Tree-Ring Bulletin, Vol. 50 (1990)
http://hdl.handle.net/10150/224036
2024-03-28T17:48:40ZTree-Ring Bulletin, Volume 50 (1990)
http://hdl.handle.net/10150/263016
Tree-Ring Bulletin, Volume 50 (1990)
Complete issue of Tree-Ring Bulletin.
1990-01-01T00:00:00ZStressed Trees Produce a Better Climatic Signal than Healthy Trees
http://hdl.handle.net/10150/261930
Stressed Trees Produce a Better Climatic Signal than Healthy Trees
Travis, David J.; Meentemeyer, Vernon; Belanger, Roger P.
The basis for the selection of trees to be used in the production of dendrochronologies has long been an issue (Douglass 1946; Fritts 1976). In humid regions the common practice has been to use trees that appear to be in good health. As a part of a larger study involving the impact of ice storms on tree-ring increments (Travis 1989), we show that trees stressed as a result of ice damage produced a stronger climatic signal than nondamaged trees.
1990-01-01T00:00:00ZEvenness Indices Measure the Signal Strength of Biweight Site Chronologies
http://hdl.handle.net/10150/261927
Evenness Indices Measure the Signal Strength of Biweight Site Chronologies
Riitters, Kurt H.
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.
1990-01-01T00:00:00ZAnalysis of Biweight Site Chronologies: Relative Weights of Individual Trees over Time
http://hdl.handle.net/10150/261911
Analysis of Biweight Site Chronologies: Relative Weights of Individual Trees over Time
Riitters, Kurt H.
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.
1990-01-01T00:00:00Z