• Tree-Ring Dating of Historic Buildings in Arkansas

      Stahle, David W.; Arkansas Archaeological Survey, University Museum, Fayetteville (Tree-Ring Society, 1979)
      Twenty-four historic log and frame buildings in Arkansas have been dated by dendrochronology. The derived historic chronologies, ranging from A.D. 1598 to 1911, have improved and extended existing modern tree-ring chronologies for the state. Dated species are southern yellow pine (Pinus sp.), white oak (Quercus sp.), eastern red cedar (Juniperus virginiana L.), and baldcypress (Taxodium distichum L. Rich). Three chronological studies integrating tree-ring, architectural, and documentary evidence offer examples of the relationship between tree-ring dates and historic records and demonstrate significant contributions which dendrochronology can make in the management of historic properties. Historic tree-ring collections should prove important in developing long term tree-ring chronologies in the eastern United States, due to widespread exploitation of living trees, the lower average age for many eastern species, and the availability of high quality tree-ring records in early historic structures.
    • Tree-Ring Skeleton Plotting by Computer

      Cropper, John Philip; Laboratory of Tree-Ring Research, The University of Arizona (Tree-Ring Society, 1979)
      Skeleton plotting is an established manual technique for representing the relative narrowness of tree rings in a single radius. These plots can be used as a visual aid to crossdating. This paper describes a method for deriving these plots by computer. The method uses a low-pass digital filter, running means, and standard deviations of ring-width measurements. When the manual and computer plots are compared for the same series, approximately 85% agreement is found. Examples of results are presented for specimens from sensitive, moderate, and complacent sites. FORTRAN program listings are included for two subroutines for (a) identifying small rings and (b) producing the plot.
    • Tree-Rings and Climate in Morocco

      Berger, A. L.; Guiot, J.; Mathieu, L.; Munaut, A. V.; Institut d'Astronomie et de Géophysique, Université Catholique de Louvain-la-Neuve; Laboratoire de Science du Sol, Faculté des Sciences Agronomiques, Gembloux; Laboratoire de Palynologie et Phytosociologie, Université Catholique de Louvain-la-Neuve (Tree-Ring Society, 1979)
      Two sites located near Ketama in the Morocco Rif have been selected, on the basis of limiting climatic factors, in order to study the relationship between tree rings and climate. After the trend associated with biological factors related to increasing age has been removed and all variables have been standardized, some statistical parameters have been computed and a variance analysis has been performed. After the persistence has been eliminated, an original technique of multiple regression on the principal components and of selection of the most significant variables has been built. Twenty -four climatic variables have been used. The principal aim of this paper is to describe this original statistical technique of data analysis and to illustrate its power with dendroclimatological data in Morocco. For the temperate site located in low altitude (1280 m), among the most important variables, we have retained total monthly precipitation for August, mean temperature of January, April, and May of the current year and mean temperature of October of the previous year. For the cold site (2100 m), total monthly precipitation for September and temperatures of January and May of the current year and precipitation for October of the previous year definitely influence the growth rate of cedars.