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Why the Concern About Forest Pests? Insects and plant diseases are found around the World. They have evolved in a variety of different habitats, including the temperate forests of North America. Within forest ecosystems they serve a variety of functions, ranging from the pollination of plants to the decomposition of trees. Worldwide an estimated 787 643 species have been identified. In our Canadian forests approximately 55 000 different insect species have been recorded. Of these, very few are considered to be major forest pests. So why should we be concerned about them? Despite being
few in number, historically, outbreaks of these major pests have
resulted in extensive tree mortality and growth loss. By way of
example,repeated defoliation by the spruce budworm in New Brunswick
from 1981 to 1983 Besides timber,
other forest values (e.g. fish and wildlife habitat, unique areas,
and recreational use/ forest aesthetics) are at risk during pest
outbreaks. Repeated loss of foliage and subsequent tree mortality
from forest pests can alter forest habitats and expose the forest
floor and
We need to be
concerned about forest pests for all of the above reasons. As pressures
increase to set aside additional forest
Forest
Management Branch | ||||||||||||||||||||||||
resulted in the loss of approximately 16 million cubic metres of
wood. This was equivalent to a two and a quarter year supply of
wood to the province. With the softwood resources of the Province
fully allocated to meet both fibre and non-fibre forest management
objectives, future losses similar to those of the past would have
drastic consequences. In Canada, annual losses from forest insects
are estimated to be one-third of the total annual harvest. Coupled
with depletions from disease and fire, annual volume losses are
equivalent to the total annual harvest. In a country and province
where forestry remains the largest industry, these timber depletions
can have serious economic implications. These implications can be
felt at all levels - federal and provincial governments, communities,
individual landowners, and forest companies (i.e. pulp and paper
mills, sawmills, value-added industries, forestry suppliers). 
watercourses to more direct sunlight. These changes can make
areas less suitable for certain types of fish, wildlife, and plant
species. Recreational use can also be jeopardized when forest aesthetics
are negatively impacted. Areas damaged by forest pests are also
at greater risk to fire as direct sunlight to the forest floor accelerates
the drying of materials. Loss of forest cover also leads to increased
runoff, potential soil erosion and siltation of streams and rivers.
Reforestation
programs that include tree improvement efforts; the growing of nursery
stock and the establishment of high-value plantations can also be
impacted by a variety of insect and disease pests. In today's global
economy there is also an increased risk with respect to the introduction
of non-native pests (e.g. Gypsy Moth). These non-native pests pose
not only a direct threat to our forests and natural ecosystems,
but with the increasing role of plant health and quarantine issues
in international trade, they are also an indirect threat to the
export and domestic movement of forest products (see Gypsy Moth
quarantine map). 