Persistence of soil moisture in the Cariboo Mountains, British Columbia.

In the Cariboo Mountains of British Columbia, nearly 50% of the annual precipitation falls as snow. Over the winter, snow accumulates, is redistributed and metamorphoses until temperatures warm and the spring melt begins. In about 2-3 weeks, the water stored in the seasonal snowpack is released at the surface to infiltrate the soil and runoff into local streams and rivers. Soil moisture is an integral component of the hydrologic cycle and knowing the contribution and persistence of soil moisture from snowmelt is important to understanding the local hydrology. Here are presented hydrometeorological data spanning from 17 July 2008 to 14 July 2009 from a cut-block site in the Mt. Tom Forest Management Area, south east of Prince George, British Columbia. Data from this period are compared to the 1971-2000 climate normals at Barkerville. The winter of 2008-2009 saw higher than average snowfall with average monthly snowfall of 58 cm compared to 44 cm for 1971 to 2000. Maximum accumulation reached 156 cm on 2 April 2009. Temperatures for the 2008 to 2009 season were cooler than average (1.9°C) at both Mt. Tom (0.4°C) and Barkerville (0.7°C). There are no long term data available for Mt. Tom so climate comparisons are based on data collected at Barkerville. Persistence of soil moisture has implications for plant and tree growth as well as for the length of the work season for industry. With increased industrial activity and the current mountain pine beetle problem in the Cariboo region, it is likely that this area will undergo significant deforestation in years to come. Coupled with a wetter climate, as projected by climate change analysts, the capacity of the soil to retain water could become more important when trying to reduce impacts of industry, such as erosion and compaction of soil. --P.ii