Learner outcomes

On completion of part 3B, you will understand the role that the stand level component — wildlife trees — plays in forest biodiversity and you will be able to

1. Describe wildlife trees

2. Describe the role of wildlife trees in biodiversity

3. Identify forest management applications for wildlife trees 

What is a wildlife tree?

List several ways that wildlife trees are a valuable habitat

A wildlife tree is any standing dead or live tree with special characteristics that provide valuable habitat for the conservation or enhancement of wildlife.

Trees in various stages of life, death, and decay are important components of the structure and function of all natural forest ecosystems. Wildlife trees are part of this cycle of life and death. They are constantly being formed by biotic and abiotic factors such as insects, fungi, fire, and weather.

Interactions between wildlife and trees

It takes decades, even centuries, for a tree to complete the cycle of germination, maturation, and decay. Careful assessment and conservation of wildlife trees during harvesting and silviculture operations help to ensure continued existence of wildlife tress in managed forests. 

Rapid death by fire produces a different kind of wildlife tree than gradual death by insects or disease. Wildlife trees are created or caused by influences such as animal excavations, disease, insect attacks, wind, snow, and lightning. Insects and disease create most of the wildlife trees in the forest. Local climate and tree species also influence the way a tree deteriorates and decays.

The value of any particular tree as wildlife habitat depends on a variety of attributes, including structure, age, condition, abundance, species, geographic location, and surrounding habitat characteristics.

When considering the needs of wildlife, it is important to recognize that all trees are not equal in value. Some of the most significant indicators of wildlife tree quality are:

• Height and diameter 
• Decay stage
• Location

No one wildlife tree management approach is suitable on all sites. Factors, such as stand type and condition, tree species, and windthrow hazard, create unique conditions for each stand. 

The consideration of long-term stand and tree dynamics (i.e., longevity, decay type and rate etc.) that impact the biodiversity value of individual trees and groups of trees left after harvest is critical.

A strategy that incorporates a diversity of approaches to stand-level retention is often the most effective.