18. Biodiversity of Canadian Forests
363
rather than elongated reserves) , and to reduce the distance among reserves. In a world of conflicting interests, where compromises must be
made, the problem lies in how much, and in relation to which feature of
the reserve to compromise.
Much of the concern with problems of species and genetic conservation
stems from the impact of human activities on natural ecosystems, and
nonsustainable exploitation of such ecosystems. It is only natural , therefore, that the impact of various forestry operations on forest ecosystems
has been the subject of much debate and not a little acrimony . Recent
events in the Carmanah valley; on South Moresby Island; and various
other areas in British Columbia have received much public attention and,
in some cases, resulted in court battles. It is now widely accepted that
protected areas alone cannot constitute a fully effective conservation
strategy, forest management outside protected areas must also incorporate
the objective of maintaining biodiversity.
Threatened Forest Ecosystems
Pojar (1980) discussed threatened forest ecosystems in British Columbia,
and drew a distinction between those that are truly threatened, and
those that are merely depleted (i.e. , capable of regeneration). In the
coastal zone, the most threatened ecosystems are associated with garry
oak (Quercus garryana) in the Mediterranean climate of sourtheastern
Vancouver Island and the islands of the Gulf of Georgia. Other lowland
forest ecosystems in the same area, as well as bottomland and bog
ecosystems of the lower Fraser valley, have also been almost completely
extirpated by a combination of logging and development. Logging is
also reducing lowland Douglas fir, western red cedar, and yellow cedar
(Chaemacyparis nootkatensis) forests , and alluvial Sitka spruce forests to
a threatened state. Finally, the introduction of Sitka black-tailed deer
(Odocoileus hemionus sitkensis) to the Queen Charlotte Islands in the
early years of this century has resulted in major changes to , and probably
losses of, forest ecosystems.
The status of "old-growth" forest , and the effect of harvesting and
the habitat fragmentation resulting from harvesting of the old-growth
ecosystem, has been the subject of great debate both in Canada and the
United States. The most well known case is that of the northern spotted
owl in the Pacific Northwest of the United States. Three characteristics of
the spotted owl have led to its prominent status : its apparent dependence
on an old-growth forest habitat (Carey, 1985), its very large home range
requirements (Sisco & Gutierrez, 1984), and its demographic fragility
(Dawson, Ligon, Murphy et aI., 1987). These characteristics demand that
if survival of the species is to be ensured, a very conservative habitat
management system involving the preservation of large areas of oldgrowth forest must be undertaken. An Interagency Science Committee
363
rather than elongated reserves) , and to reduce the distance among reserves. In a world of conflicting interests, where compromises must be
made, the problem lies in how much, and in relation to which feature of
the reserve to compromise.
Much of the concern with problems of species and genetic conservation
stems from the impact of human activities on natural ecosystems, and
nonsustainable exploitation of such ecosystems. It is only natural , therefore, that the impact of various forestry operations on forest ecosystems
has been the subject of much debate and not a little acrimony . Recent
events in the Carmanah valley; on South Moresby Island; and various
other areas in British Columbia have received much public attention and,
in some cases, resulted in court battles. It is now widely accepted that
protected areas alone cannot constitute a fully effective conservation
strategy, forest management outside protected areas must also incorporate
the objective of maintaining biodiversity.
Threatened Forest Ecosystems
Pojar (1980) discussed threatened forest ecosystems in British Columbia,
and drew a distinction between those that are truly threatened, and
those that are merely depleted (i.e. , capable of regeneration). In the
coastal zone, the most threatened ecosystems are associated with garry
oak (Quercus garryana) in the Mediterranean climate of sourtheastern
Vancouver Island and the islands of the Gulf of Georgia. Other lowland
forest ecosystems in the same area, as well as bottomland and bog
ecosystems of the lower Fraser valley, have also been almost completely
extirpated by a combination of logging and development. Logging is
also reducing lowland Douglas fir, western red cedar, and yellow cedar
(Chaemacyparis nootkatensis) forests , and alluvial Sitka spruce forests to
a threatened state. Finally, the introduction of Sitka black-tailed deer
(Odocoileus hemionus sitkensis) to the Queen Charlotte Islands in the
early years of this century has resulted in major changes to , and probably
losses of, forest ecosystems.
The status of "old-growth" forest , and the effect of harvesting and
the habitat fragmentation resulting from harvesting of the old-growth
ecosystem, has been the subject of great debate both in Canada and the
United States. The most well known case is that of the northern spotted
owl in the Pacific Northwest of the United States. Three characteristics of
the spotted owl have led to its prominent status : its apparent dependence
on an old-growth forest habitat (Carey, 1985), its very large home range
requirements (Sisco & Gutierrez, 1984), and its demographic fragility
(Dawson, Ligon, Murphy et aI., 1987). These characteristics demand that
if survival of the species is to be ensured, a very conservative habitat
management system involving the preservation of large areas of oldgrowth forest must be undertaken. An Interagency Science Committee