Tree rings records

Fig. 11-26 Decade-averaged data of Northern hemisphere tree ring records from 1750-1979 and 7th-degree polynomial fit of the data. The vertical extension of blocks represents 95% confidence limits of the mean. The open circles give the change of —0.65% in atmospheric CO2 observed from 1956 to 1978 by Keeling et al. (1979). (Adapted from Peng et al, 1983.)...

Epstein and Yapp [4] state "it is obviously necessary to calibrate more specifically the relationship between 6(D) records in cellulose nitrate from tree-ring records and known climatic records. This can probably be done best by the analysis of tree rings from widely different, well-documented environments. Such data will allow the comparison of a large variety of trees and determine the versatility of using the isotopic method for climatic temperature determination". We concur with this statement as long as "from the same population" is inserted. 

LaMarche, V. C., Jr., Paleoclimatic Inferences from Long Tree-Ring Records, Science. 1974, 153, 1043-1048. 

Scuderi, L. A., A 2000-Year Tree Ring Record of Annual Temperatures in the Sierra Nevada Mountains, Science, 259, 1433-1436 (1993). 

Becker B. and Kromer B. (1993) The continental tree-ring record—absolute chronology, cahbration, and climatic... 

Changes in the thickness of the tree rings records temperature changes if derived from temperature-sensitive tree-rings, or records precipitation if derived from precipitation-sensitive tree rings. These records are modulated to some degree by the other climatic parameters. 

Baillie, M.G.L. 2001. Tree ring records and environmental catastrophes. Interdisciplinary Science Reviews 26(2) 87-89. 

The use of tree growth rings as proxy climate indicators. Tree rings record responses to a wider range of climatic variables over a larger part of the Earth than any other type of annually dated proxy record, desertification... 

Winter, L.E., L.B. Brubaker, J.F. Franklin, E.A. Miller and D.Q. DeWitt. 2002b. Initiation of an old-growth Douglas-fir stand in the Pacific Northwest A reconstruction from tree-ring records. Canadian Journal of Forest Research 32 1039-1056. 

Records of past environmental change are preserved in a broad range of Earth materials. Past environments are inferred from "proxy" records, meaning measurements of physical and chemical parameters of marine and terrestrial sediment, polar ice, and other materials that were in some way influenced by their environment during accumulation. Examples of proxy records are the distribution of glacial deposits, the isotopic composition of terrestrial and marine sediments and ice, the abundance and species composition of plant and animal fossils, and the width of tree rings. 

It is necessary to calibrate the 14C time scale for greater dating accuracy. However, the second-order variations are at least as important as the first-order constancy of atmospheric 14C. For example, they provide a record of prehistoric solar variations, changes in the Earth s dipole moment and an insight into the fate of C02 from fossil fuel combustion. Improved techniques are needed that will enable the precise measurement of small cellulose samples from single tree rings. The tandem accelerator mass spectrometer (TAMS) may fill this need. 

Sea cores offer a data base which should in principle allow deduction of the history of the local sea surface temperature immediately above the deposition site of the core, for there is enough organic material in sea cores to provide the necessary samples for isotope measurement at frequent intervals versus depth in the core, but the time resolution is far less accurate than in varves and tree rings because burrowing sea bottom animals smear the record of the layers. 

In America, researchers at the Laboratory of Tree Ring Research at the University of Arizona, Tucson, Arizona, have developed the measurement and analysis of tree ring widths using a score or so of trees in each stand to provide pluviometric maps versus time, and find that these maps have to be established separately for each region and for each set of trees, so that we can not look to ring width records versus time for information about the cyclic evolution of climate. 

Garbe-Schonberg, C. D., Reimann, C., and Pavlov, V. A. (1997). Laser ablation ICP-MS analyses of tree-ring profiles in pine and birch from N Norway and NW Russia -a reliable record of the pollution history of the area Environmental Geology 32 9 16. 

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