Forest Investment Account (FIA) - Forest Science Program
FIA Project S084014

    Quantitative Synthesis of Wildlife Relationships to Stand-Level Green Tree Retention Following Harvest and Natural Disturbance in Lodgepole Pine Dominated (NDT3) Habitats.
Project lead: Lewis, Doug (BC Ministry of Environment)
Author: Lewis, Douglas W.
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
"Structural conditions following salvage harvest of wildfire or beetle infested forests often do not resemble the conditions after disturbance alone (Noss and Lindenmayer, 2006, Eng 2004, Lindenmayer et al. 2004). Historically, intense stand-replacing natural disturbances, while catastrophic at small scales, have allowed species and ecosystems to respond and adapt to these changes at larger scales over time. However the magnitude of the current MPB infestation and associated salvage harvest activities will result in rapid decline in the amount and quality of habitat for many species over a large geographic area in a short time period. Such rapid change in habitat conditions is of particular concern when “threshold” levels are reached in the amount and spatial arrangement of habitats in local areas for certain species (Dykstra 2004,). Dykstra (2004) states “ecological thresholds involve a change in the rate of response to ecosystem; a critical value of an ecosystem property at which previously linear or unobserved change becomes a drastic transformation”. Thus, in areas affected by Mountain pine Beetle, the degree of habitat change due to the cumulative effects of the infestation and salvage harvest could potentially achieve these threshold levels detrimental to many wildlife species or ecosystems.

Given ecosystem change is often irreversible, the only way to mitigate these detrimental effects is through effective planning of landscape and stand-level retention during salvage (Bunnell et al. 2004, Klenner 2006). Direction on appropriate stand and landscape level green and dead tree retention levels following salvage harvest in ecosystems of the province affected by mountain pine beetle has been provided to forestry practitioners (Bunnell et al. 2004, Snetsinger 2005, 2006, Klenner, 2006). However this direction offers little more than “best guesses” based in scientific literature and to date, none of the existing literature has been extensively synthesized and little information has been provided to direct managers towards appropriate targets for the amount and spatial arrangement of green and dead tree retention, targets for the amount and size of retention patches or density of dispersed wildlife trees to meet the ecological requirements for many species.

The purpose of this proposal is to synthesize existing literature to identify “threshold” values or response curves between structural indicators (i.e. snag density, live tree density, tree size) and wildlife species or species groups. The research will focus on ecological units (i.e. natural disturbance types) and will distinguish between naturally disturbed, managed (harvested or salvaged) and uncut natural habitats. In addition the synthesis will need to break down into components the ecological units, habitat conditions, species studied and study design to adequately manage for the multivariate nature of species-habitat relationships and attempt to control for this in the interpretation between values reported for use of habitat structures.
Contact: Lewis, Doug, (250) 371-6245,


Executive Summary (18Kb)

To view PDF documents you need Adobe Acrobat Reader, available free from the Adobe Web Site.

Updated August 16, 2010 

Search for other  FIA reports or other Ministry of Forests and Range publications.

Please direct questions or comments regarding publications to