Ambrose lake Overview, Physical and Biological

Posted March 27, 2000 | Categories : 28,Rare Species,Reports,Species List |

See the complete report pfd file: ambrose_lake(1)

To preserve a small coastal lake, adjacent bogland, and surrounding


The reserve occurs on undulating terrain of the Georgia Lowland, underlain by largely granitic bedrock. Its western boundary follows 1.5 km of marine shoreline along Agamemnon Channel, its eastern boundary a similar distance along the western edge of Ruby Lake. Soils are predominantly Podzols on glacial till, except for bedrock exposures and boggy areas. Ambrose Lake is located entirely within the reserve, as is most of its rather limited watershed. The lake is 30 ha in area, 33 m deep, and irregular in shape. It drains eastward into Ruby Lake.


Photo of Cascara (Rhamnus purshiana) by Virginia Skilton

Most of the reserve area consists of upland forest in which Douglas-fir and western hemlock are abundant. Western redcedar may be locally common, while western white pine, arbutus, bigleaf maple, flowering dogwood, and cascara occur more sparingly. Typical upland associations include Douglas-fir- salal-moss; western hemlock-Douglas-fir-moss; and western redcedar- Douglas-fir-sword fern. Additional trees recorded in moist and riparian situations are lodgepole pine, red alder, Sitka spruce, and Pacific crab apple.
Interesting boglands, of limited extent in this part of the province, occur along the northern margin of Ambrose Lake and along its outlet stream, southeastward from the eastern bulge of the lake. These are characterized by scattered lodgepole pine trees, shrubs such as Labrador tea, sweet gale, and
bog-laurel, sedges, and sphagnum moss. The yellow waterlily occurs in shallow bays around the lake edge. The “common” reed, twenty-three species of mosses, six liverworts, and six lichens have been recorded in the reserve.
Beaver are known to be present. Prickly sculpins are found in the lake. There is no record of Ambrose Lake ever having been stocked with sport fish.

Significant Species:
Cutthroat Trout, ssp. lewisi Blue Listed, (Cosewic special concern)
Prickly Sculpin
Vancouver groundcone
Threespine Stickleback  (Cosewic special concern)


arbutus (Arbutus menziesii)
bog-laurel, western (Kalmia microphylla)
cascara (Rhamnus purshiana)
collomia, vari-leaved (Collomia heterophylla)
crab apple, Pacific (Malus fusca)
dogwood, flowering (Cornus nuttallii)
Douglas-fir (Pseudotsuga menziesii)
fern, sword (Polystichum munitum)
gale, sweet (Myrica gale)
golden-eyed-grass (Sisyrinchium californicum)
groundcone, Vancouver (Boschniakia hookeri)

hemlock, western (Tsuga heterophylla)
Labrador tea (Ledum groenlandicum)
maple, bigleaf (Acer macrophyllum)
moss, peat (Sphagnum spp.)
pine, lodgepole (Pinus contorta)
pine, western white (Pinus monticola)
redcedar, western (Thuja plicata)
reed, common (Phragmites australis ssp. australis)
salal (Gaultheria shallon)
spruce, Sitka (Picea sitchensis)
Fauna :

Beaver, American (Castor canadensis)
Sculpin, Prickly (Cottus asper)
Stickleback, Threespine (Gasterosteus aculeatus)
Trout, Cutthroat (Oncorhynchus clarkii)