Geography Reference
In-Depth Information
large river basins - one that integrates the geomorphic
and hydrologic processes shaping landscapes and rivers,
terrestrial and aquatic communities and processes across
landscapes, and the human systems guiding their land and
water use trajectories. Basin-wide analysis of aquatic and
terrestrial ecosystems requires integration of remotely
sensed and field-gathered data to track change and iden-
tify opportunities for conservation and restoration. We
argue this is a necessary precursor to thoughtful basin
management.
The notions of dynamism in complex adaptive systems
(Levin, 1998, Holling and Gunderson, 2002) imply that
dynamic features of landscapes, like rivers, should be allot-
ted more territory than the historically wealth-motivated
processes of human settlements have been willing to give
(National Research Council, 1992, Cowx and Welcomme,
1998, Hulse and Ribe, 2000). Landscape planners and
resource managers throughout the world are faced with
the challenge of maintaining dynamic processes of chan-
nel meandering (both channel erosion and deposition)
and floodplain inundation while allowing people to use
these portions of the river floodplain and invest in infras-
tructure in this ever-changing portion of the landscape.
The analyses at the scale of the Willamette River basin and
its major subbasins demonstrate the importance of find-
ing new strategies to gain more room for river networks in
human-dominated landscapes, while acknowledging the
real and largely irreversible investments that have already
been made in these biologically and culturally important
parts of human settlements.
The primary focus of tracking landscape and river
network change for prioritising conservation and restora-
tion efforts was to (1) spatially identify patterns of key
resources as they vary over time and (2) enable regional
decision makers to account for and anticipate the loca-
tions of increases and decreases in each resource and
the potential consequences of environmental policies.
Dynamic patterns of critical terrestrial and aquatic ecosys-
tems juxtaposed with major human population centres
and land use investments create a spatial context for
identifying locations for conservation and restoration
efforts and tracking their success, or failure, over time
(Hulse and Gregory, 2001, 2004). Conservation oppor-
tunities are revealed in habitat matrices or corridors of
ecologically functional land cover and native species rich-
ness. Restoration opportunities are highlighted in areas
that demonstrate the greatest difference between current
patterns and historical or reference conditions (Hulse
and Gregory, 2004). Constraints and incentives for con-
servation or restoration created by human systems are
determined by (1) the patterns of human populations and
structural development across the landscape and (2) the
economic values and risks to productivity of the land base.
Five key lessons have emerged from this basin-scale
analysis of trajectories of aquatic and terrestrial ecosys-
tem change. First, the application of landscape scenarios
based on remotely sensed land use/land cover and eco-
logical models demonstrates that adopted policies and
practices have great influence on the recovery or con-
tinued declines of natural resources. Plausible restoration
practices and changes in land use policies can reverse long-
term trends in natural resource declines even in the face
of a doubling of the human population. Second, stream
networks and large floodplain rivers strongly influence
abundance and distribution of aquatic communities and
terrestrial wildlife (Hulse and Gregory, 2003). The state
of Oregon has used the findings and spatial information
on aquatic communities to develop a Special Investments
Partnership to conserve and restore habitats of the main-
stem Willamette River and its floodplain, investing more
than $2 million annually in conservation and restoration
actions, and more than $30 million from other sources
in 2010 alone. Third, there is a near-universal desire
for production of both short-term wealth and long-term
ecosystem services in landscapes where human settlement
is a major force of landscape change (Hulse and Ribe,
2000, Chan et al., 2006). While the relative influence of
these desires on realised landscape pattern and policy are
in constant flux, our work indicates these desires must
be reflected in any plausible future scenario. Scarcity of
either of these desired goods, fear of it or attempts to
avoid it motivates much intentional human action in
the landscape (Schroter et al., 2005, Baumgartner et al.,
2006). These actions occur at multiple societal levels
of organisation, from individual people and their fam-
ilies to citizen groups, private corporations, and public
agencies. Fourth, scientists and stakeholders are often
self-limiting in defining future scenarios. Citizen groups
may be reluctant or even unable to conceive dramatic
shifts from existing policies and regulations because of
the social upheaval accompanying such change. This is
compounded by the fifth and final key lesson that inher-
ent uncertainties are rarely explicitly represented in the
products and decisions that derive from analyses of past,
present and future conditions of large river basins.
We asserted earlier in this chapter that there are three
purposes such alternative future efforts pursue: to sup-
port scientific exploration and research, to inform and
educate, and to underpin decisions and strategic plan-
ning. For us, one of the most significant lessons of the
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