Relationship of Temperature and Light Ring Formation at Subarctic Treeline and Implications for Climate Reconstruction
| Autor: | Louise Filion, Melissa Savage, David K. Yamaguchi |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
010506 paleontology
Vulcanian eruption 010504 meteorology & atmospheric sciences Limiting 01 natural sciences Black spruce Subarctic climate Unknown Source Arts and Humanities (miscellaneous) Climatology Threshold temperature Period (geology) General Earth and Planetary Sciences Physical geography Quaternary Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Quaternary Research. 39:256-262 |
| ISSN: | 1096-0287 0033-5894 |
| Popis: | During the past 8 centuries, light rings (LRs) have occasionally formed in black spruce (Picea mariana) at treeline near Bush Lake, northern Quebec (L. Filion, S. Payette, L. Gauthier, and Y. Boutin, 1986, Quaternary Research 26, 272-279; A. Delwaide, L. Filion, and S. Fayette, 1991, Canadian Journal of Forest Research 21, 1828-1832). New analyses of climate data compiled during the period of overlapping tree-ring and instrumental records show that years of LR formation at Bush Lake have unusually cool May, June, August, and September temperatures. The analyses also show that August-September temperatures strongly correlate with May-July temperatures. Thus, late spring and entire growing-season temperatures influence LR formation at subarctic treeline. LRs formed in at least 5% of the trees at Bush Lake when May-September mean temperatures at Inukjuak fell below 4.2°C and August-September mean temperatures fell below 6.7°C. These threshold temperature/LR relationships can be used to infer limiting summer temperatures during the period preceding instrumental records. For example, the LR record suggests that May-September temperatures at northern Quebec treeline dropped below 4.2°C in A.D. 1601 after a major volcanic eruption of unknown source. Visual assessments of LR occurrence provide a new approach for extracting quantitative paleoclimatic information from tree rings. |
| Databáze: | OpenAIRE |
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