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- Info
Presettlement fire frequency regimes of the United States: a first approximation
| Author: |
Frost, Cecil C. |
| Date: |
1998 |
| Periodical: |
In: Proceedings of the 20th Tall Timbers Fire Ecology Conference; 1996 May 7-10; Biose, Idaho. Lawrence, Kansas: Tall Timbers Research, Inc. |
| Abstract: |
It is now apparent that fire once played a role in shaping all but the wettest, the most arid, or the most fire-sheltered plant communities of the United States. Understanding the role of fire in structuring vegetation is critical for land management choices that will, for example, prevent extinction of rare species and natural vegetation types. Pre-European fire frequency can be reconstructed in two ways. First is by dating fire scars on old trees, using a composite fire scar chronology. Where old fire-scarred trees are lacking, as in much of the eastern United States, a second approach is possible. This is a landscape method, using a synthesis of physiographic factors such as topography and land surface form, along with fire compartment size, historical vegetation records, fire frequency indictor species, lightning ignition data, and remnant natural vegetation. Such kinds of information, along with a survey of published fire history studies, were used to construct a map of presettlement fire frequency regions of the conterminous United States. The map represents frequency in the most fire-exposed parts of each landscape. Original fire-return intervals in different parts of the United States ranged from nearly every year to more than 700 years. Vegetation types were distributed accordingly along the fire frequency master gradient. A fire regime classification system is proposed that involves, rather than a focus on trees, a consideration of all vegetation layers. |
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