WORLD ATLAS OF BIODIVERSITY, Groombridge and Jenkins 2002

WORLD ATLAS OF
BIODIVERSITY
EARTH'S LIVING RESOURCES

^

>

IN

THE

21st

CENTURY

(\

X >r

UNEP WCMC

BRIAN GROOMBRIDGE and MARTIN

D.

JENKINS


World Atlas of Biodiversity addresses the remarkible

growth

in

concern at

all

levels for living things

and the environment and the increased appreciation
'

the links between the state of ecosystems and

the state of humankind. Building on a wealth of
search and analysis by the conservation

worldwide,

this

book provides

a

community

comprehensive

and accessible view of key global
sity. It

re-

issues in biodiver-

outlines some of the broad ecological

relationships

iterial

between humans and the

rest of the

world and summarizes information on the

health of the planet.

Opening with an outline of

some fundamental aspects of material cycles and
energy flow

in the biosphere, the

book goes on to

discuss the expansion of this diversity through geo-

logical time

and the pattern of

its

distribution over

the surface of the Earth, and analyzes trends in the

condition of the main ecosystem types and the
species integral to them.




World Atlas

of Biodiversity


Published

in

Ihe contents of

association witli

UNEP-WCMC

this

volume do not

necessarily reflect the views or policies of

by the University of

California Press

UNEP-WCfvIC, contributory organizations,

University of California Press

editors or publishers. The designations

Berl
employed and the presentations do not imply
the expression of any opinion whatsoever on

and Los Angeles, California

University of California Press, Ltd.

the part of

London, England

UNEP-WCIvIC or contributory

organizations, editors or publishers

©

2002

UNEP World

concerning the legal status of any country,

Conservation

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or

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Cloth edition ISBN

World Atlas

0-520-23668-8

of Biodiversity:

Earth's Living Resources in the 21st Century
IS

a revised

and updated edition

Cataloging-in-publication data

of

Earth's Living Resources

in

part of this book

may be reproduced

any means or transmitted

into a

by

machine

language without the written permission
the publisher

with

the 21st Century

Citation

No

is

the Library of Congress

Global Biodiversity:

of

Groombndge

120021

World Atlas of

by the

UNEP

B.

and Jenkins M.D.

Biodiversity.

Prepared

World Conservation Monitoring

Centre. University of California Press,
Berkeley, USA.


UNEP WCMC

World Atlas

of Biodiversity

Earth's Living Resources

Brian Groombridge

&

in

the 21st Century

Martin D. Jenkins

UNIVERSITY OF CALIFORNIA PRESS
Berkeley Los Angeles London


World Atlas

of Biodiversity

Prepared by

UNEP World

Conservation

Monitoring Centre
219 Huntingdon Road

Cambridge CB3 ODL, UK
Tel:

Fax:

+M

101

+44

1223 277

(01

3U

UNEP WCMC

1223 277 136

UNEP

E-mail: info0unep-wcmc.org

The

Website: www.unep-wcmc.org

Centre

is

World Conservation Monitoring

the biodiversity information and

assessment arm

of the

United Nations

Director

Environment Programme, the worlds

Marl< Collins

foremost intergovernmental environmental

UNEP-WCMC

organization.

Brian

aims

to

help

decision-makers recognize the value

Authors

Groombndge

Martin D Jenkins

biodiversity to people everywhere,

of

and

to

The

apply this knowledge to

all

Centre's challenge

transform complex

is to

that they do.

Additional contributors

data into policy-relevant information, to build

Adrian C. Newton (Project manager)

tools

Rachel Cool<

integration,

Neil Cox

nations and the international

Victoria Gaillard

they

and systems

engage

and

to

for analysis

in joint

Janina Jakubowska

Valerie

Kaissl

Kapos

Charlotte Lusty

Anna Morton
Mark Spalding
Christoph Zockier

Production of

Simon

maps

Blyth

with the assistance of
Igor

A Benson

production

27 Devonshire Road

Cambridge CBl 2BH, UK

Lysenko

Corinna Ravilious

Jonathan Rhind

Color separations

Swaingrove
Layout
Yves Messer

Printed

in

the

UK

of

community as

programs

Edmund Green
Thomas

and

support the needs

of action.


Acknowledgments

First

and foremost we would

without

express our deepest ttianks

[ike to

whose generous funding

have been undertaken. Preparation

Department

We

Trust

is

also

acknowledged

for this

book could not

book was also generously supported by the

Environment, Food and Rural Affairs IDEFRAI

of

Owen Family

of the

the Aventis Foundation,

to

work

the research and production

of the

UK Government. The

for financial support to the first edition of this text.

also acknowledge with thanks the generous assistance extended by the following, listed

same sequence

as the chapters

in

which

Christopher Field and George tvlerchant. Department

of

Global Ecology, Carnegie Institution of

approximately

Washington

in

for

Robert Lesslie

the

use

data from a global model of net primary production.

of

of the

their material appears:

Department

of

Geography, Australian National University, Canberra,

for

allowing us to use data resulting from his global wilderness analysis.

BirdLife International, of

Cambridge, UK,

for allowing

use

of spatial data

on endemic bird

areas and on threatened bird species.

Gene Carl Feldman, Oceanographer

at

NASA/Goddard Space

Flight Center, Greenbelt,

Maryland, for approving use of material from the SeaWiFS Project of NASA/Goddard Space
Flight

Center and ORBIMAGE.

The University

of

Maryland Global Land Cover

Facility, for facilitating

use

cover data.

of land

Professor Wilhelm Barthlott of the Botanisches Institut und Botanischer Garten, Rheinischen
Fnedrich-Wilhelms-Universitat, Bonn, for kindly allowing use of a

map showing

contours

of

global plant species diversity

Jonathan Loh, responsible

for the

WWF

Living Planet Report, for kindly approving use of

global trend indices from the Living Planet Report 2000.

John E.N. Veron, Chief Scientist
Queensland

for allowing

at the Australian institute of

Marine Sciences, Townsville,

use of coral generic diversity data.

Several biologists associated with IUCN/S5C specialist groups on fishes, mollusks and inland

water Crustacea,

for providing data

and expertise on important areas

for

freshwater

biodiversity collated in an earlier publication: Gerald R. Alien (Western Australian

Museum);

the late Denton Belk [TexasI; Philippe Bouchet ILaboratoire de Biologie des invertebres

marins

et

matacologie.

(Department

Museum

of Zoology,

National d'Histoire Naturelle, Paris); Keith Crandall

Brigham Young

University); Neil

Cumberlidge (Department

of


Biology, Northern Michigan University); Olivier

invertebres marins et nnalacologie,

Sven

Kottelat (Cornol, Switzerland);

Museum

Museum

Gargominy iLaboratoire de Biologie des

National d'Histoire Nalurelle, Pans); Maurice

Kullander IDepartment

0.

(Center for Intelligent Systems, State University
ILaboratoire Ichthyologie,

Ben

of

Vertebrate Zoology, Swedish

Natural History, Stockholm); Christian Leveque (ORSTOM. Pans); R. von Sternberg

ot

ten Brink, Jan

Musee Royal de

of

Bakkes and Jaap van Woerden

work on scenarios earned out

New

York at Binghamton); Guy Teugels

I'Afnque Centrale. Tervuren).

at the Rijksinstituut

for facilitating

use

of

material illustrating

voor Volksgezondheid en Milieu IRIVM),

BiUhoven, the Netherlands.

Christian

Nellemann (Norwegian

Arendal) and the Secretariat of

Institute for

GLOBIO

Nature Research), Hugo Ahlenius (UNEP GRID-

(Global methodology for

mapping human impacts on

the biosphere), for material applying this approach to scenario development.

Photographs
Pages:

U,

B.

6, L.

Olesen/UNEP/Still Pictures;

Groombndge;

15.

38, M.

Fnedlander/UNEP/Topham;

73. K.

Kaznaki/UNEP/Topham;

93,

7, L.L.

Hock/UNEP/Topham;

M. Wakabayashi/UNEP/Topham; 37. Giotto Castelli;
39.

86. M.

UNEP/Topham;

72. G.

Bluhm/UNEP/Topham;

Schneider/UNEP/Topham;

M.R. Andrianavalona/UNEP/Still Pictures; 96, H. Mundell/UNEP/Topham;

98, R.

99. UNEP/Topham; 103 J. Nuab/UNEP/Topham;

delRosanon/UNEP/Topham;110 bottom. Mazinsky/UNEP/Topham;

Fana/UNEP/Topham;

110 top. R.

118. E. Green;

U3

top, E.

151. E. Green; 152. D.

Green; bottom. M. Spalding; U4, M. Garcia Blanco/UNEP/Topham;

Nayak/UNEP/StiU Pictures;

155. D. Seifert/UNEP/StiU Pictures; 165,
174,

F.

185. K.

212.

Colombini/UNEP/Topham;

15i. E. Green;

UNEP/Topham;

178. C.K.

169. S.W.

Mmg/UNEP/Stilt Pictures;

Au/UNEP/Still Pictures;

Lohua/UNEP/Still Pictures; 194. C. Petersen/UNEP/Topham;

P Garside/UNEP/Topham;

216, C. Senanunsakul/UNEP/Still Pictures


Contents

Foreword

xi

Preface

3.5

Introduction

1

Freguency

of

percent extinction
29

per million year period

xii

3.6

Number

of family extinctions

per geological interval through

Chapter

1:

the Phanerozoic

3

The biosphere

29

Table

Maps
1.1

Physical geography of the Earth

1.2

Primary production

in

4

3.1

the

biosphere

The principal mass extinctions
in

the Phanerozoic fossil

30

record

8

Figure

Hypsographic curve

1.1

5

Chapter

4:

10

production

Estimated global carbon

1.2

budget and biomass totals

Chapter

2:

The

diversity of

organisms

13

The phylogenetic tree

19

Livestock breeds:

of

Key features
groups

of the

of living

major

organisms

20

2.1

New

2.2

Improving taxonomic

species discoveries

knowledge and capacity

4.4

Human

4,5

Terrestrial wilderness

4.6

Vertebrate extinctions since

3:

Biodiversity through time

The four eons

54

56

4.8

Critically

4.9

Threatened

mammal

species

58

endangered

mammals and

62

birds

bird

species density

64

Figures
4.1

Human

4.2

Vertebrate extinctions by

17

Tables

47

population

period since ADl 500

59

Top ten food commodities,
ranked by percentage

23

of

41

supply

of the

Periods and eras

24
the

4.2

World

4.3

Examples

4.4

diversity

through time

27

Plant diversity through time

28

diet

44

classes
of diversity in

45

agricultural systems

26

Phanerozoic

Animal family

52

contribution to global food

geological timescale

3.4

population density

Threatened

Figures

3.3

classes

diet

4.7

4.1

3.2

48

FAO world

16

Boxes

3.1

42

and status
4.3

18

possible global total

Chapter

numbers

AD1500

Estimated numbers

described species, and

2.2

34

dispersal

Early

4.2

Tables
2.1

human

4,1

11

Figure
2.1

33

Maps

Global annual net primary

1.1

Humans, food and
biodiversity

Tables

Number

of individuals

and

biomass, selected organisms
4.5

Land converted

to

cropland

46
49


A. 6

Estimated large herbivore

numbers and biomass
Mesolithic and
4.7

within protected areas

modern

genera

Numbers

of large

of extinct

lUCN categories

50

Britain

Late Pleistocene extinct and
living

4.8

Global protection of forests

5.9

in

97

Estimated plant species

5.10

animals

in

l-VI

richness

51

in

the

five

regions

of

Mediterranean-type climate

animal

105

species according to lUCN

57

Boxes

4.9

Island diversity at risk: birds

60

5.1

Defining ecosystems

74

4.10

Threatened species

61

5.2

Species and energy

78

4.11

Number

5.3

Fire in

5.4

Temperate

forest bird trends

5.5

Grassland

bird trends

104

Marine biodiversity

117

species

of
in

threatened animal

major biomes

63

Boxes
4.1

4.2

Loss

of diversity in agricultural

genetic resources

40

'Lazarus species'

51

temperate and boreal
82

forest

Chapter

6:

85

Maps
Chapter

5:

Terrestrial biodiversity

71

Maps

6.1

Coral reef hotspots

126

6 2

Shark family diversity

128
130

5.1

Photosynthetic activity on land

74

6 3

Marine

5.2

Global land cover

76

6 4

Mangrove

5.3

Diversity of vascular plant

6 5

Seagrass species

turtle diversity

134

diversity

species

88

6 6

Coral diversity

Biodiversity at country level

90

6 7

Marine fisheries catch and

5.5

Flowering plant family density

94

5.6

Terrestrial vertebrate family

5.4

density

1

00

Current forest distribution

1

06

5.8

Non-forest terrestrial

ecosystems

1

typical species-area plot

5.3

five

mam

the state

world stocks since
in

1

U7

974

global fisheries

catch since 1970

80

6.6

6.1

forest

147

Marine aquaculture
production

150

Marine population trends

158

Area and

maximum

depth

of

the world's oceans and seas
6.2

117

Relative areas of continental

shelves and open ocean

118

Important families and genera,

6.3

Marine diversity by phylum

122

and numbers

6.4

Diversity of craniates in the

81

of

of species, in four

temperate broadleaf

sea by class

deciduous forest

Biomass and carbon storage
Tree species richness

in

Estimated annual change
forest cover

1990-2000

6.5

84

6.6

Marine tetrapod diversity

6.7

Regional distribution

Diversity of fishes in the

seas by order

tropical

moist forests

123

83
in

the world's major forest types

5.8

of

81

Global area of

areas

5.7

Trends

146
in

Tables

types

5.6

6.4

6.5

effects on forest area

definitions

5.5

Global trends

71

estimates of different forest

5.4

145

major group

Different definitions of forest

Sample

to

Marine fisheries landings by

6.3

Global distribution of land area,

cover

Species contributing most
global marine fisheries

77

by latitude bands
5.2

6.1

08

Tables
5.1

US

discards

6.2

Figure

A

140

Figures

5.7

5.1

136

diversity

87
in

97

breeding

in

124
125

of

seabirds

129

mangroves

132

6.8

Diversity of

6 9

Current mangrove cover

133


1

6.10

Diversity of stony corals in
ttie

order Scleractmia

139

6.1

Coral reef area

6.12

Taxonomic distribution and

Thirty high-priority river basins 190

7.10

138

Boxes
7.1

Saline and soda lakes

7.2

Wetland loss

in

164

Asian drylands 184

status of tfireatened marine

animals

156

Chapter

119

Maps

153

8.1

World protected areas

200

8.2

Centers

202

8.3

Major areas

8:

sediments

6.1

Life in

6.2

Marine introductions

Chapter

7:

Inland water biodiversity

163

Maps
7.1

fisfi

family

170

Major areas

of diversity of

inland water fish
7.3

Major areas

Major areas

180

8.6

International protected area

8.1

179

Inland water fish

lA

River basin richness and

214

8.1

1

Pioneering

NGOs

in

biodiversity conservation

197

8.2

The precautionary

199

Systematic conservation

1

91

8.3

1

63

8.4

principle

of the

hydrosphere

203

Negotiating a multilateral treaty 213

Physical and biodiversity features

major long-lived lakes

66

APPENDICES
organisms

1

The phyla

72

2

Important food crops

244

173

3

Domestic livestock

271

waters

175

4

Recent vertebrate extinctions

278

Major inland fishery countries

179
5

Biodiversity at country level

295

Partial
of

of global

list

hotspots

freshwater biodiversity

7.4

Insects of inland waters

7.5

Fish diversity

in

Tetrapod diversity

Numbers

of

in

225

inland

threatened

freshwater fishes

in

selected

187

countries

Taxonomic

of living

68

inland

waters, by order

7.9

Major global conventions

planning

Components
of

7.8

220

maintenance

Tables

7.7

218

Possible future scenarios,

Boxes

condition of a

between 1950s and 198Ds

7.6

evaluated with

relevant to biodiversity

freshwater lakes

of

198

Table
8.1

1

sample

3.

GLOBIO

Reported global inland

Freshwater population trends

7.3

GEO

RIVM IMAGE
8.3

areas

Possible future scenarios

from

vulnerability

208

of the global

of protected

190

in

206

210

Development

182

Changes

areas

agreements

Priority river basins

7.3

7.2

bird

crustacean groups

1

7.1

204

Marine protected areas

network

introductions

7.5

amphibian

8.5

8.2

fisheries production
7.2

of

Endemic

of diversity of

Figures
7.1

of plant diversity

195

Figures

selected inland water

7.5

change

8.4

176

of diversity of

inland water mollusks
7.4

to

diversity

Freshwater
diversity

7.2

Global biodiversity:

responding

Boxes

distribution

6

Important areas for

freshwater biodiversity

and

306

status of threatened inland

water vertebrates

INDEX

329



Foreword

Klaus Topfer, Executive Director, United Nations Environment Programme
is

It

me

a great pleasure for

in

Rio de Janeiro

In

new

important

to introduce tliis

Conservation Monitoring Centre. Building on the analyses

it

bool<

from

carried out for

1992 and for the new millennium just two years ago,

once again updated and revised

its

important overview

of life

on Earth

in

tlie

UNEP World

tfie Eartii

Summit

UNEP-WCMC

has

time for a major

global event.

In

tune with the message

this

new

upon which we

we should
I

all

treasure

commend

depend
it,

use

In closing

I

It

this bool< to all

our own future and that

the

should

like

UK Department

Johannesburg World Summit on Sustainable Development,
firmly in the context of the species and ecosystems

of the

humankind

atlas places

for

who

We

our livelihoods.

wisely and share

its

are a part of biodiversity and as such

benefits

In

our own enlightened self-interest.

seel< a greater appreciation of the

Inter-dependency between

of global biodiversity.

on behalf

of

UNEP

for Environment,

to

thank most warmly the Aventis Foundation and

Food and Rural Affairs for their support

preparation of the World Atlas of Biodiversity.

In

the


Preface

Mark
The

UNEP World

Collins, Director,

diversity of

life is tfie

Conservation Monitoring Centre

defining feature of planet Earth.

It

is

we know - in
humankind has

unique - as far as

the infinity of the universe. For 11 000 years since agriculture began,

increasingly appropriated the biological resources and natural productivity of lands and seas
to

support the expansion of civilizations and technologies. Everything that

has

origins

its

a part. But

in living

achieved

the past 30 years, since the United Nations Conference on the

it

is

only

Environment

in

Stockholm

We now know

we have

animals, plants and the communities and ecosystems of which they are

in

that our

in

1972, that

own success

we have begun

is

to

Human

recognize the limits to natures

gifts.

placing strain on nature's ability to evolve, diversify,

cleanse our air and water and provide us with the raw materials

we need

for food, fuel, fiber

and health.

we began

Just ten years ago

and sustainable use

to take integrated

Development lUNCEDI saw the signing
global

agreement on

complex

of life

immune from

of the

on Environment and

Convention on Biological Diversity, the

on Earth, rather than a special case

its

ensure conservation

holistic action to

UN Conference

biodiversity that clearly positioned

humankind as an

first

integral part of the

somehow separate from

nature and

laws. The 'ecosystem approach' espoused by the Biodiversity Convention

acknowledges that our relations with the

what we do

and

resources. The

biological

ot

rest of the living

world are truly interactive, and that

to nature will in turn reflect on nature's ability to

Convention foresaw a careful balance

in

the

management

respond

to

our own needs. The

of the Earth's living

wealth through

conservation, sustainable use and equitable sharing of costs and benefits.

There could be no better time
Atlas of Biodiversity

Development

in

to

launch a fresh assessment of the

published to coincide with the World

is

Johannesburg, Republic

of

South Africa. The focus

again on sustainable development, but this time the emphasis

The message
but a

is

clear:

is

living

world. This World

Summit on Sustainable
of the

meeting

harmonized economic, social and environmental development

dream while so many

of the world's

a planned approach to their lives.

What

once

is

clearly on poverty alleviation.
will

be

people have no choices and no opportunities to take
is

the relevance of this book

in

the context of the

Johannesburg message?
The
time

in

reality

and quality
is

is

World Atlas of Biodiversity

that this

lifestyles in both the industrialized

spreading, and the value of biodiversity

environmentally, has never been
This

is

of

greater relevance

now than

at

any

the past. The world's living wealth remains the cornerstone of sustainable livelihoods

Is

not a textbook,

it

is

And

that they will take steps within their

new

it

is

today.

insights into the significance of

kit for

life

the future.

I

hope that

on Earth to their own

homes, communities and nations

enjoy living resources wisely, share' the benefits and
future generations.

of this fact

people's lives, socially, economically and

more apparent than

read

will find

in

a resource pack and a survival

who

it

and developing worlds. Recognition

hold

the capital

all

lives.

to utilize

and

trust

for

in

Introduction

OBJECTIVES
The past ten years have seen

remarkable growth

a

environment, with an increased appreciation

and the state

of

the

of

concern for wildlife and the

in

between the state

linl
human development will require, among other measures,
to managing human impacts on the biosphere. This was

equitable

approach

ecosystems

of

humankind. Many analysts have concluded that achieving sustainable and

more

taking a

effective

reinforced by the 1992

United Nations Conference on Environment and Development Ithe Earth Summit), at which
the Convention on Biological Diversity ICBD)

and management

Initiatives

framed by the CBD
In principle,

was opened

any level

of variation at

defines biological diversity as 'the variability
including, inter alia, terrestrial,

and

of

of

term

refer collectively to all such variation:

In

of life In

some

we aim

this information is accessible to a

organisms from

living

In effect,

all

CBD

sources

between species

as a convenient shorthand for the total

to

use the data now available

maps where

living

an overview
to

of

ensure that

organisms and their populations, and on

organisms and landscape elements that may be subject
intervention than to microorganisms, despite the
in

and

wide readership. While biodiversity has many dimensions,

here focused on the diversity of

and their pivotal role

to provide

helpful,

major aquatic and terrestrial ecosystem types. Far more space

latter,

text of the

given area, or on the Earth as a whole.

the present volume

is

among

The

often contracted to biodiversity', and used to

is

the current state of global biodiversity, using

attention

biological diversity.

this Includes diversity within species,

practice, the

In

encompassing

of biological organization is

marine and other aquatic ecosystems and the ecological

which they are part;

ecosystems'.

complex

to

text.

any kind

genes, populations, species and communities -

complexes

Many conservation
meet the objectives

for signature.

worldwide have arisen from efforts

to

is

given to the macro-scale

planning and

Immense metabolic

management

diversity of the

driving biosphere cycles.

STRUCTURE OF THIS BOOK
The eight chapters
outline of

(Chapter
of
Is

1).

change

fall

informally Into four thematic sections. The

some fundamental aspects
This

Is

section opens with an
in

the biosphere

followed by a synopsis of the diversity of living organisms (Chapter

In this diversity

through geological time (Chapter

largely concerned with relationships

Increasing

first

and energy flow

of material cycles

3).

2)

and

The second section (Chapter

between humankind and

biodiversity,

M

noting the

human impact on the environment from early modern humans onward, the use of
human nutrition, and reviewing trends in recent time, focusing on depletion and

biodiversity in

extinction of species.

trends
7,

in

The

third section

alms

to characterize

respectively).

Finally,

Chapter 8 introduces some

responses that have been implemented with a view
putting

communities and biodiversity

the three basic blome types: terrestrial, marine and inland waters (Chapters

human development on

to

a sustainable foundation.

of

the

5,

6 and

management and planning

maintaining ecosystem health and



The biosphere

The biosphere

1

he BIOSPHERE

rrr—

THE THIN AND IRREGULAR ENVELOPE around and

IS

including the

Earth's surface that contains all living organisms and the elements they exchange with

the non-living environment. Water makes up about tw/o thirds of an average living cell,
and organic molecules based on hydrogen, carbon, nitrogen and oxygen make up the remaining

one third. These and other elements of living cells cycle repeatedly betw^een the soil, sediment,
air and water of the environment and the transient substance of living organisms.

The energy to maintain the structure of organisms enters the biosphere when sunlight is
used by bacteria, algae and plants to produce organic molecules by photosynthesis, and all
energy eventually leaves the biosphere again in the form of heat. Photosynthetic organisms
themselves use a proportion
Is

the

amount

of the organic material they synthesize; net

Humans now

appropriate a large proportion of global net primary production, and have

caused planetary-scale perturbations

While providing the conditions necessary

it

supports

life,

least 70 percent of

The position
size

its

its

Earth

for

and has done so

for at

non-living parts of the biosphere have

history (see Chapter

and composition appear

main factors that have allowed
here.

a

be the

to

develop

ensure the permanent presence

to

amount

large

of

liquid

planets surface, and this
prerequisite of

life

as

is

and the part
called

biosphere'.

organisms

supports them

The

non-living

biosphere comprises the hydrosphere (the
waters),

the

soil

and

life,

them-

selves been profoundly affected through time

by living organisms. Most clearly, and from
the

human

presence
oxygen

significant

of

quantities

atmosphere

the

in

product

viewpoint most importantly, the

of

is

upper part

of

the

million years ago.

biosphere but

more than

The idea

in

some way

regulate

considerable attention

years, chiefly
in

in

terms

000

2

that living organ-

maintain the conditions conducive

proposed

the

oxygen-releasing photosynthesis

by cyanobacteria starting

received

free

of

entirely

isms do not merely influence conditions

it.

living

of the planet that

the

water on the

the fundamental

we know

The space occupied by

is

life

to

Most importantly, these factors have

combined
of

31.

Earth relative to the sun,

of the

the structure and composition of the

of the planet

The defining characteristic
that

carbon, nitrogen and other elements.

In cycling of

THE LIVING PLANET
Is

primary production

on Earth.

of energy-rich material left to sustain all other life

of the

in

the

them

to life
in

to

has

recent

Gaia hypothesis'

the 1970s.

lithosphere (the solid matter that forms the

rocky crust of the Earth], and the lower part of

The extent

the atmosphere (the thin layer of gas coating

At

the planet's surface).
in

ways

critical

to

These domains interact
the

operation

biosphere, and are linked
the

in

of

the

particular by

properties of water as a solvent and

of

the biosphere
the

biosphere can be

as a thin and

irregular envelope

planetary scale,

pictured

around the Earth's surface, just a few

meters deep on the globe's
radius.

Because most

living

organisms depend

on sunlight, the regions

medium that fosters the chemical reactions

directly or indirectly

basic to

reached by sunlight form the core

life.

kilo-

6 371 -kilometer

of

the

3


k

WORLD ATLAS

Map

OF BIODIVERSITY

1.1

Physical geography of
the Earth

The

relative

areas occupied

by dry land and by water,

and the general distribution
of

areas

of

extreme height

or depth.

'^,£•;
,

f-'

.ii*-.-

;

,'--fc\'

V^\

'-mi

>i'.

> ';

'

',

-

V'

•*.

'''

h

'--

i

'-•

^n

''

''r-^y.:

'.

.

-

''-'l

•i>^:\.
' '.

5%-

i
/:
/"

biosphere:

i.e.

the land surface, the top few

of

The whole

of

and the upper waters

capable

of

lakes and the ocean through which sunlight

stitutes

therefore

millimeters of the

soil,

volume

can penetrate.

The biosphere

is

not

homogenous, be-

cause actively metabolizing

living

organisms

are sparse or absent where liquid water

absent, such as

poles and

in

is

the permanent ice at the

on the very highest mountain

peaks, but abundant where conditions are
favorable.

Nor are

its

boundaries sharply

the

sea

biosphere

the

of

Depending on water

clarity,

hundred meters
biosphere

is

in

extended

darkness, down

to

into

more than

virtually

everywhere, from polar icecaps

to

several tens of kilometers above the surface
of the Earth

[approaching the upper

limit of

the stratosphere], and living microorganisms
occur^ within rocks

deep

in

more than

the lithosphere.

3 kilometers

1.1|.

but the

to a

few

marine

regions of total
10 000 meters

in

the ocean depths, by organisms that subsist

on the rain

of

organic debris falling from the

communities on the sea

disperse

[Figure

the sunlit (photic)

depth,

dormant forms

passively

and con-

zone may reach just a few centimeters

upper waters,

life

theoretically
life

majority of the

the vast

defined, because bacterial spores and other
of

is

supporting active

in

animal

addition, there are

floor

based on

microorganisms deriving their energy from

hydrogen sulfide emitted from hydrothermal
vents. Overall, however, the

material

in

most

of the

amount

of living

sea - that part

of the

open ocean below the upper hundred or so

meters

-

is

relatively low.

The biosphere

Figure

1.1

Hypsographic curve
The horizontal baseline

in

this figure represents the

Earth's total surface area
of

510 million km'.

The

figure

of this

shows

surface

is

that

71%

covered by

marine waters and 29%
dry land.

The atmosphere plays
the biosphere, not only
of

essential gases,

in

but

conditions at ground

a

vital

role

in

providing a source

temperature and providing

amount

carbon-containing (organic! compounds com-

in

a shield

against

Many organ-

posed mainly

8

the atmosphere;

known
the

air,

of their lives

however, no organism

that passes

and

living

suspended

its

complete

biomass per

above the Earth's solid or

life

unit

cycle

849

of the four

nitrogen

carbon,

also

is

shows the

mean land elevation and
mean ocean depth, and the

an aqueous medium.

weight; the remainder consists very largely of

isms, from microscopic bacteria to bats and

spend part

in

about 70 percent water by

buffering

in

excessive ultraviolet radiation.

birds,

cell is

by regulating

also

level,

molecules dispersed

The average

It

of Earth's surface,

percentage terms,

standing at any given

elements hydrogen,

and oxygen. These com-

elevation or depth.

m

in
is

in

volume

:

average elevation 840

liquid surface is

m

extremely low.

^""^^^

average depth 3 800

m

Photosynthesis and the biosphere
Life

on Earth

is

based essentially on the

chemistry of water and carbon. Indeed,

biochemical terms,

living

simply elaborate systems

of

6

~

in

organisms are
organic macro-

29%

71%

10
11

035

m

5

i

WORLD ATLAS OF BIODIVERSITY

pounds include four major types

large

of

organic molecule - proteins, carbohydrates,
lipids

-

and nucleic acids

and about 100

different small organic molecules.
of

other elements are

smaller, though

magnesium.

the biosphere

in

a

be

fully elucidated.

carbohydrate found
Energy

and

iron

variety

forms,

of

both

which are yet

of

Except for

some

to

micro-

molecules within cells

which

by

All

this

energy from the sun.

Chapter

dioxide

ICO2I

with

a

reduce carbon

to

source

of

electrons

live in

need

method. Virtually

eukaryotes (see

all

have evolved a more complex

2)

additional pathway that requires oxygen but
yields

much more

energy. This latter pathway

- aerobic respiration - essentially reverses the

basic photosynthetic reaction

The major cycling process

hydrogen)

to

by-product from the hydrogen donor.
bacteria the hydrogen donor
in

others

is

it

is

In

hydrogen gas,

hydrogen sulfide;

but,

cyanobacteria, algae and plants, water

donor

hydrogen
oxygen

IO2I

is

and

some

gaseous

in

the

is

elemental

the by-product. This

over-

is

Many

for oxygen.

produce

invariably

do

to

aerobic conditions use only

carbohydrates, water IH2OI and, generally, a

(almost

energy

obtain

cells

all

these

of

mechanism

the

is

is

down

organisms can break down sugars very

synthesis - the capture by living tissues of

energy from sunlight

and tubers.

the chemical bonds

useful work.

bacteria that

photo-

roots

The controlled breakdown

again.

the organic part of this turnover

is

in

make

key storage

the bonds are broken

directly without the

Photosynthesis essentially involves the use

shown above.
of the

biosphere,

therefore, consists of the photosynthetic fixing

carbon dioxide with water

of

organic compounds,

and oxygen;

produce

to

which energy

is

stored,

this is followed by respiration of

these compounds,
is

in

in

which the stored energy

released and carbon dioxide and water are

whelmingly the predominant and most impor-

produced. Photosynthesis therefore

tant form of photosynthesis on the planet,

responsible for the vast majority of organic

is

and

free

2nH20

+

nC02

+ light -^

nHjO

+

nCH20

+

2nO

responsible for the vast

oxygen

aerobic

in

initial

products

of

not only

photosynthesis

in

the atmosphere, without which

organisms

majority of

great

(the

organisms,

eukaryotic

The

is

production, but also for the maintenance of

described by the following equation:

Energy from the sun

production.

when

released

inorganic chemicals, the engine that drives

of

majority of organic

to

a

within these organic molecules, and energy

organisms that use energy derived from

drives photosynthesis,

needed

is

walls and

cell

and starch,

tissues,

much

sulfur,

many

plant

woody

of

These

organic and inorganic, following complex and
interlinked pathways

include cellulose, the

main component

in

these elements cycle through

All

made from glucose

quantities.

required

still vital,

phosphorus,

include

A number

Larger carbohydrate molecules

(041-1,2041.

humans)

including

could not survive.

plants are simple sugars such as glucose

Although photosynthesis
engine of the biosphere,
injects

energy

into the

the primary

is

the sense that

in

it

system and creates

basic organic molecules, production of the
full

range

of

organic molecules on which

life

depends requires additional elements. Of the
four key elements, nitrogen
in

limited supply, but

ponent

of

nucleic

it

is

one

often the

an essential com-

is

acids

and

proteins.

Although the atmosphere consists

of

percent nitrogen, this inert gaseous form
the element cannot be used by plants or

other organisms until combined
other elements.

In

pheric nitrogen

fixed by a

is

the

including cyanobacteria,

(fixed)

biosphere,

range

some

79
of

most
with

atmos-

of bacteria,

free-living soil


The biosphere

bacteria,

and most importantly by specialized

bacteria that

nodules
etc.)
in

of

Some

symbiotically

live

The accumulated matter
suite

the

in

Fixed nitrogen

also fixed by lightning

is

is

the

in

modern world,

production

made

of

fertilizer.

available to plant roots

through association with fungi ImychorrhizasI

as

From

referred to as net primary production

leguminous plants Ipeas, beans,

industrially

and

accumulated over time. This accumulation

nitrogen

storms and,

electric

the root

in

organisms decay.

nitrogen-fixing

plant

roots,

transported

is

it

to

of

humans,

organic

organisms

compounds from an

organisms are referred

Organic products pass

through the food chain,

to

as autotrophs.

be immediately recycled or revert

as heterotrophs,

to

microorganisms that use other energy sources

steps are reversed, and the fixed nitrogen

may

inorganic base or

while photosynthesizers and the few l
synthesize organic

cells.

including

sizes,

harness energy from inorganic sources. Such

to

plant

available to the vast

all

cannot synthesize their own

that

On death, these

metabolizing

is

of

is

iNPPl.

compounds are

referred

as predation.

to

elemental nitrogen.

PRODUCTIVITY AND THE CARBON CYCLE
About

half of the solar

upper atmosphere
Most

reflected.

of the

of the

energy reaching the
Earth

is

immediately

remainder interacts with

atmosphere, ocean or land, where

the

evaporates water and heats

it

so driving

air,

atmospheric and ocean circulation. Much less
than

1

percent of the incoming

intercepted and absorbed

energy

is

by photosynthetic

organisms. On land these photosynthesizers
are overwhelmingly green

although

plants,

cyanobacteria and algae are also present, the
latter particularly in the symbiotic associations

with

known as

fungi

particularly

habitats,

photosynthesis

is

lichens.

the

aquatic

In

virtually

sea,

all

carried out by cyanobacteria

and algae, although green plants are also
present

shallow coastal and inland waters.

in

Photosynthesizers

fix

carbon and therefore

accumulate organic mass or biomass

measured
tissues

in

of

extracted].

dry form - that

organism

an

is,

loften

the once-living

the

with

water

These organisms are the primary

producers. The amount of carbon fixed

is

referred to as gross primary production and
is

ICl

typically

per unit

measured
of

in

grams

(gl

of

carbon

space larea or volume) per unit

of time.

meet

their

own energetic needs. Under

some circumstances,

respiration

synthesizers over a given period

of

photo-

may balance

their carbon fixation, so that there

accumulation

of

is

no net

organic carbon. More nor-

mally, however, there

is

a surplus of fixation

over respiration, so that organic matter

is

may pass through

heterotrophs before

down again

to

a

being

finally

photo-

a

number

of

brol
inorganic constituents.

its

Conventionally this can be viewed as a food
chain. At macroscopic

may be
itself

is

eaten by a

animal

which

is

some

is

by

remainder

an enormous over-

The plant

will

have a complex network
associated

the

with

is

bacteria and fungi.

this

reality,

simplification.

consumed

partially

scavengers,

decomposed by

of

lizard,

eaten by a hawk, which dies and

disassembled and

use

green plant

a

level,

eaten by a herbivore - a grasshopper,

say - which

In

The photosynthetic producers also respire
to

Food webs

An organic product produced by
synthesizer

through processes such

with

its

of the

almost certainly

of

symbiotic fungi

roots,

which

make

gross production of the

some
may shed
broken down by

plant but which also provide

it

with

essential nutrients. The plant itself

leaves which are directly

other fungi, protoctists such as slime molds.

7


8

WORLD ATLAS OF BIODIVERSITY

Map

1.2

Primary production

In

the

biosphere

Global spatial variation

in

r.

annual net primary
production INPPI,

in g

C

per m" per year, calculated

from an integrated model
of

production based on

g

C per m' per year

satellite indices of

absorbed solar
Source:

radiation.

Map created (rom

1

782

-3 859

1

107

-

1

1

106

data

781

supplied by Chrts Field and George

Merchant, Department

of

Global

Ecology, Carnegie Institution of

881

-

671

-

880

487

-

670

3A1

-

486

Washington. See
/>flab,

html, and Field et

3l.

,

230- 340

U361

229

142

-

0-60

and many forms

hopper

is likely to

of

smaller organisms,

themselves

in

bacteria.

The grass-

be parasitized by a host of

some

which

of

turn parasitized.

It

are

will also

support a host of benign microorganisms
its

intestine that are

in

themselves constantly

growing and reproducing. The

may

lizard

die

and decompose and the hawk may eat the

grasshopper

directly.

in

is

web

respires,

eventually dissi-

the form of heat, carbon dioxide and

water At each stage, therefore, some carbon
is

returned

carbon cycle.

consume, so that

product.

to
In

the

is

These organic wastes are theor-

inorganic

part

addition, all living

produce waste products, some

of

of

the

organisms

etically available to other

the

in

web. The assimilation efficiency

food

from

the food

not

excreted as waste

proportion of this

of

any but the simplest

also

some

web

in

are

their appropriation of

heterotrophic organisms

releasing energy which
in

in

the organic material they

20

terrestrial

the

Each organism

organisms

of

ecosystems.

pated

Heterotrophic

completely efficient

The overall pattern

feeding relationships thus forms a

immense complexity

incompletely metabolized organic compounds.

case

percent

the

(in

herbivores!
of

some

may be

to

case
90

of

anything
of

some

percent

carnivores),

with

(in

the

remainder excreted.
Of

the

proportion

amount

is

assimilated,

a

high

expended as respiration, with

the remainder available to add biomass,

enable the organism

to

i.e.

to

grow and reproduce.

organisms

The proportion available

which are

dependent on the organisms involved as well

to

add biomass

is


The biosphere

'jr
./

^

"

*

X,

V
as a range

other factors.

of

can be as low as

It

10 percent or less and as high as 50 percent
or more. This proportion

measure

a

is

of the

purposes

of

analysis,

ecological

particularly involving productivity estimates,

gross growth

the

efficiency

commonly used measure.
product

net

the

of

growth efficiency

heterotroph and
portion of food
that,

is

a

10

coarse

percent

widely

acknowledged that
the

figure

planktonic

is

in

likely

and

and

particular
of

that

the

pro-

organism

respiration,

its

used,

is

growth. As a

generalization,

is

simply the

a

of

consumed by

excretion

after

is

most

efficiency

measure

ultimately available for

very

This

assimilation

the

the

is

a

value

although

it

to

be

lower and

and

is likely to

be higher. Using the

every

of

kilo

plant

example above,

for

matter eaten by the

to its

body weight.

eaten by the

When

lizard, this

the grasshopper

would add

the lizards body weight, and

when

1

was

gram

to

the lizard

was eaten by the hawk, this would add
0.1 grams to the hawks weight. This explains
why,

at

the species level, so-called higher

predators are rarer than herbivores and

in

any

given area have a lower biomass, while the

biomass
all

of

primary producers exceeds that

of

heterotrophs combined.

of
is

terrestrial herbivores

communities

it

figure of 10 percent in the

grasshopper, the latter would add 10 grams

net growth efficiency of the organism.

For

carnivores

,

in

terrestrial

Measures

of local

and global productivity

Primary productivity varies enormously, both

Most ob-

spatially

and temporally,

viously,

under natural conditions productivity

at all scales.

9