Geoscience Reference
In-Depth Information
A theoretical understanding of how wetland
ecosystems function and results from numerous
restoration projects implemented globally pro-
vide key design principles to promote their
success. Scientists have argued that using a
systems approach, restorations should be self
sustaining, employ renewable and locally avail-
able resources, and focus on rebuilding the
structure and functional characteristics of wet-
lands. Moreover, they should rel ect the geo-
graphic context and balance objectives to benei t
local communities and ecosystem needs. Resto-
ration efforts should adopt principles of adap-
tive management, ensuring l exibility in
implementation based on new or unanticipated
information. Clearly dei ned monitoring and
evaluation criteria and performance expecta-
tions for restored ecosystems are used to assess
whether goals and objectives have been met.
Specii c approaches and techniques employed
in restoring systems are varied. Active or passive
approaches are chosen based on the scope
and scale of the problem being addressed, the
resources available for restoration, enhancement
or creation, and the distinctive characteristics of
the geographic site itself. Artii cially constructed
treatment wetlands provide one example of an
active approach to creating a wetland that takes
advantage of the water-quality improvement
and purii cation functions provided by these
ecosystems.
Even with the most carefully planned restora-
tion and enhancement projects, scientii c data
suggest that the outcomes of such undertakings
are difi cult to predict with any degree of cer-
tainty. This is, in part, due to the complexity of
factors that govern wetland functioning. As
Zedler (2001) suggested, dynamic water regimes,
topographic and soil conditions, external distur-
bances, exotic species invasions, failed re-
colonization efforts, and human involvement all
may inl uence the ultimate success or failure of
wetland rehabilitation projects.
