Items starting with P
PAC
Provincial Advisory Council
Parent Material
The mineral or organic matter from which the upper layers of soil are formed.
Park-like Structure
Stands with large scattered trees and open growing conditions, usually maintained by ground fires.
Partial cutting
Removal of part of a stand of trees for purposes other than regenerating a new age class. Partial cutting is not a regeneration method.
Partial Retention
A visual quality objective which, in general, means man's activities may be evident but must remain subordinate to the characteristic landscape.
Passive (natural) management
Management approach in which human intervention in an ecosystem is minimal, with natural processes such as fire and insect and disease infestations allowed to play out their 'natural' role. For fire management, this would mean allowing some lightning fires to burn or allowing only prescribed fires with burning prescriptions that mimicked the natural fire regime in size, intensity, and frequency.
Patch
An area of homogeneous vegetation, in structure and composition.
Patch Cut
A clearcut that creates small openings in a stand of trees, usually between 15 and 40 acres in size. On the Dixie National Forest and elsewhere, patchcuts are used to provide the disturbance needed to regenerate aspen.
Percolation
Downward flow or infiltration of water through the pores or spaces of rock or soil.