Background
GRMW Projects1997 Whole Tree Project
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Helicopter placing whole tree in river. Photo courtesy GRMW. |
Project Summary
The 1997 Whole Tree Project placed whole trees and large boulders in 3.7 miles of the upper Grande Ronde River. The emphasis of this project was to improve instream habitat diversity by placing large conifer trees with attached rootwads in the channel and riparian area. The rootwads and limbs were added to trap additional debris moving through the river system, as well as to detain suspended sediment and bedload. Trees were placed on the inside of meanders to enhance development of point bars which would decrease the river channel width to depth ratio and result in less elevated stream temperatures. The whole trees would also reduce stream velocities and create slackwater areas, along with pools, for use as resting areas for salmon and steelhead and resident salmonids. Large boulders were placed to facilitate sediment storage within the channel, take pressure off eroding banks during high flows, and provide hydraulic constraints for pool development.
U.S. Forest Service stream monitoring (see tables below) shows improvements in fish habitat diversity; including increases in pool frequency and decreases in channel width to depth ratio (W/D). In addition, large woody debris (LWD), as well as natural recruitment of LWD, has improved exponentially with increases of 40 to 50 times more LWD per project reach.
USFS Region 6 Stream Survey Data*
Post-Project:
* Data provided by La Grande Ranger District |
Project Objectives
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Project Actions
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Project Partners
* Project Lead |
Project Pictures
1997 Whole Tree Project(click photo to view enlargement) |
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Photo point 27, looking downstream - prior to project. Photo courtesy of La Grande Ranger District |
 Photo point 27 (downstream view) - one year after project. Photo courtesy of La Grande Ranger District |
 Photo point 27 (downstream view) - three years after project. Photo courtesy of La Grande Ranger District |
 Photo point 27 (downstream view) - five years after project; showing narrowing of stream channel and development of streambank vegetation and point bar. Photo courtesy of La Grande Ranger District |
1997 Whole Tree Project(click photo to view enlargement) |
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Photo point 27, looking upstream - prior to project. Photo courtesy of La Grande Ranger District |
 Photo point 27 (upstream view) - one year after project. Photo courtesy of La Grande Ranger District |
 Photo point 27 (upstream view) - three years after project. Photo courtesy of La Grande Ranger District |
 Photo point 27 (upstream view) - five years after project. Stream channel has narrowed, point bars and vegetation have developed. Photo courtesy of La Grande Ranger District |