Geoscience Reference
In-Depth Information
across a range of scales is vital in allowing
the quantification of interactions between habitat
and biology and to further the understanding
of ecological response to river management
(Carbonneau
et al
., 2004, 2006). For cost-effective
action, river managers need to know what type of
physical intervention and where in the catchment
will lead to greatest improvements in ecological
condition. Overall, while legislative change such
as the WFD has meant that predictive assessment
of ecology and physical habitat has become a
major driver for applied research and management,
the underlying problem remains that rivers
are individually unique, patchy, discontinuous
and strongly hierarchical systems (Frissell
et al.
,
1986; Poole, 2002). In essence, rivers and their
floodplains have proved difficult to manage in the
past - and the widespread perception is that they
remain so. For example, in the UK, media coverage
of what is perceived as an increasing incidence and
severity of flood episodes since 2000 ignores the
fact that the rise in damage and the costs of repair
are inevitable consequences of more people living
in flood-prone areas.
ecology, hydraulics and flood risk management, so
this structural organization has failed to support a
truly inter-disciplinary approach. Better integration
and clear communication between river scientists
and local communities is needed to improve
knowledge transfer and in particular the beneficial
role of hydromorphology in river classification
and management. Fluvial geomorphologists
need to demonstrate the wider socio-economic
and environmental benefits of applying their
knowledge and scientific expertise, especially
for identifying the best multi-disciplinary ways
of
achieving
good
ecological
status
and
good
ecological potential for the WFD.
River conservation should benefit from an
improved understanding of relationships between
physical habitat and ecology and from better
communication between the scientific community,
users and practitioners. Hydromorphology is
central to river conservation and management
because it provides the physical template or
'habitat' upon which all river ecosystems are
based (Poff and Ward, 1990). However, the
ecological impact of habitat degradation and loss
is often difficult to establish in rivers because
species are often highly mobile, adapted to
system stresses and may, therefore, be capable
of using sub-optimal habitats (Orr
et al
., 2008).
In addition, system alteration is often chronic
and biological change
per se
is not evident until a
threshold is reached beyond which it is hard for
the ecosystem to recover. Although degraded river
systems are characterized by reduced diversity,
ecosystem function impairment and structural
degradation, the relative importance of physical
habitat degradation alone compared with other
pressures (e.g. diffuse pollution) is still not clear
(Vaughan and Ormerod, this volume).
Because hydromorphology is important
in the WFD, river managers need to know
what aspects of physical habitat and at which
locations intervention will yield the greatest
improvements in ecological condition (Raven
et al
., 2000). This implies that information on the
hydromorphological character and condition for
complete river systems (or at least a representative
proportion)
Geomorphology: a side-lined
discipline?
While there have been notable exceptions (Amoros
et al
., 1987), several commentators such as Tooth
(2009) and Rice
et al
. (2010) have concluded that
geomorphologists have traditionally been slow to
engage with inter-disciplinary research agendas. As
a result the discipline has become somewhat 'side-
lined' over time in terms of its direct relevance
to society. Perhaps a more important question
is why, despite several attempts, an integrated
approach to river management has failed to
produce inter-disciplinary tools for practitioners.
The answer is probably two-fold: first, research
funding traditionally has a single disciplinary
focus and this has hampered the development
of integrated methods and insights; second,
institutionally, river management in the UK and
elsewhere has been run on the basis of parallel
strands of specialist disciplines such as fisheries,
is
needed.
Establishing
baselines
