Memorandum
Date: August 8, 1996
To: Robert W. Williams, Regional Forester, Forest Service, Region 6
From: Donald R. Knowles, Executive Director
Subject: Regional Ecosystem Office Review of the Davis and Metolius Late-Successional Reserve Assessments, Deschutes National Forest
Summary
The Regional Ecosystem Office (REO) and the interagency Late-Successional Reserve (LSR) Work Group have reviewed the Davis and Metolius LSR Assessments (LSRA). The REO finds that the Davis and Metolius LSRAs provide a sufficient framework and context for future projects and activities within their respective LSRs. Future silvicultural and salvage activities described in these LSRAs that meet both the criteria and objectives of the respective LSRAs and the Standards and Guidelines (S&Gs) in the Northwest Forest Plan (NFP) are exempted from subsequent project-level REO review.
Basis for the Review
Under the S&Gs for the NFP a management assessment should be prepared for each large LSR (or group of smaller LSRs) before habitat manipulation activities are designed and implemented. As stated in the S&Gs, these assessments are subject to REO review. The REO review focuses on the following:
1. The review considers whether the assessment contains sufficient information and analysis to provide a framework and context for making future decisions on projects and activities. The eight specific subject areas that an assessment should generally include are found in the NFP S&Gs (page C-11). The REO may find that the assessment contains sufficient information or may identify topics or areas for which additional information, detail, or clarity is needed. The findings of the review are provided to the agency or agencies submitting the assessment.
2. The review considers potential treatment criteria and treatment areas addressed in the LSRA. When treatment criteria are clearly described in the LSRA--their relationship to achieving desired late-successional conditions are also clear--subsequent projects and activities within the LSR(s) may be exempted from REO review, provided they are consistent with the LSRA criteria and NFP S&Gs. REO authority for developing criteria to exempt these actions is found in the S&Gs (pages C-12, C-13, and C-18).
Scope of the Assessment and Description of the Assessment Area
Davis--The LSRA addresses the 48,890-acre Davis LSR (#0-57), located east of the Oregon Cascade Crest on the Crescent Ranger District, Deschutes National Forest. Much of the Davis LSR is occupied by dry mixed conifer forest that is characterized as a "fire climax" ecosystem. Many of these forest stands are heavily stocked and at high risk for insect and disease infestation and catastrophic fire.
Metolius--The LSRA considers the 75,762 acre Metolius LSR (#0-51), located in the Deschutes Province on the Sisters Ranger District, Deschutes National Forest. Roughly 2/3 of the Metolius LSR is occupied by a mixed conifer plant group, with almost 1/3 occupied by the ponderosa pine plant group. Minor components of mountain hemlock and lodgepole pine occur. The LSRA identifies 4 major vegetation trends: (1) greatly increased stand densities, (2) increasing mortality of larger trees and insect and disease damage, (3) species composition shifting from early to late seral species, and (4) stand structure shifting from larger to smaller trees and from single or double canopy layers to multi-canopy layers. Given these trends, and considering that almost 2/3 of the ponderosa pine and mixed conifer plant groups are considered a dry type, there is concern over the occurrence of large-scale stand replacing events.
Review of the Assessments
Documents submitted for review of the Davis LSRA included the LSRA, fire plan, two "white papers" (included as appendices) entitled "Definition and Procedures for Classifying Stands as Imminently Susceptible to Insect Attack and Wildfire" and "Desired Late-Successional Reserve Condition," and appendices. Documents submitted for review of the Metolius LSRA included the LSRA (June 25, 1996 version) and its attached appendices "Vegetation," "Desired Condition for Late-Successional Habitats," and "Fire Management Plan." In addition, the document Deschutes National Forest: a Late-Successional Reserve Overview (September 1, 1995) was submitted with both assessments to set the context for site- specific LSR Assessments.
The LSRAs and the associated "Forest Overview" provide an excellent description of the area and its history. It identifies important conditions and processes, disturbance regimes, historic and current uses, and their implications for future management. It also identifies plant and animal species of interest or concern within the LSRs, and addresses connectivity within the LSR and with other LSRs.
Late-successional stand conditions necessary for late-successional species were compared with stand conditions that were considered sustainable under east Cascades fire regimes (as determined, in part, by stand density and fuel loading). The LSRAs developed and documented a strategy that would foster the retention, to the greatest extent practicable, of suitable habitat. This is balanced with maintaining the LSRs in sustainable habitat conditions where maintaining suitable habitat may put LSRs at an unacceptable risk to large-scale stand replacing disturbances.
The difference between "suitable habitat" and "sustainable habitat" required the determination of a balance of vegetative conditions that would allow the LSR to function as intended and be sustainable in the short and long term. The following considerations were factored into quantifying the desired balance:
Habitat threshold for late-successional old-growth associated species.
Context of the LSRs within the surrounding landscape and management allocations.
The "upper management zone" (UMZ) for each "plant association group" (PAG). The UMZ for a given PAG is that point at which tree suppression or mortality begins due to competition.
The historic range of variability.
The cycling of structural stages to provide different habitat through time.
Davis--The Forest has divided the Davis LSR into 28 management strategy areas (MSA) based on: (1) common plant association groups, (2) known late-successional associated species, (3) rural interface areas, (4) common silvicultural opportunities, and (5) common fire management strategies. For each MSA the LSRA discusses existing conditions for wildlife, botany, and invertebrates; forest dynamics; insect and fire risk; the social context; and risks. For each MSA, the document also presents treatment criteria, displays management options and identifies monitoring needs. Descriptions of conditions that characterized silvicultural treatments were presented in tabular format with the following categories of information presented for each PAG: snag and downed wood levels (in number of logs, tons/acre and ft3); canopy cover; canopy layers; and density measures (including the number of trees/acre by broad tree size class).
Metolius--Criteria for developing treatments are described for each of 4 seral classes within each PAG. Under each seral class is a description of (1) the existing stand condition, (2) objectives and thresholds for action, (3) treatment strategies, (4) a description of the resulting stand after treatment, and (5) how the treatment meets LSR objectives. The LSR is divided into 13 MSAs. Current conditions, goals, objectives and management recommendations are described for each MSA. The treatment criteria by PAG and seral class provides sideboards for treatment in specific vegetative conditions; treatments are then further refined by MSA goals and objectives, thus providing guidance for designing future activities within the LSR.
Assumptions
Davis--In reviewing this LSRA the REO assumed that the wording in the LSRA (page 3-28) regarding regeneration cutting will be replaced with the following:
"Overstory removal of trees highly infected with dwarf mistletoe may occur where conditions are such that the developing understory (of the same species) in areas greater than 10 acres will be prevented from reaching late-successional condition. Each large (>21") tree will be considered individually."
Metolius--In reviewing this LSRA the REO assumed that the wording in the LSRA regarding small group treatment (e.g., pages 76 and 82) will be replaced with the following:
Small Group Treatments--Designed to reduce the spread of root rot and subsequent loss of late-successional conditions and natural diversity in vast areas over time by removing susceptible tree species from small (2 to 9 acre) root rot pockets. Where they exist, leave all or most (thin from below if necessary) of the trees of resistant species; e.g., pine and larch. If necessary to maintain some short-term structure, consider leaving 10 to 15 of the largest (>21" dbh) trees of root rot susceptible species, and interplant with seral, resistant species. Also, in order to create a mix of composition and structure across the landscape to benefit development and retention of late-successional conditions, small group treatments can be used to reestablish seral species where no seed source exists because of mortality or the dominance in the stand of climax species.
In addition, there are locations in the Metolius LSRA that describe ranges of earlier seral conditions or smaller size classes (e.g., Tables 13 & 14; pages 66, 72, 78, 84) that could lead the reader to conclude these conditions are desirable to maintain within the stated range. After discussions with the forest staff, it is understood that these ranges are presented solely to help understand historic vegetative conditions and how that may contribute to sustainable habitats. There is no intention to move a late-successional or large size class stand to an early-successional stage or a smaller size class; the objective for these earlier seral stands is move them towards a late-successional condition.
Additional Comments
Historic Range of Variability (HRV) has been used in this document to help understand historic vegetation composition and fire regimes. While HRV may help determine what amount of late-successional (climactic-climax) habitats can be sustained through time across the landscape, it should not be the sole determinant. The LSR assessment teams considered habitat needs for late-successional species. The teams defined acceptable levels of risk of loss from large-scale stand-replacement events to help determine a logical mix of fire-climax and late-successional structure. The resulting structure will provide for late-successional species as well as meet an acceptable level of risk from large-scale stand replacement events. Such stands could be maintainable outside the historic range of variability. Maintenance of existing late-successional habitats and their associated species is an important component of the NFP, especially for the current planning period and until the more sustainable portions of the LSRs become fully functional.
Conclusions
Based on documentation submitted with and found in the Davis and Metolius LSRAs, field visits by members of the interagency Work Group, discussions held with members of the Deschutes National Forest staff, and the above noted assumptions, the REO finds that the Davis and Metolius LSRAs provide sufficient context and framework for decisions on future projects within each LSR. In addition, silvicultural and salvage activities described in the LSRAs that are consistent with Forest Plan S&Gs and with the respective LSRA objectives and treatment criteria are exempted from further REO review.
cc: REO Reps, RIEC, Tom Nygren, Crescent & Sisters Ranger Districts
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