Rangeland Ecology & Management

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HISTORICAL VEGETATION IN SOUTHWEST OREGON, AS AFFECTED BY INDIAN BURNING PRACTICES, BASED ON GLO SURVEYS
Author
Hickman, Gene
Chrisy, John A.
Publisher
Society for Range Management
Publication Year
2015
Body

This project southeast of Roseburg, Oregon, was conducted to develop a landscape perspective of historical vegetation at the beginning of European settlement. The study area is transitional between dry interior valleys of the Umpqua River and the moist Cascade Mountains. Historical GLO (General Land Office) land survey notes were used to create a baseline vegetation cover for the study area from surveys that began in the 1850's. The historical vegetation matrix included prairie, brushfields, oak-mixed conifer savanna, and open to thick forest types. Natural prairies and open grassy oak-conifer types were enhanced and probably enlarged by periodic burning as an Indian cultural practice. However, GLO surveys recorded small scattered brushfields which we attributed to wild fires. Partly stocked mixed conifer woodlands with shrubby undergrowth may be from either wildfire or incidental burning by the Indians. A prominent historical landscape feature was open grassy savanna types found primarily on warm southerly topography. Most were converted from oak-mixed conifer woodland or dry mixed conifer forest, to savanna types, through periodic understory burning by the Indians. This was the largest landscape feature in the project area that was an artifact of historical burning treatments. With fire exclusion, most of it has reverted to denser canopies and woody undergrowth.  For very moist forest types there was no GLO evidence of widespread type conversion to open savanna. Surveys identify mostly full canopies and shrubby understories. However, witness tree data suggest canopies were a composite of small patches, quite variable in tree diameters, stand ages, species composition and density. We believe these were due to both numerous incidental ignition sites by Indians and small wildfires throughout the forest. In the moist forest ecosystems, important Indian impacted treatment areas probably surrounded important cultural sites. None appeared to have impacted large areas of adjacent moist forest.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Sacramento, CA