Skid Trail Growth Impacts - 130-502

Description: Understanding the impact of management activities on the tolerant hardwood and pine dominated forests in the area of the undertaking requires improved information to ensure sustainable management of the resource. Current practices of single-tree selection and shelterwood silviculture require re-entry into stands every 20-30 years for additional partial harvests. The system has proven that with careful entries an improved forest product can be harvested in future harvests. Although logging damage (damage to stem bole, crown and roots, regeneration) cannot be totally eliminated, efforts that minimize the level of these impacts greatly reduces the negative effect of our attempt to improve current and future growth and yield and product quality(OFAB 2002).

Recent second entries (20 years past the last entry) into tolerant hardwood stands have identified that expected basal area growth rates were less than was expected or modeled in our strategic wood supply models ensuring our levels of sustainability. The reduction in growth rate has been attributed to many potential factors: over-cutting, mediocre site quality, minimum limit of quality, and logging and site damage. Understanding the cause and effects of these reduced growth rates are required to meet Ontario’s current policy directions (OMNR 1999, OFAB 2002).

This project will examine this issue of skid trail impacts on the growth of the residual hardwood and pine forest and will provide new science that will be used to adjust silvicultural practices. Training sessions will be held to educate resource managers and harvesting operators on proper skid trail layout and the science results of this study.

Forest Modeling and Growth and Yield

The goal of this project is to quantify the impact of skid trails (including rutting and soil compaction, root shearing) on residual tree diameter increment and ultimately, forest productivity. This 3 year project will test the approach and expand to cover a range of species and site conditions. Information gathered from this project will be used to modify current growth and yield estimates in wood supply modeling. A direct linkage between other projects such as the Benchmark Yield Curves, FVSOntario and Logging Damage Study can be made with this project to calibrate the prediction of growth, yield and quality estimates of these products.

Unlike most Growth and Yield projects that are always considered long-term, this project will utilize methods permitting immediate quantification of skid trail impacts on tree diameter increment. A methodology (described more completely below) incorporating increment core sampling on trees in stands with known histories will permit immediate transfer of results to practice. The calibration of growth estimates of trees and stands in these forest types can permit our modeling to more accurately represent the reality of managing this resource and ultimately permit better informed strategic decision making for mill expansions (value added products, additional shifts) or mill closures and the resultant community impacts (positive or negative).


Improved understanding of resource sustainability

An unexplored potential impact to sustainable management of the tolerant hardwood resource and the subsequent development of high-value products is the short and long-term impacts of skid trails and other trails caused by mechanical harvesting equipment. Creating access into the forest in order to perform stand improving partial harvests is a prerequisite. However, a current best management practice (considered a standard) (OMNR 1998) of limiting the percentage of the landbase covered in skid trails to twenty per cent, was based primarily on expert opinion.  A maximum of twenty percent skid trail coverage was proposed as a proxy to represent the maximum level of regeneration loss that could be tolerated without impacting the success of the silvicultural treatment (development of saplings through all size classes in the future). It is unclear if any consideration was given to the impact the trails may be having on the growth rate of the residual crop trees that were left for the future. This project will help to improve our understanding of resource sustainability in tolerant hardwood forests in relation to skid trail and logging damage impacts.

The objectives of the proposed project are to:
1.      Complete a literature search documenting the impacts of harvesting, stem damage, root impacts and rutting on residual tree growth;
2.      Compile a searchable database to support this project and future studies;
3.      Quantify the impact of skid trails on the growth rate of tolerant hardwood stands and provide yield adjustments to wood supply estimates;
4.      Analyze the partial harvesting impacts of removal cuts in white pine dominated stands and propose methods of minimizing losses;
5.      Deliver a Careful Logging Training workshops to resource managers and forest operators


The Project Team: Murray Woods and Dave Deugo, OMNR, and Jian Wang, Lakehead University




Quantification of Skid Trail Impacts on Tolerant Hardwood Tree Diameter Growth: Field Sampling Protocol- A Working Document - 2006

Quantification of Skid Trail Impacts on Tolerant Hardwood Tree Diameter Growth: Field Sampling Protocol- A Working Document - 2007

Quantification of Skid Trail Impacts on Tolerant Hardwood Tree Diameter Growth: Field and Laboratory Procedures- Summary Report - 2008


Technical Notes/ Reports:

Smith, M.L. et al. 2010. Skid trail and bush road impacts on sugar maple (Acer saccharum Marsh.) growth in the Great Lakes- St. Lawrence forest of central Ontario. Ont. Min. Natur. Resour., Science and Information Branch, Southern Sci. and Info., SSI Tech. Rpt. SIB SSI TR-130. 17p.



Logging Damage Studies Update, Feb & March 2008


Tree Tips:

Tree Tip for Project 130-502


Status Reports:

Status Report (2007-2008)

Project Work Report (2007-2008)

Status Report (2008-2009)

Financial Summary (2008-2009)

Status Report (2009-2010)


For Additional Information Contact:

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