YFM definition
Examples of YFM in a sentence
This data was then compared with inventory data for each stand to determine if minimum thresholds for YFM (either open- or closed-canopy) were present.
A minimum of 500 acres will be commercially thinned in the White Salmon SOSEA under these prescriptions in the first decade to provide YFM.
For purposes of defining YFM habitat under this SHA, conifer dominated stands age 60 or greater, conifer dominated stands age 50-59 that have been thinned under the thinning prescriptions defined herein, conifer dominated stands age 50-59 that are un-thinned but have had the commercial thinning snag and wildlife tree prescription applied, and/or stands of any age that have been surveyed and found to contain all YFM definitional components will all be considered YFM habitat.
These prescriptions include 1) retaining some smaller sub-merchantable trees, especially shade-tolerant and hardwood species where they exist; 2) retaining some intermediate trees where they exist with the objective of creating areas within the stand with 2 or more canopy layers for vertical diversity; 3) retaining a variable diameter distribution of leave trees where they exist; and 4) targeting total canopy closure of greater than or equal to 70% (thereby achieving YFM – Closed).
Under the SHA, all commercial thinning applications on the Applicants covered lands in Oregon and Washington will apply prescriptions designed to create YFM habitat by incorporating certain habitat characteristics (Appendix B).
As shown by recent surveys to identify stands in the Washington portions of the covered area that meet the Washington state definitions of Eastside Young Forest-Marginal (YFM) Habitat, this habitat can occur as young as 38 years, but more commonly after age 45, and almost assuredly after age 60 (▇▇▇▇▇▇▇ Associates, Inc., unpubl.
If several of the stands that did not meet YFM habitat definitions had been thinned at some point in their development, intermediate trees would likely have been present by the time we sampled them.
Of this amount, 6,168 acres is dispersal habitat, 6,685 acres is YFM habitat, and 5,885 acres is Sub-Mature habitat.
In addition, the SHA provides for 33% of the commercial forest acreage to be YFM or better quality habitat within 0.7 mile circles of the 14 spotted owl site centers in the White Salmon SOSEA, the deferral of any removal of habitat within the 0.7 mile radius circle for the first ten years of the SHA, protection of nesting core areas, and other measures to maintain a biologically sound core area that minimizes the potential for take associated with habitat removal in the outer areas.
It was also determined that stands older than 60 years will likely meet the Washington Forest Practices Rules definition of Young Forest Marginal (YFM).