Stoloniferous pussytoes (Antennaria flagellaris) COSEWIC assessment and status report: chapter 5
Habitat
Habitat requirements
Antennaria flagellarisoccurs in the southern interior of British Columbia along the Similkameen River valley in the lower montane zone in the Interior Douglas-firbiogeoclimatic zone (Hope et al. 1991). Climatic conditions in this region are continental, characterized by hot, dry summers, a fairly long growing season and cool winters. A rainshadow effect prevails in this area due to the presence of the Coast-Cascade Mountains to the west.
Within this zone, A. flagellaris occurs on calcareous, gravelly-clay soils or gravelly sands.Detailed soil mapping for the area indicates a complex of the Belfort, Lamont, and Roany soil series (Green and Lord 1979). Of particular interest is the Roany soil series (Figure 4), a till-derived soil type with a Solonetzic Dark Gray Chernozem classification, that occupies an area of 1750 ha. Pockets of bentonite (an absorptive and colloidal clay mineral) and eroded banks are a characteristic feature of the Roany soil series. The unusual soil moisture regimes of the A. flagellaris sites may be due to bentonite outcroppings or other soil characteristics. The Roany soil series also has high pH and salt crystals at depth.
The A. flagellaris sites are characterized by a unique hydrology. The slopes, which are moderate (20-30%) with open southerly aspects, are eroded, unstable, and characterized by ephemeral seepage. These moist microsites are saturated by underground water in the winter and dry up in the summer.The slow down-slope movement that occurs as a result of the unusual hydrology is unique in the region and excludes many taxa that are not able to tolerate the conditions. As a result, the slope is disturbed and sparsely vegetated with A. flagellaris the dominant component. No non-native species occur in these sites.
Vegetation in the vicinity of the A. flagellaris sites is characterized by Artemisia tridentata (big sagebrush) shrub/grassland with scattered Pinus ponderosa (Ponderosa pine) and Pseudotsuga menziesii (Douglas-fir). The sites occur at the western edge of the distribution of open shrub/grassland at that elevation.
In these sites, A. flagellaris occurs with Eriogonum ovalifolium var. nivale, E. heracleoides var. angustifolium, Lomatium ambiguum, Arenaria capillaris ssp. americana, Elymus trachycaulus, Danthonia unispicata, Ericameria nauseosus var. speciosa, and Erigeron compositus var. glabratus. No non-native species were found in association with Antennaria flagellaris.
Trends
Past range use appears to have been light in the specific habitat type that Antennaria flagellaris occupies.
Summary of Populations and Associated Vascular Plant Species.
- Populations : Associated vascular plant species (including community dominants and co-dominants)
- Princeton, South of Stevenson Lake : Ericameria nauseosus var. speciosa and Pseudotsuga menziesii
- Princeton, Tracey Lake : Unknown
- Princeton, Stevenson Lake :
- Arenaria capillaris, Danthonia unispicata, and Eriogonum heracleoides.
- Eriogonum ovalifolium, Erigeron compositus var. glabratus and Arenaria capillaris
- Arenaria capillaris, and Elymus trachycaulus
Protection/ownership
The populations of A. flagellaris in British Columbia occur on two private properties in the Agricultural Land Reserve.