2 Overview of post-harvest and post-treatment soil inspection procedures
Important aspects of soil conservation are the inspections carried out to check that detrimental impacts to forest soils are being minimized. This section of the guidebook outlines survey procedures appropriate for given situations.
Soil conservation surveys examine:
Pre-harvest silviculture prescriptions, silviculture prescriptions and stand management prescriptions set maximum limits for some or all, three of these factors. The limits depend on the standards in effect when the particular prescription was approved. Compliance surveys can be conducted for each factor.
A number of significant changes to soil conservation requirements have been introduced over the years. Before any soil conservation survey is undertaken, the first step is to determine what soil conservation requirements were specified and what definitions apply. Each soil conservation survey must be based on the standards specified in the prescription and must use the definitions in place when the prescription was approved.
In the time prior to full Forest Practices Code compliance, there are three periods during which different soil conservation requirements and different definitions applied to prescriptions. (Requirements and definitions for these periods can be found in the first edition of the Soil Conservation Surveys Guidebook ).
Since the Code was introduced, there have continued to be some changes, including the elimination of requirements to specify limits for forest floor displacement and forest floor reduction, and modification of how limits for temporary access structures are specified. A further description of these changes is provided in Appendix 1.
In addition, soil conservation requirements for areas under woodlot licences have also undergone some changes and can be different from those of other tenures. These are discussed in a later section in this guidebook entitled "Woodlot licence area requirements."
Unless otherwise specified, the following sections of this guidebook provide the soil conservation requirements and definitions of the regulations and Act in effect at the time of this guidebook's publication.
Under the current requirements, silviculture prescriptions must specify:
Soil conservation compliance reports are required in all areas where the government must establish a free-growing stand (in keeping with the Silviculture Practices Regulation). The district manager must complete a report that states the extent to which an area under a silviculture prescription is in compliance with the allowable limits prescribed for the area that may be occupied by permanent access structures and the amount of soil disturbance.
An assessment should be in the form of a visual inspection to confirm that the maximum limits in the prescription have not been exceeded. No formal survey measurements need to be done, unless it is apparent that the limits may have been exceeded.
For major licensees, soil conservation surveys are not mandatory. However, if visual inspections indicate that their operations may be in non-compliance, the district manager, in accordance with the Silviculture Practices Regulation, can direct the licensees to conduct surveys. The purpose of these surveys is to inspect a) the nature and extent of the total area under the silviculture prescription occupied by permanent access structures, and b) soil disturbance in the NAR, including temporary access structures.
Silviculture prescriptions must specify the maximum percentage of the total area under the plan that can be occupied by permanent access structures (e.g. permanent haul roads, landings, gravel pits, borrow pits, and permanent logging trails). The types and definitions of access structures that count towards the maximum percentage in the prescription have changed over time, but the field measurement procedures are very similar.
Assessment of access structures begins with visual inspection. Where problems appear, a more detailed road and landing survey procedure is used to determine the percentage of the area occupied by permanent access structures.
Maximum soil disturbance limits are specified in a prescription by standards unit. For each standards unit, the prescription should state the assessed hazards for soil compaction, soil displacement, and soil erosion, and indicate the likelihood of landslides (if detailed terrain stability mapping has been done). The assessed hazards should be used to determine:
When a person is checking for compliance, it is important to know both of these factors. Separate strata must be used when surveying standards units that have different maximum limits or different categories of soil disturbance that count.
Where the method of timber harvesting is cable or aerial, it is not necessary to specify the soil hazards, only the likelihood of landslides (if warranted). Where soil hazards have not been assessed, compacted areas and all categories of dispersed disturbance must be counted as soil disturbance (i.e., those categories normally counted only on more sensitive sites).
Measuring soil disturbance begins with a visual inspection. Where disturbance appears to exceed the limits set out in the silviculture prescription, a transect survey may be required to determine the percentage of the area occupied by soil disturbance.
Transect surveys classify survey points along transect lines. Survey points are classified based on the soil conditions observed at and around each point.
In some cases, surveys may be conducted on strata that are smaller than the standards unit. The procedures and criteria for site stratification are discussed in the section "Survey methods for soil disturbance - Site stratification."