UBC Theses and Dissertations
A vegetation description of two ecological reserves in interior British Columbia Larmour, Shirley Dale
The purpose of this thesis is to provide a vegetation description of two Ecological Reserves in Interior British Columbia. The Ecological Reserves studied were Trout Creek, near Penticton and Tranquille, near Kamloops. These areas were studied using quadrats placed within community types subjectively determined on the basis of species dominance and physiognomy. Soil samples were taken and brief profile descriptions made. Field data were examined subjectively and modifications of the original units made where necessary. A Bray-Curtis Ordination was done on the data from each reserve. Four communities were defined in Trout Creek. The most extensive community is the Pinus ponderosa/Agropyron spicatum community. This occurs on terraces and slopes and is dominated by Pinus ponderosa in the tree layer and Agropyron spicatum in the herb layer. Chrysothamnus nauseosus is the most common shrub. On talus slopes is the Pinus ponderosa/Pseudotsuga menziesii/Amelanchier alnifolia community. Pinus and Pseudotsuga occur together in the overstory and Amelanchier alnifolia is the most common shrub. The ground cover is sparse. In small areas of rock outcropping are Selaginella wallacei communities in which the ground cover is dominated by this vascular cryptogam. In one very small, protected area, is the Pinus ponderosa/Pseudotsuga menziesii/Calamagrostis rubescens community. This community has a dense layer of young Pinus and Pseudotsuga and a ground cover of the grass Calamagrostis rubescens. Four communities were also defined in Tranquille. On the flat valley bottom, is the Artemisia tridentata/Poa sandbergii/Stipa comata community. Artemisia tridentata dominates the shrub layer and Poa sandbergii and Stipa comata are codominants in the herb layer. There is no tree layer. This community is probably overgrazed. Most of the lower slopes of the reserve are covered by the Pinus ponderosa/Agropyron spicatum community. This community is dominated by Pinus ponderosa in the canopy and Agropyron spicatum in the herb layer. The sparse shrub layer is composed mainly of Chrysothamnus nauseosus and Artemisia tridentata. Also on the lower slopes, in small areas interspersed within the Pinus/Agropyron community is the Pinus ponderosa/ Aristida longiseta community, in which the grass Aristida longiseta becomes a codominant in the herb layer. Above about 760 meters, the vegetation is predominantly the Pseudotsuga menziesii/Pinus ponderosa/Agropyron spicatum community. Pseudotsuga becomes codominant or dominant in the canopy layer. Agropyron spicatum is still dominant in the herb layer but the clumps are smaller and more widely spaced. The Bray-Curtis Ordinations support the community breakdowns. The soils are Brunisols in Trout Creek and Regosols and Chernozems in Tranquille. Soil profile descriptions are given and data on various physical and chemical characteristics of the soils are presented. A comparison of the reserves is made. It is recommended that the Trout Creek Reserve be high priority for fencing. This is not necessary for Tranquille.
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