Geoscience Reference
In-Depth Information
CHAPTER 25
What Have Rivers Ever Done For Us?
Ecosystem Services and River Systems
Mark Everard
Environment Agency, Bristol, UK
Introduction
agricultural purposes, enabled by publicly-funded
land drainage and flood defence schemes (Scrase
and Sheate, 2005). Subsequent recognition of the
cumulative loss of biodiversity and the associated
benefits of water storage and purification, soil
fertility and stability is now reversing this policy
- for example, favouring the re-flooding of land
that has proved uneconomic to defend and
farm (Woods, 2006). Land-use change for urban
or agricultural development is a particularly
significant cause of global ecosystem degradation
(OECD, 2008; IUCN, 2009), and is one of many
examples of narrowly focused development
decisions resulting in the cumulative reduction of
ecosystem integrity and functioning (Everard and
Appleby, 2009).
An ecosystem services approach provides a more
comprehensive framework for assessing multiple
societal benefits from restoration and enhancement
initiatives (UNEP, 2007), as well as the basis for
comparing the breadth and balance of positive
and negative impacts (Millennium Ecosystem
Assessment, 2005). This creates opportunities to
recognize, protect and aid the recovery of a wider
range of ecosystem services provided by rivers and
wetland habitats. In so doing, it thereby recognizes
the interests of an extended set of beneficiaries,
many of whom may have previously been unaware
or excluded from decision-making.
This chapter outlines lessons learned from a
range of case studies that have attempted to assess
River restoration initiatives that specifically
incorporate social outcomes in their design provide
evidence that management to enhance the natural
biodiversity, character and functioning of river
ecosystems can also result in broader societal
benefits (Nielsen, 1998; Bannister
et al
., 2005;
Aberg and Tapsell, this volume). However, it is
not common practice for all potential societal,
economic and nature conservation outcomes,
both positive and negative, to be considered in
integrated post-project appraisal (Everard, 2009a;
Langford and Frissell, 2009). Consequently, there
have been insufficient quantitative studies to
substantiate the broad supposition that aquatic
ecosystem
restoration
produces
public
benefits
automatically.
'Ecosystem services' define the multiple benefits
provided to society by ecosystems, including
tangible goods such as food, regulation of the
environment, cultural benefits such as recreation,
and maintenance of ecosystem integrity and
resilience (Millennium Ecosystem Assessment,
2005). Many of these services have been
degraded historically by ecosystem management
or exploitation to maximize a few selected
services. For example, agricultural intensification
in Europe following the Second World War was
driven by the need to boost food production and
resulted
in
substantial
conversion
of
land
for
