Ecological Land Units of Bear Creek Watershed and Their Relationship to Water Quality,

摘要

During 1975and 1976 a sedimentation study was conducted in the Bear Creek watershed,located in the southeastern corner of central Oregon's Crook County. The Bear Creek watershed was divided into eight ecological land units which were further refined into 14tentative habitat types and four unclassified communities. These divisions are based upon an association table developed from vegetation and soil field data. One-and two-factor analysis of variance was used to analyze the differences within habitat types,between habitat types within a unit,and when appropriate,between treatments or ecological condition within the habitat type or unit. Tractor logging in the mixed forest unit caused a significant increase in soil loss. Non-forest units exhibited a high natural variability in sediment production within the site which tended to override any differences that may have resulted from a management treatment. Significant differences that did occur appeared to be closely related to differences in soils or ecologic condition.