1941. Root system of Tree Number 2 washed out in September of 1941. 20 inches dbh. Class 3D, Risk 4. Klamath Basin near Bly, Oregon.
Root system of Tree Number 2 washed out in September of 1941. 20 inches dbh. Class 3D, Risk 4. Klamath Basin near Bly, Oregon.
Photo by: W.D. Bedard
Date: October 15, 1941
Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection.
Collection: Bureau of Entomology and Portland Station Collections; La Grande, Oregon.
Image: BUR-8891 and PS-551
From Biology and Control of the Western Pine Beetle, pages 163-164:
In 1941 Bedard used hydraulic pressure to wash out the root systems of six ponderosa pines of known risk ratings in the Klamath Basin near Bly, Oregon. He summarized previous studies on ponderosa pine root systems and reviewed literature pertaining to root anatomy, morphology, and physiology. In connection with this review he stated:
"Root form is quite specific, and in addition there is considerable reciprocity between the crown and root system. Root development is of critical importance to continued plant growth. It is important that root development keep pace with crown development."
In the Klamath Basin study, Bedard selected three pairs of high-risk and low-risk mature ponderosa pines on a site where it was practical to wash out the root system. The results did little more than reveal some physical differences between high- and low-risk trees.
"In the low risk trees the roots branch out from the main axis deeper below the soil surface and penetrate the soil at a greater angle than the roots of high-risk trees. Additional slight differences were found, but they were not statistically significant. These differences were that high risk trees had fewer roots of smaller size, a greater percentage of dead roots, and fewer small feeding roots per lineal foot."
In summing up these studies, Bedard listed the following factors as essential to root development: Physical and chemical properties of the soil, soil moisture, mycorrhizae, soil gases, heat, toxic decomposition residues, competition, beneficial plant associates, and heredity.
For more, see: archive.org/stream/biologycontrolof800mill#page/162/mode/2up
To learn more about this photo collection see:
Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest insect investigations on the Pacific Slope, 1903-1953. Part 2. Oregon and Washington. American Entomologist, 48(3), p. 178-185.
For additional historical forest entomology photos, stories, and resources see the Western Forest Insect Work Conference site: wfiwc.org/content/history-and-resources
Image provided by USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
1941. Root system of Tree Number 2 washed out in September of 1941. 20 inches dbh. Class 3D, Risk 4. Klamath Basin near Bly, Oregon.
Root system of Tree Number 2 washed out in September of 1941. 20 inches dbh. Class 3D, Risk 4. Klamath Basin near Bly, Oregon.
Photo by: W.D. Bedard
Date: October 15, 1941
Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection.
Collection: Bureau of Entomology and Portland Station Collections; La Grande, Oregon.
Image: BUR-8891 and PS-551
From Biology and Control of the Western Pine Beetle, pages 163-164:
In 1941 Bedard used hydraulic pressure to wash out the root systems of six ponderosa pines of known risk ratings in the Klamath Basin near Bly, Oregon. He summarized previous studies on ponderosa pine root systems and reviewed literature pertaining to root anatomy, morphology, and physiology. In connection with this review he stated:
"Root form is quite specific, and in addition there is considerable reciprocity between the crown and root system. Root development is of critical importance to continued plant growth. It is important that root development keep pace with crown development."
In the Klamath Basin study, Bedard selected three pairs of high-risk and low-risk mature ponderosa pines on a site where it was practical to wash out the root system. The results did little more than reveal some physical differences between high- and low-risk trees.
"In the low risk trees the roots branch out from the main axis deeper below the soil surface and penetrate the soil at a greater angle than the roots of high-risk trees. Additional slight differences were found, but they were not statistically significant. These differences were that high risk trees had fewer roots of smaller size, a greater percentage of dead roots, and fewer small feeding roots per lineal foot."
In summing up these studies, Bedard listed the following factors as essential to root development: Physical and chemical properties of the soil, soil moisture, mycorrhizae, soil gases, heat, toxic decomposition residues, competition, beneficial plant associates, and heredity.
For more, see: archive.org/stream/biologycontrolof800mill#page/162/mode/2up
To learn more about this photo collection see:
Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest insect investigations on the Pacific Slope, 1903-1953. Part 2. Oregon and Washington. American Entomologist, 48(3), p. 178-185.
For additional historical forest entomology photos, stories, and resources see the Western Forest Insect Work Conference site: wfiwc.org/content/history-and-resources
Image provided by USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth