Mapping the web of life

Mapping the web of life


gives an insider's view of the compiling of the
Global Biodiversity Assessment
and of the main lessons to be drawn from it

woman holding plant

It is just over a year since the massive volume known as the Global Biodiversity Assessment (GBA) was launched at the second Conference of the Parties to the Convention on Biological Diversity in Jakarta. After initial shock at its sheer size (1,140 pages) and detail, it is now well established as a major and essential reference work for any considerations of biodiversity, and material from it is frequently cited.

More than 1,000 biological and social scientists from over 60 counties participated in preparing the report as coordinators, contributors or reviewers: the text was submitted to extensive peer review. The GBA thus provides an unprecedented source of information for decision makers, officials, scientists and others interested in any aspect of biological diversity. Divided into 13 sections, each with a detailed contents list and an executive summary, it contains a vast amount of data - in text, boxes, tables, diagrams and figures - and about 6,000 literature references. It is extensively cross-referenced and there is a glossary and index.

The Convention on Biological Diversity, unlike similar treaties, was negotiated in the absence of any prior assessment of knowledge. The GBA, therefore, is not part of the Convention process, and has no formal intergovernmental component, but is an independent undertaking commissioned by UNEP and funded by the Global Environment Facility. During its preparation we were very conscious of the political sensitivities involved and - as Elizabeth Dowdeswell points out in her Foreword - it was decided at a very early stage that it would not include country-level or regional assessments of data on biodiversity. It does not claim to be a consensus document or present a series of recommendations to policy makers, though the consequences for biodiversity of adopting particular policies or actions are frequently indicated. Some reviewers have criticized it on these two scores, but are clearly unaware of the very difficult tightrope we had to walk in reassuring the Parties to the Convention that the GBA would not trespass into this disputed territory. Fortunately, the serious misgivings expressed by some countries about its preparation were gradually overcome when they realized that it was not being presented as a set of recommendations for action (properly the concern of the Parties to the Convention) but as a comprehensive review of current knowledge and understanding of the broad field of biodiversity.

The GBA, as a review of our current state of knowledge, reflects the published literature which is predominantly in English, even though it very often refers to non English-speaking parts of the world. (Indeed if recently published leading texts on conservation biology are consulted one would be hard pressed to discover any references to papers not in English.) Great efforts were made to ensure that relevant literature in other languages was cited in the GBA and this requirement was drawn to the attention of all those involved in preparing or reviewing the text. Similarly, authors were asked to use as wide a range as possible of examples of ecosystems, biotopes and species - although again we were dependent on the very biased coverage in the available literature. In view of these problems, we have tried to avoid the trap of viewing biodiversity only through the eyes of western scientists.

What lessons can be learned from the GBA? The interaction between humans and the environment is a recurring theme. Humans are seen as the dominant influence on biodiversity. The scale of transformation, management and utilization of ecosystems in the past two to three centuries is so enormous that no part of the world can be considered as truly 'undisturbed'. The Assessment also makes it clear that humans have to be seen not so much as the problem as part of the solution; there is a focus on socio-economic strategies, on using biodiversity sustainably, conserving it, and sharing its benefits.

Policy failures

It is also clear from the GBA that more attention must be paid to evaluating biodiversity economically and to applying equitable systems of values. Under the present system, economic markets fail to recognize the true value of biodiversity, and typically undervalue it. Biological resources are inadequately regulated and often overexploited. Governments and institutions are responsible for these policy failures which - rather than lack of scientific knowledge - are usually responsible for the accelerating losses of biodiversity.

The GBA comes up with no great surprises regarding the state of our knowledge of biodiversity in terms of genes, species and ecosystems - but it confirms that most of it has yet to be recognized, catalogued and described. It estimates, after careful and detailed analysis, that 13 to 14 million species probably now exist on Earth, and that only about 13 per cent of them have yet been described. Most biodiversity, both described and not, refers to arthropods: fungi and microorganisms are among other species-rich groups.

Any attempt to complete the inventory of species diversity is faced with major problems, both over scientific issues and over infrastructure and human and technical resources. Biodiversity is distributed very unequally over the globe, as are institutional resources and manpower, with a tendency for an inverse relationship between the two, so that the greater the biodiversity, the fewer the means of handling it. Numbers of species is only one measure of biodiversity. Individual species comprise populations which contain differing amounts of genetic diversity but little is known of the extent of this in most species, apart from a handful that are important as genetic resources in agriculture. Our knowledge of biodiversity at the ecological level is also woefully incomplete. We do not even have a generally agreed system for describing vegetation types. Perhaps the greatest surprise is that, despite this widespread ignorance about the basic facts of biodiversity, we are confident enough to state that it is being lost at an unprecedented rate, largely as a result of human action.

The GBA adopts a very broad approach to managing biodiversity; it advocates a bioregional and landscape approach in which all uses of land, from natural and semi-natural ecosystems and nature and wildlife reserves to agriculture, forestry, fishing, grazing, industrialization and urbanization, are integrated for planning purposes. Jonathan Lash has recently referred to 'storm-battered islands of biodiversity in a sea of human settlement'.

Human values

A great deal of attention is given to human and social aspects of biodiversity in the GBA, but the treatment is less exhaustive than we would have liked. UNEP has arranged for a stand-alone volume on human values of biodiversity to be prepared: publication is planned for this year.

The subject is so complex - and the volume so large - that producing an electronic version, which would allow easier access to the data, was envisaged at an early stage. Furthermore, rapid advances in biodiversity studies and knowledge, leading to a dramatically growing literature, indicate that it would be highly desirable to have an electronic updating system for all or part of the GBA. As I remarked during its presentation in Jakarta, the Assessment is the beginning of a process, not the end.

Professor Vernon Heywood is Emeritus Professor in the School of Plant Sciences at the University of Reading, United Kingdom, and Executive Editor of UNEP's Global Biodiversity Assessment.

Global Biodiversity Assessment cover

Global Biodiversity Assessment

(eds. R. T. Watson, V. Heywood et al.)

is published for UNEP by Cambridge University Press, as a 1,140 page report (hardback $120/paperback $44.95) and a 56 page Summary for Policy-Makers ($14.95).

They are available from:

SMI (Distribution Services) Ltd.,
P.O. Box 119,
SG1 4TP,

Fax: +44 1438 748844
Tel: +44 1438 748111

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