284
G.A . Bradshaw et al.
Concurrent with this conceptual shift has been the dramatic ascendence
of techno logy used in the natural sciences. Computer accessibility and the
development of accurate and innovative measurement tools have broadened the scope of field and laboratory experimentation previou sly hindered
by feasibility constraints. For instance , satellite imagery and GIS maps
provide media by which spatiall y explicit information from several disciplines (e .g., geomorphology, vegetation, stream hydrology, and fish
population biology) can be integrated (Michener et aI., 1994; Goodchild,
1993). In conjunction with the se conceptual and technological advances ,
there has been increased concern regarding human impacts on the
environment. The result has been increased conflict over natural resource
management. Recognition of the cumulative effects of pollution on global
climate has underscored the connectivity of local environments to events
at distances and scales outside everyday perception ; the range of human
impact on ecosystems extends well beyon d artificial borders. As a result
of all three factors (i.e ., conceptual, technological , and social), research
and management interests have been directed to spatial and temporal
aspects of natural ecosystems. The manipulation of forested landscapes,
and the consequences thereof, are now consciously considered in conservation and management designs. Increasingl y, management concerns
are shifting to the " forest" rath er than the " trees."
The temp erate forest s of the Pacific Northwest (PNW) , U .S.A .,
represent a prime example of a setting in which scientific and socioeconomic concerns have converged. The Northwe st landscapes form a
focal point for many current political and socioeconomic debates in the
U.S. environmental arena (V.S .D.A. , 1993). The region has undergone a
significant change in its disturb ance regime due to intensive and extensive
land-use practices (e.g ., timber har vesting, grazing, fire suppr ession , and
mining) (see Harris, 1984; Spies, Ripple , & Bradshaw, 1994). Before the
onset of intensive timber harvesting activity, which began roughly 100
years ago and has continued intens ely on public lands the past fort y years,
the PNW lands west of the Cascade Range crest were characterized by a
fairly continuous forest cover. At present , the public and private forests
of Washington, Oregon , and even Alaska are punctuated with c1earcuts
and managed plantations (Figure 14.1; Spies, Ripple, & Bradshaw, 1994).
Widespread .declines and shifts in the habitat and abundances of late
successional animal species have forced a reevaluation of forest management practices regarding the effects on landscape fragmentation and
population viability (Harris, 1984). Management and conservation designs
developed for this region serve as a template for analogous plans in
oth ers North American regions and countries. ,
Ironicall y, land-use practices in the se forests have provid ed landscap e
ecologists with a regional-scale fragmentation experiment. A strong
pattern outside the natural range of variabilit y has been superimposed on
G.A . Bradshaw et al.
Concurrent with this conceptual shift has been the dramatic ascendence
of techno logy used in the natural sciences. Computer accessibility and the
development of accurate and innovative measurement tools have broadened the scope of field and laboratory experimentation previou sly hindered
by feasibility constraints. For instance , satellite imagery and GIS maps
provide media by which spatiall y explicit information from several disciplines (e .g., geomorphology, vegetation, stream hydrology, and fish
population biology) can be integrated (Michener et aI., 1994; Goodchild,
1993). In conjunction with the se conceptual and technological advances ,
there has been increased concern regarding human impacts on the
environment. The result has been increased conflict over natural resource
management. Recognition of the cumulative effects of pollution on global
climate has underscored the connectivity of local environments to events
at distances and scales outside everyday perception ; the range of human
impact on ecosystems extends well beyon d artificial borders. As a result
of all three factors (i.e ., conceptual, technological , and social), research
and management interests have been directed to spatial and temporal
aspects of natural ecosystems. The manipulation of forested landscapes,
and the consequences thereof, are now consciously considered in conservation and management designs. Increasingl y, management concerns
are shifting to the " forest" rath er than the " trees."
The temp erate forest s of the Pacific Northwest (PNW) , U .S.A .,
represent a prime example of a setting in which scientific and socioeconomic concerns have converged. The Northwe st landscapes form a
focal point for many current political and socioeconomic debates in the
U.S. environmental arena (V.S .D.A. , 1993). The region has undergone a
significant change in its disturb ance regime due to intensive and extensive
land-use practices (e.g ., timber har vesting, grazing, fire suppr ession , and
mining) (see Harris, 1984; Spies, Ripple , & Bradshaw, 1994). Before the
onset of intensive timber harvesting activity, which began roughly 100
years ago and has continued intens ely on public lands the past fort y years,
the PNW lands west of the Cascade Range crest were characterized by a
fairly continuous forest cover. At present , the public and private forests
of Washington, Oregon , and even Alaska are punctuated with c1earcuts
and managed plantations (Figure 14.1; Spies, Ripple, & Bradshaw, 1994).
Widespread .declines and shifts in the habitat and abundances of late
successional animal species have forced a reevaluation of forest management practices regarding the effects on landscape fragmentation and
population viability (Harris, 1984). Management and conservation designs
developed for this region serve as a template for analogous plans in
oth ers North American regions and countries. ,
Ironicall y, land-use practices in the se forests have provid ed landscap e
ecologists with a regional-scale fragmentation experiment. A strong
pattern outside the natural range of variabilit y has been superimposed on