Memorandum
Date: January 27, 1997
To: Robert W. Williams, Regional Forester, Forest Service, Region 6
From: Donald R. Knowles, Executive Director
Subject: Regional Ecosystem Office Review of the Cultus/Sheridan Late-Successional Reserve Assessment, Deschutes National Forest
Summary
The Regional Ecosystem Office (REO) and the interagency Late-Successional Reserve (LSR) Work Group have reviewed the Cultus/Sheridan LSR Assessment (LSRA). The REO finds that the Cultus/Sheridan LSRA provides a sufficient framework and context for future projects and activities within the LSR. Future silvicultural and salvage activities described in this LSRA that meet both the criteria and objectives of the LSRA 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:
First, 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 and/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.
Second, the review considers potential treatment criteria and treatment areas addressed in the LSRA. When treatment criteria are clearly described and their relationship to achieving desired late-successional conditions is 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
Cultus--The LSRA addresses the 18,000-acre Cultus LSR, located in the Deschutes Province on the Bend/Fort Rock Ranger District, Deschutes National Forest. Much of the Cultus 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.
Sheridan--The LSRA also addresses the 31,030 acre Sheridan LSR, located in the Deschutes Province on the Bend/Fort Rock Ranger District, Deschutes National Forest. Two-thirds of the LSR is classified as forested lavas. The LSR also contains almost 3,000 acres of mixed conifer wet plant association group. Therefore, most of this LSR has only moderate fire risk. Insect and disease risk varies from low to high within the LSR.
Review of the Assessment
Documents submitted for review include the Cultus/Sheridan LSRA and fire plan. These documents contain several process papers which support the conclusions of the LSRA. REO had previously received a LSR overview document from Deschutes National Forest (September 1, 1995) that sets the context for site-specific LSR Assessments.
The LSRA and the associated overview document provide an excellent description of the area and identify important conditions and processes, disturbance regimes, historic and current uses, and their implications for future management. Plant and animal species of interest or concern and connectivity within the LSRs and with other LSRs are also addressed.
The LSR assessment team considered habitat needs for late-successional species and defined acceptable levels of risk of loss from large-scale stand-replacement events to help determine a logical, sustainable mix of fire-climax and late-successional structure. Late-successional stand conditions necessary for late-successional species were compared with stand conditions that were considered sustainable under east Cascades fire regimes, determined in part by stand density and fuel loading. The LSRA proposes a strategy for retaining, to the greatest extent practicable, habitat for late-successional species. This is balanced with 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 LSRs 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.
Cultus--The Forest has divided the Cultus LSR into eight management strategy areas (MSA) based on: (1) common plant association groups (PAGs), (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 per acre and ft3), canopy cover, canopy layers, and density measures (including the number of trees per acre by broad tree size class).
Sheridan--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 eight 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
The assessment raised the issue of fragmentation for both LSRs. This is primarily due to the forest road network. REO's consistency finding assumed that the Land and Resource Management Plan strategy for reducing open road volume is being followed.
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 the amount of late-successional (climactic-climax) habitats that can be sustained through time across the landscape, it should not be the sole determinant. Late-successional habitat within LSRs should be maintained outside the historic range of variability to the extent sustainable, 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 Cultus/Sheridan LSRA, field visits by members of the interagency LSR Work Group, discussions held with members of the Deschutes National Forest staff, and the above noted assumption, the REO finds that the Cultus/Sheridan LSRA provides a sufficient context and framework for decisions on future projects within each LSR. In addition, silvicultural and salvage activities described in the LSRA, 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, Arnie Holden, Bend/Fort Rock Ranger District
869/jw