Environmental Engineering Reference
In-Depth Information
EDITORS' INTRODUCTION
stakeholders, landscapes and biodiversity - not to
mention ecosystem services (see Part 4) - are all crucial
to effectively moving ' the ball ' forward.
We have arranged the next 11 chapters in an order
that corresponds with current textbooks on climatol-
ogy, global ecology and biogeography, and also to
provide a convenient way to consider our world as a
whole. Imagine that you drop out of the sky and land
in the equatorial region of Africa, and then start
walking north. After leaving the tropical forests, you
pass into the subtropical semi-arid and arid semidesert
and desert regions of the Sahel and Sahara, before
arriving, somewhat thirsty, in the Mediterranean
Basin. Further north, you fi nd the temperate forests,
temperate dry grasslands and heathlands of Europe,
and then fi nally reach the Arctic, or the Alpine regions,
depending on whether you continue north or climb up
a mountain. These biomes are in fact treated, more or
less worldwide, in Chapters 9 - 15 . Thereafter, we leave
the terrestrial ecosystems altogether, and move to the
wetlands. Chapters 16 - 19 treat four different aquatic
ecosystem types, namely, mires, rivers and fl oodplains,
freshwater lakes and fi nally salt marshes.
As compared to the fi rst edition of this topic, we are
pleased to note that - in addition to the eight updated
chapters - three of the guided visits we will make in this
'walk around the world' are brand new. We are indebted
to Karen Holl for contributing a chapter on restoration
of tropical forests (Chapter 9), to David Bainbridge for
his chapter on restoration of arid and semi-arid lands
(Chapter 10) and to Dean Apostol and Ayn Shlisky for
presenting their views on the restoration of temperate
forests in western North America (Chapter 13), where
human impact is of a more recent date as compared to
the situation in Europe (see Chapter 12).
All the chapters in this part follow a similar approach.
They start by a description of ecosystem characteristics
in an historical perspective, in search for the identifi ca-
tion of 'reference ecosystems', and an analysis of the
effects of disturbance factors. A relatively large part of
each chapter is devoted to understanding past and
current ecosystem structures and processes, a condi-
tion for any ecological evaluation of various ecological
restoration approaches. Each chapter uses the same
terminology, distinguishing between natural recovery,
near-natural restoration, ecological restoration, reha-
bilitation and reclamation (see the glossary at the end
of the topic). Each chapter fi nishes off with a discus-
sion called 'Perspectives'. So, now it is time to start our
walk. Onward.
In the 'walk around the world' we now begin, the
intrepid reader of Part 3 will be visiting ongoing resto-
ration programmes across an array of ecosystem types
stretching from the Arctic to the Amazon. A near com-
plete cross-section of biomes is included, with the one
major exception we have noted before, the Earth's over-
exploited, polluted and - to speak plainly - imperilled
oceans. Each chapter's authors will describe and
analyse the effects of past and current disturbance
factors, as well as which restoration measures and
interventions have been, are being or should be tried.
An ecological evaluation of failures and successes
across 11 ecosystem types, set in a huge array of socio-
cultural and political settings, will help pave the way
towards the practical recommendations and research
horizons we will discuss later, in Part 4.
In Chapter 2 of this topic, we introduced a trio of
perspectives of ecological restoration, focused on land-
scape ' integrity ' , ecosystem ' health ' and ' biodiversity ' ,
i.e. 'keeping all the parts', in the sense of Aldo Leopold,
and all conservationists since him. Then, in Part 2 we
presented the 'ecological foundations' upon which we
are building, according to that trio of distinct angles of
approach. Here in Part 3, we have asked the authors to
bear these three approaches in mind, and we invite
you, the reader, to do the same, as you read this series
of biome - specifi c reviews and case studies. Here, the
question is not so much which ecological foundations
are applicable to ecological restoration, but rather
what does the practice of ecological restoration entail
in the 'real world', in a specifc place and setting? What
can we learn from the evaluation of future perspectives
of ecosystem development in a large array of biomes,
as presented here?
You will recall that throughout the topic we endorse
the view advocated by SER (2004) that, ultimately,
whole ecosystems are the appropriate level of atten-
tion, and intervention, for projects and programmes of
ecological restoration. Indeed, whether the overarch-
ing level of interest is the reintegration of a disturbed
and dysfunctional landscape, the restoration of an
impaired or destroyed ecosystem, or the maintenance
of biodiversity (e.g. the reinforcement or reintroduc-
tion of threatened species in a given set of biotic com-
munities and ecosystems), knowledge of ecosystem
patterns and processes is essential. But when it comes
to resolution, in the sense of how we perceive 'nature',
and also to interaction and consensus building with
Search WWH ::




Custom Search