Regional District of Central Okanagan   Parks Operational Wildfire Protection Plan- Part A An Operational Plan for Wildfire Hazard Abatement within the RDCO Parks System    Final DRAFT   Submitted by: Amelia Needoba, Kyle Broome and Bruce Blackwell B.A. Blackwell and Associates Ltd. 3087 Hoskins Road North Vancouver, BC V7J 3B5   Submitted to: Cathy Mackenzie Regional District of Central Okanagan Parks and Recreation Department 1450 K.L.O. Road Kelowna, BC V1W 3Z4       March 2010

Executive Summary

The Regional District of the Central Okanagan (RDCO) initiated this project in order to identify and prioritize fuel hazards across the RDCO parks system. Within the RDCO, major wildfire events occurred during the recent 2003 and 2009 fire seasons. RDCO parks were impacted by wildfire in both seasons.

A number of parks contain forest that could be treated to reduce wildfire hazard. However, the parks are geographically dispersed over a wide area and there is great diversity in values at risk and treatment complexity across the parks system. For these reasons, a strategic approach has been developed to prioritize treatments within parks.

The objectives of this Operational Wildfire Protection plan are to:

1.      Complete wildfire hazard mapping that identifies and maps fire hazard.

2.      Prioritize areas for treatments based on proximity to urban interface, values at risk, fire hazard rating and treatment complexity.

3.      Recommend fuel hazard reduction treatments that: 1) Will reduce stand density to decrease fire behaviour potential, create more historically similar stand conditions and improve tree vigour; and, 2) Remove accumulations of surface fuels while retaining some coarse woody debris to provide ecosystem benefits.

4.      Within the prioritized treatment areas, encourage the development of fuel management prescriptions that are of a consistent standard for fuel management in parks and green spaces.

5.      Identify polygons that are not a priority for fuel treatments but that require monitoring over time for future fire hazard potential or hazard tree removal.

The total area of park covered in this analysis was 2,014 ha. Fuel types were mapped using Vegetation Resource Inventory data and then ground-truthed in September of 2009. For the purposes of treatment area identification, all parks with forested fuel types were included. Two parks (Kaloya and Reiswig), classified as non-fuel due to their landscaped and manicured grounds, were retained in the analysis because trees are present (though not a fuel hazard). Removal of all other non-fuel and grass fuel polygons netted the study area down from 2,014 ha to 1,327ha (67% of the total study area) within 42 parks (out of a total of 52).

The ten un-treed parks excluded from the analysis and not considered for fuel treatment were: Cove Resort Walkway, Pine Point, Cedar Mountain, Okanagan Centre Safe Harbour, Robert Lake, Ellison Primary, Scotty Creek, Fintry Access #2, Fintry Access #3 and Ellison Estates Trail.

For all other parks, the treed polygons were recommended for either monitoring or treatment based on fuel type and ground-truthing. The ‘monitor’ polygons were retained in the analysis but are not prioritized for fuel treatment. These polygons are not considered a wildfire hazard but require monitoring for future action at the discretion of the RDCO to address hazard trees, surface fuels or ingrowth.

All ‘treat’ polygons were prioritized for fuel treatments because they contain coniferous fuel types considered potentially hazardous from a wildfire perspective. Treatment priority was determined in a GIS analysis that considered the following factors:

·         Proximity to interface

·         Percent pine

·         Park infrastructure

·         Fire behaviour rate of spread

·         Crown fraction burned

·         Head fire intensity

Treatment complexity was also assessed for each polygon in a GIS analysis that considered:

·         Slope

·         Access

·         Tenure

·         Red and blue listed species occurrences

·         Community watershed

·         Sensitive ecosystem

Treatment priority was used to rank ‘treat’ polygons from low to very high priority across the parks system. Treatment complexity was used to inform treatment cost estimates and provides useful information for future prescription work.

Each polygon was assigned a treatment type, hand or machine harvest and debris disposal method based on its fuel type, accessibility and slope characteristics. It should be noted that changes in market conditions or available technology may provide additional options at the time of prescription development.

Treatment costs were estimated based on assigned treatment type and costs per hectare ranged from $8,000 to $14,000. The cheapest treatments are hazard tree removal with surface fuel removal and the most expensive treatments are thinning by hand with pruning and surface fuel removal. In other municipalities, treatment costs have varied from $2,000/ha to $25,000/ha. It is expected that similar variations could occur within the RDCO; however the $8,000-$14,000/ha cost range is considered a realistic average. The final costs/ha on each site will be dependent on the area being treated, the equipment used, equipment mobilization costs, crew costs, current market conditions and the density of trees or amount of biomass being removed. It is beyond the scope of this analysis to presicely predict those costs for each treatment polygon.

Finally, treatment polygons were grouped by park into treatment units based on proximity to one another. Those that were within 2 km from one another were assigned to the same unit. The intention of this grouping is to achieve efficiency in prescription development and treatments to maximize the area treated and minimize costs associated with both machine and crew mobilization. Parks that contained only ‘monitor’ polygons are not recommended for prescription development and were therefore excluded from treatment units.

The results of the analysis are presented in three ways:

1.      Tabular format: Listed by polygon, highest priority to lowest priority.

2.      Tabular format: Listed by treatment unit, approximately from highest to lowest priority.

3.      Map format: The map results are contained in a separate document titled ‘PARKS OPERATIONAL WILDFIRE PROTECTION PLAN - PART B’.

 In summary:

·         Total area recommended for ‘monitor’ or ‘treat’: 1,327.2 ha

·         Total area recommended for ‘treat’: 768.4 ha

·         Total estimated cost of treating all polygons (recommended for ‘treat’ or ‘monitor’): $11,981,171.29

·         Estimated cost of treating only polygons where ‘treat’ is the recommended action: $8,111,204.33

Where they overlap, the results of the analysis are consistent with wildfire protection plans and hazard assessments completed in adjacent municipalities and fire protection area.

 

                                                             

Table of Contents

1.0        Introduction... 2

1.1        Parks Assessed.. 2

1.2        Fuel Type Descriptions. 2

2.0        Fuel Types within the Parks System... 2

2.1        Fuel Types and Biogeoclimatic Ecosystem Classifications. 2

3.0        Methodology for Treatment Prioritization... 2

3.1        Treatment Priority Rating. 2

3.2        Treatment Complexity Rating. 2

3.3        Monitor or Treat Recommendation and Treatment Type. 2

3.4        Recommended Treatment Units. 2

3.5        Mapping. 2

4.0        Prioritization Results, Treatment Recommendations and Costing.. 2

4.1        Prioritization, Treatment Type and Costing by Treatment Polygon.. 2

4.2        Recommended Treatment Units for Prescription Development and Funding. 2

4.3        Parks Excluded from Treatment Units. 2

5.0        Consistency with Community Wildfire Protection Planning in Adjacent Jurisdictions  2

6.0        Considerations for Developing Treatment Prescriptions. 2

6.1        Key Content for Fuel Management Prescriptions. 2

6.2        Additional Considerations for Developing Prescriptions within the RDCO.. 2

Appendix 1 - Area Summary of Fuel Types by Park.. 2

Appendix 2 – Polygon Attributes Driving Priority and Complexity Ratings. 2

Appendix 2 – Polygon Attributes Driving Priority and Complexity Ratings. 2

Appendix 3 – Sample Fuel Treatment Prescription... 2

 

Index of Figures

Figure 1. Typical O1 fuel type within the study area. 2

Figure 2. Typical C2 fuel type within the study area. 2

Figure 3. Typical C3 fuel type within the study area. 2

Figure 4. Typical C4 fuel type in the study area. 2

Figure 5. Typical C5 fuel type in the study area. 2

Figure 6. Typical C7 fuel type within the study area. 2

Figure 7. Typical D1 fuel type within the study area. 2

Figure 8. Typical M2 fuel type within the study area. 2

Figure 9. Conceptual examples of hazard coniferous and mixed deciduous fuel types treated to achieve a reduction fire behaviour potential. 2

 

Index of Tables

Table 1. Fuel type summary for the entire park system... 2

Table 2. Priority rating table. 2

Table 3. Complexity rating table. 2

Table 4. Estimate treatment costs per hectare for each treatment type. 2

Table 5. Summary of treatment recommendations and costs by priority polygon. 2

Table 6. Recommended treatment units for prescription development and funding. 2

Table 7. Summary of target stand conditions by site ecology and exposure (note that deciduous species are not specified but are always retained as a preferred species). 2

1.0                           Introduction

The Regional District of the Central Okanagan (RDCO) initiated this project in order to identify and prioritize fuel hazards across the RDCO parks system. Within the RDCO, major wildfire events have recently occurred during the 2003 and 2009 fire seasons. RDCO parks were impacted by wildfire in both seasons.

A number of parks contain forest that could be treated to reduce wildfire hazard. However, the parks are geographically dispersed over a wide area and there is great diversity in values at risk and treatment complexity across the parks system. Wildfire hazard is also increased in some areas as a result of the ongoing mountain pine beetle infestation and, in some cases, due to Douglas-fir tussock moth. For these reasons, a strategic approach has been developed to prioritize treatments within parks based on several key considerations. This approach involved detailed fuel typing of the parks system to identify those areas that would be treatment candidates. An analysis was then run in GIS to rate treatment priorities and constraints based on the following considerations:

·         Proximity to urban interface

·         Percent pine

·         Park infrastructure

·         Fire behaviour rate of spread

·         Crown fraction burned

·         Head fire intensity

·         Slope

·         Access

·         Tenure

·         Red and blue listed species occurrences

·         Community watershed

·         Sensitive ecosystem

The methodology is described in detail in Section 3.0.

Fuel treatments within the RDCO parks system can be developed to provide benefits beyond direct wildfire hazard reduction. Forest health is an ongoing concern for RDCO parks, particularly because of tree mortality due to mountain pine beetle, Douglas-fir tussock moth and drought. In addition, some ecosystems have been degraded due to forest encroachment and ingrowth. Fuel treatments can incorporate ecosystem restoration objectives and create stands with improved tree vigour and resistance to both drought and insect attack.

The objectives of this Operational Wildfire Protection plan are to:

1.      Complete wildfire hazard mapping that identifies and maps fire hazard.

2.      Prioritize areas for treatments based on proximity to urban interface, values at risk, fire hazard rating and treatment complexity.

3.      Recommend fuel hazard reduction treatments that: 1) Will reduce stand density to decrease fire behaviour potential, create more historically similar stand conditions and improve tree vigour; and, 2) Remove accumulations of surface fuels while retaining some coarse woody debris to provide ecosystem benefits.

4.      Within the prioritized treatment areas, encourage the development of fuel management prescriptions that are of a consistent standard for fuel management in parks and green spaces.

5.      Identify polygons (bounded areas) that are not a priority for fuel treatments but that require monitoring over time for future fire hazard potential or hazard tree removal.

1.1                             Parks Assessed

1.      Antlers Beach

2.      Bear Creek Boat Launch

3.      Bertram Creek

4.      Black Knight Mountain Crown

5.      Bouleau Lake

6.      Cedar Mountain

7.      Cinnabar Creek

8.      Coldham

9.      Cove Resort Walkway

10.  Daves Creek Corridor

11.  Ellison Estates Trail

12.  Ellison Primary

13.  Fintry Access #1

14.  Fintry Access #2

15.  Fintry Access #3

16.  Gellatly Heritage

17.  Gellatly Nut Farm

18.  Glen Canyon

19.  Hydraulic Lake Crown (includes McCulloch / Hydraulic Lake Forest Rec Site and McCulloch Station)

20.  Joe Rich Community Hall

21.  Kalamoir

22.  Kaloya

23.  Killiney Beach

24.  Killiney Community Hall

25.  Kopje

26.  Lakeshore Road

27.  Lebannon Creek Greenway

28.  Mill Creek

29.  Mission Creek

30.  Mission Creek Greenway

31.  Mount Boucherie

32.  Okanagan Centre Safe Harbour

33.  Okanagan High Rim Trail (Goudie-Philpott)

34.  Philpott Trail

35.  Pine Point

36.  Raymer Bay

37.  Reiswig

38.  Robert Lake

39.  Rose Valley

40.  Scenic Canyon

41.  Scotty Creek

42.  Shannon Lake

43.  Spion Kop Crown

44.  Star

45.  Stephens Coyote Ridge

46.  Sunset Ranch Park

47.  Three Forks

48.  Traders Cove

49.  Trepanier Creek Crown

50.  Trepanier Creek Greenway

51.  Westshore Estates Community Park

52.  Woodhaven Nature Conservancy

1.2                             Fuel Type Descriptions

Fuel types are an integral part of hazard mapping as they provide a method for classifying fuels on the landscape in order to model fire behaviour. Certain fuel types, particularly C2, C3 and C4 are prone to hazardous fire behaviour under extreme fire weather conditions. In general, fuel treatments focus on modifying these fuel types to reduce the fire behaviour potential within a stand. Following are general descriptions of the dominant fuel types within the study area.

O1 fuel type

Structure Classification	Grassland
Dominant Tree Species	Generally no overstory, occasionally ponderosa pine, Douglas-fir or deciduous cover.
Tree Species Type	See above
Understory Vegetation	High (75-100% cover)
Stand Density	0-100 stems/ha
Crown Closure	0 – 10 %
Height to Live Crown	0-2 m
Surface Fuel Loading	Grass loading up to 0.4 kg/m2 (dry weight), a shrub component may be present
Frequency within RDCO	Very common in the lower elevation

Figure 1. Typical O1 fuel type within the study area

C2 fuel type

Structure Classification	Regeneration to pole sapling or mature multi-aged spruce stand
Dominant Tree Species	Pseudotsuga menziesii (Douglas-fir), Picea engalmanii (Engelmann spruce), Pinus contorta (lodgepole pine) and Abies lasiocarpa (subalpine fir)
Tree Species Type	> 80% Coniferous
Understory Vegetation	Sparse – None (< 10% cover)
Stand Density	>2000stems/ha
Crown Closure	80 – 100 %
Height to Live Crown	0-2 m
Surface Fuel Loading	< 3 kg/mPPPP2
Frequency within RDCO	Very common in the mid to upper elevations

Figure 2. Typical C2 fuel type within the study area
C3 fuel type

Structure Classification	Late pole sapling to mature forest
Dominant Tree Species	Pinus ponderosa (ponderosa pine), Pseudotsuga menziesii (Douglas-fir), Pinus contorta (lodgepole pine), Picea engelmannia (Engelmann spruce) and Abies lasiocarpa (subalpine fir)
Tree Species Type	> 80% Coniferous
Understory Vegetation	Moderate (40-80% cover)
Stand Density	600 – 1,200 stems/ha
Crown Closure	40 – 100 %
Height to Live Crown	3-8 m
Surface Fuel Loading	< 5 kg/mPPPP2
Frequency in the RDCO	Common from low to high elevations

Figure 3. Typical C3 fuel type within the study area.

C4 fuel type

Structure Classification	Pole sapling
Dominant Tree Species	Pseudotsuga menziesii (Douglas-fir), Pinus contorta (lodgepole pine), Picea engelmannii (Engelmann spruce) and Abies lasiocarpa (subalpine fir)
Tree Species Type	> 80% Coniferous
Understory Vegetation	Low (0-40% cover)
Stand Density	700 – 2000 stems/ha
Crown Closure	40 – 80 %
Height to Live Crown	Average 2-4 m
Surface Fuel Loading	< 5 kg/mPPPP2
Frequency in the RDCO	Common from low to high elevations

Figure 4. Typical C4 fuel type in the study area

C5 fuel type

Structure Classification	Mature and old forest
Dominant Tree Species	Pseudotsuga menziesii (Douglas-fir), Tsuga heterophylla(western hemlock), Thuja plicata (western redcedar), Larix occidentalis, (western larch), Pinus contorta (lodgepole pine), Abies lasiocarpa (subalpine fir) and Pinus ponderosa (ponderosa pine)
Tree Species Type	> 80% Coniferous
Understory Vegetation	Moderate (> 40% cover)
Average Age	> 80 yrs
Average Height	30 – 40 m
Stand Density	300 – 700 stems/ha
Crown Closure	40 – 100 %
Height to Live Crown	Average 18 m
Surface Fuel Loading	< 5 kg/mPPPP2
Frequency in the RDCO	Generally rare, particularly at low elevation

Figure 5. Typical C5 fuel type in the study area

C7 fuel type

Structure Classification	Young forest to mature forest
Dominant Tree Species	Pseudotsuga menziesii (Douglas-fir) and Pinus ponderosa (ponderosa pine)
Tree Species Type	> 80% Coniferous
Understory Vegetation	Moderate - High (50-90%)
Stand Density	Variable, typically less than 500 stems/ha
Crown Closure	20 – 40 %
Height to Live Crown	0 to > 6 m
Surface Fuel Loading	Typically woody fuel load <2kg/m2. Understory generally grass (up to 0.4kg/m2) possibly with a shrub component.
Frequency in the RDCO	Very common from low to mid elevations, rare in high elevations

Figure 6. Typical C7 fuel type within the study area

D1 fuel type

Structure Classification	Pole sapling to Mature forest
Dominant Tree Species	Populus trichocarpa (cottonwood), Populus tremuloides (Aspen) and Betula papyrifera (paper birch)
Tree Species Type	> 80% Deciduous
Understory Vegetation	High (> 90% cover)
Stand Density	600 – 2,000 stems/ha
Crown Closure	20 – 100 %
Height to Live Crown	< 10 m
Surface Fuel Loading	< 3 kg/mPPPP2
Frequency in the RDCO	Generally found around waterways but rare overall

Figure 7. Typical D1 fuel type within the study area

M2 fuel type

Structure Classification	Pole sapling, young forest, mature and old forest
Dominant Tree Species	Pseudotsuga menziesii (Douglas-fir), Abies lasiocarpa (subalpine fir), Populus trichocarpa (cottonwood), Populus tremuloides (Aspen)
Tree Species Types	Coniferous 10-80% / Deciduous
Understory Vegetation	Variable
Stand Density	600-1500 stems/ha
Crown Closure	40 – 100 %
Height to Live Crown	6 m
Surface Fuel Loading	< 3 kg/mPPPP2
Frequency in the RDCO	Generally around waterways at low elevations, more dispersed with increasing elevation but rare overall

Figure 8. Typical M2 fuel type within the study area.

2.0                           Fuel Types within the Parks System

The total area of park covered in this analysis is 2,014 ha. Table 1 lists an area summary by fuel type for the entire park system. Appendix 1 breaks down fuel type by park. The majority of the forested fuel types are contained in 40 of the 52 parks assessed. The remaining 12 parks are either completely non-fuel, manicured gardens or contain only grass fuel types.

Table 1. Fuel type summary for the entire park system

*M2regen is treated as M2 during fire behavior modeling but is separated out in mapping to represent dense stands of regeneration <4 m tall.

2.1                             Fuel Types and Biogeoclimatic Ecosystem Classifications

The RDCO parks system spans three Biogeoclimatic Ecosystem Classification (BEC) zones: the Ponderosa Pine (PP), Interior Douglas-fir (IDF) and Montane Spruce (MS) Zones. The majority of parks are within the PP and IDF BEC zones. These three zones can be further divided into five biogeoclimatic variants occurring across the parks system. BEC variants represent specific climatic and geographic characteristics with distinct vegetation types (Lloyd et al., 1990). The following five sections, adapted from Lloyd et al. (1990), describe the characteristics of each BEC variant in terms of their typical stand types and species of trees, shrubs and herbs.

2.1.1.1                 Ponderosa Pine very dry hot variant (PP xh1/xh1a)

The PP xh1 is the driest forested zone in the province. It is characterized by open ponderosa pine stands, with little to no shrub cover. The herb layer is dominated by bluebunch wheatgrass and lesser amounts of arrow-leaved balsamroot, Idaho fescue and timber milk-vetch. Drier sites have very low-density stands and big sagebrush will accompany bluebunch wheatgrass in the shrub layer. Wetter sites include Douglas-fir and trembling aspen with a more developed understory shrub layer. Mosses are usually absent or sparse. The PPxh1a represents a grassland phase.

Within parks, the fuel types most common in this variant are O1, C7 and C3. Much of this subzone is also classified as non-fuel because it is largely developed urban or rural area. Within the PP zones, fire, drought, insect defoliators, bark beetles, stem rusts, needle casts, and root rot are common natural disturbance agents. In recent years outbreaks of mountain pine beetle, spruce budworm and Douglas-fir tussock moth have caused widespread mortality in both ponderosa pine and Douglas-fir stands.

The parks located in this variant are:

1.      Antlers Beach

2.      Bear Creek Boat Launch

3.      Bertram Creek

4.      Cedar Mountain

5.      Cinnabar Creek

6.      Coldham

7.      Cove Resort Walkway

8.      Gellatly Heritage

9.      Gellatly Nut Farm

10.  Glen Canyon

11.  Kalamoir

12.  Kopje

13.  Lakeshore Road

14.  Mission Creek

15.  Mission Creek Greenway

16.  Mount Boucherie

17.  Okanagan Centre Safe Harbour

18.  Pine Point

19.  Raymer Bay

20.  Robert Lake

21.  Rose Valley

22.  Scenic Canyon

23.  Shannon Lake

24.  Spionkop Crown Land Interests

25.  Star

26.  Stephens Coyote Ridge

27.  Traders Cove

28.  Trepanier Creek Greenway

29.  Trepanier Creek Crown

30.  Woodhaven Nature Conservancy

 

2.1.1.2                 Interior Douglas-fir very dry hot variant (IDF xh1/xh1a)

The IDF xh1 has a relatively long growing season with common moisture deficits. It is characterized by open stands of Douglas-fir and ponderosa pine and a sparse shrub layer dominated by birch-leaved spirea. The herb layer is dominated by pinegrass. Drier sites are more open and include shrubby penstemon, Saskatoon berry and bluebunch wheatgrass as additions to the shrub layer. Wetter sites may include paper birch and a more developed shrub layer of Douglas maple, snowberry, red-osier dogwood and black gooseberry with a more developed herb layer. The IDF xh1a represents a grassland phase.

Within parks, the fuel types most common in this subzone are C3, C7, O1 and C4. In IDF zones, fire, drought, insect defoliators, bark beetles, stem rusts, needle casts, and root rot are common natural disturbance agents. In recent years outbreaks of mountain pine beetle, spruce budworm and Douglas-fir tussock moth have caused widespread mortality in both ponderosa and Douglas-fir stands.

 

The parks located in this variant are:

1.      Bouleau Lake

2.      Black Knight Mountain Crown

3.      Cedar Mountain

4.      Coldham

5.      Daves Creek Corridor

6.      Ellison Estates Trail

7.      Ellison Primary

8.      Fintry Access #1

9.      Fintry Access #2

10.  Fintry Access #3

11.  Kaloya

12.  Killiney Beach

13.  Killiney Community Hall

14.  Mill Creek

15.  Mission Creek

16.  Mission Creek Greenway

17.  Philpott Trail

18.  Reiswig

19.  Scenic Canyon

20.  Scotty Creek

21.  Spionkop Crown Land Interests

22.  Sunset Ranch Park

23.  Westshore Estates Community Park

 

2.1.1.3                 Interior Douglas-fir moist warm variant (IDF mw1)

The IDF mw1 has a relatively long growing season with common moisture deficits. It is characterized by lodgepole pine, western larch and paper birch stands in which Douglas-fir and western red cedar may develop in the understory potentially becoming climax species. There are well-developed shrub, herb and moss layers commonly composed of Douglas maple, birch-leaved spirea, falsebox, twinflower, prince’s pine, and feathermoss. Drier sites are open Douglas-fir stands with occasional ponderosa pine. Bluebunch wheatgrass may be added in the understory with a sparse moss layer. Wetter sites are denser, may not include Douglas-fir and have a more open shrub layer with a prominent herb layer and sparse moss layer.

This subzone is rare in the parks system, limited to the Joe Rich area. Fuel types most common in this subzone within the study area are C3, C4 and M2. In recent years outbreaks of mountain pine beetle, spruce budworm and Douglas-fir tussock moth have caused widespread mortality in both lodgepole and Douglas-fir stands.

The parks located in this variant are:

1.      Joe Rich Community Hall

2.      Philpott Trail

3.      Three Forks

2.1.1.4                 Montane Spruce dry mild variant (MS dm1)

The MS dm1 has cold winters and short, warm summers. It is characterized by stands and lodgepole pine, white spruce and subalpine fir with a moss dominated understory. Drier sites have more open lodgepole pine stands and an understory dominated by the herb layer. Wetter sites may additionally have horsetails and sedges.

This subzone is very rare in the parks system, limited to the Hydraulic Lake Crown Area (including McCulloch/Hydraulic Lake Forest Recreation site). Fuel types most common in this subzone within the study area are C3, C2, C4 and C5. Mountain pine beetle and fire are common disturbance agents in these stands.

2.1.1.5                 Interior Cedar Hemlock moist cool variant (ICH mk1)

The ICH mk1 has cool winters and warm, wet summers. It is characterized by western redcedar, hybrid white spruce and subalpine fir with lodgepole pine, Douglas-fir and western larch also commonly occurring. Drier sites are dominated by Douglas-fir with pine grass and falsebox common in the understory. On wetter sites, ferns and horsetails dominate the understory and Douglas-fir and lodgepole pine do not occur.

This subzone is very rare in the parks system, limited to the Hydraulic Lake Crown Area (including McCulloch Station). Fuel types most common in this subzone within the study area are C3, C2, C4 and C5. Mountain pine beetle and fire are common disturbance agents in these stands.

3.0                           Methodology for Treatment Prioritization

The initial study area consisted of all RDCO parks. Fuel types were mapped using Vegetation Resource Inventory (VRI) data and then ground-truthed in September of 2009. Based on this information, the RDCO parks were divided into polygons classified by fuel type. For the purposes of treatment area identification all parks with forested fuel types were included. Two parks (Kaloya and Reiswig), classified as non-fuel due to their landscaped and manicured grounds, were retained in the analysis because trees are present (though not a fuel hazard). Removal of all other non-fuel and grass fuel polygons netted the study area down from 2,014 ha to 1,327ha (67% of the total study area) within 42 parks (out of a total of 52).

The ten un-treed parks excluded from the analysis and not considered for fuel treatment were: Cover Resort Walkway, Pine Point, Cedar Mountain, Okanagan Centre Safe Harbour, Robert Lake, Ellison Primary, Scotty Creek, Fintry Access #2, Fintry Access #3 and Ellison Estates Trail.

For all other parks, the treed polygons were then recommended for either monitoring or treatment based on fuel type and ground-truthing. The ‘monitor’ polygons were retained in the analysis but are not prioritized for fuel treatment. These polygons are not considered a wildfire hazard but require monitoring for future action at the discretion of the RDCO to address hazard trees, surface fuels or ingrowth.

All ‘treat’ polygons were prioritized for fuel treatments because they contain coniferous fuel types considered potentially hazardous from a wildfire perspective. The fuel types targeted in the treatment prioritization were: C2, C3, C4, C5 and M2regen.

The rationale for selecting only these fuel types for treatment was that:

·         Fuel treatments would only occur to modify coniferous stands and to clean up heavy surface fuels. Mixed (M2) fuel types were not prioritized for treatment because of their heavy deciduous component and association with riparian areas within the parks system.

·         The M2regen fuel type generally consists of dense young conifer stands. M2regen fuel types are treatment targets because of their high density and the likelihood that they will continue evolving into a more hazardous fuel type as they age.

·         The C7 fuel types generally have low crown closure and grass in the understory and, while surface fuel hazards, ingrowth or dead pine may need to be addressed over time and should therefore be monitored, C7 is not an inherently hazardous fuel type based on stand structure characteristics; therefore, it is not automatically a treatment candidate.

·         While grasslands (O1) are capable of rapid fire spread, they support surface fires which are generally easier to suppress than crown fires, and the surface fuel loads in grasslands tend to be relatively low. In addition, treatment options are basically limited to mowing or burning on an annual basis, which is generally not practical or desirable in the RDCO parks system.

·         Deciduous (D1) fuel types reduce wildfire behaviour and do not need modification from a wildfire protection perspective. However, heavy surface fuel loads have been created due to hazard tree modification in some parks, therefore D1 is still recommended for monitoring.

·         C5 types are not likely to require treatment for fuel hazard; however extensive tree mortality would create a wildfire hazard in this fuel type, therefore it was included in the treatment prioritization.

3.1                             Treatment Priority Rating

For each of the ‘treat’ polygons, treatment priority was determined in a GIS analysis that considered the following factors:

·         Proximity to interface

·         Percent pine

·         Park infrastructure

·         Fire behaviour rate of spread

·         Crown fraction burned

·         Head fire intensity

Each of these factors was mapped across the park system based on available data and ground-truthing. The vectors were then converted into a 50x50m cell raster and each cell was given a score from 0-10 as per Table 2. The targeted fuel type polygons were then overlaid on this raster data and the score of each priority factor was averaged for the polygon using zonal statistics in ArcGIS. The final score for each priority factor was then summed (up to a maximum of 60) to derive a treatment priority rating for the polygon. For ease of interpretation and to generalise the results, the numeric treatment priority value was converted into a relative descriptor:

·         Low (0-20)