Improve the Health of Your Forest with Active Management
By Michael Ahr and Miles Merwin
On February 20, 2013, SRN held a meeting to provide neighbors information on how to manage their woodlands. In particular, we talked about the theory and practice of thinning forests. Thinning is the act of cutting some, but not all, of the trees in a stand. The intent is to leave a healthy stand of trees on the site that are free to grow with less competition now that other trees have been removed.
Amy Grotta from OSU Extension said that thinning is but one part of “active management.” Active management helps make forests more resilient to stress and improves not only tree growth, but also wildlife habitat, biodiversity and landowner income. She gave a detailed discussion about the principles of forest thinning and also discussed inventorying a stand to estimate how many trees you have and average diameters and spacing.
Symptoms of over-stocked stands in need of thinning include a sparse understory, heavy shade, interlocked tree crowns and live branches occupying 40% of less of total tree height. To decide how much to thin, Amy said it is best to consult a forester. But she said you can also apply the “D+” rule of thumb, which gives the target spacing (ft.) between trees after thinning based on the average diameter (D in inches) of the “leave” trees.
Finding a logging contractor who has equipment appropriate for small stands is important. Small thinning jobs are likely to be more expensive than clearcuts since more care must be taken by the operator. Amy recommends seeking names of reputable contractors from neighbors or organizations such as OSU Extension, WMSWCD, and the Oregon Dept. of Forestry.
Michael Ahr from West Multnomah Soil & Water Conservation District talked about some examples of sites that had been thinned in our area. He talked about the services that the District can provide, including helping to craft a conservation plan, inventory the trees, and present recommendations on thinning, invasive species removal, and other conservation practices.
Several forested sites in the SRN neighborhood could benefit from thinning, Michael said. In some cases, the trees are still quite young, but it would benefit the forest to reduce the competition and cut trees in what is called a pre-commercial thin. In several other areas, landowners could feasibly thin forests where the harvested trees would be large enough to sell to local mills as sawlogs, i.e., 16+ ft. long with minimum 8” bottom diameter and 5” top. Whether a thinning job will pay for itself depends on many factors, Michael said, including tree size, stand size, streams, slope, etc.
Michael recommends that people who have interest in thinning contact him. If several neighbors are interested, he could help arrange a logger to come work with several landowners in the area which would bring down logging costs. Contact him at [email protected] or 503-238-4775, Extension 109.
Lastly, John Dummer from the Washington County Small Woodlands Association came to share some information about his organization. This is a group of landowners that meet in North Plains once a month, and every meeting has an interesting speaker discussing woodland topics. You are encouraged to attend an upcoming meeting. To learn more, visit www.wcswa.org.
Find forestry publications and information for forestland owners at these sites: http://extension.oregonstate.edu/catalog/ and http://KnowYourForest.org.
On February 20, 2013, SRN held a meeting to provide neighbors information on how to manage their woodlands. In particular, we talked about the theory and practice of thinning forests. Thinning is the act of cutting some, but not all, of the trees in a stand. The intent is to leave a healthy stand of trees on the site that are free to grow with less competition now that other trees have been removed.
Amy Grotta from OSU Extension said that thinning is but one part of “active management.” Active management helps make forests more resilient to stress and improves not only tree growth, but also wildlife habitat, biodiversity and landowner income. She gave a detailed discussion about the principles of forest thinning and also discussed inventorying a stand to estimate how many trees you have and average diameters and spacing.
Symptoms of over-stocked stands in need of thinning include a sparse understory, heavy shade, interlocked tree crowns and live branches occupying 40% of less of total tree height. To decide how much to thin, Amy said it is best to consult a forester. But she said you can also apply the “D+” rule of thumb, which gives the target spacing (ft.) between trees after thinning based on the average diameter (D in inches) of the “leave” trees.
Finding a logging contractor who has equipment appropriate for small stands is important. Small thinning jobs are likely to be more expensive than clearcuts since more care must be taken by the operator. Amy recommends seeking names of reputable contractors from neighbors or organizations such as OSU Extension, WMSWCD, and the Oregon Dept. of Forestry.
Michael Ahr from West Multnomah Soil & Water Conservation District talked about some examples of sites that had been thinned in our area. He talked about the services that the District can provide, including helping to craft a conservation plan, inventory the trees, and present recommendations on thinning, invasive species removal, and other conservation practices.
Several forested sites in the SRN neighborhood could benefit from thinning, Michael said. In some cases, the trees are still quite young, but it would benefit the forest to reduce the competition and cut trees in what is called a pre-commercial thin. In several other areas, landowners could feasibly thin forests where the harvested trees would be large enough to sell to local mills as sawlogs, i.e., 16+ ft. long with minimum 8” bottom diameter and 5” top. Whether a thinning job will pay for itself depends on many factors, Michael said, including tree size, stand size, streams, slope, etc.
Michael recommends that people who have interest in thinning contact him. If several neighbors are interested, he could help arrange a logger to come work with several landowners in the area which would bring down logging costs. Contact him at [email protected] or 503-238-4775, Extension 109.
Lastly, John Dummer from the Washington County Small Woodlands Association came to share some information about his organization. This is a group of landowners that meet in North Plains once a month, and every meeting has an interesting speaker discussing woodland topics. You are encouraged to attend an upcoming meeting. To learn more, visit www.wcswa.org.
Find forestry publications and information for forestland owners at these sites: http://extension.oregonstate.edu/catalog/ and http://KnowYourForest.org.