i Hauer Hauer Hauer Hauer Brothers Brothers Brothers Brothers Lumber Lumber Lumber Lumber BC Timber Sales Robson Valley Timber Supply Area Timber Supply Review 3 Data Package – Draft 1.0 January 31, 2004 Prepared for: Robson Valley Timber Supply Area Defined Forest Area Management (DFAM) Group A Project Forest Ecosystem Solutions Ltd. Submitted by: #210 – 275 Fell Avenue North Vancouver BC V7P 3R5 Contact: Chris Niziolomski R.P.F tel. (604) 998-2222 fax.(604) 986-0361 email: [email protected]Timber Supply Analysis Timber Supply Analysis Timber Supply Analysis Timber Supply Analysis Data Pa Data Pa Data Pa Data Pa ck ck ck ck age age age age – – – – Draft 1 Draft 1 Draft 1 Draft 1
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Robson Valley Timber Supply Area Timber Supply Review 3 Data Package – Draft 1.0 January 31, 2004 Prepared for: Robson Valley Timber Supply Area Defined Forest Area Management (DFAM) Group
A Project FoSubmitted by: #2 No Contact: Ch tel fax em
Robson Valley DFAM TSR 3 Data Package – Draft 1.0 ii
Acknowledgements The development of this data package could not happen without the dedicated efforts and hard work of the organizations below. Also, special thanks to Grant Sime, Craig Pryor, Emile Begin, Ainslie Jackman, Gord Sluggett, Norma Stromberg-Jones, Sharron Schiefelbein, Max Tanner, Qiong Su, Albert Nussbaum, Melanie Boyce, Chris Ritchie, Ron Planden, Ron van der Zwan, Frank Spears. Slocan Forest Products Ltd. – Valemount Division McBride Forest Industries Ltd. Hauer Brothers Ltd. Bell Pole Company BC Timber Sales – Kamloops Business Area BC Ministry of Forests – Prince George Forest District and Northern Interior Forest Region BC Ministry of Sustainable Resource Management – Prince George BC Water Land and Air Protection BC MOF Forest Analysis Branch
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List of Acronyms Acronym Definition
AAC Allowable Annual Cut AU Analysis Unit BCTS BC Timber Sales BEC Biogeoclimatic Ecosystem Classification BEO Biodiversity Emphasis Option CFLB Crown forested land base DBH Diameter at Breast Height DIB Diameter Inside Bark DWB Decay, Waste, and breakage ECA Equivalent Clearcut Area ESA Environmentally Sensitive Area FDP Forest Development Plan FESL Forest Ecosystem Solutions Ltd. FIZ Forest Inventory Zone FPC Forest Practices Code FSOS Forest Simulation Optimization System GIS Geographic Information Systems ITG Inventory Type Group LRMP Land Resources Management Plan LU Landscape Unit LUPG Landscape Unit Planning Guide MAI Mean Annual Increment MFI McBride Forest Industries MHA Minimum Harvestable Age MOF British Columbia Ministry of Forests MP Management Plan MSRM British Columbia Ministry of Sustainable Resource Management MSYT Managed Stand Yield Table NSR Not Satisfactorily Restocked NSYT Natural Stand Yield Table OAF Operational Adjustment Factor OGMA Old Growth Management Area OGSI Old Growth Site Index RMZ Riparian Management Zone RRZ Riparian Reserve Zone RVQC Recommended Visual Quality Class SI50 Site Index for age 50 SIBEC Site index Biogeoclimatic Ecological Classification Slocan Slocan Forest Products Ltd.
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Acronym Definition
THLB Timber Harvesting Land Base TIPSY Table Interpolation Program for Stand Yields TSA Timber Supply Area TSR Timber Supply Review UWR Ungulate Winter Range VAC Visual Absorption Capacity VDYP Variable Density Yield Prediction VEG Visually Effective Green-up VRI Vegetation Resources Inventory WHA Wildlife Habitat Area WTP Wildlife Tree Patch WTR Wildlife Tree Retention
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Table of Contents Acknowledgements ............................................................................................................................ii List of Acronyms ...............................................................................................................................iii Table of Contents................................................................................................................................ v List of Tables.....................................................................................................................................vii 1 Introduction ................................................................................................................................... 1
1.1 Purpose of the data package ................................................................................................. 2 1.2 Process .................................................................................................................................. 3
2 Inventory and Model Files ............................................................................................................ 5 2.1 Data sources.......................................................................................................................... 5
3 Land Base...................................................................................................................................... 9 3.1 Timber harvesting land base definition................................................................................. 9
3.1.1 Reasons for changes to the THLB since TSR 2 .......................................................... 11 3.2 Exclusions from the Crown Forested Land Base ................................................................ 11
3.2.1 Land not managed by BCFS ....................................................................................... 11 3.2.2 Non-forest and non-productive forest ......................................................................... 12 3.2.3 Existing roads, trails and landings............................................................................... 13 3.2.4 Parks, UREPs and Ecological Reserves ...................................................................... 14 3.2.5 Protected areas............................................................................................................. 14 3.2.6 Agriculture land reserve .............................................................................................. 15 3.2.7 Alpine (not previously removed from the THLB........................................................ 15 3.2.8 Non-commercial brush................................................................................................ 15 3.2.9 Inoperable areas........................................................................................................... 15 3.2.10 Environmentally sensitive areas.................................................................................. 15 3.2.11 Immature stands with low timber growing potential .................................................. 16 3.2.12 Non-merchantable mature stands ................................................................................ 16 3.2.13 Essential caribou habitat.............................................................................................. 18 3.2.14 Grizzly bear habitat ..................................................................................................... 18 3.2.15 Areas with high value for recreation ........................................................................... 19 3.2.16 Mule deer habitat......................................................................................................... 20 3.2.17 Riparian reserve and management zones .................................................................... 20 3.2.18 Inaccessible areas ........................................................................................................ 21 3.2.19 Stand-level biodiversity (WTP) .................................................................................. 21
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3.2.20 Future roads, trails, and landings ................................................................................ 23 3.2.21 Cultural heritage resource deductions ......................................................................... 23 3.2.22 Further exclusions to the timber harvesting land base ................................................ 24
4 Management zones and analysis units ........................................................................................ 25 4.1 Management groups and objectives ....................................................................................... 25 4.2 Analysis units........................................................................................................................ 25
5 Growth and Yield ........................................................................................................................ 27 5.1 Site index ............................................................................................................................. 27
5.1.1 Site index adjustments................................................................................................. 27 5.2 Utilization level ..................................................................................................................... 28 5.3 Decay, waste and breakage for unmanaged stands ................................................................. 28 5.4 Operational adjustment factors for managed stands ............................................................... 28 5.5 Volume exclusion for mixed species ........................................................................................ 29 5.6 Other issues related to yield table development ....................................................................... 29
5.6.1 Yields for Existing and Future Managed Stands......................................................... 29 5.6.2 Yields for Natural (Unmanaged) Stands ..................................................................... 29 5.6.3 Existing timber volume check..................................................................................... 30
6 Silviculture .................................................................................................................................. 31 6.1 Silviculture management regimes ....................................................................................... 31 6.2 Gene resources — use of select seed ...................................................................................... 32 6.3 Backlog and current not satisfactorily restocked .................................................................... 32
9 Timber harvesting ....................................................................................................................... 43 9.1 Minimum Harvestable age by analysis unit.............................................................................. 43 9.2 Logging methods and silvicultural systems......................................................................... 43 9.3 Initial harvest rate............................................................................................................... 44 9.4 Harvest scheduling priority................................................................................................. 44 9.5 Deferral of seed production stands ..................................................................................... 44 9.6 Timber supply model ........................................................................................................... 44
10 Timber Supply Forecast/Options/Sensitivity Analyses............................................................... 45 10.1 Harvest flow objectives for the base case and sensitivity analyses..................................... 45 10.2 Sensitivity analyses.............................................................................................................. 45
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List of Tables Table 1: Timber Supply Review Steps with Roles and Responsibilities .............................................. 3 Table 2: Inventory Information for the Robson Valley TSA ............................................................... 5 Table 3: Timber harvesting land base determination for the Robson Valley TSA............................ 10 Table 4: Ownership codes in the Robson Valley TSA........................................................................ 11 Table 5: Areas in non-forest and non-productive forest ..................................................................... 12 Table 6: Reductions for existing roads............................................................................................... 13 Table 7: Area in parks, UREPs and ecological reserves ..................................................................... 14 Table 8: Protected areas in the Robson Valley TSA.......................................................................... 14 Table 9: Reductions from environmentally sensitive areas ............................................................... 16 Table 10: Site index (SI50) exclusions for immature stands............................................................... 16 Table 11: Mature stand exclusions..................................................................................................... 17 Table 12: Critical grizzly bear habitat reductions to the timber harvesting land base ........................ 18 Table 13: High recreation areas .......................................................................................................... 20 Table 14: Timber harvesting land reduction from riparian reserves and management zones............. 20 Table 15: Summary of the procedure used to calculate the wildlife tree retention reduction............. 22 Table 16: Management grouping definitions ...................................................................................... 25 Table 17: Analysis Units .................................................................................................................... 26 Table 18: Old-Growth Site Index (OGSI) Adjustment Equations ..................................................... 27 Table 19: Minimum utilization levels in the Robson Valley TSA...................................................... 28 Table 20: The percentage of harvested areas that will be managed under managed yields................ 29 Table 21: The percentage of previously harvested areas that will be managed under unmanaged
yields ........................................................................................................................................... 30 Table 22: Existing timber volume check............................................................................................. 30 Table 23: Regeneration assumptions for managed stands .................................................................. 31 Table 24: Not satisfactorily restocked (NSR) backlog areas .............................................................. 33 Table 25: Unsalvaged volume losses (m3/year) due to beetle in the Robson Valley TSA by licensee.
..................................................................................................................................................... 34 Table 26: Total unsalvaged volume losses.......................................................................................... 35 Table 27: Range of allowable percent alteration................................................................................. 37 Table 28: Predicted P2P ratios for slopes for all visual designs, based on average slope .................. 37 Table 29: Associated visually effective green-up heights by slope class .......................................... 38 Table 30: Community watersheds....................................................................................................... 38 Table 31: Endangered or threatened (red-listed) species in the Robson Valley TSA......................... 39 Table 32: Vulnerable (blue-listed) ..................................................................................................... 39 Table 33: Landscape Units of the Robson Valley TSA ...................................................................... 40 Table 34: Old seral targets through the TSR3 planning horizon......................................................... 41 Table 35: Minimum volume per hectare to be considered harvestable.............................................. 43 Table 36: Sensitivity issues specific to the Robson Valley TSA ....................................................... 45 Table 37: Standard sensitivity analysis .............................................................................................. 46
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1 Introduction The Timber Supply Review (TSR) process facilitates the public and First Nations review of the timber supply analysis, the incorporation of their inputs into the analysis, and the determination of allowable annual cuts (AAC) by the provincial Chief Forester. Timber supply analysis is the forecast of timber supply given the current management regime and associated sensitivity analyses. This document provides the information and management assumptions proposed for timber supply analysis. Under the proposed Defined Forest Area Management (DFAM) legislation, timber supply analysis is the collective responsibility of the DFAM group. The DFAM group includes the holders of replaceable forest licenses (Slocan Forest Products Ltd, McBride Forest Industries Ltd, Bell Pole Company, and Hauer Brothers Lumber Ltd.) and BC Timber Sales. The DFAM group will complete the following steps for timber supply analysis: � Collect data and prepare a data package, which summarizes the data assumptions and
critical issues to be examined in the analysis; � Complete the timber supply analysis and report; and � Provide for public and First Nations review.
TSR is conducted a minimum of every five years in order for new data, management assumptions and polices to be included. The last TSR (TSR 2) for the Robson Valley Timber Supply Area (TSA) was completed in May 2000 and the AAC determination in June 2001. TSR 3 aims for the data package review to be completed by March 31, 2004 and the AAC determination at latest September 2006. Three primary documents will be provided through this process: 1) the data package, 2) the analysis report and 3) the Chief Forester’s AAC determination report. The data package is a technical document that summarizes the data and inputs for the analysis. The analysis report summarizes the timber supply analysis results and serves as the focus for public discussion. The public and First Nations are encouraged to review the data package and analysis report so that their input could be taken into account for the analysis and/or by the Chief Forester for the AAC determination. This determination will be documented in a final report describing the Chief Forester’s AAC decision and the rationale for it. Public and First Nations input is valuable for this TSR process. Please send any written comments on the data package by March 31, 2004 to: Mail: Chris Niziolomski, R.P.F.
Forest Ecosystem Solutions Ltd. 210-275 Fell Avenue North Vancouver, BC V7P 3R5
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Copies of the data package can be obtained on the following website: http://www.forestecosystem.ca/RobsonValleyTSR3DataPackage.html
1.1 Purpose of the data package The purpose of this data package is to provide a clear description of information sources, assumptions, issues, and any relevant data processing or adjustments related to the land base, growth and yield, and management objectives and practices. Through its use, this package will: � Provide a detailed account of the factors related to timber supply that the Chief Forester
must consider under the Forest Act when determining an allowable annual cut (AAC) and how these factors will be applied in the timber supply analysis;
� Provide a means for communication between the staff from the licensees, BCTS,
Ministry of Forests, Ministry of Sustainable Resource Management, Ministry of Water, Land, and Air Protection, the public and First Nations in the TSA.
� Provide the public, First Nations, and staff of the different ministries with the
opportunity to review data and information that will be used in the timber supply analysis before it is initiated;
� Ensure that all relevant information is accounted for in the analysis to an acceptable
standard; and � Reduce the risk of having analyses rejected because input assumptions and analysis
methods were not agreed upon in advance. During the analysis, various sensitivity analyses, harvest flow alternatives, and management options will be tested to determine the influence of various factors on harvest levels. All analyses and the final proposed option will be submitted to the Chief Forester for determination of the allowable annual cut (AAC).
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1.2 Process The responsibility to conduct timber supply analysis on a periodic basis (at least once every 5 years) is the collective responsibility of the DFAM group. The DFAM group includes BC Timber Sales (BCTS) and the forest licensees: Slocan Forest Products Ltd (Slocan), McBride Forest Industries Ltd (MFI), Bell Pole Company, and Hauer Brothers Lumber Ltd (Hauer Brothers). The roles and responsibilities for the specific timber supply review steps are outlined in Table 1. Following completion of these steps, the Chief Forester or designate will review the final timber supply analysis report, assess its acceptability for supporting the AAC determination, and if necessary request additional information. After acceptance of the analysis, the Chief Forester determines an AAC, considering all the factors as required in the Forest Act, section 8 (8).
Table 1: Timber Supply Review Steps with Roles and Responsibilities
BC Ministry of Forests DFAM Group Timber Supply
Branch District & Regional
Staff Compiling data needed for the timber supply analysis, including forest cover and other data related to forest and land characteristics, administration and management regimes.
Providing information to the public and First Nations (government retains consultation responsibilities with respect to First Nations).
Compiling a data package that documents the data, management strategies, and methods that will be applied in the timber supply analysis, according to standards provided by the Ministry of Forests (Supplemental Guide for Preparing Timber Supply Analysis Data Packages is used as a template for this data package).
Reviewing and accepting the data package (focus on how data is to be applied in timber supply analysis).
Reviewing the data package (confirming current practice).
Performing and documenting a timber supply analysis according to standards provided by the Ministry of Forests.
Submitting a file containing the complete dataset used in the timber supply analysis. This requirement is primarily to assist government in compiling and maintaining a complete coverage of the province for tracking of land base, management, and other strategic issues, as well as to enable audit analysis.
Reviewing and accepting (together with the chief forester) the analysis report
Reviewing the analysis report to ensure local issues and current practices are adequately reflected.
Providing additional information as required by the chief forester.
Compiling and preparing information, primarily from the analysis report, for presentation to the
Assisting in compiling and preparing information, primarily from the analysis report, for presentation to the
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BC Ministry of Forests DFAM Group Timber Supply
Branch District & Regional
Staff chief forester for the AAC determinations.
chief forester for the AAC determinations.
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2 Inventory and Model Files This section outlines the inventory, data and spatial coverages used in the preparation of the data package and will be used for the timber supply analysis in the Robson Valley TSA.
2.1 Data sources Most of the data were provided from the Ministry of Forests (MOF), the Ministry of Sustainable Resources Management (MSRM), the licencees and BC Timber Sales. A list of the data is shown in Table 2. Table 2: Inventory Information for the Robson Valley TSA
Coverage Name Source Vintage Update Scale
Ecosystem Vegetation Resources Inventory MSRM 2001 1:20 000Biogeoclimatic Ecosystem Classification MOF 1986 2003 1:50 000Ecoregion Ecosystem Classification Units version 2.0 MSRM 2003 1:250 000Administrative TSA boundary MOF 1993 2002 1:20 000Licensee Operating Areas MOF 1999 2003 1:20 000Ownership MOF 1993 2003 1:20 000Operability MOF 1997 2000 1:20 000Agricultural Land Reserve LRC 1996 1:20 000Landscape Units MOF 1995 1998 1:50 000McBride Community Forest MOF 2003 1:20 000TRIM 1 MSRM 1985 1:20,000Operational Planning Cells MOF 1996 2003 1:20 000Public Sustained Yield Units 2003 1:20 000District Region and Compartments MSRM 2002 1:20 000Timber Supply Blocks MOF 2002 1:250 000Forest Development Plans licensees 2003 1:20 000Depletions MOF 2003 1:20 000Water Community and domestic watersheds MSRM 2003 1:20 000 Environmentally Sensitive Areas (ESA) MSRM 2003 1: 20 000
Old growth management areas (draft OGMA) MOF 2001 Crown land plans BC Assets &
Land Corp. 1999 1: 10 000 to
1:50 000Natural Disturbance Natural Disturbance Units MOF 2001 2002 1: 20 000 to
1:250 000Armillaria root disease zones MOF 1991 2003 1: 20 0001 MOF= Ministry of Forests, MELP= Ministry of Environment, Land, and Parks, WLAP= Ministry of Water, Land and Air Protection, LRC = Land Reserve Commission, LUCO= Land Use Coordination Office
2.1.1 Vegetation Resource Inventory The Vegetation Resource Inventory (VRI) is in its Phase 1, whereby the old standard for forest cover inventory was rolled over into VRI format. VRI has been projected to the beginning of 2002.
2.1.2 Landscape Unit Inventory Landscape units have been established in the Robson Valley TSA but biodiversity emphasis options (BEOs) are still draft and in the process of being reviewed for approval.
2.1.3 TRIM data Streams and roads were extracted from TRIM I. Because they are linear features, a buffer width was applied to each to fully account for the area in each type. The buffers will be described in more detail in Section 3.
2.1.4 Forest Development Plans Spatial coverages of information obtained from forest development plans (FDP) such as cutting permits, non-satisfactorily restocked (NSR) areas, salvaged areas, past, approved and information cutblocks were compiled for all licensees. The type of information available varied by licensees. Slocan, Bell Pole, Hauer Brothers and BCTS provided their 2003-2007 FDP and MFI provided their 2001-2006 FDP.
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2.1.5 Depletions Inventory The depletions coverage was provided by the MOF and is considered to be up-to-date to the summer of 2003. The spatial coverage and database contains information from ISIS and identifies area that has been previously harvested by year.
2.1.6 Grizzly Bear Habitat Inventory A mapping project was conducted for WLAP and MOF where avalanche tracts, an important indicator of critical grizzly bear habitat, were identified through orthophotos (Boreas Environmental Services, 2003). Each tract was classified as high, medium or low based on the percentage of the tract falling on warm aspects. Warm aspects were defined as slopes facing 135o to 225o. Tracts with <25% area falling on warm aspects were given a low, 25 to 75% a medium, and > 75% a high classification.
2.1.7 Caribou Habitat Inventory On November 14, 2003, the Ungulate Winter Range Order #U7-003 was passed. The Order established areas in the Omineca Forest Region as high and medium caribou habitat and corridor areas and established management objectives inside the ungulate winter range. Forest cover constraints used to meet these management objectives and will be outlined later in Section 8.5
2.1.8 Mule Deer Habitat Inventory The mule deer ungulate winter range has recently been established in the TSA. Forest cover constraints are used to model management of identified mule deer habitat. The areas for mule deer habitat areas have been developed replacing previous wildlife ESA (i.e. the wildlife ESA in the TSA will not be modelled).
2.1.9 Elk Habitat Inventory An elk habitat coverage was provided by WLAP and three candidate areas have been identified for elk habitat: Rearguard Falls, Lost Lake and Swift Creek. Although these areas have not been formally designated, the regional wildlife biologist indicated that they would likely be approved within the next 5 years. They are kept in the resultant but no forest cover constraints will be modelled in the base case because no management guidelines have been established. Draft rules could be applied to this zone for a sensitivity analysis.
2.1.10 Road Spatial Coverage The spatial road coverage is a compilation of road features from TRIM I (1985), Forest Tenure Administration System (FTAS) and roads from forest development plans provided by the licensees.
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2.1.11 Armillaria Inventory The Ministry of Forests provided Armillaria root disease risk maps for the years between 1991 and 2002. The maps were compiled into one inventory indicating the risk level. The inventory covered the entire Robson Valley TSA identifying severe and moderate risk areas as well as those areas without Armillaria presence. The moderate incidence rating (2 to 8%) relates to scattered incidence and severe incidence rating (> 8%) relates to concentrated incidence of large patches.
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3 Land Base This section describes the Robson Valley TSA land base and the reductions that are applied to eventually define the timber harvesting land base (THLB) or the area that is available for harvest. The total TSA area initially contains a variety of land types, which are not Crown, controlled or considered part of the TSA including private land, federal land, woodlots, and first nations reserves. After the TSA area is defined then areas, which do not contain trees are removed such as water bodies, brush, non-forest and non-productive areas to identify the productive Crown forest land base (CFLB). Finally, the THLB can be defined after the removal of non-productive areas, non-forested areas, land not managed by the BC Forest Service and Parks, and forested areas that contribute to non-timber values.
3.1 Timber harvesting land base definition The THLB is identified by a netdown process, in which areas ineligible for harvest are sequentially removed from the total land base. Once an area has been removed, it cannot be deducted further along in the process. For this reason, the gross area of netdown factors is often greater than the net area removed; a result of overlapping resource issues. A summary of the netdown order is in Table 3. Use Public Recreation, and Enjoyment (UREPs), parks and ecological reserves are part of Crown productive forest or CFLB because although they may be reserved from harvest, these areas may still contribute to forest cover and biodiversity objectives.
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Table 3: Timber harvesting land base determination for the Robson Valley TSA
Classification
Total area (ha)
Net Area Removed
(ha)
Crown Forest Land
Area (ha)
Percent of Crown
forest land
Percent of Current THLB
Described in Section
Total TSA area 1,458,548Land not managed by BCFS (Private, woodlots, community forest (40N and 77N) Non-productive including water bodies Existing roads, trails and landings Total productive forest managed by BCFS and BC Parks (Crown forest land base) Reductions to Crown Forest Mount Robson Park UREPs, Ecological reserves and other parks Protected areas Agricultural land reserves Alpine (not previously accounted for) Non-commercial cover (brush) Inoperable areas Environmentally sensitive areas Immature stands with low productivity Non merchantable mature stands Essential caribou habitat Grizzly bear habitat Areas with high value for recreation Riparian reserves Inaccessible areas Existing wildlife tree patches Mule deer habitat Total Current Reductions Current Timber Harvesting Land Base (including NSR *) Future reductions Future roads, trails, and landings Future wildlife tree patches Future timber harvesting land base
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3.1.1 Reasons for changes to the THLB since TSR 2 Since TSR 2 was completed for the Robson Valley TSA there have been numerous changes to input data and assumptions that will alter the individual land base reductions as well resulting timber harvesting land base area. Some of those changes include:
1. Addition of Mount Robson Park as well as other parks, UREPs and ecological reserves as contributing biodiversity to the TSA for the analysis.
2. New armillaria inventory. 3. New grizzly bear habitat inventory. 4. Formal designation of caribou habitat. 5. Incorporation of mule deer and elk ungulate winter range areas, which will replace all
previous wildlife ESAs. 6. Semi-spatial reduction of roads. 7. Revised operability. 8. Modelling of partial cutting in VQO areas.
3.2 Exclusions from the Crown Forested Land Base This section will define the THLB by describing areas that are excluded from the CFLB. Individual portions of the timber harvesting land base are described in Table 3.
3.2.1 Land not managed by BCFS Areas in private ownership, woodlots, and Indian, federal, military, and miscellaneous reserves are 100% excluded from the productive CFLB and THLB. Areas managed by the BC Forest Service and Parks are included in the CFLB (although only areas from ownership 62C, 69N, 69C can potentially contribute to the THLB) as shown in Table 4.
Table 4: Ownership codes in the Robson Valley TSA
Ownership Area in TSA
(ha) % Contribution
to CFLB % Contribution to
THLB Private (40N) 0 0 Reserves (60N, 61N) 100 0 UREP Reserves (61C) 100 100 Park (63N, 67N) 100 0 Woodlot (77N) 0 0 McBride Community Forest 0 0 No ownership 0 0 Miscellaneous Reserves (69C) 100 100 Miscellaneous Reserves (69N) 100 0 Forest management unit (62C) 100 100 Total Non-Crown land
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Total TSA area 1,458,562 Notes: LaSalle Recreation Area was added to Parks (63N).
3.2.2 Non-forest and non-productive forest All areas identified as non-forest or non-productive (NPD_descriptor) in VRI will not be part of the CFLB or THLB. These areas include alpine (A), alpine forest (AF), clearing (C), clay bank (CL), gravel bar (G), mud flat (MUD), non-productive (NP, NPBR, NPBU), no typing (NTA), open range (OR), rock (R), swamp (S), and urban/road (U). These areas comprise of 809,962 ha of the entire Robson Valley TSA. Rivers (RI) and lakes (L), also identified by NPD_descriptor, encompass 22,359 ha of the TSA. In total, the TSA contains 832,321 ha of non-forest area. TSR 2 identified non-forest by type id, which will not be used in this analysis. However for comparison, in the current analysis, there are 67,062 ha in type id 6, areas in alpine, lakes, rocks, etc. There are no polygons with type id 8 (no typing available). Lakes, rivers, and wetlands will be identified by NP_descriptor in VRI rather than by the BC Land Classification because the inventory is based on the FIP data and not a complete VRI. A summary of non-forest and non-productive areas for the Robson Valley TSA is provided in Table 5.
Table 5: Areas in non-forest and non-productive forest
Non Productive Description
Area in TSA (ha)
Net Area removed (ha)
Alpine 700,784 Alpine forest 55,112 Clearing 11,963 Clay bank 156 Gravel bar 105 Gravel pit 67 Lake 16,448 Mud flat 965 Non-productive or NP forest 13,439 Non-productive brush 6,733
Non-productive burn 5,785 No typing 367 Open range 115 Rock 4,530
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River 5,911 Swamp 4,698 Urban or road 5,143 Non-productive 832,321 Productive 626,241Total 1,458,562
3.2.3 Existing roads, trails and landings Road-related disturbances such as landings and gravel pits are captured in the forest cover inventory and are removed as non-productive areas. Existing roads, however, are not accounted for in the forest cover inventory. Existing roads were buffered using GIS functionality. The road buffers are not spatially tracked in the resultant dataset but instead polygon-specific percent reductions were calculated. The reductions for each road type along with the length and buffer width are provided in Table 6. Road width is defined as the distance from stem to stem on old roads and between plantable ground on new roads. Average road widths by type were provided by the DFAM group.
Table 6: Reductions for existing roads
Type Length
(km) Road Width
(m) Buffer used
(m) Notes
Deactivated 60.8 0 0 Not buffered because it will be planted. Source: FDP.
Proposed 1,305.9 0 0 Not buffered because they do not exist yet. Source: FDP.
Forest Service Road 180.6 20 10 From FDP and FTAS.
Logging 960.4 20 10
Roads identified in FDP but are not categorized as any of above FDP roads. These include temporary deactivated, existing roads and spurs.
The roads were buffered according to the above road widths and the total area of roads for the Robson Valley TSA is 9,245 ha.
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A similar assumption as TSR 2 for reductions due to landings will be made. It will be assumed that on average a 0.2 ha landing serves a 10 ha block (i.e. a 2% total land reduction). There are 55,537 ha of cutblocks in the depletion coverage. Using the same 2% reduction assumption, 1,111 ha in existing landings will be removed from the CFLB.
3.2.4 Parks, UREPs and Ecological Reserves Area in parks, use, public recreation, and enjoyment (UREP) and ecological reserves will not contribute to the THLB but will contribute to biodiversity. The gross area of the above reserves in the TSA is 293,873 ha (Table 7). These collective reserves will be part of the CFLB but not the THLB.
Table 7: Area in parks, UREPs and ecological reserves
Description Area in TSA
(ha) % Contribution
to the TSA % Contribution
to the CFLB Mount Robson Park 221,637 Ecological reserves 508 UREP reserves 940 Other parks 70,788 Total 293, 873
3.2.5 Protected areas Ten protected areas as outlined in the Robson Valley Land and Resource Management Plan (LRMP 1999) have been established and a total area of 69,915 ha will be removed from the CFLB (Table 8). Table 8: Protected areas in the Robson Valley TSA
Protected Area (LRMP RMZ name)
TSA Area (ha)
% Contribution to the CFLB
Betty Wendle 14,441 Cariboo River 6,327 Foster Arm 969 Holiday Creek Arch 408 Jackman Flats 681 Lower Raush 1,263 Small River Caves 1,854 Swiftcurrent River 6,045 Upper (middle) Raush 5,559 West Twin 32,367 Total 69,915
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3.2.6 Agriculture land reserve Since agriculture land reserve (ALR) areas are not currently managed by the licensees or by the BC Forest Service and there is little data or information available on the current inventory and management activities, they will be removed from the THLB.
3.2.7 Alpine (not previously removed from the THLB All area classified as alpine tundra and subalpine parkland (AT) will be considered as non-commercial land for the timber supply analysis. Where trees do occur in these areas their growth is usually stunted and the trees are very widely spaced. Individual trees rarely meet the minimum harvestable dimensions and, therefore, have no merchantable value. Alpine and alpine forest have already been excluded from NP_descriptor in VRI as ‘nonproductive/nonforested’ (Section 3.2.2). Additional alpine tundra (AT un and AT unp) areas as identified by BEC will also be excluded from the THLB.
3.2.8 Non-commercial brush Areas classified as non-commercial and non-commercial brush species will be excluded from the CFLB, which is identified by type_id 5, or NC and NCB under NF_descriptor in VRI. For the entire TSA, there are 34 ha of non-commercial forest and 1,748 ha of non-commercial brush.
3.2.9 Inoperable areas An operability map for the Robson Valley TSA was produced by the Northern Interior Forest Region and refers to the logging method that could be expected based on the slope of the land. The four operability codes are A (conventional ground based equipment), C (cable), M (mixed cable and conventional), and I (inoperable). From the operability map, areas identified as inoperable are excluded from the CFLB. The licencees have also identified further areas that are to be removed from the CFLB. At the time of writing this document, the new operability classification was being added to the data set so summaries are not yet available.
3.2.10 Environmentally sensitive areas Some forest lands are environmentally sensitive and/or significantly valuable for other resources. Many of these areas are identified and delineated during a forest inventory and are referred to as environmentally sensitive areas (ESAs). The ESA system uses the following categories: soil (Es), forest regeneration problems (Ep), snow avalanche (Ea), recreation (Er), and wildlife (Ew). With the exception of avalanche, two ESA categories are recognized: high and moderately sensitive. It is assumed that where a forest cover polygon has both ESA1 (high sensitivity) and an ESA2 (moderate sensitivity) category that the area of the ESA does not overlap within the polygon. The ESA1 will reduce the polygon by 90% and the ESA2 will reduce the remaining 10% of the polygon for a 100% reduction (Table 9).
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Note that compared to TSR 2, there are currently no ESA wildlife because they have effectively been traded off for the establishment of mule deer ungulate winter range areas.
Table 9: Reductions from environmentally sensitive areas
ESA category ESA description
Area in TSA (ha)
Net Area removed
(ha)
Reduction percent
(%) Es1 Soil sensitivity: terrain stability class V
terrain 90
Es2 Soil sensitivity: terrain stability class IV terrain
10
Ep1 and Ep2
Forest regeneration problems 90
Ea1 Snow avalanche 90 Er1 Recreation 100
3.2.11 Immature stands with low timber growing potential A minimum site index (SI) was used to determine stands with low productivity, which will not be part of the THLB (Table 10). The derived SI reflects the minimum productivity required to attain a minimum volume by 140 years. The minimum volume for the conventional, mixed, and cable operability codes are 140 m3/ha, 200 m3/ha, and 250 m3/ha, respectively. Stands that do not meet the criteria but have been harvested or treated in the past will remain in the timber harvesting land base. In VRI stands that have been logged or rehabilitated (disturbance code of ‘L’ or ‘R’), or have been managed for site improvement or stand tending (SI or ST) will remain in the THLB.
Table 10: Site index (SI50) exclusions for immature stands
Operability code Stands < 140 years
Stands < 100 years Stands <140 years
Douglas- fir Cedar Hemlock Balsam Spruce Pine Aspen Birch Cottonwood
3.2.12 Non-merchantable mature stands Non-merchantable forest types are stands, which contain non-commercial species, low timber volumes, or have low productive potential for timber harvesting. There is little performance in deciduous forest types within the TSA but there is currently a partition of the allowable annual
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cut for the harvest of deciduous species. There is also a direction from the District Manager that while deciduous harvest remains low there is growing interest and proposals for its utilization. Therefore, those mature deciduous-leading stands that have attained minimum height and volume criteria will remain in the THLB for the base case in order to assess the deciduous timber supply. A sensitivity analysis is proposed whereby the leading deciduous stands will be removed from the timber harvesting land base. Mature coniferous stands that have not reached minimum height or volume criteria are considered unavailable for timber harvesting. Table 10 and Table 11summarize the site index cut-offs for immature stands and the merchantability cut-offs for mature stands.
Table 11: Mature stand exclusions
Type group (leading species)
Age class
Volume (m³/hectare)
Height class
Stocking class
Operability code
1-8 (Douglas-fir) ≥ 7 2 1 or 2 All ≥ 7 1 All All 9-11 (Cedar) ≥ 7 < 3 All All 12-17 (Hemlock) ≥ 6 < 3 All All 18-20 (Balsam) ≥ 6 4 2 C ≥ 6 3 2 All ≥ 6 2 1 or 2 All ≥ 6 1 All All 21-26 (Spruce) ≥ 7 2 1 C ≥ 7 2 2 All ≥ 7 1 All All 27-31 (Pine) ≥ 5 3 3 C ≥ 5 3 4 All ≥ 5 2 1 M or C ≥ 5 2 2-4 All ≥ 5 1 All All 1-34 (All coniferous species) ≥ 8 < 250 All All C
≥ 8 < 200 All All M ≥ 8 < 140 All All A 35-42 (Deciduous) All All All All M or C ≥ 4 All < 3 All A ≥ 4 All All > 1 A
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Type group (leading species)
Age class
Volume (m³/hectare)
Height class
Stocking class
Operability code
35,36, 40 (Birch or Cottonwood) ≥ 8 < 140 All All A
(41-42) Aspen ≥6 < 140 All All 9-11 (Cedar) and 12-17 (Hemlock), supply blocks A, B, I, J
All All All All M or C
Age class: 4 = 61-80 years; 5 = 81-100 years; 6 = 101-120 years; 7 = 121-140 years; Height class: 1 = 0.1-10.4 metres; 2 = 10.5-19.4 metres; 3 = 19.5-28.4 metres; 4 = 28.5-37.4 metres; Operability code: A = conventional, C = cable, M = mixed cable and conventional, I = inoperable.
3.2.13 Essential caribou habitat As stated in the Robson Valley LRMP, harvesting is deferred between 1999-2009 in high quality winter range caribou habitat. As of the time of writing this data package there was no clarification on the management of the winter range caribou habitat post-2009. This was discussed with Chris Ritchie (Section Head, Ecosystems, MWLAP), who could not provide any further details regarding future management. Therefore, the high quality winter range habitat will be permanently excluded from the THLB.
3.2.14 Grizzly bear habitat A grizzly bear suitability map for the TSA was provided from WLAP where all warm aspect (south-east to south-west facing) avalanche paths in the ESSF zone have been identified as low, medium, or high suitable habitat. To maintain habitat quality, the current policy has been to retain 50 m wide buffers on these slide chutes. These avalanche areas have been spatially identified, buffered with 50 m, and removed from the THLB (Table 12). The Robson Valley LRMP also recommends a 100 metre buffer on avalanche paths in important grizzly bear habitat; however, these areas have not been formally identified or approved. To represent the direction of the LRMP, a sensitivity analysis will be conducted where the low quality tracts will retain its 50 m buffer but the medium and high quality tracts will be given a 100 m buffer.
Table 12: Critical grizzly bear habitat reductions to the timber harvesting land base
Grizzly Habitat Area in CFLB
(ha) Net Area Removed
(ha) Reduction percent
(%) Avalanche path 203,060 100
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50 m buffer 86,938 100 Total 289,999 100
3.2.15 Areas with high value for recreation In addition to ESA recreation areas, developed and undeveloped recreation areas are identified on the inventory file through the recreation management class and recreation feature significance labels. Four management classes are defined:
Management Class Definition
0 Area is of outstanding recreational, educational or heritage value and is more appropriately managed primarily for the recreation values noted. Referral to recreation staff is required.
1 Area requires special management considerations to protect or maintain recreation values noted. Referral to recreation staff is required.
2 Current forest management practices may be adequate to maintain recreation values. Consultation with recreation staff is desirable, but not essential.
X Unclassified. More information is required for evaluation of recreation values within the polygon.
Four recreation feature significance classes reflect the highest rating of three factors: feature scarcity/uniqueness, activity attraction capability, and scenic attractiveness. The classes are:
Recreation Feature Significance Class Definition
A Very high B High C Moderate D Low
Areas with a recreation management class 0 and any feature significance (A, B, C, or D) are identified as high value areas and will be 100% excluded from the area available for timber harvesting. Forested land with a recreation management class 1 that does not coincide with a VQO, will be modelled as follows (Table 13):
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1) 50% of each area with a feature significance B (high) will be excluded from the THLB 2) 25% of each area with feature significance C (moderate) will be accounted for within a riparian reserve or management zone (as indicated by checks of sample maps), and 3) one-half of the remaining area (50% x 75% = 37.5%) will be excluded from the THLB. There are no areas with feature significance A (very high) in recreation management class 1. All areas with recreation management classes 2 and X will be included in the THLB.
Table 13: High recreation areas
Attribute Area in CFLB
(ha)
Net Area Removed
(ha)
Reduction percent
(%) Management Class 0 1,169 100 Management class 1- Significance B, without VQO 33,074 50 Management class 1- Significance C, without VQO 84,021 37.5 Total 38,711
3.2.16 Mule deer habitat Under the Mule Deer Ungulate Winter Range Areas for Designation in the Robson Valley, 2003, it has been proposed that a minimum of 66% canopy closure be retained for stands that are 141+ years and that openings should not be greater than 10 ha in size and less than 250 m wide for any harvesting. An initial query of these areas shows that almost the entire habitat area is ≥ 141 years old and that generally, the canopy closure is less than 66%. This amounts to a gross area reduction of 463 ha which will be excluded from the THLB.
3.2.17 Riparian reserve and management zones No significant stream classification study has been conducted in the TSA since the last TSR. Therefore, assumptions on stream classification and reserve/management widths were made by the DFAM Group. From TRIM II, large streams such as S1 streams are identified. It is assumed that double line streams in TRIM represent the S2 streams and the single line streams represent the remaining S3-S5 streams, where the latter would be aggregated and assumed a compiled riparian reserve and management zone of 20 metres. Wetlands and lakes are buffered according to the Riparian Management Area Guidebook. There are no W2 and W4 wetlands or L2 and L4 lakes. The total area of the timber harvesting land base affected by riparian management is determined by applying the assumptions in (Table 14) to the forest cover inventory file water features and running a GIS buffering process. Table 14: Timber harvesting land reduction from riparian reserves and management zones
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Riparian Feature
Riparian class
Reserve zone width (metres) 100% reduction
Management zone width
(metres)
Management Zone Volume
Reduction (%)
Combined buffer width for RZ and
RMZ (metres)
Net Area Removed (ha)
Streams Fraser River 50 20 50 60 S1 (except large rivers
3.2.18 Inaccessible areas Further inaccessible and inoperable areas were identified by the DFAM group. These areas will also excluded from the THLB: � upper Nevin (King) Creek (Planning cell B029), � Baker (Holliday) Creek (Planning cell B031), � Small Creek Cell (Planning cell F006) falling into the Swift Current Creek (isolated by
PAS area), and � Foster and Cariboo landscape units.
To best represent current management, the Foster and Cariboo landscape units will be excluded from the THLB (which were included in the TSR 2). Performance within these areas has been limited and there is a new park in the Caribou LU. MFI have identified the rest of the Caribou LU as uneconomical and inaccessible. BCTS have approved cut blocks in the Foster landscape unit (LU) but currently find it uneconomical to harvest since it requires a significant investment for access. A sensitivity analysis is proposed to include the Caribou and Foster LU in the THLB.
3.2.19 Stand-level biodiversity (WTP) After all other removals are completed, additional reductions are required to account for the amount of timber retention required for wildlife trees and wildlife tree patches (WTP). Section 3.2 and Appendix 3 of the Landscape Unit Planning Guide (updated in March 2000) will be the basis for modeling wildlife tree management in this timber supply analysis. The procedure for calculating WTR requirements is outlined in the following 6 steps and summarized in Table 15.
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Table 15: Summary of the procedure used to calculate the wildlife tree retention reduction.
Step 1 Step 2 Step 3 Step 4 Step 5 Step 6
LU name
BEC subzone*
Crown forested
(ha)
Current THLB
(ha)
% subzone available
for harvest
% THLB harvested without WTR
WTR target (%)
THLB requiring
WTR (ha)
Area removed
(ha)
Total *Note that representation is to subzone as directed in the Land Use Planning Guide, revised March 2000.
Step 1 WTR requirements are calculated separately for each biogeoclimatic subzone within each landscape unit. Step 2 The crown forested area is all polygons within the TSA that are classified as forested in the netdown. The Current Timber Harvesting Land Base (THLB) is the total area remaining from the netdown process, except for future road reductions and the wildlife tree retention being calculated in this process. Step 3 The percentage of the BEC subzone within the landscape unit available for harvest is calculated as follows: (THLB/crown forested area)*100% Step 4 The purpose of this step is to estimate the portion of the THLB where previous harvesting does not meet WTR objectives. For the purposes of estimating this area, it is assumed that harvesting activities before the introduction of the Biodiversity Guidebook in 1995 do not meet WTR objectives. Therefore, the area that has been harvested without wildlife tree retention is assumed to be all forested polygons with a history of logging that are greater than 7 years old. Step 5 Based on the information derived in steps 1-3, total wildlife tree retention targets are determined from Table A3.2 in the revised Appendix 3 of the Landscape Unit Planning Guide.
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Step 6 Reserves such as riparian reserve zones contribute to wildlife tree retention targets. The Landscape Unit Planning Guide states that there should be no more than 500m between wildlife tree patches. To determine the proportion of the THLB requiring wildlife tree patches, a 250-meter GIS buffer is applied to existing reserves (defined as >80% retention). WTR targets are applied uniformly to the areas beyond the 250 meters buffer from existing reserves. There are no established wildlife habitat areas (WHAs) in the TSA but species at risk have been identified under Volume I of the Identified Wildlife Management Strategy (IWMS) 1999. A list of the identified wildlife is in Section 8.5.1.
3.2.20 Future roads, trails, and landings The depletions coverage, which contains ISIS information, was used to predict the percentage of roads, trails, and landings (RTLs) in cutblocks using NP UNN (non-productive, unnatural). Between 1995 and 2001, the average NP UNN area in cutblocks is 5.5%.
The forest development plan (FDP) and the depletion coverages contain cutblock information. The FDPs generally contains recent cutblocks and the Depletion coverage contains blocks harvested since 1945 with possible information missing in the earlier years; nonetheless, the coverages together contain the most thorough information on past and current harvest. These two coverages were overlaid with the road coverage (see Section 3.2.3 for details on the analysis of roads) to determine an appropriate road density (ha/ha) in cutblocks is 4 %. Trails were assumed to have no reduction as few if any plantable spots are affected by the trails. As such, it may be assumed that 1.5% (5.5% - 4%) of cutblocks are in landings. The landing reduction is similar to the 2% reduction estimated in TSR 2. A buffer analysis will be conducted to determine the future RTLs. All existing roads will be buffered by 200m, the average yarding distance for the Robson Valley TSA. It is assumed that cutblocks within the 200m buffers can be accessed using existing roads. The area inside the buffer will be the roaded area. All areas outside the buffer will be the non-roaded area. Assuming that the RTL density in the roaded area will also apply to the non-roaded area, a future 5.5% RTL will be applied to the THLB in the non-roaded area. There is a growing concern from the DFAM Group to react to the emerging mountain pine beetle infestation in the valley; specifically, the potential for a shift of operations to mature pine types (and a potential increase in road development and sanitation/control harvest (cut) over the next few years). There are currently no road density studies (extent and impacts of increased road development related to the harvest of mature pine leading (susceptible/infested) types in the TSA) and therefore no further reductions are proposed at this time.
3.2.21 Cultural heritage resource deductions Archaeological overview and cultural heritage value inventories for the entire Robson Valley TSA are yet to be completed or are not comprehensive enough to include in the timber supply
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analysis. The impacts of measures required to protect known sites remain unknown at this time. If any new information becomes available it will be included in the data package in subsequent revisions.
3.2.22 Further exclusions to the timber harvesting land base The Canoe Mountain agreement is to develop an all-season resort on Crown land just outside Valemount. The development involves the exclusion of a base area of 138 hectares and an additional 1,214 hectares of Crown land will be tenured for a gondola lift to an alpine viewing area and a community ski hill. These areas will not be included in the THLB for the base case analysis.
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4 Management zones and analysis units
4.14.14.14.1 Management groups and objectivesManagement groups and objectivesManagement groups and objectivesManagement groups and objectives The concept of management groups is used to differentiate areas with distinct management emphasis and homogeneous forest cover. For example, a group may be based on a harvesting system, silviculture system, visual quality objective or wildlife consideration. The forest cover data set can also be grouped by different variables. In addition, the productive crown forest land base may be included for consideration in attaining forest cover objectives. Groups may be thought of as layers of different objectives, which must be tracked over time. The management groups used for this analysis are shown in Table 16.
Table 16: Management grouping definitions
Group Objectives
Visual quality Established visual quality objectives 1. Preservation 2. Retention 3. Partial retention 4. Modification 5. Maximum modification
Watersheds Community watersheds Caribou Caribou habitat management zones
1. Medium 2. Corridor
Integrated resource management (IRM)
Integrated resource management (IRM)
Landscape units See Section 8.6.1.1
4.24.24.24.2 Analysis unitsAnalysis unitsAnalysis unitsAnalysis units An analysis unit represents a combination of stands dominated by specific tree species or a silviculture regime with a set range of timber growing capability – as indicated by the species and site index in the forest inventory file. Each analysis unit is assigned its own timber volume projections for existing and future stands. Fourteen primary analysis units have been identified for the Robson Valley TSA (Table 17). The analysis units may be further delineated after the THLB and volume curves have been determined.
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Table 17: Analysis Units
Analysis unit
Analysis unit (leading species)
Inventory type groups BEC zone Additional Criteria
05 Douglas-fir (Fdi) 1-8 All Except armillaria areas 06 Subalpine fir
(Balsam) (Bl) 18-20 ESSF
07 Subalpine fir (Balsam) (Bl)
18-20 ICH/SBS
08 Western redcedar (Cw)
9-11 All Except supply blocks A, B, I, and J
09 Western hemlock (Hw)
12-17 All Except supply blocks A, B, I, and J
10 Deciduous (Dec.)
35-42 All
11 Cedar (Cw) (Cw-Hw partition)
9-11 ICH Supply blocks A, B, I, and J
12 Hemlock (Hw) (Cw-Hw partition)
12-17 ICH Supply blocks A, B, I, and J
13 Douglas-fir (Fdi) 1-8 Armillaria moderate zone14 Douglas-fir (Fdi) 1-8 Armillaria severe zone
Note: there are no Inventory Type 6, 32, 37, 38, and 39. There are two Armillaria root disease incidence ratings: moderate (2 to 8%), which relates to scattered incidence and severe (> 8%), which relates to concentrated incidence of large patches.
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5 Growth and Yield This section describes the issues, information sources and assumptions, and methods related to growth and yield estimates for existing and future stands under both unmanaged and managed conditions.
5.1 Site index Site index is a measure of the productive capacity of a given site to sustain the growth of trees to harvestable age. It is a key variable in predicting the growth of timber and its yield at harvest. Site index is defined as the height of a “site” tree at 50 years breast height age. Site index curves that are consistent with the accepted MOF standards are used.
5.1.1 Site index adjustments Because the VRI is in Phase 1, no site index adjustments have been done. Also, there is no ecosystem mapping completed for the Robson Valley TSA. As such a sensitivity analysis will be completed using the OGSI methodology. There are old growth site index (OGSI) adjustment equations available for adjusting site index from natural old age stands (age > 140 years) regenerating to managed second growth stands. The equations for OGSI adjustment are derived from the report Site Index Adjustments for Old-growth Stands Based on Veteran Trees, MOF. The site index adjustments are applied to “old” stands upon harvest to determine the second growth (SG) site index (Table 18). Adjustments will be applied based on the leading species by analysis unit. These adjustments will only apply to the SIOG for managed stands following the guidelines given in the OGSI reports. As there is no locally calibrated reliable OGSI data, the OGSI adjustments will not be used in the base case. The OGSI sensitivity analysis will show the impact of these SI adjustments. Table 18: Old-Growth Site Index (OGSI) Adjustment Equations
Old-Growth Species OGSI Adjustment Equation Hardwoods (Hwd) SISG = 12.67 + 0.4279* SIOG Western redcedar (Cw) SISG = 20.69 Subalpine fir (Bl) SISG = 8.824 + 0.5682* SIOG
Douglas-fir (Fdi) SISG = 8.215 + 0.6211* SIOG
Lodgepole pine (Pli) SISG = 7.885 + 0.7167* SIOG
White spruce (Sw) SISG = 9.303 + 0.6212* SIOG
Western hemlock (Hw) SISG = 11.42 + 0.5430* SIOG
Western Larch (Lw) SISG = 22.08
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Ponderosa pine (Py) SISG = 8.311 + 0.6081* SIOG
5.25.25.25.2 Utilization levelUtilization levelUtilization levelUtilization level The utilization levels define the maximum stump height, minimum top diameter inside bark (dib) and minimum diameter at stump height (dsh) by species and are used in the analysis to calculated merchantable volume (Table 19). The DFAM group reviewed these utilization standards and agree to their application for TSR 3.
Table 19: Minimum utilization levels in the Robson Valley TSA
Analysis Unit Min dbh (cm) Max Stump Height (cm) Min top dib (cm) Lodgepole pine (Pli) 15.0 30.0 10.0 All other conifers and deciduous trees 20.0 30.0 10.0
Western red cedar is actually utilized to a 15 cm dib but this will not be reflected in the analysis because data for modelling is unavailable. For deciduous species, the top diameter will be 10 cm or where the branching habit of the species dictates, utilization to the first major branches will be required. For the purposes of producing volume yield curves for this analysis, it is assumed that 15 cm dsh is equivalent to 12.5 cm diameter at breast height (dbh), and 20 cm dsh is equivalent to 17.5 cm dbh.
5.35.35.35.3 Decay, waste and breakage for unmanaged standsDecay, waste and breakage for unmanaged standsDecay, waste and breakage for unmanaged standsDecay, waste and breakage for unmanaged stands Decay, waste and breakage factors by species are applied to unmanaged stand yield tables to obtain net volumes per hectare. These factors are the standard values incorporated into the Variable Density Yield Prediction (VDYP) model.
5.45.45.45.4 Operational adjustment factors for managed standsOperational adjustment factors for managed standsOperational adjustment factors for managed standsOperational adjustment factors for managed stands Operational adjustment factors (OAF) are applied to yield curves for managed stands to reduce potential yields generated by growth and yield models to operational yields. The common default values are OAF 1 of 15% and an OAF 2 of 5%. OAF 1 includes accounting for openings in stands (4%), distribution of stems or clumpiness (4%), endemic pests and diseases (4%), and other risks to potential yield (3%) for a total of 15%. OAF 2 is applied to account for decay, waste and breakage. The 5% factor originates from estimates for older immature stands documented in the 1976 Metric Diameter Class Decay, Waste and Breakage Factors. It increases linearly at this rate (10% at 200 years, 15% at 300 years etc). The default factors are used with the exception of spruce weevil and Armillaria areas notes below. Spruce-leader weevil damage to spruce-leading stands in the ICH and SBS zones were estimated to account for up to a 200 m3 loss in volume over the rotation of a spruce stand. In TSR 2, the MOF used TIPSY SWAT (TIPSY with spruce weevil and brush impacts) to
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determine the losses caused by both brush and the spruce-leader weevil. They derived an OAF 1 of 10% to account for them in addition to the standard adjustment of 15%; therefore, all spruce leading regenerated stands will receive an OAF 1 of 25%. It was agreed upon the DFAM Group that these OAFs still reflect current growth reductions. In areas identified as moderate and severe incidence of Armillaria root disease, the Prince George regional pathologist estimated for TSR 2 that on average the volume reduction will be 20% to 25% over a rotation, however, further surveys and research are needed. OAF 2 has been adjusted to 10% and 20% for moderate and severe incidence, respectively. The DFAM Group estimates these OAFs reflect current growth losses. Details of OAFs for each analysis unit are provided in Section 6.1.
5.5 Volume exclusion for mixed species The deciduous component in conifer-leading stands will not contribute toward the estimated stand volume and total harvest volume and will be excluded from the estimation of stand volume.
5.65.65.65.6 Other issues related to yield table development Other issues related to yield table development Other issues related to yield table development Other issues related to yield table development
5.6.1 Yields for Existing and Future Managed Stands Managed stand yield tables (MSYT), generated from using the B.C. Forest Service table interpolation program for stand yields (TIPSY 3.0h) growth and yield model will be applied to existing immature forest where the density (stems per hectare) was controlled through planting and/or spacing. In the Robson Valley TSA, all harvested areas have been planted and therefore, all NSR, recent and future harvested stands will be managed under MSYTs. To account for managed stands over the past few decades, a similar approach was taken as in TSR 2 where it was found from ISIS and MLSIS that the majority of the stands less than 35 years were considered managed as indicated in Table 20. Stands over 15 years of age and less than 35 were split into a managed and unmanaged components based on the percentages on Table 20. Yield tables for each analysis unit will be derived by employing average area-weighted attributes (e.g. site index, species composition) to generate a single aggregated table.
Table 20: The percentage of harvested areas that will be managed under managed yields
Area managed (%) Analysis unit Age 1 – 15 Age 16 – 25 Age 26 – 35
All 100 95 83
5.6.2 Yields for Natural (Unmanaged) Stands Yield tables for unmanaged immature stands will be predicted with Batch Variable Density Yield Plots (VDYP) version 6.6d. In each analysis unit, the portion of natural stands receiving
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naturally regenerated growth curves are defined in Table 21. Yield curves will be derived by area-weighting each growth curve generated from each polygon into an aggregate curve by analysis unit.
Table 21: The percentage of previously harvested areas that will be managed under unmanaged yields
Area (%) Analysis unit Age 16 – 25 Age 26 – 35
All 5 17
5.6.3 Existing timber volume check After the growth curves have been determined for each analysis unit, they will be verified to determine whether any errors were made in aggregation and that no significant aggregation bias exists. If necessary, new analysis groupings may need to be developed depending on the % difference between the inventory volume and yield table volumes. Once the yield curves are completed, the total volume of the current inventory using polygon-specific inventory volumes will be compared to the total volume of the current inventory based on analysis unit volumes (Table 22).
Table 22: Existing timber volume check
Polygon volume derived using:
Inventory volume Yield table (AU)
volume Percent (%) difference
Total Volume (m3)
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6 Silviculture This section describes the history of silvicultural activities as well as the assumptions made on silvicultural management regimes used in the Robson Valley TSA.
6.1 Silviculture management regimes In the Robson Valley TSA, harvested lands have been managed by planting and density control for the past 15 years. Regeneration assumptions will thus be provided for managed stands and for all natural stands, no regeneration delay is assumed since these sites often contain advanced regeneration. The average age of the planting stock is 1.4 years (60% of the planting stock is one year old and 40% is two years old). Therefore, the effective regeneration delay is 4 – 1.4 years = 2.6 years. The DFAM Group felt that the regeneration assumptions from TSR 2 (Table 23) reflected current practice but data from ISIS is currently being reviewed to support this assumption. Specific regeneration assumptions need to be developed for the VQO partial cutting regime. This is currently being developed and will be further described in Section. An explanation of the OAF values is described in Section 5.4.
Table 23: Regeneration assumptions for managed stands
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AU # BEC zone % Regenerating Species %*
Regen-eration delay OAF1 OAF2 Type %
Initial density
11 Cw (partition) ICH
12 Hw (partition) ICH
13 Fdi –
Armillaria moderate
All 2.6 15 10 Plant 100 1450
14 Fdi –
Armillaria severe
All 2.6 15 20 Plant 100 1450
* this information will be completed once the ISIS review of the regeneration assumptions is complete. Historically stands have not been managed for deciduous tree species. However, stands harvested under the deciduous partition are assumed to regenerate to deciduous-leading stands.
6.26.26.26.2 Gene resources Gene resources Gene resources Gene resources ———— use of select seed use of select seed use of select seed use of select seed At the time of writing this information was not complete. It will be incorporated in to the next data package revision.
6.36.36.36.3 Backlog and current not satisfactorily restockedBacklog and current not satisfactorily restockedBacklog and current not satisfactorily restockedBacklog and current not satisfactorily restocked Backlog NSR is any area that was denuded prior to 1987 and is not yet fully stocked. All other NSR is considered current NSR. Current NSR is calculated from the depletion coverage (3,336 ha) provided by MSRM as well as the 1,650 ha of NSR (not captured in the depletion coverage), originating from the FDP data. It is assumed that current NSR will be regenerated following normal regeneration delay schedule. It is likely many of the current NSR stands are regenerated but not updated in the database. At the time of writing, there were some existing discrepancies between what is reported for backlog NSR in VRI, depletions and ISIS. This information is being discussed with Forest Analysis Branch and any changes will be provided in the next version of the data package. Once completed, the regeneration schedule will also be provided (Table 24).
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Table 24: Not satisfactorily restocked (NSR) backlog areas
Year
AU regenerated to
Area Regenerated
(hectares)
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7 Unsalvaged Losses Unsalvaged losses are timber losses that occur due to insect and disease epidemics, fire and blowdown. In modeling timber supply, these loss estimates are typically taken out of the forecasted timber volume that is reported by the model. Except for unrecoverable losses due to the bark beetles in the TSA, no new studies have been undertaken since the last TSR and therefore, the same numbers will be used for estimating unsalvaged losses. For losses other than from the bark beetles, the Forest Insect and Disease Survey (FIDS Reports) were used and the areas affected were averaged over 10 years and annual fire loss summary reports were averaged over 20 years. The DFAM Group however noted that since the last TSR, hemlock looper has decreased but the mountain pine beetle infestation has increased. For unsalvaged losses due to the bark beetles, each licensee except for BCTS, provided an estimate of the average unsalvaged losses (i.e. volume loss after taken into account salvage volumes) for their operating areas over the last three years (Table 25). Mountain pine beetle is the most significant insect disturbance agent and the DFAM Group has expressed concern over its future impact to the TSA but through the DFAM Forest Health initiative, it will further provide supporting data on unsalvaged losses due to the beetles. Table 25: Unsalvaged volume losses (m3/year) due to beetle in the Robson Valley TSA by licensee.
Disturbance Factor Bell Pole
Hauer Brothers
McBride Forest
Industries
Slocan Forest
Products
BC Timber Sales* Total
Mountain Pine Beetle
500 7,000 5,250
12,750
Spruce Beetle 100 500 875 1,475 Douglas Fir Beetle
50 100 500 875
1,525
Balsam Bark Beetle
50 5000 875
5,925
Total 50 750 13,000 7,875 1,663 23,338 * BCTS could not provide an unsalvaged loss estimates in their operating area. However, from the analysis of the other licensees, the average beetle-related unsalvaged losses are approximately 1.58 % of a licensees’s operating area. BCTS’s operating area is 105,374 ha; therefore, it is assumed that BCTS will have about 1,663 m3/year of unsalvaged losses from beetle attacks. The unsalvaged losses in the Robson Valley TSA due to natural disturbance agents is provided in (Table 26).
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Table 26: Total unsalvaged volume losses
Disturbance Factor TSR 2 Assumed
Net Loss Net Volume Loss
(m3/year) Mountain Pine Beetle 13,945 23,338 Hemlock Looper 39,111 * Fire 34,673 34,673 Wind Damage 2,125 1,000 Disease Damage 2,750 1,125 Total Losses 92,604 66,724
* the assumption for hemlock looper is currently being reviewed and will be revised in future versions of the data package.
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8 Resource Management Emphasis This section provides details on how the modeling methodology will integrate non-timber resource values with timber objectives, which is often done through forest cover requirements.
8.1 Management Zones and Multi-Level Objectives Management zones are geographically specific areas that require unique management considerations. Areas requiring the same management regime or the same forest cover requirements are grouped into management zones.
8.2 Forest Cover Requirements Timber supply analysis will account for forest cover objectives primarily at the landscape level. Forest cover management aims to protect biodiversity, identified wildlife habitat, domestic water use, and visual quality by specifying target height and age distributions. The primary sources of direction for forest cover management in the Robson Valley TSA is the Robson Valley Land and Resource Management Plan (1997).
8.3 Visual resources The updated visual quality inventory produced 517 visual quality polygons over 613,954 ha in the Robson Valley TSA. 438 polygons (220,381 ha) of the VQO polygons are known scenic areas with established Visual Quality Objectives (VQOs). The remaining polygons have not been formally established, but the recommended Visual Quality Class (VQC) will be the basis for modelling visual quality management. Based on these two attributes, two visual forest cover requirements—percent denudation and visually effective green-up—are determined separately for each visual quality polygon. On December 12, 2003, the MOF release a bulletin titled Modelling Visuals in TSR III. This bulletin updates the recommendations outlined in Procedures for Factoring Visual Resources into Timber Supply Analyses (the Procedures). The updated procedures include a new approach for calculating percent denudation, and recommendations for modelling the effect of retention harvesting systems on VQOs. The Robson Valley TSR 3 will incorporate these procedures where possible, including:
• Modeling VQO constraints individually for each scenic polygon; • Customization of allowable alteration values (percent denudation in perspective) that
reflect the visual effect of demonstrated retention harvesting in scenic areas (which will account for some variability within the % alteration by including VAC as a modifier).
• Calculation of polygon-specific percent denudation values using plan-to-perspective (P2P) factoring; and
• Calculation of visually effective green-up (VEG) on a polygon-specific basis.
The rationale and methodology for each of these approaches are outlined below.
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8.3.1.1 Polygon-Specific VQO constraints District and Provincial MOF staff has indicated that visual constraints should be applied at the polygon level. This means that the maximum allowable alteration cannot be exceeded within any polygon delineated by the visual quality inventory.
8.3.1.2 Percent Denudation The MOF bulletin Modelling Visuals in TSR III identifies a range of allowable % alteration in perspective view for each visual quality objective (Table 27). The appropriate values for the Robson Valley TSA are currently being developed and cannot be reported at this time. Percent denudation applies to the crown forested land base, not the productive or timber harvesting land base. For visual quality analysis, the crown forested land base will include roads and as well as any forested non-productive (NP) land.
Percent denudation is the permissible percent alteration in plan view, and is the value used for timber supply analysis. To convert from perspective view to plan view, a plan-to-perspective (P2P) ratio is calculated based on the average slope of the polygon, as identified in Modelling Visuals in TSR III and shown in Table 28. Since VQOs will be modeled on a polygon-specific basis, the P2P ratio and the percent denudation will be different for every polygon. The P2P ratio for visual polygons in the Robson Valley TSA is 2.2 on average, and ranges from 1.04 to 4.68.
Table 28: Predicted P2P ratios for slopes for all visual designs, based on average slope
8.3.1.3 Visually Effective Green-up Allowable percent denudation refers to the proportion of a visual polygon that can be less than the visually effective green-up (VEG) height. As noted in the Procedures for Factoring Visual Resources into Timber Supply Analyses, VEG height is highly dependent on slope. To account for this effect, the Procedures specify VEG tree heights for seven slope classes. This timber supply analysis will use the area-weighted average of these slope classes to calculate VEG
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height for each visual quality polygon. All 517 visual quality polygons in the Robson Valley visual inventory are included in this analysis and will receive polgyon-specific VEG heights (Table 29).
Table 29: Associated visually effective green-up heights by slope class
8.4 Community watersheds There are four community watersheds (Dominion, Edand, Martinson, and Swift) totalling 14,746 ha within the Robson Valley TSA. Using the Community watershed guidelines from the Forest Practices Code Community Watershed Guidebook, forest cover requirements as presented in Table 30 will be applied to the CFLB within the watersheds. There are also 323 domestic watershed or point of diversion (POD) and each have been given a 100 m buffer for a total of 1,200 ha that will receive forest cover requirements to the CFLB portion of the watersheds. Table 30: Community watersheds
Watershed Type
Productive area (ha)
Timber harvesting land base area (ha)
Allowable ECA (max)
Hydrological Recovery
Height (m) Community watershed
5% < 3
Domestic watershed
* *
* at the time of writing these parameters were still being reviewed.
8.5 Caribou habitat Order #U7-003 from the Ministry of Water, Land and Air Protection has designated Corridor, High, and Medium suitability zones for caribou winter range within the Robson Valley TSA. Pursuant to this Order, the following forest cover requirements will be used to model current management of mountain caribou (Rangifer tarandus caribou) habitat: Caribou Corridor Zone: Maintain a minimum of 20% of the forest area in each corridor as 100+ years of age in a contiguous, windfirm corridor where no more than 20% of the area is in less than 3 m green-up condition at any time. Caribou High: Exclude from harvest, except Category A approved cut blocks and associated roads authorized at the time of ungulate winter range designation.
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Caribou Medium: Partial cutting with <30% volume removal on a cut block area every 80 years. Mean opening size should be ≤ 0.5 ha.
8.5.1 Identified wildlife Identified wildlife refers to those species at risk (red- or blue-listed) that are considered to be sensitive to habitat alteration associated with forest and range practices, and that have not been adequately accounted for with existing management strategies, such as those for biodiversity, riparian management, ungulate winter range or through the application of other forest cover constraints (Table 31 and Table 32). Wildlife habitat areas (WHAs) and general wildlife measure (GWMs) have not been established for the Robson Valley TSA. It is understood that the wildlife tree patches, in addition to the non-harvesting land base, will contribute to the forest cover habitat requirements for these identified wildlife species.
Table 31: Endangered or threatened (red-listed) species in the Robson Valley TSA
Scientific name Common name
Acipenser transmontanus pop. 5 White Sturgeon (Upper Fraser River population) Martes pennanti Fisher Rangifer tarandus pop. 1 Caribou (southern population)
Table 32: Vulnerable (blue-listed)
Scientific name Common name Ardea herodias herodias Great Blue heron, herodias subspecies Asio flammeus Short-eared Owl Botaurus lentiginosus American Bittern Clossiana alberta Albert's Fritillary Colias meadii Mead's Sulphur Erebia magdalena Magdalena Alpine Gulo gulo luscus Wolverine, luscus subspecies Myotis septentrionalis Northern Long-eared Myotis Numenius americanus Long-billed Curlew Oeneis bore edwardsi White-veined Arctic, edwardsi subspecies Oncorhynchus clarki lewisi Cutthroat Trout, lewisi subspecies Ovis canadensis Bighorn Sheep Salvelinus confluentus Bull Trout Somatochlora brevicincta Quebec Emerald Ursus arctos Grizzly Bear
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8.6 Biodiversity The Landscape Unit Planning Guide establishes old seral cover and wildlife tree habitat as the current priorities for landscape unit biodiversity management in BC.
8.6.1.1 Landscape units and Biodiversity Emphasis Optionsl The Robson Valley TSA encompasses 21 landscape Units, listed in Table 33. Draft Biodiversity Emphasis Options (BEOs) have been assigned to the landscape units and will be used in the base case to determine forest cover requirements.
Table 33: Landscape Units of the Robson Valley TSA
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BEO Landscape Unit Total Area
(ha) West Kinbasket 17,641
8.6.1.2 Old Seral Forest Cover Requirements Using the methodology outlined in the Landscape Unit Planning Guide (LUPG), old seral cover requirements are the minimum percent area of productive forest older than a specified age for each BEC variant within each landscape unit. The minimum age and percent cover for each landscape unit/BEC variant combination is determined by the BEO of the landscape unit and the natural disturbance type (NDT) in the Appendix 2 of the LUPG. The LUPG recommends that old growth cover targets in low BEO landscape units be drawn down by two-thirds for the first rotation (70 years), and restored to the full target over the subsequent two rotations (Table 34).
Table 34: Old seral targets through the TSR3 planning horizon.
% Cover requirement during the planning
horizon Natural Disturbance Type (NDT)
BGC Zone
Biodiversity Emphasis
Option (BEO)
Old Seral Definition (stand age) 0-70 yrs
70-140 yrs >140 yrs
H >250 yrs 19 19 19 I >250 yrs 13 13 13 ICH L >250 yrs 4.3 8.7 13 H >250 yrs 28 28 28 I >250 yrs 19 19 19
1
ESSF L >250 yrs 6.3 12.7 19 H >250 yrs 13 13 13 I >250 yrs 9 9 9 2 All L >250 yrs 3 6 9 H >140 yrs 16 16 16 I >140 yrs 11 11 11 3 SBS L >140 yrs 3.7 7.3 11
Draft spatial OGMA have been developed by MSRM to identify locations of old forest necessary to satisfy the landscape biodiversity goals. As they are not yet legally established, the OGMAs will be applied as a sensitivity analysis and not in the base case.
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8.6.1.3 Disturbing the non-timber harvesting land base To prevent the contributing, non-timber harvesting land base from continually aging and providing a disproportionate and often improbable amount of old forest cover conditions to satisfy landscape biodiversity requirements, a disturbance function must be applied. The document Modeling Options for Disturbance Outside the THLB – Working Paper provides direction for disturbing areas of the landscape outside of the THLB. There are a variety of possible approaches to applying a disturbance in the contributing non-timber harvesting land base. While each approach has its strengths and weaknesses there remains a significant amount of uncertainty what the most appropriate methodology would be. At the time of writing this document, the age reset by variant for the contributing, non-timber harvesting land base is proposed. The methodology (Modeling Options for Disturbance Outside the THLB – Working Paper) is as follows:
1. List the estimated return interval for disturbance in each variant and NDT in the TSA (Landscape Unit Planning Guide Appendix 2).
2. Establish the estimated minimum target % of old seral that would be expected (Landscape Unit Planning Guide Appendix 2).
3. Calculate a rotation age based on the age distribution described in step 2. (target age/(1-target %).
4. Divide the contributing non-THLB area in the variant by the calculated rotation age to determine the annual minimum disturbance target for each variant.
5. Establish the estimated minimum target % of old seral (bullet 2) as well as the annual minimum disturbance target for each variant (bullet 4).
This methodology is currently being reviewed and discussed. If necessary, it may be modified in future versions of the data package.
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9 Timber harvesting This section describes the harvest systems and merchantability standards used in the timber harvesting land base.
9.1 Minimum Harvestable age by analysis unit The minimum harvestable age is the time required for stands to grow to harvestable size, it defines the lower age limit for harvesting within the timber supply model. Minimum harvestable ages are simply minimum criteria. While harvesting may occur in stands at the minimum requirements in order to meet forest level objectives (e.g., maintaining overall harvest levels for a short period of time or avoiding large inter-decadal changes in harvest levels), most stands will not be harvested until well past the minimum timber production ages because the management for other resource values take precedence (e.g. requirements for the retention of older forest). A minimum harvestable age is reached at a volume per hectare indicated in the Table 35. The criteria listed are consistent with forest district staff and DFAM Group experience with present harvesting operations.
Table 35: Minimum volume per hectare to be considered harvestable
Inventory operability description Code
Minimum volume to be harvestable (m³/hectare)
Conventional A 140 Mixed conventional / cable M 200 Cable C 250
9.2 Logging methods and silvicultural systems As described earlier, the operability coverage details the logging methods anticipated for use across the TSA. The logging methods employed in the Robson Valley TSA in the last three years are conventional ground (55%), cable (42%) and helicopter (2%). In the Robson Valley TSA, the majority of harvesting has historically been clearcut based systems. However, more recently the amount of partial harvesting has increased due to the concentration of operations within visually sensitive areas, especially along the main highway road corridors throughout the TSA. McBride Forest Industries have provided information supporting the assumption of increased partial harvesting and its expected continuation in the future. The DFAM Group concurs that further use of partial harvest systems is likely both within visually sensitive areas as well as to manage for other values outside of the scenic areas. The use of partial harvesting outside of visually sensitive areas now and in the future is currently uncertain, and therefore, will only be applied to the VQOs for the base case. A sensitivity analysis is proposed where partial harvesting will be applied to other resource management zones.
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The growth and yield assumptions for partial harvesting will be described in Section 4.2. At the time of writing these assumptions have not been finalized. Once completed, they will be incorporated into future versions of the data package.
9.3 Initial harvest rate The initial harvest rate for the 2004 analysis is set to the current AAC of 669,211 m3/year, which includes a partition of 6,000 m3/year for the deciduous dominated stand and volume attributed to unsalvaged losses.
9.4 Harvest scheduling priority The harvest scheduling priorities will initially be directed by the licencees forest development plan which has been incorporated into the analysis data and will be established as a fixed harvest schedule for the first period of the analysis. Following this, further priority will be assigned to those areas eligible for salvage. This will be dictated mostly by the growing concern of mountain pine beetle and to a lesser degree hemlock looper and fire losses. The stand types or spatial areas associated with these events will be targeted initially. Following this a harvest rule of oldest first will be applied. There is always a degree of uncertainty with picking a single harvest rule to represent the current and future priorities for harvest. As such, other harvest rules will be tested through sensitivity analysis (Section 10.2).
9.5 Deferral of seed production stands Four seed production stands with a total area of 3368 hectares have been identified as sources of better than average spruce and Douglas-fir seed. There are no class A seeds for Douglas fir in the TSA and therefore, these better than average spruce and Douglas-fir seed stands have been collected in the lower elevation and have been used for planting in the TSA as representing the best available seed. These stands will be deferred from harvesting for 65 years. Following this period of time they will be made available for harvest.
9.6 Timber supply model The model that will be used for this analysis will be:
Model Name: FSOS Model Developer: Dr. Guoliang Liu Model Development: UBC, Hugh Hamilton Limited, Forest Ecosystem Solutions Ltd. Model Type: Forest and Landscape, Spatial/Non-spatial, Simulation and Optimization Model
FSOS has been used on over 24 management units (TFLs and TSAs) from small (<15,000 ha) to very large (> 4 million ha) forest areas throughout BC, Alberta, Manitoba and Ontario. FSOS has also been accepted for use in timber supply analysis by the Chief Forester in British Columbia and is currently being reviewed in Ontario for management plan use.
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This section provides a summary of the harvest forecasts to be provided: the set of assumptions pertaining to each option and sensitivity analysis.
10.1 Harvest flow objectives for the base case and sensitivity analyses
The base case is the reference timber supply forecast by which timber supply implications of different management assumptions and of uncertainty in data and assumptions may be measured. The base case is based on current performance or a reasonable extrapolation of current performance. The harvest flow objectives for the base case and other sensitivity scenarios will follow standard provincial polices and is outlined in Harvest flow Considerations for Timber Supply Draft Working Paper, 2003. In general the harvest flow objectives are:
• Sustain the current harvest level until reductions are necessary for long-term sustainability;
• Control the mid-term harvest level so that it does not drop below the sustainable long-term harvest.
• Where decreases in the harvest rate are necessary, volume harvested will decrease by no more than 10% per ten-year period; and
• Maintain even flow in the long term with non-declining growing stock.
10.2 Sensitivity analyses Sensitivity analysis provides a measure of the timber supply impact if uncertainty in management assumptions and/or data integrity exists. The magnitude of the increase or decrease in a particular variable should reflect the degree of uncertainty surrounding the assumption. By developing and testing a number of sensitivity analyses, it is possible to determine which variables most affect results. Issues that are particular to the Robson Valley TSA are shown in Table 36 along with a list of standard sensitivity analysis that are generally carried out in all TSAs are shown in Table 37. Table 36: Sensitivity issues specific to the Robson Valley TSA
Issue to be tested Sensitivity levels Recommended visual quality classes outside established VQOs
Apply forest cover requirements as if the visual quality classes were established VQOs. Assign higher level RVQC and apply forest cover requirements as if they were established VQOs.
Percentage reduction for environmentally sensitive areas
+ 10%
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Issue to be tested Sensitivity levels Cedar-hemlock contribution to cut
Include all stands on cable and mixed operability ground in supply. Remove all cedar and hemlock-leading stands in the ICH zone from McBride west from the timber harvesting land base.
Partial harvesting Replace harvest in visually sensitive areas with clearcut system Apply partial harvesting to other resource emphasis areas
Spruce management in weevil high risk zone
OAF 1 +/- 5%
Armillaria incidence OAF 2 +5% for yield curves associated with moderate or severe incidence of Armillaria
Douglas-fir management Apply Douglas-fir management guidelines in the SBS biogeoclimatic zone.
Crown land plan Delete any areas in the timber harvesting land base that are within the Crown land plan. Delete areas in agriculture development areas within the Crown land plan.
Volume per hectare to be considered harvestable
+/- 50 cubic metres per hectare for cable, mixed and conventional operability classes and all stand types.
Regeneration delay + 5 years OGMA Turn off landscape biodiversity rules and apply OGMA as a
permanent reserve. There may be other sensitivity analysis required for this topic.
Grizzly bear habitat Apply 100m buffer widths to high and medium value habitat areas Mountain pine beetle infestation
Areas that are susceptible to mountain pine beetle (i.e. worst case scenarios, all pine stands) will be removed from the timber harvesting land base.
Table 37: Standard sensitivity analysis
Issue to be tested Sensitivity levels Existing stand yields +/- 10% Regenerated stand yields +/- 10% Minimum harvestable age +/- 10 years Old-growth site index adjustments Use old-growth site index adjustments equations as per
working paper 36 and 37. Land base changes +/- 10% Visual quality objectives Top and bottom of range % denudation.
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Issue to be tested Sensitivity levels Harvest flow alternatives Maintain present harvest level for 15 to 20 years.
Maintain present harvest level as long as possible. Harvest flow rules Relative oldest first
Random harvest Green-up periods +/- 5 years Integrated resource management zone
Change maximum area below green-up age to 25%.
Community watersheds Change maximum disturbance and minimum retention by +/- 5%.
Seral stage distribution Apply the early and mature and old-seral stage requirements.
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11111111 ReferencesReferencesReferencesReferences BC Ministry of Forests. 1986. Community Watershed Guidebook. Victoria: Province of British Columbia. BC Ministry of Forests and Ministry of Environment, Lands and Parks 1995a. Biodiversity Guidebook. Forest Practices Code of British Columbia. Victoria: Province of British Columbia. BC Ministry of Forests and Ministry of Environment, Lands and Parks 1995b. Riparian Management Area Guidebook. Forest Practices Code of British Columbia. Victoria: Province of British Columbia. B.C. Ministry of Forests, Forest Practices Branch. 1998. Procedures for factoring visual resources in timber supply analyses. Victoria, B.C. REC-029. BC Ministry of Sustainable Resource Management. 1999. Robson Valley Land and Resource Management Plan. Victoria: Province of British Columbia. BC Ministry of Forests and Ministry of Environment, Lands and Parks 1999. Landscape Unit Planning Guide. Forest Practices Code of British Columbia. Victoria: Province of British Columbia. BC Ministry of Forests and Ministry of Environment, Lands and Parks 1999. Green-up Guidebook, 2nd edition. Forest Practices Code of British Columbia. Victoria: Province of British Columbia. BC Ministry of Forests 2001. Robson Valley Timber Supply Area—Rationale for Allowable Annual Cut (AAC) Determination, Effective June 1, 2001. Victoria: Province of British Columbia. BC Ministry of Forests, Forest Analysis Branch. 2003. Supplemental Guide for Preparing Timber Supply Analysis Data Package. Victoria: Province of British Columbia. BC Ministry of Water, Land and Air Protection. 2003. Mule Deer Ungulate Winter Range Areas for Designation in the Robson Valley. Victoria: Province of British Columbia. BC Ministry of Water, Land and Air Protection 2003. Order - Ungulate Winter Range #U7-003. Victoria: Province of British Columbia. BC Ministry of Forests, Forest Analysis Branch. 2003. Harvest flow Considerations for Timber Supply Draft Working Paper. Victoria: Province of British Columbia. BC Ministry of Forests. 2003. Modelling Visuals in TSR III Bulletin. Victoria: Province of British Columbia.
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Boreas Environmental Services. 2003. Grizzly bear avalanche tracks mapping project in the Robson Valley. Prepared for the Ministry of Forests and Ministry of Water, Land and Air Protection.
