Recovery Plan for the Northern Spotted Owl - DRAFT
Recovery Plan for the Northern Spotted Owl - DRAFT Recovery Plan for the Northern Spotted Owl - DRAFT
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I. Summary of Literature Reviewand ExperienceThis report discusses management of forest stands for northern spotted owlhabitat. We present examples of silvicultural systems and treatments whichresemble natural forest disturbances. These systems can be used to acceleratethe development of stand structures used by owls and to grow habitat instands where it is not likely to occur through natural stand development. Weuse stand structure (density, stocking by tree species and size class, snags,logs on the forest floor) of stands that contain owl nest sites as goals (or desiredfuture conditions) for these silvicultural systems. We use data from actualstands to develop examples of silvicultural systems which will produce owlhabitat.A silvicultural system is a series of treatments to trees, shrubs, and otherplants designed to produce a desired stand through time-in this case, astructure that provides habitat for northern spotted owls. The treatments andtechniques employed necessarily will vary throughout the range of northernspotted owls. For example, in some forests in northern California and easternWashington Cascades where there has been a history of harvesting individualtrees or small groups of trees, there are mixed-species stands composed oftrees of various sizes or ages. In these forests, silvicultural systems shouldmaintain this diverse structure, while ensuring that there will be large trees inthe future and protecting stands against fire, insects, and disease. In theseforests, mimicking natural disturbance (i.e., fire) too closely may reduce owlhabitat. In other forests of California, Oregon, and Washington, stands arecomposed of trees of relatively uniform sizes and ages. Here, silviculturalsystems that attempt to mimic natural, small-scale disturbances and increaseunderstory tree regeneration to develop multilayered stands seem appropriate.In many of these forests, windthrow and the regeneration of trees in denseunderstories of shrubs are probably of more concern than fire.Not all these stands "need" to be treated to develop into suitable habitat. Somestands already provide habitat or will provide it in a short time without intervention.However, many other stands have been managed for wood production,not for owl habitat, and they will not readily produce multistoried standswithout treatment. Thus, there are many stands in which treatment mayhasten development of habitat, and many stands in which maintenance ofhabitat and wood production may occur simultaneously. The potential for astand to produce owl habitat varies from stand to stand and depends onvariables such as tree and shrub species composition; site productivity: andthe age, size, number, and spatial distribution of trees. For example, standswith a high stocking of conifers will not quickly produce large trees with deepcrowns or develop a multistoried structure. Stands with a dense understory ofshrubs may not produce additional layers of trees because regeneration oftrees cannot occur under the shrubs. Stands must be evaluated individuallyto determine their potential for producing habitat and which silviculturesystem to apply, if any. The possibilities for managing stands for owls areconsiderable. For example, we estimate that within the habitat conservationareas (HCAs) proposed by the Interagency Scientific Committee (ISC) there aremore than 2 million acres in stands on federal lands in Oregon and Washingtonthat are not suitable owl habitat.Planning for silviculture systems to provide owl habitat must be done at thelandscape and stand levels. Landscape variables to evaluate include locationof owls: habitat for owl prey: types of stands not providing habitat including485
- Page 450 and 451: Table F.4. Important forest insects
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- Page 454 and 455: D. DiseasesForest diseases in the P
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- Page 464 and 465: InsectsDiseasesInsects in this subr
- Page 466 and 467: __hardwoods are immune. Shade toler
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- Page 474 and 475: B. Management Effects on StandsMana
- Page 476 and 477: units (underburning or lop/scatter)
- Page 478 and 479: In the higher elevation White Fir a
- Page 480 and 481: growth often increases (Reinhardt a
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- Page 486 and 487: The introduced disease, white pine
- Page 488 and 489: VI. Conclusionsmortality will resul
- Page 490 and 491: Baker, F.A. 1988. The influence of
- Page 492 and 493: Habeck, J.R. 1990. Old-growth ponde
- Page 494 and 495: Perry, D.A., and J.G. Borchers. 199
- Page 496 and 497: Weatherspoon, C.P., and C.N. Skinne
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- Page 504 and 505: Stand AFigure G.2. A--unthmnned Dou
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- Page 508 and 509: II. Review of Natural Vegetation an
- Page 510 and 511: western hemlock, and sometimes othe
- Page 512 and 513: year intervals (Appendix F). With t
- Page 514 and 515: Live crown ratiobecent)6050IStand A
- Page 516 and 517: Basal area growth continued to incr
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- Page 524 and 525: acre, 4 to 12 inches in diameter),
- Page 526 and 527: allow redwood sprout clumps maximum
- Page 528 and 529: KAge 15 years - 511 trees per acre,
- Page 530 and 531: 6Stems per acre100 _ Stand A. Natur
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- Page 536 and 537: Drew, T.J. and J.W. Flewelling. 197
- Page 538 and 539: Miller, R.E.; D.L. Reukema, and R.L
- Page 540 and 541: Tappeiner, J.C., P.M. McDonald, and
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