Location
The Pothole Creek Study Area is located in southern British Columbia, Canada, about 25 km southeast of Merritt, B.C. Access to the site is via the Coquihalla connector (Highway 97C) between Merritt and Kelowna, north of the Loon Lake exit, 10 Km
east of Aspen Grove. Click here to see a map showing the location of Pothole Creek Study Area. The study area is on the South Thompson Upland, one of a series of rolling highlands and steppes which
comprise the Interior
Plateau.
Dominant Species and Ecosystems
In general, the forest cover is dominated by stands of uneven-aged Douglas-fir (Pseudotsuga menziesii var. glauca). There is a minor amount of lodgepole pine (Pinus contorta var. latifolia) on gentle mid to lower
slopes and level benches. Hybrid spruce (engelmanii x glauca) and subalpine fir (Abies lasciocarpa) occur on adjacent seepage sites and stream banks. The understorey is dominated by Calamagrostis rubescens (pinegrass),
Shepherdia canadensis (soapberry or soopolallie), Arctostaphylos uva-ursi (kinnikinnick), Aster conspicuus (showy aster), Achillea millefolium (yarrow), Linnaea borealis (twinflower), and Pleurozium
schreberi (red-stemmed feathermoss).
Site series map of Pothole Creek Study Area
 Three biogeoclimatic variants occur in the vicinity of Pothole Creek: the Thompson Dry Cool
Interior Douglas-fir variant (IDFdk1), the Okanagan Very Dry Hot Interior Douglas-fir variant (IDFxh1), and the Very Dry Cool Montane Spruce subzone (MSxk) (Lloyd et al. 1990). The entire Pothole Creek Research site is located within the
IDFdk1. There are three site series at the Pothole Creek Study Site:
| 01 |
mesic to submesic |
Pl Fd - pinegrass - twinflower |
| 02 |
subxeric to very xeric |
Fd - juniper - pinegrass |
| 04 |
submesic to subxeric |
Fd - pinegrass - yarrow |
Geomorphology and Soils
Like much of the Interior Plateau, the South Thompson Upland is a Tertiary erosion surface that has been significantly influenced by Pleistocene glaciation. Evidence of glaciation is throughout the study site. Glacial till blankets most of the
site and fractured bedrock, likely the result of pressure release upon deglaciation in combination with frost action, is exposed in localized outcrops.
The study area lies within the Intermontane Belt, one of five morphogeological belts that make up British Columbia. Bedrock on the site is consistent with that characteristically found throughout the belt: folded and faulted sedimentary and
volcanic rock. Massively bedded metasedimentary rocks of both clay and silt grade are found in small, highly fractured outcrops, particularly in the northwest portion of the study area.
Relatively low relief characterizes this area. The site occupies an upper slope position and is mostly shedding. Drainage is predominantly subsurface and partly feeds into a small, south-flowing creek in the south-east corner of the site.
The most common soils on the site are Orthic Eutric Brunisols, with poorly developed, coarse surface horizons on top of colluvial or morainal parent material. Orthic Melanic Brunisols
are also common and tend to develop where there is abundant grass cover, particularly in receiving sites where water supply is not limiting. The soils are coarse, with mostly angular meta-mud/siltstone and a few granitic
fragments.
Climate
The region encompassing the study site has a climate transitional between the
maritime west coast and the southern interior dry belt. Data from a climate
station installed about 2 km from the research site is shown in Table 1. Table 1. Climatic conditions for Pothole Creek.
Compiled from data collected from 1998 to 2006.
| Elevation
|
1250 - 1300 m |
| Biogeoclimatic subzone/variant
|
IDFdk1
|
| Growing season precipitation (May-Sept.)
|
182 mm |
| Mean annual soil temperature |
5.2oC |
| Mean annual air temperature |
3.5oC
|
| Mean growing season air temperature (May-Sept.)
|
11.3oC
|
| Mean January temperature
|
4.4oC
|
Frontal storms originating in the Pacific dominate the fall, winter and early spring climatic regime,
while convective storms dominate the summer precipitation regime. June is the wettest month and about 38% of the precipitation occurs as snow.
Snowmelt is usually complete by mid to late April. The low summer precipitation usually creates a growing season moisture deficit for trees and understorey plants.
References: Lloyd, D., K. Angove. G. Hope, and C. Thompson. 1990. A guide
to site identification and interpretation for the Kamloops Forest Region. B.C.
Min. For., Res. Br., Victoria, B.C.
Ecosystem Mapping for the Pothole Creek Research Site
Draft Report
Dennis Lloyd and Hana Masata
May 1998 Soil Assessment of the Pothole Creek Research Forest
Work Term Report
Chris Braybrook
Summer 1997
| 
