Forest Genetics Program
Purpose: The objective of the Forests' genetic resource management program is to produce high quality seed for both planned and unforeseen reforestation needs. High quality seed produces trees with good growth rates, proper stem and crown form, high quality wood, and resistance to pests.
Breeding Blocks: The Winema National Forest has been subdivided into four breeding blocks or zones. These breeding blocks have been further subdivided into 500' elevational bands based upon the natural distribution patterns of native tree species. The zones are 4,500' to 4,999', 5,000' to 5,499', 5,500' to 5,999' and 6,000' plus in elevation. Blocks for western white pine and sugar pine species are not split into separate elevation bands.
Management Intensity: The Forests' tree improvement program consists of three levels of intensity chosen to ensure that seeds of the correct tree species are available when needed. These intensities differ primarily in the amount of labor that is spent on the improvement program and subsequent seed production methods. We expect more intensive programs to yield greater returns.
In the low intensity program (Level 1), high quality trees are selected from wild stands or mass selection plantations as the sole source of reforestation seed. In the medium
intensity (Level 2), seed or clonal material from select trees are planted in an orchard
situation so they may interbreed. Once seed orchards reach reproductive maturity (15-20
years, depending on the tree species and site), seed for reforestation will be obtained
primarily from seed orchard parents. In the high intensity (Level 3), we also test the offspring of select trees over a number of diverse locations within the breeding zone. The
information generated by these tests is used to determine the genetic worth of parents in
order to rogue (cull) the seed orchards of poorer performing parents and to develop
advance generation breeding populations.
Economic goals: Once an orchard is established, the goals are to lower the seed collection costs, decrease the time and administration costs for collection, improve the ease of administration, and collect superior production seed to produce seedlings for planting which will have better growth and quality characteristics than the parent population.
Based on an economic analysis of the costs and benefits associated with the use of
improved planting stock, three seed orchards and six mass selection plantations have
been established on the Winema portion of the Forest.
"Family positions" in the seed orchards are made up of offspring of a single tree. Initially, five seedlings are planted in each family position. The goal is to reduce the number of seedlings to the best tree in each family position as differences become apparent.
There is are two mass selection plantations and one seed orchard on each of the three ranger districts of the Winema portion of the Forest. For more information on each site, choose from the menu to the right.
-- Derived from Winema Genetics Resource Plan by Charles Hicks --
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