tree cores were collected from five stands known to have been polluted and from three control stands. Age effects were removed from crossdated ring-width series by fitting theoretical growth curves, and, subsequently, tree-ring chronologies were developed for each stand. We assumed that macroclimatic variation was estimated by the average of the control chronologies and two lagged values thereof. These control variables along with annual estimates of sulfur emissions were used in regression models to predict variation in the tree-ring chronologies from each of the polluted stands. Separate analyses were performed for years before and after installation of two tall stacks, for drought and nondrought years, and for years prior to initiation of smelting. In each case following initiation of smelting, the variation explained by sulfur decreased with distance from the smelter, and, concomitantly, the variation explained by the control variables increased with distance. Furthermore, chronology statistics suggested an increase in synchronous high frequency variation in chronologies from polluted sites that persisted beyond implementation of pollution controls, which reduced emissions ten-fold.
    • Tree-Rings and Radiocarbon

      Ferguson, C. W.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1986-01-08)
    • Tropical Cyclones of the Eastern North Pacific and Their Effects on the Climate of the Western United States: A Study of Circulation Features That May Be Recorded by Tree Rings, Final Report

      Douglas, Arthur V.; Fritts, Harold C.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1973)
      Introduction: In an earlier paper by Douglas (1972) the summer climatology of tropical storm development is reviewed with reference to Sea Surface Temperature (SST) distribution and upper- and lower -level winds. An apparent increase in yearly storm totals recorded since 1965 is believed to be the direct result of satellite detection of small, well off -shore storms. However, monthly variations in storm totals appear to be caused by anomalous SST either off Baja California or along the equator west of South America. During the tropical storm season the region of greatest storm formation is found to shift towards the northwest and then southeast. This regional variation in storm development may be caused by changes in SST and upper troposphere shearing off Baja California and in the movement of the Inter- Tropical Convergence Zone (ITCZ) off mainland Mexico. Data presented by Douglas (1972) indicate that tropical storm formation is most common during the months of July, August and September. During the latter part of August through the first part of October, tropical storms can enter the southwestern United States from either a track up the Gulf of California or up the Pacific Coast of Baja California. This report will review some additional circulation features associated with tropical storm activity in the eastern North Pacific. The major emphasis will be directed towards the effects of these storms upon the climatological conditions of the southwestern United States.
    • Two Lectures on Water Law

      Clark, Robert Emmet (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1965-02-25)
    • The Use and Limitations of Dendrochronology in Studying Effects of Air Pollution on Forests

      Cook, Edward R.; Tree-Ring Laboratory, Lamont-Doherty Geological Observatory of Columbia University (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1985-05)
      The annual ringwidths of trees can be used to search for hypothesized air pollution effects on forests. This search is extremely complicated by the inherent statistical properties of ringwidth data and the high level of uncertainty regarding the sources of variance observed in the ringwidths. A linear aggregate model for ringwidths is described which highlights the general classes of variance which may be found in a tree-ring series. Dendrochronological principles and techniques are described which can be used to create a tree-ring chronology that is suitable for rigorous statistical analysis and hypothesis testing. The need to model climatic influences on tree growth prior to the search for pollution effects is necessary and a method for achieving this is described. Only after the variance due to age trends, stand dynamics effects and climatic influences has been accounted for can any confidence be placed on inferred pollution effects. An analysis of a red spruce tree -ring chronology indicates that a decline in ringwidths since 1968 cannot be explained by a linear temperature response model using monthly climatic variables. However, threshold responses to climate that could be responsible for the decline need to be considered before the anomalous decline can be attributed to non-climatic influences such as pollution.
    • Using Dendrochronology To Measure Radial Growth of Defoliated Trees

      Swetnam, Thomas W.; Thompson, Marna Ares; Sutherland, Elaine Kennedy; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (U.S. Department of Agriculture, Forest Service, Cooperative State Research Service, 1985-06)
    • Western Spruce Budworm Outbreak History in the Sacramento Mountains, New Mexico, U.S.A.

      Archambault, Sylvain; Swetnam, Thomas W.; Lynch, Ann M.; Centre d'etudes nordiques, Universite Laval, Ste-Foy (Quebec) Canada; Laboratory of Tree-Ring Research, University of Arizona; USDA Forest Service, Rocky Mountain Forest and Range Experiment Station (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 2013-10-04)
      Western spruce budworm (Choristoneura occidentalis Freeman) outbreak history was reconstructed for the Sacramento Mountains of south-central New Mexico, at the southern limit of the species distribution range. Six host tree-ring width chronologies (Douglas -fir and white fir) and three non -host control chronologies (ponderosa pine) were used for this reconstruction spanning from 1800 to 1990. Both the host and non-host species had similar climatic response so the non-host chronologies were confidently used as climatic controls. Up to eight defoliation events were documented within individual stands and at least seven major regional outbreaks were identified among the stands back to 1800. At least five major outbreaks occurred in the twentieth century: 1890s- 1900s, 1910s- 1920s, 1940s, 1960s, and 1980s. The 1960s and 1980s outbreaks were verified by Forest Service aerial and ground survey records. These recent outbreaks seemed to have been more synchronous among the different stands than outbreaks that occurred in the 19th century. There were similarities between this outbreak history and an outbreak history reconstructed for northern New Mexico, a distance of about 340 km to the north. The regional-scale pattern identified in these histories lends support to a hypothesis that past logging and fire suppression has changed western spruce budworm dynamics.
    • Western U.S. Tree-Ring Index Chronology Data for Detection of Arboreal Response to Increasing Carbon Dioxide

      Graybill, Donald A.; Laboratory of Tree-Ring Research, University of Arizona (Laboratory of Tree-Ring Research, University of Arizona (Tucson, AZ), 1985-04-26)
      Ongoing research designed to expand a grid of tree-ring chronologies in the western U.S. that can be used to examine tree growth response to increasing atmospheric CO2 is summarized in this interim report. Current and projected sampling is designed to cover most of the Great Basin and the Southwestern U.S., focusing on long -lived species growing under stressful climatic conditions. Older trees growing in these circumstances provide the best potential for analytical discrimination of climatic and CO2 signals. A descriptive statistical summary of all current data sets is provided and potential directions of the project are discussed.