Water Stewardship Information Sources

ID 1774
Citation Teti, P. 2008. Effects of overstory mortality on snow accumulation and ablation. Natural Resources Canada. Mountain Pine Beetle Working Paper 2008-13.
Organization NRCAN
URL http://www.cfs.nrcan.gc.ca/pubwarehouse/pdfs/29047.pdf
Abstract/Description or Keywords Total annual runoff and peak streamflows from watersheds draining B.C.'s Interior
Plateau are largely driven by spring snowmelt, which in turn is influenced by the
condition of forests. Those forests are dominated by Lodgepole pine and are undergoing
rapid change due to the mountain pine beetle epidemic. This project has documented
physical stand characteristics, snow accumulation, and snow ablation rates of growing
managed stands and deteriorating natural stands in six groups of plots.
Thirty-six long-term research plots were established in six groups in the Vanderhoof,
Quesnel, Chilcotin, Central Cariboo, and Kamloops Forest Districts. Plot characteristics
were documented by doing detailed tree and coarse woody debris surveys, and by taking
fisheye canopy photos from which solar radiation transmittances and other opticallyderived
parameters were calculated. Snow accumulation and ablation rates were
documented by ground surveys and aerial photography in 2006 and 2007.

In four of the six groups, where snow accumulation data are considered most reliable,
snow water equivalents were highest in plots that had been clearcut or burned in a
wildfire within the last 10 years. Snow accumulation was lowest in old foliated stands
and managed stands greater than 25 years old. Accumulation in beetle-attacked stands
relative to nearby cutblocks less than 10 years old ranged from 77% (Rosita) to 90%
(Vanderhoof). Also in four of the six groups, snow ablation rates were highest in stands
that had been logged less than 15 years earlier. Ablation rates in managed stands more
than 30 years old were similar to those in old intact forests. These results suggest that
logging dead pine stands will increase the total amount and rate of spring snowmelt over
what would have otherwise occurred for about 15 years.
Keywords: mountain pine beetle, snow hydrology, hydrologic recovery, forest canopy,
transmitted solar radiation
Information Type report
Regional Watershed All
Sub-watershed if known
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Comments
Project status complete
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