Fall directions and breakage of trees along streams in the Pacific Northwest, 2000-2002

This database contains data on patterns of fall and breakage by riparian trees along streams in the Pacific Northwest. Data in these tables were collected from 2000-2002. Two tables are included. (1) site descriptions and (2) tree fall. The site descriptions table contains information on the geographic location (general physiographic location, political state, and river drainage basin), physical aspects of the channel (active channel width, valley floor width, and channel gradient), and structure of the riparian forest (general age, tree density and basal area, and average tree height/diameter breast height ratio of down trees at the site). Physical aspects of the channel are average values taken at 20-m intervals within the site except for channel gradient, which are average values for 100-m intervals. Stand density (trees per ha) and basal area (m² per ha) were measured with the point- center quarter method, please see Dan Sobota's Master's thesis (Pub 4337) for more details. The tree fall table contains information on individual trees measured at each site in the study. Species, geomorphic landform of rooting position, streamside location, and type of tree fall (stem break or root throw event) are descriptive variables for each tree. Tree height, diameter at breast height and diameter at the top of the tree describe tree size. Side slope at tree base and distance from the active channel describe the physical location of the tree along the stream. Number of pieces only includes those produced when the tree first fell. Fall direction is normalized to 0 degrees upstream and 90 degrees directly towards the stream for trees located on both stream banks.