Soap Lake Ecological Reserve #3 Overview: Biological and Physical

Posted April 5, 2000 | Categories : 3,Reports,Species List |


To conserve an alkaline lake, its associated flora and fauna, and representative ecosystems of the Interior Douglas-Fir Zone

Physical: Soap Lake, about 9 ha in size and located in a shallow valley in the center of the reserve, is very alkaline (pH 9.1) due to high evaporation and limited outflow. A band of encrusted salts up to 6 m wide occurs around the lake edge, and two alkaline ponds occur to the east of the lake. Gently sloping mountains with a variety of slope exposures rise to the north and south of the lake; upper slopes of the Nicola Valley occur in the northeast corner.

Biological: The shores of Soap Lake and adjacent ponds support concentric bands of plants which are adapted to high alkalinity. The most common species here are Nuttall’s alkaligrass, saltgrass, foxtail barley, and pahute weed. A treeless community dominated by big sagebrush, bluebunch wheatgrass, and arrow-leaved balsam- root occurs outside this band of alkaline adapted plants, on southeast-facing slopes in the northern part of the reserve, and on the slopes of the Nicola Valley. Other dry, low-elevation slopes support ponderosa pine stands with an understory of wheatgrass and balsam-root. Douglas-fir communities cover much of the reserve area; dominant understory species vary from bluebunch wheatgrass in open fir stands to pinegrass in closed stands and snowberry in moist draws. A small stand of trembling aspen, willow, and water birch occurs near the two ponds.

Mammals recorded in the reserve include Mule Deer, Black Bear, Coyote, and Pocket Gopher. Many shrubs are heavily browsed by deer. A variety of dry forest birds is present, and Killdeers occur around the shoreline.

Interesting invertebrates associated with the alkaline lake are swarms of brine flies around its margin and brine shrimp in the lake itself.

Cultural: The lake’s alkaline and sulphur-rich mud, as well as the mineral-rich spring water were used by local First Nations for medicinal purposes. Traditional plant gathering and hunting is said to take place in the reserve

Red Lister: satin grass, wedgescale orache,

Blue listed: thyme-leaved spurge, Edward’s wallflower

Climate Change:

As the lake in this reserve displays high evaporation rates and lies in a shallow valley, warming temperatures may lead to accelerated evaporation, subsequently increasing the salinity of the lake while reducing its area and depth. Drying and drought in the southern and interior areas of North America has been observed; the drying of the wetlands and Soap Lake could result in the loss of the associated flora and fauna and a decrease in productivity due to lack of moisture.


alkaligrass, Nuttall’s (Puccinellia nuttalliana)
aspen, trembling (Populus tremuloides)
balsam-root, arrow-leaved (Balsamorhiza-sagittata)
barley, foxtail (Hordeum jubatum)

birch, water (Betula occidentalis)
Douglas-fir (Pseudotsuga menziezii)
grass, satin (Muhlenbergia racemosa)
orache, wedgescale (Altriplex truncata)
pahute weed (Suaeda caleoliformis)
pine, ponderosa (Pinus ponderosa)
pinegrass (Calamagrostis rubescens)
sagebrush, big (Artemesia tridentate)
saltgrass (Distichlis sp.)

snowberry (Symphoricarpos sp.)
spurge, thyme-leaved (Chamaesyce serpyllifolia)
wallflower, Edwards (Eutrema edwarsii)
wheatgrass, bluebunch (Pseudoroegneria spicata)
willow (Salix sp.)


Bear, Black (Ursus americanus)
Coyote, (Canis latrans)
Deer, Mule (Odocoileus hemionus)
Gopher, Northern Pocket (Thomomys talpoides)
Killdeer (Charadrius vociferous)