Managing Windthrow

The suggested reserve sizes for significant karst features and values in this section are default recommendations. However, local site conditions should be carefully considered when planning reserve shapes and sizes.

The planning and design of all karst reserves should be based on a thorough windthrow assessment. If the default karst reserve recommendations cannot be maintained due to severe windthrow potential, professional judgment should be used to develop site-specific management practices that achieve as many of the management objectives for the reserve as possible.


Figure 3-1: Extending reserves and management zones on steep slopes.

In addition, the default recommendations for reserve size are based on relatively flat terrain. Where features occur on slopes, there may be a need to alter the shape and size of the reserve and/or management zone. On steep slopes, this could involve extending the reserve and/or management zone on the upslope side of features (e.g., sinkholes) to account for the increased risk of slumping and soil erosion. Reserves and management zone widths on slopes should be measured using slope distance.

For more information on assessing windthrow risk, see the Windthrow Handbook for British Columbia Forests (Research Program Working Paper 9401) at: http://www.for.gov.bc.ca/HFP/FORDEV/windthrow/

Windthrow Assessment Field Cards (FS712 – 1, 2,3,4 HFP98/05) are available at: http://www.for.gov.bc.ca/pscripts/isb/forms/forms.asp