BC Conservation Data Centre: Conservation Status Report
Pseudotsuga menziesii - Pinus ponderosa / Pseudoroegneria spicata
Douglas-fir - ponderosa pine / bluebunch wheatgrass
| Scientific Name: | Pseudotsuga menziesii - Pinus ponderosa / Pseudoroegneria spicata |
|---|---|
| English Name: | Douglas-fir - ponderosa pine / bluebunch wheatgrass |
| Provincial Status Summary | |
| Status: | S3 |
| Date Status Assigned: | March 19, 2016 |
| Date Last Reviewed: | March 19, 2016 |
| Reasons: | This woodland community occurs extensively in lower elevations of the Thompson, Nichola, Okanagan and Similkameen Valleys. Although many forests have been harvesting in the past, the relatively lower forest productivity and less operable soils make this ecological community less desirable for ongoing forest harvesting. It is also less susceptible to forest ingrowth associated with fire suppression than forests on more mesic sites. It is extensively grazed by domestic livestock and somewhat susceptible to invasive alien plants. |
| Range | |
| Range Extent: | E = 5,000-20,000 square km |
| Range Extent Estimate (km2): | 7390 |
| Biogeoclimatic Unit: |
IDFxc/02
IDFxc/03 IDFxh1/02 IDFxh2/02 IDFxh2/03 IDFxw/04 |
| Range Extent Comments: | The range extent estimate of this ecological community is based on Version 9 of the Biogeclimatic Ecosystem Classification (BEC) map (B.C. Ministry of Forests, Lands and Natural Resource Operations, Biogeoclimatic Ecosystem Classification Map Version 9). The area is limited to lower elevations of the climate regions where it is known to occur. |
| Area of Occupancy (km2): | F = 100-500 km² |
| Area of Occupancy Comments: | In total, 16.4% (1213 km2) of the range of this ecological community has Terrestrial Ecosystem Mapping (TEM). Within the IDFxh1, this element occurs on 9.2% (116 km2) of the mapped area (TEM 1996a, TEM 1999d, TEM 2001c, TEM 2002i, TEM 2003h, TEM 2009c, TEM 2011a, TEM 2012). Only a small portion of the IDFxh2 has TEM coverage (0.12%; TEM 2000i). This element occurs on 10% of the mapped area (0.5 km2). None of the IDFxw has TEM coverage. At a minimum, the area of occupancy is greater than 116 km2. Applying the 9% of the area already mapped to the total range would result in an estimate of up to 700 km2. However, the limited area mapped does not provide enough information to estimate the upper level of the estimated Area of Occupancy with confidence and the lower range is used here. |
| Spatial Pattern: | Large patch |
| Occurrences | |
| Number of Occurrences: | U = Unknown |
| Number of Occurrences with Good Viability / Ecological Integrity: | Rank Factor not assessed |
| Percent Area with Good Viability / Ecological Integrity: | CD = Small to moderate percentage (5-20%) |
| Comments: | Within the area that has Terrestrial Ecosystem Mapping (TEM), 57% of this ecological community was mapped as a mature or old forest, though forest harvesting may have occurred since stand age data was compiled. There is likely a minimum of 61 km2 of mature and old forests, though some forest harvesting may have occurred since the time of mapping. Many of these forests may have understories that are slightly to severely affected by cattle grazing as 45% of the range is under active range tenure. Some of these forests may also be degraded by forest ingrowth. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | B = High |
| Comments: | Although there has been forest harvesting of this ecological community, extensive areas have recovered to become mature forests. The primarily threats to this ecological community include fire suppression, inappropriate grazing practices, invasive alien species, fragmentation, and residential and commercial development. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | G = Relatively Stable (<=10% change) |
| Comments: | Terrestrial Ecosystem Mapping (TEM) indicates 28% of the area mapped is classified as early succession (TEM 1996a, TEM 1999d, TEM 2001c, TEM 2002i, TEM 2003h, TEM 2009c, TEM 2011a, TEM 2012). This is higher than the maximum recommended area in the Biodiversity Guidebook (1995), and suggests a small decline of this forested ecosystem over the short term. Losses are primarily due to forest harvesting and a very minor area of rural and urban development. Degradation from livestock grazing and invasive species has continued to occur. Forest harvesting levels are likely to be small because these sites are not very productive and occur on less accessible sites. |
| Long-Term Trend: | F = Decline of 10-30% |
| Comments: | With a natural disturbance regime of frequent stand-maintaining fires, this ecological community would have historically been dominated by uneven-aged old forests (Biodiversity Guidebook 1995). This ecological community belongs to Natural Disturbance Type 4, with frequent stand-maintaining fires. The Biodiversity Guidebook (1995) recommends at least 31% old forest (more than 250 years old) and more than 63% mature plus old (more than 100 years old). The Biodiversity Guidebook does not reflect the historical distribution of stand ages, but rather represents targets for forest management. Ten percent of the land within the range of this ecological community has been converted to human dominated land cover (Hectares BC, Land Cover Theme, February 2016). Degradation from livestock grazing was more extensive in the past. Improved management practices have reduced livestock grazing impacts in recent decades (B.C. Forest Practices Board 2002). |
| Other Factors | |
| Intrinsic Vulnerability: | B=Moderately vulnerable |
| Comments: | The shallow soils of this ecological community are vulnerable to disturbance-induced erosion. |
| Environmental Specificity: | C=Moderate. Generalist or community with some key requirements scarce. |
| Comments: | This ecological community occurs on sites that are susceptible to drought, with shallow soils on steep upper slopes or ridge crests on warm aspects (Lloyd et al. 1990). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | |
| Inventory Needs: | |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Iverson, K. E. and C. M. Cadrin |
| Date: | March 19, 2016 |
| References | |
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B.C. Ministry of Forests, Lands, and Natural Resource Operations. Biogeoclimatic Ecosystem Classification (BEC) Map, WHSE_FOREST_VEGETATION.BEC_BIOGEOCLIMATIC_POLY [ESRI ArcSDE format]. Version 9. Ministry of Forests, Lands, and Natural Resource Operations, Forest Analysis and Inventory Branch, Victoria, B.C. Updated Regularly.
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B.C. Ministry of Forests, Lands, and Natural Resources Operations and Rural Development. Digital Road Atlas (DRA) - Master Partially-Attributed Roads, WHSE_BASEMAPPING.DRA_DGTL_ROAD_ATLAS_MPAR_SP [ESRI ArcSDE format]. Ministry of Forests, Lands, and Natural Resource Operations, GeoBC. Victoria, B.C. Updated Regularly.
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B.C. Ministry of Forests, Lands, and Natural Resources Operations. Range Tenures, WHSE_FOREST_TENURE.FTEN_RANGE_POLY_SVW [ESRI ArcSDE format]. Ministry of Forests, Lands, and Natural Resource Operations, Provincial Range Operations, Victoria, B.C. Updated Regularly.
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British Columbia Government, Ministry of Forests. Victoria, BC. Timber Harvesting Landbase.
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British Columbia Government. Hectares BC. Victoria, BC. Land Cover theme. Available: http://hectaresbc.ca/app/habc/HaBC.html
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British Columbia Government. Hectares BC. Victoria, BC. Vegetation Resources Inventory theme. Available: http://hectaresbc.ca/app/habc/HaBC.html
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Daigle, P. 1996. Fire in the Dry Interior Forests of British Columbia. British Columbia Ministry of Forests Research Program Extension Note 08:5pp.
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Flynn, Samantha. 2000. Plant Association Status Ranking 1999-2000. Access Digital Database. BC Ministry of Environment, Conservation Data Centre. Victoria, BC.
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Haughian, S.R., P.J. Burton, S. W. Taylor, and C. L. Curry. 2012. Expected effects of climate change on forest disturbance regimes in British Columbia. BC Journal of Ecosystems and Management 13(1):1-24
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Heyerdahl, E., K. Lertzman and S. Karpuk. 2007. Local-scale controls of a low-severity fire regime (1750 ? 1950), southern British Columbia, Canada. Ecoscience 14(1):40-47.
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Lloyd, D., K. Angove, G. Hope, and C. Thompson. 1990. A guide to site identification and interpretation for the Kamloops Forest Region. B.C. Minist. For., Res. Branch, Victoria, B.C. Land Manage. Handb. No. 23. 399pp.
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Steen, O.A. and R. A. Coupé. 1997. A field guide to forest site identification and interpretation for the Cariboo Forest Region. B.C. Min. For., Victoria, B.C. Land Manage. Handb. No. 39.
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Terrestrial Ecosystem Mapping (TEM) of the South Okanagan and lower Similkameen Valley: refined and updated 2012. K. Iverson and A. Haney. 1:20,000 spatial data.
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Terrestrial Ecosystem Mapping [TEM] of portions of the IDFxh1 in the Bella Vista - Goose Lake Range. 2003h. Prepared for the Okanagan Indian Band, Allan Brooks Nature Centre, City of Vernon and B.C. Ministry of Water, Land and Air Protection by K. Iverson and J. Shypitka. 1:20,000 spatial data.
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Terrestrial Ecosystem Mapping [TEM] of portions of the PPxh1 and IDFxh1 in the Central Okanagan. 2002i. Prepared for the Regional District of the Central Okanagan and the Ministry of Sustainable Resource Management, by K. Iverson, C. Erwin, C. Sinnemann, L. Lacelle and D. Spaeth Filatow. 1:20,000 spatial data.
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Terrestrial Ecosystem Mapping [TEM] of the Central Okanagan Gap Areas. 2011. K. Iverson. 1:20,000 spatial data.
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Terrestrial Ecosystem Mapping [TEM] of the Central Okanagan Valley: updated Mar. 2009c. Prepared for Okanagan Collaborative Conservation program by A. Haney and K. Iverson. 1:20,000 spatial data.
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Terrestrial Ecosystem Mapping [TEM] of the TFL 35 study area with Wildlife Interpretations. 2000j. Prepared for Weyerhaeuser Company, Kamloops, B.C., by C. Clement and J. Ryder, Shearwater Mapping LTD, Victoria, B.C. 1:20 000 spatial data.
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Terrestrial Ecosystem Mapping [TEM] of the TFL 35 Study Area with Wildlife Interpretations. 2001c. Produced for Weyerhaeuser Company by Shearwater Mapping Ltd. Victoria, B.C. 1:20,000 spatial data.
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Terrestrial Ecosystem Mapping [TEM] of Weyerhaeuser Canada Ltd., Tree Farm License 15. 1999d. Prepared for Weyerhaeuser Canada Ltd., Okanagan Falls in partnership with FRBC and the Ministry of Forests, Kamloops, B.C., by Bruhjell, D. and S. Robertson 1:20 000 spatial data.
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Terrestrial Ecosystem Mapping [TEM]: Cathedral Provincial Park Bioterrain And Ecosystem Inventory Draft. March 25 1996. Prepared for Judy Miller, BC Parks, Summerland, B.C., by JMJ Holdings Inc., Nelson, B.C. 1:20 000 spatial data.
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Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2016. Conservation Status Report: Pseudotsuga menziesii - Pinus ponderosa / Pseudoroegneria spicata. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Feb 20, 2025).