DESCRIPTION OF THE AREA
Tunkwa Lake lies in the Interior Douglas-fir zone which dominates low to mid-elevation landscapes of the Southern Interior Plateau and the Rocky Mountain Trench. The vegetation is characteristic of upper grasslands and Douglas-fir zones as described in Chapter 7, British Columbia Rangeland and in Appendix 1.
The Tunkwa Lake Range Unit is located about 40 km west and 20 km south of Kamloops. Tunkwa Lake itself is at an elevation of about 1100 m and is surrounded by rolling grasslands and pine forest. The lower portion of this unit falls within the dry portion of the Interior Douglas-fir biogeoclimatic zone. The unit also extends westward into a higher elevation conifer forest (Montane Spruce) where seeded cutblocks are available for grazing at elevations greater than 1280 m.
This area has a continental climate characterized by warm, dry summers, cool winters (low snowfall) and about 85-90 frost-free days. Mean annual precipitation is 438 mm of which, on average, 193 mm occurs during the growing season. The mean annual temperature is 3.4 C and the mean growing season temperature is 11.1 C.
Soils for the most part are light-textured Chernozems (with coarse fragments) on grassland sites and on forested sites which have recently encroached upon the grasslands. Brunisols and luvisols are common under longer-term forested cover.
Current Land Use
Livestock grazing occurs seasonlong, with continuous use from May through October 31. High cattle numbers (cow/calf pairs) suggest that overstocking may occur. About 8000 AUMs are under tenure. Seeded cutblocks are available at higher elevation, although cattle do not tend to remain on these areas. The lower grassland and lodgepole pine zones are not cross-fenced. About 60 feral horses use the area year round.
Deer hunting and duck hunting are popular activities in the Tunkwa Lake area. Wildlife use includes a good mule deer population at the forest/grassland interface, with a majority of use in the forested Interior DF and MS. Waterfowl use is substantial but populations of sharptail grouse and blue grouse are limited. Some ruffed grouse use the area, but habitat for upland game birds is not in good condition. Tunkwa Lake itself supports world-class rainbow trout fishing; Tunkwa creek is a spawning and brood channel.
The area has recently been declared a protected area (a park) but existing uses will continue. Among these are horseback riding (Logan Lake riders use the area extensively), ATV riding (with associated impacts), hunting, and livestock grazing.
Vegetation Characteristics
Community Descriptions
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Approximate locations
Figure 5.1 Upland
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Approximate locations
Figure 5.4 Riparian
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Figure 5.0 Aerial view and Figure Key of Tunkwa Creek and Tunkwa Lake.
Upland Grassland Community
The upland grassland community is currently dominated by Kentucky bluegrass and Sandberg’s bluegrass (Figure 5.0 and 5.1). Low pussy-toes and fringed sage occur with minor amounts of bluebunch wheatgrass, junegrass, spreading needlegrass, and needle-and-thread. The community is currently in an upper poor to low fair range condition which approximates an upper early-seral stage. Biodiversity is relatively low.
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Historically the area was characterized as bluebunch wheatgrass-rough fescue grassland. Currently, rough fescue is the dominant species at climax or PNC. An exclosure built in the early 1960’s west of Tunkwa Lake is now dominated by rough fescue. This successional pattern is evidenced on similar sites throughout much of the Kamloops Region where long-term rest is provided. |
Figure 5.1 Upland grassland near Tunkwa Lake.
Forested Community
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The forested community is dominated by seral lodgepole pine with a few veteran Douglas-fir (Figure 5.2). Douglas-fir is considered the climax dominant on these sites. The understorey has been radically altered with a reduction in the shrub layer and introduction of domestic forages. Pinegrass would normally dominate the understorey and there should also be rose, Canada buffaloberry, and spirea. |
Figure 5.2 Forest community near Tunkwa Lake.
Riparian Community
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A reduction in willow and narrowing of the riparian zone has occurred in the area. The Tunkwa Creek moist/wet riparian zone is now only a few metres wide (1-3 m) and is dominated by sedge with a few scattered sprigs of willow (Figure 5.3). |
Figure 5.3 A typical stretch of Tunkwa Creek riparian zone.
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Kentucky bluegrass, mat muhly, and silver cinquefoil now dominate a 3-5 metre band on either side of the creek (Figure 5.4). |
Figure 5.4 Lack of wet species
This riparian zone lacks willow and other woody species normally associated with moist/wet conditions.
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As a consequence of overgrazing and trampling, a dry riparian zone has been created. The shoreline of Tunkwa Lake and banks of Tunkwa Creek evidence livestock impacts (Figure 5.5 and 5.6). |
Figure 5.5 Cattle use of the Tunkwa Lake shoreline.
Cattle use of the Tunkwa Lake shoreline and surrounding areas is essentially seasonlong from May through October.
Figure 5.6 Damage to streambank soils and vegetation is obvious and severe.
