a comparison of regimes across West Arm Lake, Kootenays, British Columbia


 
 
 
DISCUSSION

This preliminary investigation into the location of sample sites within the study area reveals that sites represent 
physical attributes of all vegetated polygons that support fire within the study area. Old stands make up 22% of 
all stands that contain vegetation and support fire. Patterns of timber harvest locate old stands above young 
stands as compared between mean elevations. Presumably, settlers and timber companies harvested trees from 
low-elevations stands where (1) proximity to transportation corridors along the lake facilitated the removal of (2)
valuable, large-diameter species, such as ponderosa pine (Pinus ponderosa), Rocky Mountain Douglas-fir 
(Pseudotsuga menziesii var. glauca), and western larch (Larix occidentalis). Since age depended on elevation, 
sample sites need to be located within the range of elevations for young stands to represent a landscape 
dominated by young stands. Fire histories compiled at sample sites selected from old stands using a stratified
random approach and located within the range of elevations of young stands represent fire histories across the 
landscape.

Future analyses that test for representativeness using GIS could employ alternative methods and benefit 
from improvements and updates to provincial sources of data. I determined elevation for each stand using the 
value at the point I assigned to the centre of each stand. An alternatively approach would calculate an average 
elevation using values from across the stand rather at the centre point. In such highly dissected terrain, 
average values may differ from centre values and lead to different results. Another source of error in the 
project was the underlying data obtained from the provincial government. The DEM contained artifacts that 
presumably originated during sampling and appeared as strips which recurred at 200 meter intervals when I 
calculate a hillshade. For this reason, I resorted to a federal DEM for all analyses. Finally the layer of Vegetation
Resource Inventory (VRI) contained numerous stands that were misclassified according to age. 
Misclassifications were noted during reconnaissance when we hiked into stands classified as ≥ 200 years 
old and found either clear cuts or recently planted trees. The forthcoming VRI update for the region that contains
the study area should remedy these discrepancies.