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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Analysis of Growth Rings in Black Spruce (Picea mariana) in Relation to Site and Climatic Factors / Analysis of Growth Rings in Black Spruce

Usik, Lily 05 1900 (has links)
The annual earlywood, latewood and total radial growth in black spruce from organic and mineral soils of varying depths, composition, ad moisture regimes of three locations in Ontario were investigated. Growth in relation to site, temperature, and precipitation was assessed. Statistical analyses of the radial width increments expressed as percentages of trend over thirty years' growth, showed significant crossdating. Total annual and earlywood increments are correlated with mean March-April and March temperature; latewood increments are not. There is no relationship between growth and precipitation. These findings hold for trees from organic and mineral soil sites up to approximately five hundred miles apart. It is concluded that spring mean temperature is independent of site or other climatic factors, and results suggest that spring temperature indirectly controls radial growth. Primary direct controls are presumably internal, i.e. physiologic and genetic. / Thesis / Doctor of Philosophy (PhD)
12

Tree-Rings and Runoff in the South Platte River Basin

Schulman, Edmund 01 1900 (has links)
No description available.
13

Dendrochronology in Mexico, I

Schulman, Edmund 01 1900 (has links)
No description available.
14

Root Growth-Rings and Chronology

Schulman, Edmund 07 1900 (has links)
No description available.
15

Annual Ring Contrast Enhancement Without Affecting X-Ray Densitometry Studies

Parker, M. L., Barton, G. M., Smith, J. H. G. January 1976 (has links)
No description available.
16

The Decomposition of Tree-Ring Series for Environmental Studies

Cook, Edward R. January 1987 (has links)
Signal extraction in tree-ring research is considered as a general time series decomposition problem. A linear aggregate model for a hypothetical ring-width series is proposed, which allows the problem to be reduced to the estimation and extraction of five discrete classes of signals. These classes represent the signals due to trend, climate, endogenous disturbance, exogenous disturbance, and random error. For each class of signal, some mathematical/statistical techniques of estimation are described and reviewed. Except for the exogenous disturbance signal, the techniques only require information contained within the ring-width series, themselves. A unified mathematical framework for solving this decomposition problem has not yet been explicitly formulated. However, the general applicability of ARMA time series models to this problem and the power and flexibility of state space modelling suggest that these techniques will provide the closest thing to a unified framework in the future.
17

Analysis of Biweight Site Chronologies: Relative Weights of Individual Trees over Time

Riitters, Kurt H. January 1990 (has links)
The relative weights on individual trees in a biweight site chronology can indicate the consistency of tree growth responses to macroclimate and can be the basis for stratifying trees in climate-growth analyses. This was explored with 45 years of ring-width indices for 200 trees from five even-aged jack pine (Pints banksiana Lamb.) stands. Average individual-tree relative weights were similar, but most trees had at least one transient occurrence of low relative weight. The standard deviations of individual-tree relative weights suggested that some trees had mom variable growth responses than others. The trees were classified by the average and standard deviation of their relative weights, and biweight site chronologies were then calculated for these subgroups. Chronologies derived from trees with low average weights, and from trees with high standard deviation of weights, sometimes appeared to be different from chronologies derived from the remaining trees.
18

The Influence of Temperature and Precipitation on Ring Widths of Oak (Quercus Robur L.) in the Niepolomice Forest Near Cracow, Southern Poland

Bednarz, Z., Ptak, J. January 1990 (has links)
Analysis of the relationship between ring-width indices of pedunculate oaks (Quercus robur L.) in the Niepotomice Forest with average monthly air temperatures (1826-1980) and total monthly precipitation (1881-1985) in Cracow revealed a strict relationship between tree -growth and the precipitation of June-July, May-July, and June-August. These relationships are described by a high percentage of agreement, at or around 70 %, and coefficients of correlation (rx) of 0.40 (June-July), 0.36 (May-July) and 0.30 (June-August). The group of 10 oaks with the highest coefficients between growth and precipitation yielded still higher correlations: 0.50, 0.50, and 0.41, respectively. High total monthly precipitation in June and July favors radial growth, while low precipitation reduces radial growth. The influence of air temperature on oak ring-width indices is less significant. The highest positive correlation occurs for January to April of the preceding year. Correlations for the years of radial growth have values close to or below (June) zero except for August.
19

Evenness Indices Measure the Signal Strength of Biweight Site Chronologies

Riitters, Kurt H. January 1990 (has links)
The signal strength of a biweight site chronology is properly viewed as an outcome of analysis rather than as a property of the forest-climate system. It can be estimated by the evenness of the empirical weights that are assigned to individual trees. The approach is demonstrated for a 45-year biweight chronology obtained from 40 jack pine (Pinus banksiana Lamb.) trees. The annual evenness of the empirical weights is calculated by indices derived from the Shannon and Simpson diversity indices, and the variances are found by the jackknife procedure. The annual estimates are then averaged to find an overall estimate of biweight signal strength for the 45-year period. These techniques are most useful for determining sample sizes for the biweight procedure, and for comparing different methods of detrending and standardizing data sets prior to applying the biweight mean-value function.
20

Special Sanding Films and Sandpapers for Surfacing Narrow-Ring Increment Cores

Yamaguchi, David K., Brunstein, F. Craig January 1991 (has links)
Special sanding films (400 grit to 23 micron) and fine sandpapers (1200-1500 grit) can be used to surface increment cores containing narrow rings (e.g., >50 rings per cm) so that rings are clearly visible for microscopy and photography.

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