Forest Investment Account

Abstract of FIA Project 6067004

" ALT="See below to download" WIDTH="100" HEIGHT="129" BORDER="0" bordercolor="#000000">

Fungal Inoculation of Trees as a Habitat Enhancement Tool in Second-Growth Forests

Author(s): Manning, Todd
Subject: British Columbia, Biodiversity, Silviculture/Forest Management Systems, Wildlife
Series: Forest Investment Account (FIA) - Land Base Investment Program - Innovative


In British Columbia, 80 species of birds, mammals and amphibians depend on wildlife trees (dead or dying trees with special characteristics such as size, condition and species) for nesting, denning, feeding, perching or roosting. Some of these species, including the Williamson's Sapsucker (Sphyrapicus thyroideus) the Vancouver Island Pygmy-Owl (Glaucidium gnoma swarthi) and the QCI Hairy Woodpecker (Picoides villosus picoideus), are on the provincial endangered or threatened status lists. Our largest primary cavity excavator, the Pileated Woodpecker (Dryocopus pileatus), is considered an important keystone species in forested ecosystems throughout the province (i.e., its nest and roost cavities provide habitat for numerous secondary cavity using birds and mammals).
High value wildlife trees have attributes that are generally associated with older trees (e.g., large size, heavy branching, internal decay). These traits are often not available in second-growth stands that have previously been managed without objectives for wildlife tree retention. In particular, a lack of trees with wood softened by heart rot will result in primary cavity dwellers not being able to excavate nests in the area. This is especially true for the larger Pileated Woodpecker and Hairy Woodpecker (Picoides villosus), which generally require trees greater than 40 cm diameter at breast height (dbh) with heart rot. This lack of cavities in turn restricts the availability of habitat for secondary cavity using species that depend on wildlife trees (e.g., various owls, flying squirrels, cavity nesting ducks, etc.). In some areas of B.C., especially where forest harvesting has been practiced for many years and second-growth stands are predominant, or where ecosystem restoration may be required (e.g., riparian rehabilitation), there is often a shortage of suitable wildlife tree habitat. Healthy, secondgrowth stands containing trees from 50-100 years of age can still take many decades before developing the primary wildlife tree attribute of heart rot. However, this natural process can be significantly accelerated through fungal inoculation. In these situations, artificial creation methods may be warranted in order to recruit wildlife trees more quickly than would otherwise occur through natural cycles. In Oregon, fungal inoculation trials have achieved trees with heart rot suitable for cavity excavation in 4-6 years, much earlier than natural fungal colonization and decay rates (C. Parks, USDA For. Service, pers. comm. 2000; Parks 1996).
Consequently, an operational trial to create wildlife trees in second-growth Douglas-fir stands using fungal inoculation was initiated in TFL 44 (southwest Vancouver Island, B.C.) during 2002. Partial cutting (variable retention) silvicultural systems are being implemented, where biodiversity and retention of stand structure are among the management objectives.

PDF Document

Download FIA-03-04-0040.pdf (0.5 MB)

[Get Adobe Acrobat Reader] To view this document you need Adobe Acrobat Reader,
available free from the Adobe Web Site.

Updated September 08, 2005 

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

Please direct questions or comments regarding publications to