Forest resources

Insects and diseases

About insects and diseases

Boreal forests are disturbance-driven and insect and disease outbreaks often occur on a large scale. These natural disturbances are essential to the productivity and renewal of forests.


Insects are an important variable in the life cycle of the boreal forest. Large insect outbreaks that occur regularly help to renew the forests. Insects release nutrients stored within trees. Infestations also eliminate sick and aging trees, reducing competition among trees and making the ecosystem more productive. Insects found in NWT forests include: 


Diseases contribute to the forest ecosystem by speeding up the mortality of weak and over-mature trees, clearing the way for forest renewal and increasing biodiversity. Diseases also break down dead plant material, a process that recycles nutrients and organic matter. Root diseases are among the most common in boreal forests.  Forest diseases found include: