Forest Ecology and Conservation: A Handbook of Techniques (Techniques in Ecology & Conservation)

471 Pages·2007·4.64 MB·English

by  Adrian Newton

Forest Ecology and Conservation
Techniques in Ecology and Conservation Series
Series Editor: William J. Sutherland
Bird Ecology and Conservation: A Handbook of Techniques
William J. Sutherland, Ian Newton, and Rhys E. Green
Conservation Education and Outreach Techniques
Susan K. Jacobson, Mallory D. McDuff, and Martha C. Monroe
Forest Ecology and Conservation
Adrian C. Newton
Forest Ecology and
Conservation
A Handbook of Techniques
Adrian C. Newton
1
3
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To my father, Alan Newton, for all his support and
encouragement over the years.
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Preface
For the past 25 years, forests have been the focus of international conservation
concern. High rates of deforestation and forest degradation are common in many
parts of the world, but it was the rapid loss of tropical rain forests that particularly
captured the attention of the world’s media from the early 1980s onwards. More
recently, it has been increasingly recognized that many other ecologically impor-
tant forest types, such as temperate rain forests and tropical dry forests, are also
being lost at an alarming rate. In response, particularly following the United
Nations Conference on Environment and Development in 1992, major interna-
tional efforts have been devoted to forest protection and sustainable management.
There have been some notable successes during this time, yet still the widespread
loss of forests continues.
Despite the growth in the number of forest conservation and development
projects, as well as in the scientific discipline of forest ecology, practitioners are
often unsure how best to tackle the problems that they face. A lack of access to
information about appropriate techniques is hindering both the development of
the science and its application to forest conservation. This book was written in
response to this need, and is part of a series providing information on methods in
ecology and conservation, focusing on different species and habitats. The target
audience is ecologists involved in forest research or conservation projects, includ-
ing both established professionals and those just starting out on their careers. It is
hoped that the book will also be of value to practising foresters. Although foresters
have traditionally been trained primarily in management of forests for timber, the
profession has undergone something of a revolution in recent years. The individ-
ual forest manager is now often expected to be familiar with social, economic, and
ecological aspects of forests, as well as timber production. Hopefully this book will
be of value to those practitioners aiming at the elusive goal of truly sustainable
forest management.
Forest ecology and conservation is an enormous subject. I have therefore had to
be highly selective in selecting material for this book. Inevitably, this choice has
been influenced by my own interests and experience, and for this bias, I apologize.
Although it is recognized that different forest types differ substantially in their
ecology and composition, the book is designed to be relevant to all kinds of forests.
This is undoubtedly an ambitious goal, but I am comforted by the fact that in my
own experience I have been more struck by the similarities between different
forests than by their differences, particularly regarding the conservation problems
that they face. Many of the techniques described here have been applied to forests
growing in very different parts of the world, although perhaps with some adapta-
tion. These methods should therefore be applied flexibly, not as rigid protocols.
There is no substitute for common sense!
viii | Preface
It is important to remember that techniques are not fossils. This is a living
discipline, in every sense. This means that there is scope to improve on all of the
methods described here. Refining a method, or developing a new approach, is a
worthwhile focus of research in its own right. Users of this book are therefore
encouraged not to consider the techniques presented as a finished article, but
rather as a starting point for further experimentation and innovation. I have
deliberately provided extensive references, to provide examples of these methods
being used in practice, and to encourage readers to investigate their chosen
techniques in greater depth. Citing these examples illustrates the fact that different
workers use techniques in different ways, and in many cases the best way of doing
something is an issue still open to both critical appraisal and debate.
In preparing this book, I particularly thank the many wonderful postgraduate
students and research assistants with whom I have had the privilege of working,
and who have grappled with many of the methods described: Theo Allnutt,
Claudia Alvarez Aquino, Siddhartha Bajracharya, Sarah Bekessy, Niels Brouwers,
Philip Bubb, Elena Cantarello, Cristian Echeverría, Duncan Golicher, Jamie
Gordon, Carrie Hauxwell, Gus Hellier, Valerie Kapos, Tracey Konstant, Fabiola
López Barrera, Rizana Mahroof, Elaine Marshall, John Mayhew, Francisco Mesén,
Lera Miles, Khaled Misbuhazaman, Gill Myers, Simoneta Negrete, Theresa
Nketiah, Daniel Ofori, Tanya Ogilvy, Ashley Robertson, Patrick Shiembo, Tonny
Soehartono, Kerrie Wilson.
While writing the text I became increasingly aware of how much I owe the
people that taught me as a student. It was surprising to discover how many of the
techniques described here were introduced to me when studying at Cambridge
more than 20 years ago. It is easy to take a good education for granted. I was very
fortunate to be taught by some eminent plant ecologists, and I here record a debt
of gratitude to all of those who so generously shared their knowledge and expertise,
particularly David Briggs, David Coombe, Peter Grubb, Bill Hadfield, Donald
Pigott, Oliver Rackham, Edmund Tanner, Max Walters, and Ian Woodward.
Many thanks also to everyone who responded positively to a request for
photographs, and to my wife Lynn for checking the text.
Forests are magnificent places. I deeply respect those individuals who dedicate
their lives to forest conservation, and I very much hope that this book will be of
some value in supporting their efforts. Please let me know if the book proves to be
of use, and more importantly, how it could be improved.
Adrian C. Newton
School of Conservation Sciences
Bournemouth University
[email protected]
May 2006
Contents
Abbreviations xiv
1. Introduction 1
1.1 Defining objectives 2
1.2 Adopting an investigative framework 5
1.3 Experimental design 8
1.4 Achieving scientific value 9
1.5 Achieving conservation relevance 12
1.6 Achieving policy relevance 16
1.7 Defining terminology 21
1.8 Achieving precision and accuracy 26
1.9 Linking forests with people 27
2. Forest extent and condition 32
2.1 Introduction 32
2.2 Aerial photography 33
2.2.1 Image acquisition 34
2.2.2 Image processing 36
2.2.3 Image interpretation 38
2.3 Satellite remote sensing 39
2.3.1 Image acquisition 42
2.3.2 Image processing 47
2.3.3 Image classification 49
2.4 Other sensors 54
2.5 Applying remote sensing to forest ecology and conservation 55
2.5.1 Analysing changes in forest cover 55
2.5.2 Mapping different forest types 60
2.5.3 Mapping forest structure 62
2.5.4 Mapping height, biomass, volume, and growth 63
2.5.5 Mapping threats to forests 66
2.5.6 Biodiversity and habitat mapping 66
2.6 Geographical information systems (GIS) 68
2.6.1 Selecting GIS software 71
2.6.2 Selecting data types 73
2.6.3 Selecting a map projection 74
2.6.4 Analytical methods in GIS 75