Forest Investment Account (FIA) - Forest Science Program
FIA Project Y103039

    Assessing soil disturbance and tree growth after stumping
Project lead: Stefan Zeglen (Ministry of Forests and Range)
Author: Courtin, Paul J.
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
This project meets long-term FIA-FSP research strategies under the sustainability theme by addressing (1.2.c), evaluating the effects of forest management (e.g. soil disturbance) on productivity and (3.1.a), indicators and monitoring systems are needed for each of the 11 FRPA values( e.g. soils).

Stumping is the process of excavating tree stumps to remove as much of the root biomass as possible. When done correctly, the stump is lifted out of the soil and placed back in the hole upside down. This reduces the belowground inoculum of Phellinus weirii, a pathogen causing root disease and extensive mortality of susceptible conifers such as Douglas-fir. Douglas-fir is often the most appropriate species to replant on root rot infected sites as these are often site series where Douglas-fir is recommended for regeneration. Stumping allows greater options in reforestation prescriptions.

Maximum allowable soil disturbance is set by legislation at 5 or 10% dependent upon soil sensitivity rating. Soils are considered sensitive if they rate high or very high to any one of compaction, displacement or erosion hazards.

If a block is infected with root rot, limiting soil disturbance is circumvented by the necessity to remove infected stumps. However, the objective of soil conservation to limit soil disturbance (FPC Soil Conservation Guidebook) regardless of the necessity to meet a forest health objective should be maintained.

One way to accomplish this is to characterize levels and types of disturbance on stumped sites so that current disturbance surveys can be expanded to accommodate stumped sites. In addition to this, we need to assess tree growth versus disturbance so that long-term impacts of stumping disturbance can be made.

Several locations will be chosen where blocks have been completely or partially stumped. Soil disturbance description will follow procedures described in FPC Soils Conservation Surveys Guidebook (2001). Additional classes of disturbance will be described on the stumped areas. These will likely include areas of soil deposits, small mounds, buried forest floors which are characteristic of stumped areas but not of non-stumped areas.

Tree growth will be characterized by measuring tree height, caliper and condition of planted trees by disturbance environment. These will include: no disturbance, wide or very wide scalp (forest floor removal), wide, long or deep gouging, soil deposit (eg berm at edge of stump hole), mixed soils (including buried forest floors)
Related projects:  FSP_Y081039FSP_Y092039


2nd year final report (2.0Mb)

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Updated August 19, 2010 

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