disturbed by mining - Government of British Columbia Home page

27The Interior Dry Belt of British Columbia's Southwest Interior is characterizedby the "rain shadow" effect which exists on the east side of the CoastRange Mountains. It is a region of limited precipitation, reduced cloudcover, abundant sunshine and frequent, strong, surface winds. Summers tendto be very hot and dry in the lower valleys with moderation at the higherelevations. Maximum summer temperatures in excess of 100° Fahrenheit arenot uncommon in the communities of Ashcroft and Spences Bridge. Annualprecipitation in these communities varies between seven and ten inches.Natural vegetation along the Thompson River at these localities is sparse,consisting of sage brush, juniper, and small cactus, an assemblage typicalof semi-desert conditions. Benchlands above the river are dotted withPonderosapine.Just a few miles to the east lies the Highland Valley which geographicallyoccurs within the Interior Plateau land form at elevations ranging from3,000 feet to 5,000 feet above sea level. This is a forested area of gentlyrolling hills with grassy meadows along the valley floor. Precipitation hereranges between 9 and 25 inches per year, most of which occurs during thewinter months in the form of snow. Summer temperatures here are moderatewith average maximum temperatures of 82° Fahrenheit. Winters tend to belong and occasionally very cold. Strong southwesterly winds are prevalentduring the months of April through June.The valley borders two biogeoclimatic zones; the Interior Douglas f i r zone ofDouglas f i r , Ponderosa and Lodgepole pine; and the Engelmann spruce-subalpinef i r zone. Lower slopes of the drier north side of the valley are forestedwith Ponderosa pine and Douglas f i r . Lodgepole pine are also presentdepending upon the fire history of the area. Higher up the north side ofthe valley, the forests are predominantly Lodgepole pine with an Engelmannspruce component. Native plant species other than those which have alreadybeen mentioned include dwarf juniper, willow, trembling aspen, sedge,pinegrass, bluebunch wheatgrass, bluegrass, soapberry, wild rose, white