SBSdk/07 Sxw – Horsetail Ecologically Acceptable Tree Species Site Level: minimize mineral soil exposure to establish seedlings; elevated microsites preferred planting sites (drainage, cold soils, frost); consider cluster planting and reduced stocking; high risk of compaction and windthrow (fine-textured and high water table) and surface erosion (fluvial sites). [Source: p.7-70]. Shade tolerance Sxw > Pl Act At Ep Frost tolerance Pl > At Ep > Act Sxw Snow tolerance Sxw > Pl Act At Ep Drought tolerance Pl > Sxw > At Ep > Act Water table tolerance Act > Sxw > At Ep Pl Nutritional requirements Act > Sxw At Ep > Pl Productivity Pl > Sxw Natural regen potential Open Shade High: Act At Ep Pl Med: Pl Sxw Wind tolerance Act > At Ep Pl > Sxw Conifers: Sxw PlBroadleaves: Act At Ep Seral Species Relationships: # Age (yrs) BGC subzone/variant context: Historical species distribution Vegetation potential: Very High: Wet Alder and Cottonwood Tree Species Notes: Pl is limited by shade intolerance and saturated soils; Sxw is limited by growing season frosts; Act, At, Ep – limited in productivity, reliability and/or feasibility [Source: PR (LMHB 26); and the Reference Guide for FDP Stocking Standards Footnotes]. Silvicultural Considerations Relative Tree Species Characteristics: Reference Guide to Forest Development Plan Stocking Standards Tree species Compendium: Sxw Pl Act At Ep Region: Northern Interior - Prince Rupert Insects: SxwPl root collar weevilLL spruce beetleL white pine weevilM black army cutwormM lodgepole pine terminal weevil L mountain pine beetleL Diseases: SxwPl Comandra blister rustM Western gall rustM Pine dwarf mistletoeH Stalactiform blister rustM Tomentosus root rotMM Mammals: SxwPl Snowshoe hareL porcupineL SBSdk Pest Concerns: (appendix D – Forest Health Charts) Sxw Pl At Ac t

SBSdk/07 Sxw – Horsetail Ecologically Acceptable Tree Species: Act At Ep Pl Sxw Shade tolerance Sxw > Pl Act At Ep Frost tolerance Pl > At Ep > Act Sxw Snow tolerance Sxw > Pl Act At Ep Drought tolerance Pl > Sxw > At Ep > Act Water table tolerance Act > Sxw > At Ep Pl Nutritional requirements Act > Sxw At Ep > Pl Site Index (1 st approx.) Pl = 21 Sxw = 21 Natural regen potential Open Shade High: Act At Ep Pl Med: Pl Sxw Wind tolerance Act > At Ep Pl > Sxw Tree Species Composition: Historic 2 nd Growth Recommended Sxw At (Act Pl) Pl (Sxw) Sxw (At Act Pl) Tree Species Notes: Pl is limited by shade intolerance and saturated soils; Sxw is limited by growing season frosts; preserve advance regeneration; Act, At, Ep – limited in productivity, reliability and/or feasibility [Source: PR (LMHB 26); and the Reference Guide for FDP Stocking Standards Footnotes]. Relative Tree Species Characteristics: Link to Reference Guide to Forest Development Plan Stocking StandardsReference Guide to Forest Development Plan Stocking Standards Additional Tree Species information: Sxw Pl Act At Ep Other Fire Tolerance Pl Sxw > At Ep > Act Site Limiting FactorsManagement ImplicationsProposed Management Options Cold, wet, poorly aerated fine-textured soils Root restriction, reduced productivity, windthrow, soil compaction Mounding and/or elevated microsites for seedling establishment Frost/cold airSeedling damage / mortalityMounding and/or elevated microsites for seedling establishment; partial canopy retention PorcupineReduced Pl productivityMixed species composition Pine dwarf mistletoeReduced Pl productivity Mountain Pine BeetleReduced Pl productivity; Pl mortalityMixed species composition Competing vegetationSeedling mortality and reduced growth rateEarly planting post-harvest and/or minimize mineral soil exposure Voles and HaresSeedling mortality Market Value Tree Species Ecological Amplitude: actual soil moisture soil nutrient VD MD SD F M VM W A B C D E Act At Ep Pl Sxw Silvicultural site considerations: (link to Silvicultural BGC subzone considerations)

SBSdk – Sub-Boreal Spruce Dry Cool Biogeoclimatic Subzone Link to the Reference Guide to Forest Development Plan Stocking StandardsReference Guide to Forest Development Plan Stocking Standards Additional Tree Species Information : Sxw Pl Act At Ep Fd Sb Other species Site series Number Frost / Cold Air High Water table Moisture Deficit Nutrient Deficit Root RestrictionSubzone Presence 01Some sites Fine-textures30% 02/03Severe Shallow soils15% (less 02) 04Commonshallow soils5% 05Common Fine-textures8% 06Fine-textures12% 07YYFine-textures5 08YYHigh water table8 09YYHigh water table5 10YYHigh water table12 Subzone Notes: Summers in the SBSdk are relatively warm and dry while the winters are typically cold and dry (snowpack < 50cm). The most common tree species include Sxw, Pl, At, Act and Ep. Climax forests are dominated by Sxw however, due to the recurrent disturbances common to this variant many forests are often dominated by Pl and At. Fd and Ep are relatively uncommon but where they do occur they are usually associated with drier sites. Sb is typically restricted to wetlands and Act is most common along rivers and streams in association with Sxw. SBSdk Site Series Characteristics: (use site series number to link to site pages) Silvicultural Subzone Considerations: Subzone ConcernsIdentified Risks / ImplicationsManagement Options 2 nd growth shift in species compositionResilience of ecosystems, forest health risksAdopt appropriate mix of species Overstocking on wet sites Understocking on Pl dry sitesLong term economics (I.e. forest health issues)Increase Pl density Climate change – inc. in growing season tempReduced Sxw productivity on drier sitesShift proportions of species mix (introduce Fd) Increase in MPB in the southern portionsPl mortality Tree Species Composition Considerations: SiteOld growth2 nd growthFuture options Dry Forest Pl (Fd Sxw)PlPl (Fd) Mesic Forest Sxw Pl (At Fd)Pl (Sxw At)Sxw (Pl At Fd) Wet Forest Act Sb (Sxw)Sb Act SxwAct Sb (Act) Notes: Future options are based on historic trends in species composition and current landscape concerns. These are intended to be used as guide and are expected to change as new forest management issues arise.