Above Significant Caves

The following section summarizes the management objectives and recommended best management practices for above significant caves. As these are only brief summaries, you should also check out more detailed information in the Karst Management Handbook for British Columbia.

Management objectives

The following is a summary of the management objectives designed to protect the area above significant caves. Reserves should:

Maintain stable conditions for karst processes above and within significant caves (e.g., temperature, humidity, infiltration rates, drip water chemistry)
Prevent the migration of surface fines/sediment into significant caves through fissures or cavities in the overlying epikarst
Protect delicate cave features, cave fauna, etc. from being damaged by vibrations associated with road construction and timber harvesting.

Recommended best management practices

Run your mouse over the following bullets to assist you in learning about the recommended best management practices.

	Establish reserves and management zones of an appropriate size to protect the reserve from windthrow above significant caves situated less than three times the greatest dimension (height or width) of the cave passage below the surface of the ground.

	Base the size and shape of the reserve on the principle that the cave is primarily affected by diffuse percolation within a 45-degree angle on either side of the outside wall of the cave passage.



Figure 3-3: Reserves are recommended if significant caves are situated less than three times the greatest dimension (height or width) of the cave passage or less than 10 metres below the surface of the ground.


	The size and shape of the reserve can be projected to the surface using cave maps.

	Significant caves situated less than 10 metres below the surface should receive a reserve in all cases, regardless of whether the cave meets the 3x depth criteria or not.

Where the cave ceiling lies more than three times the greatest dimension (height or width) of the cave passage and at least 10 metres below the surface, harvesting can occur safely in most instances.



Figure 3-4: No reserve is recommended for significant caves where the ceiling lies more than three times the greatest dimension (height or width) of the cave passage and at least 10 metres below the surface (including soil cover).

	Significant caves that are deeper than three times the greatest dimension (height or width) of the cave passage and at least 10 metres below the surface, but are known to contain exceptional features or values, should receive special consideration.

	Consider using specialized harvesting practices such as partial cutting, maximum/full suspension yarding, and leaving coarse woody debris and non-merchantable vegetation, to maintain soil humidity above caves with exceptional features or values.



Figure 3-5: A management zone is recommended for significant caves with exceptional features or values, even if situated more than three times the greatest dimension (height or width) of the cave passage and at least 10 metres below the surface.

	The size of the management area for specialized harvesting practices can be projected to the surface using the 45-degree principle.

	If 0.5 metres or more of soil is likely to be left after harvesting, the use of partial cutting and maximum/full suspension yarding may not be required. However, retaining more coarse woody debris and non-merchantable vegetation should be considered to help maintain soil humidity above the cave.