Mountain Zones

As you explore the park, pay attention to its life zones; doing so will help you tune in to both the ecology of individual plants, and the complex relationship between climate on the one hand and the distributions of birds, mammals, insects, on the other. The following brief summary of Wells Gray’s vegetational subzones should get you started.

Hemiboreal Zone
Hemiboreal Zone
In the bottom-most of the subzones – called the Hemiboreal Subzone (hemi, Greek for “half”) – deciduous trees such as Trembling Aspen and Paper Birch are very common. By contrast, Spruce is sparse (restricted to moist sites), and Subalpine Fir is essentially absent. The Wells Gray road passes a representative section of Hemiboreal between km 11.5 and km 20. Likewise, most of the Hemp Creek Canyonlands belong to this subzone.

Above about 550 m, the Hemiboreal gives way to the Lower Boreal Subzone. Here Spruce becomes more common, and Subalpine Fir turns up, though only in moister sites. It is here too that blueberries and huckleberries first begin to appear. From km 20 to Clearwater Lake, the park road should give you a good feeling for this subzone.

Upward again, at about 1000 m, the Middle Boreal Subzone cuts in. Here Engelmann Spruce and Subalpine Fir are again more common, whereas other tree species are dropping out. First to go are the deciduous trees, next Douglas-fir, and then Western Red-cedar and Western Hemlock. At the top of this subzone, Spruce and Subalpine Fir are the only trees left, at least in mature forest types. A good place to explore the Middle Boreal Forest is along the upper portions of the road to Calagata Lake or, if you don’t mind hiking, on the trail to Philip Lake.

Middle Boreal Zone
Middle Boreal Zone
Above 1450 m, an obvious thinning of the forest begins, and the understory gradually gives way to dense thickets of Mountain Rhododendron (Rhododendron albiflorum) and False Azalea (Menziesia ferruginea). This is the Upper Boreal Subzone; of all the forested subzones, here plant diversity is lowest. The lower several hundred metres of the Trophy Meadows trail belong to this subzone, but much of the forest here has recently been liquidated.

It is in the Hemiarctic Subzone, above 1800 m, that the thickets finally give out, and the arctic element first appears. As you continue upward along the Trophy Meadows trail, for instance, note how the forests become interspersed with ever-larger subalpine meadows. Eventually the Hemiarctic Subzone opens up completely, and the forests are replaced by extensive flower meadows in which, however, clumps of trees may still persist. Whether on the Trophies or on Battle Mountain, the Hemiarctic is everybody’s favourite subzone.

At about 2100 m, the flower meadows uniformly give way to heaths comprised of various low heathers, willows and sedges. This is the Lower Arctic Subzone. Recognize it also by the trees, which are now suddenly, and quite conspicuously, dwarfed. Two indicator species to look for are the White Mountain Heather (Cassiope mertensiana) and Yellow Mountain Heather (Phyllodoce glanduliflora). The highest of Wells Gray’s lakes and are located in this subzone, though none contain fish.

Hemiarctic Zone
Hemiarctic Zone
The peaks of the Trophies, above 2400 m, rise into the Middle Arctic Subzone. This is a cold, windy world, in which snowdrifts persist through the summer in the lees of the ridges. No trees at all exist in this subzone – dwarfed or otherwise. As for the heaths, they are now represented only by scattered turfs that manage to eke out a spartan existence in shallow depressions. The plants that grow here may be small, but their flowers are often large and colourful. A land of vistas and broken rock.

Finally, there is the Upper Arctic Subzone. Only about eight peaks in the park extend upward past its lower limits at 2700 m, of which the most accessible is Garnet Peak. Practically no flowering plants occur at all, and snow regularly falls even in July. The only plants left are a few mosses and lichens which on favourable exposures somehow maintain a meagre photosynthesis.

This zonation system just described is internationally known as the Bioclimatic Zone System. In middle latitude mountains, many authors prefer to add the prefix “oro” (oros, Greek for mountain), as a way of distinguishing them from the “true” arctic and boreal zones of the far north. Thus Hemiboreal becomes Orohemiboreal, Lower Boreal becomes Lower Oroboreal, Middle Boreal becomes Middle Oroboreal, and so on.

Lower Arctic Zone
Lower Arctic Zone
The Bioclimatic Zone System was developed in northern Europe, and was first applied to North America in Wells Gray by Leena Hämet-Ahti. It is, however, only one of many different systems describing the patterning of vegetation over space. In British Columbia, many foresters prefer to use the Biogeoclimatic Zone System, in which the zones are named according to the dominant climax tree species. Translated to this system, the zones represented in Wells Gray would be called the Interior Cedar-Hemlock Zone, the Engelmann Spruce-Subalpine Fir Zone and the Alpine Tundra Zone.

The following table lists the more conspicuous or otherwise noteworthy plants of Wells Gray, and gives the approximate subzonal distribution of each.

Trees, Shrubs and Flowers of Wells Gray Park
ABUNDANCE: (in appropriate habitat)
*** = abundant   ** = sparse   * = rare
HB = Hemiboreal; LB = Lower Boreal; MB = Middle Boreal;
UB = Upper Boreal; HA = Hemiarctic; LA = Lower Arctic;
MA = Middle Arctic; UA = Upper Arctic
Frequency Species Subzonal Range
*** Western Red-cedar (Thuja plicata) HB-MB
*** Douglas-fir (Pseudotsuga menziesii) HB-MB
*** Subalpine Fir (Abies lasiocarpa) LB-HA
* Mountain Hemlock (Tsuga mertensiana) HA? (reported)
*** Western Hemlock (Tsuga heterophylla) LB-MB (wet)
*** Lodgepole Pine (Pinus contorta) HB-HA (burns)
** Western White Pine (Pinus monticola) LB-MB
* Whitebark Pine (Pinus albicaulis) HA
*** Engelmann Spruce (Picea engelmannii) LB-HA
*** White Spruce (Picea glauca × engelmanii) HB-LB
*** Trembling Aspen (Populus tremuloides) HB-MB
*** Paper birch (Betula papyrifera) HB-LB
*** Black Cottonwood (Populus trichocarpa) HB-MB
*** False Azalea (Menziesia ferruginea) MB-UB
** Oval-leaf Blueberry (Vaccinium ovalifolium) LB-HA
* Redstem Ceanothhus (Ceanothus sanguineus) HB-LB
*** Devil’s Club (Oplopanax horridum) HB-MB
*** Falsebox (Paxistima myrsinites) HB-MB
*** Hardhack (Spiraea douglasii) HB-MB
*** Hazelnut (Corylus cornuta) HB-LB
*** White Moss Heather (Cassiope mertensiana) HA-LA
** Red Mountain Heather (Phyllodoce empetriformis) UB-LA
** White Mountain Heather (Cassiope tetragona) HA-MA
*** Yellow Heather (Phyllodoce glanduliflora) LA-MA
** Tall Mountain Huckleberry (Vaccinium membranaceum) LB-HA
* Rocky Mountain Juniper (Juniperus scopulorum) HB
* Shrubby Penstemon (Penstemon fruitcosus) HB
*** Mountain Rhododendron (Rh. albiflorum) MB-UB
* Snowbrush (Caenothus velutinus) HB-LB
*** Soopolallie (Shepherdia canadensis) HB-LB
*** Bebb’s Willow (Salix bebbiana) HB-LB
* Western Yew (Taxus brevifolia) LB
** Moss Campion (Silene acaulis) LA-MA
** Skunk Cabbage (Lysichiton americanum) HB-MB
*** Queen’s Cup (Clintonia uniflora) HB-MB
** Spreading Dogbane (Apocynum androsaemifolium) HB-LB
*** Dwarf Dogwood (Cornus canadensis) HB-MB
*** Fireweed (Epilobium angustifolium) HB-HA
*** Foamflower (Tiarella unifoliata) LB-UB
** Columbia Lily (Lilium columbianum) HB-LB
** Corn Lily (Veratrum viride) UB-HA
*** Glacier Lily (Erythronium grandiflorum) HA
** Wild Lily-of-the-valley (Maianthemum canadense) LB
*** Arctic Lupine (Lupinus arcticus) LB-HA
* Dwarf Mistletoe (Arceuthobium americanum) LB
** White-rein Orchid (Platanthera dilitata) LB-HA
* Indian Pipe (Monotropa uniflora) HB-LB
** Rattlesnake Plantain (Goodyera oblongifolia) HB-MB
*** Woolly Pussytoe (Antennaria lanata) HA
** Prince’s Pine (Chimaphila umbellata) HB-MB
*** Trailing Rubus (Rubus pedatus) LB-UB
** Wild Sarsaparilla (Aralia nudicaulis) HB-LB
** False Solomon’s Seal (Smilacina racemosa) HB-MB
** Meadow Spiraea (Luetkea pectinata) HA
* Round-leaved Sundew (Drosera rotundifolia) LB-MB
* Touch-me-not (Impatiens capensis) LB
*** Twinflower (Linnaea borealis) HB-MB
** Rosy Twistedstalk (Streptopsus roseus) LB-UB
* Bluebunch Wheatgrass (Agropyron spicatum) HB
** One-sided Wintergreen (Orthilia secunda) HB-MB

Text extracted, with partial updates, from the 2nd edition of Nature Wells Gray: A Visitors’ Guide to the Park, by Trevor Goward & Cathie Hickson © 1995, for several years out of print, and now awaiting sponsorship toward a third, much improved edition.