Eugene Record of Decision and Resource Management Plan

Acronyms and Abbreviations

Eugene Record of Decision

Eugene District Resource Management Plan Table of Contents:

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- Appendices

Appendix E
Silvicultural Systems and Harvest Methods


Introduction

A variety of general silvicultural systems are proposed for the major land use allocations under the plan. The choice of silvicultural systems for management of forest stands would depend on 3 general factors:

    1. Resource Management Objectives - Silvicultural systems will be designed to meet a wide range of management objectives, including the aquatic conservation strategy, development or maintenance of particular habitat types, restoration or maintenance of forest health, and production of merchantable forest products. These objectives vary by land use allocation.
    2. Ecological Type and Site Conditions - Silvicultural systems will be selected to meet the ecological requirements of the communities of plants and animal species present. The silvicultural systems selected must also be compatible with soil conditions, slope, aspect, elevation, blowdown potential, and other physical characteristics of each site.
    3. Forest Condition - The selection of silvicultural treatments will vary depending on the current condition of each stand. Factors considered include species mix, stand age and structure, density, vigor, previous management, damage or disturbance, and insect or disease problems.

Silvicultural systems will be adapted in some locations to meet the requirements of experimental designs. Many field trials and research studies will be needed to help explore the outcomes of the new management approaches being considered.

Livestock grazing can be utilized as a management tool only after a NEPA assessment and then only if it does not retard or prevent attainment of Aquatic Conservation Strategy Objectives. Where objectives cannot be met, eliminate the use of grazing.

Watershed analysis and interdisciplinary reviews will be used to help select and design silvicultural systems through better understanding of landscape-level patterns and ecological processes.

In the following sections, the selection of silvicultural systems is discussed for each of the major land use allocations.

General Forest Management Area

Silvicultural systems in the General Forest Management Area will be designed to promote production of merchantable timber, while retaining some larger trees and snags and maintaining forest health and productivity. All treatments will be compatible with the ecological requirements of the communities of native plant, fungi, and animal species present, and will be tailored to the condition of each stand. The results of watershed analysis will be used to help select and design silvicultural systems through better understanding of landscape-level patterns and ecological processes.

The quality of wood, value of logs ultimately produced, and economic efficiency will be important considerations for all planned treatments.

Lands available for harvest will be managed generally as even-aged stands with partial overstories of larger trees. The silvicultural prescription will provide for the retention of down logs necessary for ecological function. Harvest systems utilized will be consistent with the Best Management Practices (BMP) as described in Appendix C.

Silvicultural Treatments

Management actions will consist of 6 general types of treatments:

  • regeneration harvest with partial retention;

  • site preparation following harvest;

  • reforestation treatment;

  • management of young stands;

  • commercial thinnings in mid-aged stands; and

  • management of overstory trees, snags, and large woody debris.

Each of these silvicultural treatments is described below.

  Regeneration Harvest: Regeneration harvests on available forest lands will generally occur in stands at or above the age of the Culmination of Mean Annual Increment (CMAI) except during the first decade when stands as young as 56 years old will be cut. On the Eugene District, the CMAI varies from stand age 70 to 90 years. Regeneration harvest will not be planned for stands less than 56 years of age.
  Site Preparation: Following regeneration harvest, residual vegetation and logging debris will be treated if necessary to reduce fire hazard, improve access for planting of tree seedlings, lessen initial competition from other vegetation, and limit the cover for seedling-damaging rodents. Methods used will include prescribed fire, manual cutting and piling, and mechanical clearing.
  Reforestation: Normally, all sites that receive regeneration harvest and do not require burning will be reforested within one year of cutting. If slashing and/or burning is required to prepare sites for planting, reforestation may be delayed beyond one year pending burn prescriptions and smoke management clearance. Most areas will be planted with seedlings grown from genetically-selected seed. The selection of tree species, planting density, and stock types will depend on site characteristics, the composition of the original stand, and projected future management of each stand. Areas having identified root disease will be planted with species resistant or immune to the disease or the areas will be treated in a manner that will reduce the likelihood of spreading the disease.
  Management of Young Stands: During the first 10 to 15 years after planting, young stands will receive treatments as necessary and as funding allows to promote establishment, survival, and growth by managing competing vegetation, protecting seedlings from severe local site conditions, and preventing excessive animal damage. These treatments could include but not be limited to manual cutting of brush and seedling protection measures such as placement of plastic mesh tubes or nets on seedlings, and installation of tree shades or mulches. Animal damage control measures will be implemented to reduce their populations when they are high enough to threaten forest stands.

Suitable stands aged 10 to 20 years will receive treatments designed to improve growth, value, and wood quality, when funding is available. These treatments include precommercial thinning, release, pruning, and fertilization.

  Commercial Thinnings: Stands approximately 30 to 70 years of age will be considered for commercial thinning potential. One or two thinnings may be scheduled over the life of an individual stand.
    Commercial thinning may include one or more of the following objectives:

  • Increase the proportion of merchantable volume in the stand.

  • Produce larger, more valuable logs.

  • Harvest anticipated mortality of small trees as the stand develops.

  • Maintain good crown ratios and stable, windfirm trees.

  • Accelerate development of trees that can later provide large-diameter snags and down logs.

  • Manage species composition.

  • Promote development of desired understory vegetation.
  Nitrogen fertilizer may be applied following completion of thinnings. Pruning of selected trees may be considered to increase future value.

In any case, the decision to thin any given stand will depend on site-specific factors such as slope and topography, distance to roads, soil types, stand density, species composition, and average tree diameter.

  Management of Overstory Trees, Snags, and Large Woody Debris: During partial cut or regeneration harvests, existing snags will be reserved from cutting whenever feasible and to the extent necessary to meet snag habitat objectives. However, some snags may need to be removed for road construction, safety reasons, or to make way for log yarding in some situations.

The large trees reserved from regeneration harvest will normally not be considered available for future harvest. Some may be damaged or killed during slash burning, while others may blow down or break off during windstorms. Such trees will then become part of the supply of snags and large woody debris. Many of the reserved trees will likely survive and grow, providing additional structural and functional habitat diversity as younger stands develop beneath them. Some of the trees reserved for snag recruitment may be topped, girdled, or felled over time to help meet long-range goals for snags.

Selection of Harvest Areas

Listed below are harvest area selection guidelines for Regeneration Harvest and Commercial Thinning.

  Regeneration Harvest: For available forest lands, treatment areas will be selected when feasible from the least productive stands first. Stands that appear to have low stocking, damage, disease, generally low growth rates, or a predominance of noncommercial species resulting from past management will receive higher priority for harvest.
  Commercial Thinning: Treatment areas will be selected from well-stocked or overstocked stands where density reduction is needed to maintain good diameter growth rates, live crown ratios, and stand stability. Selection of thinning areas may depend on access and logging feasibility.

Landscape Design

Harvest units, including regeneration harvest and commercial thinnings, will be placed where needed to meet management and landscape objectives on 3 levels of scale: the physiographic province, the landscape block or watershed, and the stand.

Regeneration Harvest Design

Silvicultural prescriptions for regeneration harvest will be based on knowledge of plant communities, successional relationships, and ecosystem functions. Knowledge of these relationships will be used to help prevent vegetation management problems before they occur. Harvest plans will provide for maintenance of long-term site productivity and forest health.

Regeneration harvest units will vary in size depending on factors such as ownership, topography, reserve boundaries, road locations, and other land use allocations. Appropriate treatment areas will be determined through watershed analysis.

Harvest unit shapes will be irregular, conforming where possible to topographic features, but limited in many cases by logging feasibility, ownership boundaries, reserve boundaries, or other land use allocations. An average of 6 to 8 live trees per acre will be reserved from harvest as clumps, strips, and scattered individual trees. The distribution of reserved trees will be designed to help meet habitat goals and to minimize interference with log yarding.

In addition to the previous green tree retention management action/direction, green trees will be retained for snag recruitment in timber harvest units where there is an identified, near-term (less than 3 decades) snag deficit. These trees do not count toward green-tree retention requirements. Some of the trees reserved for snag recruitment may be topped, girdled, or felled over time to help meet long-range goals for snags and large woody debris.

Partial Cut Harvest Design

Commercial thinnings will generally be designed to maintain good volume productivity of the stand. To accomplish this, a stand might be thinned before relative density exceeds 0.60, leaving a residual relative density of approximately 0.40. Depending on stand age, tree size, and the specific objectives of the thinning, stand density after thinning would range from approximately 50 to 150 trees per acre. Stand densities after thinning vary depending on stand age, tree size, the number of thinnings already completed, and the specific objectives of the thinning.

Commercial thinning treatment areas will vary in size, depending on factors such as operability and site conditions. Appropriate treatment areas will be determined through watershed analysis. A variety of thinning intensities may be designated within a treatment unit in order to reflect current within-stand spatial patterns or to meet stand development objectives.

In some portions of stands, thinning may consist only of removal of the smaller (intermediate and suppressed) trees in the stand. In other areas, the larger codominant and dominant trees may also be removed.

Where root diseases such as laminated root rot (Phellinus weirii), black stain (Ceratocystis verticicladiella), or Port Orford cedar root rot (Phytophthora lateralis) are present in stands to be thinned, the thinning will incorporate state-of-the-art recommendations for treatment. When consistent with management and landscape objectives, openings created will be planted with seedlings of species resistant or immune to the disease, or in a manner to reduce the rate of disease spread.

Connectivity/Diversity Blocks

Silvicultural systems in the Connectivity/Diversity blocks will be designed to promote development of late-successional forest structure within a longer rotation, while providing an output of merchantable timber and maintaining forest health and productivity. All treatments will be compatible with the ecological requirements of the communities of native plant, fungi, and animal species present and will be tailored to the condition of each stand. The results of watershed analysis will be used to help select and design silvicultural systems through better understanding of landscape-level patterns and ecological processes.

The quality of wood, value of logs ultimately produced, and economic efficiency will be important considerations for all planned treatments.

Lands available for harvest will be managed generally as even-aged stands with substantial overstories of larger trees. The silvicultural prescription will provide for the retention of down logs necessary for ecological function. Harvest systems utilized will be consistent with the BMPs as described in Appendix C.

Silvicultural Treatments

Management actions will consist of 6 general types of treatments:

  • regeneration harvest with partial retention;
  • site preparation following harvest;
  • reforestation treatments;
  • management of young stands;
  • density management thinning in mid-aged stands; and
  • management of overstory trees, snags, and large woody debris.

Each of these treatments is described below.

  Regeneration harvest: Regeneration harvests on available forest land will be planned for a 150-year area control rotation. This means that approximately 1/15 of the available acres will receive regeneration harvest in any decade. On the Eugene District, portions of some stands will be cut at stand ages as low as 56 years during the first decade, where older stands are not available or to develop a better distribution of age classes over time. Regeneration harvest will not be planned for stands less than 56 years of age.
  Site preparation: Following regeneration harvest, sites will receive treatment of understory vegetation and logging debris if necessary to reduce fire hazard, improve access for planting of tree seedlings, lessen initial competition from other vegetation, and limit the cover for seedling-damaging rodents. Methods used will include prescribed fire (underburning), machine piling, manual cutting and piling, and mechanical clearing.
  Reforestation: Normally, all sites that receive regeneration harvest and do not require burning will be reforested within one year of cutting. If slashing and/or burning is required to prepare sites for planting, reforestation may be delayed beyond one year pending smoke management clearance. The selection of tree species, planting density, and stock types will depend on site characteristics, the composition of the original stand and remaining overstory, projected future management of each stand, and distribution of root disease infection. Harvested areas having identified root disease will be planted with species resistant or immune to the disease or the areas will be treated in a manner that will reduce the likelihood of spreading the disease.
  Management of Young Stands: During the first 10 to 15 years after planting, the understory will receive treatments as necessary and as funding allows to promote establishment, survival, and growth by managing competing vegetation, preventing excessive animal damage, and managing overstory density. These treatments will include but not be limited to manual cutting of brush and seedling protection measures, such as placement of plastic mesh tubes or nets on seedlings. Animal damage control measures would be implemented to reduce their populations when they are high enough to threaten forest stands.

Suitable stands aged 10 to 20 years may receive treatments designed to improve growth, value, and wood quality when funding is available. These treatments may include release, precommercial thinning, pruning, and fertilization. Consideration will be given to retention of the natural species composition of the stand.

  Density Management Thinnings: Stands approximately 30 to 110 years of age will be considered for density management thinnings. An individual stand may be thinned 3 to 4 times at intervals of 20 to 30 years within one 150-year rotation.

Density Management may include one or more of the following purposes:

  • to accelerate growth of trees that would later provide large-diameter snags and down logs;

  • to promote development of understory vegetation and multiple canopy layers;

  • to produce larger, more valuable logs;

  • to harvest mortality of small trees as the stand develops;

  • to maintain good crown ratios and stable, windfirm trees; and

  • to manage species composition.

The decision to thin a particular stand will depend on site-specific factors such as slope and topography, distance to roads, soil types, stand density, species composition, average tree diameter, and degree of structural variability in the stand.

  Management of Overstory Trees, Snags, and Large Woody Debris: During partial cut or regeneration harvests, existing snags will be reserved from cutting whenever feasible to the extent necessary to meet snag habitat objectives. However, some snags would need to be removed for safety reasons, road construction, or to make way for log yarding in some situations.

The large trees reserved from regeneration harvest will not normally be considered available for future harvest. Some may be damaged or killed during slash burning, while others may blow down or break off during windstorms. Such trees will become part of the supply of snags and large woody debris. Most of the reserved trees will likely survive and grow, providing substantial structural and functional habitat diversity as the canopies of younger stands develop beneath them.

Selection of Harvest Areas

Listed below are harvest area selection guidelines for Regeneration Harvest and Density Management Thinnings.

  Regeneration Harvest: Treatment areas will be selected from mature stands having the least degree of late-successional forest structure. In addition, the more productive stands will be deferred so the less productive stands would be harvested first, when feasible. Stands that appear to have low stocking, damage, disease, generally low growth rates, or a predominance of noncommercial species resulting from past management will receive higher priority for harvest.
  Density Management Thinnings: Treatment areas will be selected from well-stocked stands where density reduction is needed to promote development of late-successional forest structure. This will generally be stands that are predominantly even-aged, evenly spaced, and of a fairly uniform diameter and height. Selection of thinning areas will also depend on access and logging feasibility.

Landscape Design

Harvest units, including regeneration harvest and density management thinning, will be placed where needed to meet management and landscape objectives on 3 levels of scale: the physiographic province, the landscape block or subwatershed, and the stand.

Regeneration Harvest Design

Silvicultural prescriptions for regeneration harvest will be based on knowledge of plant communities, successional relationships, and ecosystem functions with consideration of forest health. Knowledge of these relationships will be used to help prevent vegetation management problems before they occur. Harvest plans will provide for maintenance of long-term site productivity and forest health.

Regeneration harvest units will vary in size depending on factors such as ownership, topography, reserve boundaries, other land use allocations, and road locations. Appropriate treatment areas will be determined through watershed analysis.

Harvest unit shapes will be irregular, conforming where possible to topographic features, but limited in many cases by logging feasibility, reserve boundaries, other land use allocations, and ownership boundaries. An average of 12 to 18 live trees per acre will be reserved from harvest as clumps, strips, and scattered individual trees. The distribution of reserved trees will be designed to help meet habitat goals and to minimize interference with log yarding.

In addition to the previous green tree retention management action/direction, green trees will be retained for snag recruitment in timber harvest units where there is an identified, near-term (less than 3 decades) snag deficit. These trees do not count toward green-tree retention requirements. Some of the trees reserved for snag recruitment may be topped, girdled, or felled over time to help meet long-term goals for snags and large woody debris.

Partial Cut Harvest Design

Density management thinning will generally be designed to encourage rapid development of vertical and horizontal stand diversity. To accomplish this, a stand might be thinned before relative density exceeds 0.55, leaving a residual relative density of approximately 0.35. Patches of denser forest will be retained in some places to meet particular wildlife habitat criteria. Depending on stand age and the specific objectives of thinning, stand density after thinning may range from approximately 30 to 200 trees per acre. Trees left per acre vary depending on stand age, tree size, the number of thinning already completed, and the specific objectives of the thinning. Density management areas will vary in size depending on factors such as operability and site conditions. Appropriate treatment areas will be determined through watershed analysis. A variety of treatment intensities may be designated within a thinning unit in order to reflect current within-stand spatial patterns or to meet stand development objectives.

For example, some dense patches of perhaps 0.25 acre to several acres may be reserved from cutting. Other patches of 0.5 to 1 acre may be completely removed as group selections and those areas planted with tree seedlings after the thinning is completed. Group selection patches larger than one acre in size will contain reserved trees and snags as provided in regeneration harvest units.

In each density management thinning entry, some of the larger codominant and dominant trees may be removed.

Where root diseases such as laminated root rot (Phellinus weirii), black stain (Ceratocystis verticicladiella) or Port Orford cedar root rot (Phytophthora lateralis) are present in stands to be thinned, the thinning will incorporate state-of-the-art recommendations for treatment. When consistent with management and landscape objectives, openings created will be planted with seedlings of species resistant or immune to the disease, or in a manner to reduce the rate of disease spread.

Late-Successional Reserves

Forest stands less than 80 years of age within the Late-Successional Reserves will be considered for silvicultural treatments where stocking, structure, or composition are expected to prevent or significantly retard development of late-successional conditions. Such stands will generally be composed of trees less than 10 to 20 inches diameter at breast height, and would show no significant development of a multiple-canopy forest structure. Stands that have desired late-successional structure or that will soon develop it would not be treated unless such treatment is necessary to accomplish risk reduction objectives (as described below).

Silvicultural Treatments

Late-Successional Reserve (LSR) assessments will assist in the determination of activities to be conducted. LSR assessments are subject to Regional Ecosystem Office (REO) review. Within LSR, silvicultural treatments should be beneficial to the creation of late-successional forest conditions and could include density management and reduction of large-scale disturbance risk. Silvicultural prescriptions will provide for the retention of down logs necessary for ecological function. Harvest systems utilized will be consistent with the BMPs as described in Appendix C.

  Density management: Density management prescriptions will be designed to produce stand structure and components associated with late-successional conditions including large trees, snags, down logs, and variable-density, multistoried, multispecies stands. By removing a portion of the stand, the remaining trees would be provided room to maintain or increase diameter growth rates. In addition, openings in the canopy would permit development of an understory of seedlings, saplings, and other vegetation. Some of the overstory trees may be converted to snags over time to help meet snag habitat targets or felled to provide large woody debris. Trees cut but surplus to habitat needs would be removed for commercial use.

A wide variety of silvicultural practices will be employed, rather than relying on a limited variety of techniques. Silvicultural activities, when needed, would be conducted in suitable stands whether or not the action would generate a commercial return.

In general, acres treated will be limited to 5 percent of the total area within Late-Successional Reserves in the initial 5-year period of implementation unless the need for larger-scale actions is explicitly justified.

Reduction of Large-Scale Disturbance Risk

In some areas, stands will be made less susceptible to natural disturbances by focusing salvage activities on reduction of catastrophic insect, disease, and wildfire threats, and by designing treatments to provide effective fuel breaks wherever possible. These treatments would be designed so they would not result in degeneration of currently suitable spotted owl habitat or other late-successional conditions.

Risks will be reduced in older stands if the proposed management activity would clearly result in greater assurance of long-term maintenance of habitat; is clearly needed to reduce risks;, and would not prevent Late-Successional Reserves from playing an effective role in attaining the objectives for which they were established.

Unless exempted from review, proposed risk reduction projects will be submitted to the Regional Ecosystem Office.

Riparian Reserves

Some stands within the Riparian Reserves will be considered for silvicultural treatments that will contribute to meeting objectives of the Aquatic Conservation Strategy.

Silvicultural Treatments

In Riparian Reserves the watershed analysis will assist in development of silvicultural treatments. Treatments would include density management and conifer underplanting. Silvicultural prescriptions will provide for the retention of down logs necessary for ecological function. Harvest systems utilized will be consistent with the BMPs as described in Appendix C.

  Density Management: Where portions of young, even-aged conifer stands are located within the Riparian Reserves, they will be considered for density management treatments. The objectives of such treatment would be to promote development of large conifers, recruitment of large woody debris, and to improve diversity of species composition and stand density. Merchantable logs will be removed only where such action would not be detrimental to the purposes for which the Riparian Reserves were established.
  Conifer Underplanting: Where hardwood stands dominate streamside areas and there is a lack of large conifers to provide inputs of large wood for instream structure, efforts will be made to reestablish conifers within the Riparian Reserve. This will involve cutting or girdling some hardwoods to create openings in the canopy, followed by cutting of brush and planting of a variety of conifer seedlings in the openings created. In most cases, follow-up stand maintenance and protection treatments will be necessary to ensure successful establishment of an adequate number of conifers in the riparian area.