Tree Cores
Bristle cone pine trees have been known to live beyond 4,000 years, but trees of many kinds can give clues to climate history. By aligning the rings from trees of different ages, it is possible to create a continuous record that extends beyond the life span of any single tree. Long-term, quantitative temperature and precipitation records can be determined from tree rings by relating recent tree-ring data to corresponding instrumental observations of temperature and precipitation.
Wide spaces between the rings indicate temperature and precipitation conditions that favored rapid growth for that particular species of tree. Tightly spaced rings indicate harsher conditions that inhibited growth. Other factors, such as fires, disease, and shading can also affect tree-ring widths and complicate interpretation.
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Radial/cross section from a giant sequoia log (Sequoiadendron giganteum)
Long-term, quantitative temperature and precipitation records can be determined from tree rings. |
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