Ecological Land Classification of Mount Revelstoke and Glacie r ...

ENGELMANN SPRUCE - SUBALPINE FIR ECOREGIO NThe Engelmann Spruce-Subalpine Fir Ecoregion occurs at altitudes above the Interior Cedar-Hemloc kEcoregion and below the unforested Alpine Ecoregion . It is divided into Lower Subalpine and Uppe rSubalpine portions .Lower Subalpin eThe Lower Subalpine is characterized by closed forests dominated by Picea engelmannii and Abies lasiocarpa. Tsuga mertensiana is often codominant and Tsuga heterophylla occurs in the lower part ofthe Lower Subalpine . The Lower Subalpine occurs from 1500 to 1900 m in MRNP and 1450 to 200 0m in GNP . This range is slightly higher on warm aspects and lower on cooler aspects . Typical v .t .sinclude Engelmann spruce-subalpine fir/tall bilberry/liverwort (C21), mountain hemlock-subalpinefir/rhododendron-tall bilberry (C47), Engelmann spruce-mountain hemlock/rhododendron-tall bilberry(C48), mountain hemlock-Douglas fir-subalpine fir-Engelmann spruce/rhododendron-tall bilberry(C49) and Engelmann spruce-subalpine fir/rhododendron-tall bilberry (021) . The drier climat eeast of the Beaver River in GNP is also reflected in the vegetation of the Lower Subalpine as in th eICH Ecoregion . Pinus contorta occurs here and not further west, Tsuga mertensiana is mostly absent ,and Pachystima myrsinites is more common and widespread .The Lower Subalpine corresponds to the lower part of the Interior Subalpine Forest Section (SA.2) ofRowe (1972), although his lower boundary is about 300 m lower than recognized here . The Lowe rSubalpine west of the Beaver River corresponds to the lower part of the Wet Forested EngelmannSpruce-Subalpine Fir Subzone (ESSFb) of the biogeoclimatic classification of the Nelson Forest Region(Utzig et al. 1983) . It seems to correspond wholly with the Wet Central EngelmannSpruce-Subalpine Fir Subzone (ESSFw) of the Kamloops Forest Region, just to the west (Lloy d1983) . The Lower Subalpine east of the Beaver River comes closest to the Moist Southern ForestedEngelmann Spruce-Subalpine Fir Subzone (ESSFc, Utzig et al. 1983) . Since eastern GNP is clearly inthe transition between the Wet and Moist Climatic Regions, it does not fit the central concept o fESSFc fully . For example, some Tsuga heterophylla occurs in eastern GNP, although it is typicall yabsent in ESSFc .Upper SubalpineThe Upper Subalpine typically has open forests dominated by Picea engelmannii and Abies lasiocarpa .Closed Engelmann spruce-subalpine fir forests occur on warm aspects and in the lower part of th eUpper Subalpine, but characteristically contain Cassiope mertensiana, Phyllodoce empetriformis andLuetkea pectinata and lack Menziesia glabella or Oplopanax horridum . Tsuga mertensiana is alsocommon, often as a codominant . The Upper Subalpine occurs from 1900 to 2200 m in MRNP an d2000 to 2300 m in GNP, the boundary being lower on cool aspects and higher on warm ones . Typicalv.t .s include subalpine fir-mountain hemlock/heather-luetkea (020), subalpine fir-whitebarkpine-(Engelmann spruce)/tall bilberry-heather (022) and mountain hemlock-subalpine fir/rhododendron-tallbilberry (C47) . The Upper Subalpine east of the Beaver River is drier but the difference i snot as great as in the Lower Subalpine and Interior Cedar-Hemlock . The primary effect is a de -creased amount of Tsuga mertensiana and more of the Engelmann spruce-subalpine fir/heather (010 )v .t . Lush herb meadows (fleabane-valerian (H16)) are also typical of the Upper Subalpine .The upper part of the Interior Subalpine Forest Section (Rowe 1972) corresponds to the Upper Sub -alpine . The Upper Subalpine west of the Beaver River corresponds to the upper part of the WetForested Engelmann Spruce-Subalpine Fir Subzone (ESSFb) and to the Wet Parkland EngelmannSpruce-Subalpine Fir Subzone (ESSFbp) in the biogeoclimatic classification of the Nelson Forest Region(Utzig et al. 1983) . In the Kamloops Forest Region (Lloyd 1983), the Upper Subalpine fits bestthe Wet Upper Engelmann Spruce-Subalpine Fir (ESSFu) and Wet Parkland Engelman nSpruce .Subalpine Fir (ESSFbp) Subzones . The Upper Subalpine east of the Beaver River is closest tothé Moist Southern Parkland Engelmann Spruce-Subalpine Fir (ESSFbp) (Utzig et al . 1983) .36