PILOT ANALYSIS OF GLOBAL ECOSYSTEMS - GRASSLAND ECOSYSTEMS ROBINWHITE SIOBHANMURRAY MARKROHWEDER - WORLD RESOURCES REPORT
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
PILOT ANALYSIS OF GLOBAL ECOSYSTEMS
Grassland Ecosystems
Robin White Siobhan Murray Mark RohwederPILOT A N A LY S I S OF GLOBAL ECOSYSTEMS
Grassland
Ecosystems
R OBIN P
P.. WHITE
S IOBHAN MURRAY
URRAY
M ARK ROHWEDERCAROL ROSEN
PUBLICATIONS DIRECTOR
HYACINTH BILLINGS
HYACINTH
PRODUCTION MANAGER
MAGGIE POWELL AND KATHY DOUCETTE
KATHY
COVER DESIGN AND LAYOUT
MELISSA EDEBURN
EDITING
Each World Resources Institute report represents a timely, scholarly treat- inquiry. It also solicits and responds to guidance of advisory panels and
ment of a subject of public concern. WRI takes responsibility for choosing expert reviewers. Unless otherwise stated, however, all the interpretation
the study topic and guaranteeing its authors and researchers freedom of and findings set forth in WRI publications are those of the authors.
Copyright © 2000 World Resources Institute. All rights reserved. Photo Credits:
Cover: Digital Imagery © Copyright 2000 PhotoDisc, Inc.; African savanna
ISBN: 1-56973-461-5 Smaller Ecosystem Photos: Forests: Digital Vision, Ltd.; Agriculture: Philippe Berry, IFPRI;
Grasslands: PhotoDisc; Freshwater: Dennis A. Wentz; Coastal: Digital Vision, Ltd.
Library of Congress Card No. 00-111019
Prologue: Bruce G. Stumpf © Copyright 1999-2000; Grasslands of the Masai Mara, Kenya
Printed in the United States of America on chlorine-free paper with Grassland Extent and Change, Digital Stock Corporation © Copyright 1996; Wildebeest
Food, Forage, and Livestock: Digital Vision Ltd.; Cattle herding.
recycled content of 50%, 20% of which is post-consumer. Biodiversity: R. P. White; Upland Sandpiper
Carbon Storage: © 1999 FEC; Burning mesquite-tobosagrass rangeland
Tourism and Recreation: IUCN-The World Conservation Union, 1999; Tourist bus in
Serengeti.Pilot Analysis of Global Ecosystems
Grassland
Ecosystems
R OBIN P
P.. WHITE
S IOBHAN MURRAY
URRAY
M ARK ROHWEDER
With analytical contributions fr om:
from:
Stephen D. Prince, University of Maryland, Geography Department
Kirsten M.J. Thompson, World Resources Institute
Published by World Resources Institute
Washington, DC
This report is also available at http://www.wri.org/wr2000Pilot Analysis of
Global Ecosystems (PAGE)
Project Management A series of five technical reports, available in print and on-line at
Norbert Henninger, WRI http://www.wri.org/wr2000.
Walt Reid, WRI
Dan Tunstall, WRI AGROECOSYSTEMS
Valerie Thompson, WRI Stanley Wood, Kate Sebastian, and Sara J. Scherr, Pilot Analysis of Global Ecosystems:
Arwen Gloege, WRI Agroecosystems, A joint study by International Food Policy Research Institute and World
Elsie Velez-Whited, WRI Resources Institute, International Food Policy Research Institute and World Resources
Institute, Washington D.C.
Agroecosystems November 2000 / paperback / ISBN 1-56973-457-7 / US$20.00
Stanley Wood, International Food
Policy Research Institute C O A S TA L E C O S Y S T E M S
Kate Sebastian, International Food Lauretta Burke, Yumiko Kura, Ken Kassem, Mark Spalding, Carmen Revenga, and
Policy Research Institute Don McAllister, Pilot Analysis of Global Ecosystems: Coastal Ecosystems, World Resources
Sara J. Scherr, University of Institute, Washington D.C.
Maryland November 2000 / paperback / ISBN 1-56973-458-5 / US$20.00
Coastal Ecosystems FOREST ECOSYSTEMS
Lauretta Burke, WRI Emily Matthews, Richard Payne, Mark Rohweder, and Siobhan Murray, Pilot Analysis
Yumiko Kura, WRI of Global Ecosystems: Forest Ecosystems, World Resources Institute, Washington D.C.
Ken Kassem, WRI October 2000 / paperback / ISBN 1-56973-459-3 / US$20.00
Mark Spalding, UNEP-WCMC
Carmen Revenga, WRI F R E S H WAT E R S Y S T E M S
Don McAllister, Ocean Voice Carmen Revenga, Jake Brunner, Norbert Henninger, Ken Kassem, and Richard Payne
International Pilot Analysis of Global Ecosystems: Freshwater Systems, World Resources Institute,
Washington D.C.
Forest Ecosystems October 2000 / paperback / ISBN 1-56973-460-7 / US$20.00
Emily Matthews, WRI
Richard Payne, WRI GRASSLAND ECOSYSTEMS
Mark Rohweder, WRI Robin White, Siobhan Murray, and Mark Rohweder, Pilot Analysis of Global Ecosystems:
Siobhan Murray, WRI Grassland Ecosystems, World Resources Institute, Washington D.C.
November 2000 / paperback / ISBN 1-56973-461-5 / US$20.00
Freshwater Systems
Carmen Revenga, WRI
Jake Brunner, WRI
Norbert Henninger, WRI The full text of each report will be available on-line at the time of publication. Printed
Ken Kassem, WRI copies may be ordered by mail from WRI Publications, P.O. Box 4852, Hampden
Richard Payne, WRI Station, Baltimore, MD 21211, USA. To order by phone, call 1-800-822-0504 (within
the United States) or 410-516-6963 or by fax 410-516-6998. Orders may also be
placed on-line at http://www.wristore.com.
Grassland Ecosystems
Robin White, WRI The agroecosystem report is also available at http://www.ifpri.org. Printed copies may
Siobhan Murray, WRI be ordered by mail from the International Food Policy Research Institute, Communica-
Mark Rohweder, WRI tions Service, 2033 K Street, NW, Washington, D.C. 20006-5670, USA.
iv Pilot Analysis of Global EcosystemsContents
FOREWORD ............................................................................................................................................................................ viii
ACKNOWLEDGMENTS ............................................................................................................................................................. x
INTRODUCTION TO THE PILOT ANALYSIS OF GLOBAL ECOSYSTEMS ............................................................................. 1
GRASSLAND ECOSYSTEMS: EXECUTIVE SUMMARY ........................................................................................................ ..1
Scope of Analysis
Key Findings and Information Issues
Conclusions
Recommendations for Future Grassland Assessments
PROLOGUE: GRASSLAND ECOSYSTEMS—WHY THEY MATTER, HOW THEY’RE DOING ........................................... ..7
GRASSLAND EXTENT AND CHANGE ................................................................................................................................... 11
A Working Definition of Grasslands
Extent of Global Grassland Cover
Global Grassland Cover: Information Status and Needs
FOOD, FORAGE, AND LIVESTOCK ....................................................................................................................................... 29
Global Grassland Production of Food, Forage, and Livestock
Trends in Grassland Production of Food, Forage, and Livestock
Grassland Modification to Produce Food, Forage, and Livestock
Capacity of Grasslands to Sustain Production of Food, Forage, and Livestock
Grassland Production of Food, Forage, and Livestock: Information Status and Needs
BIODIVERSITY ........................................................................................................................................................................ 39
The Diversity of Grasslands
Trends in Grassland Biodiversity
Human Modification of Grassland Biodiversity
Capacity of Grasslands to Sustain Biodiversity
Grassland Biodiversity: Information Status and Needs
CARBON STORAGE ................................................................................................................................................................ 49
Grassland Storage of Carbon
Carbon Stores in Grasslands and Other Terrestrial Ecosystems
Human Modification of Grassland Carbon Stores
Capacity of Grasslands to Maintain or Increase Terrestrial Carbon Stores
Grassland Carbon Storage: Information Status and Needs
TOURISM AND RECREATION ................................................................................................................................................ 55
Grasslands as Tourist and Recreational Attractions
Trends in Grassland Tourism and Recreation
Grassland Modification to Support Tourism and Recreation
Capacity of Grasslands to Sustain Tourism and Recreation
Grassland Tourism and Recreation: Information Status and Needs
Grassland Ecosystems vABBREVIATIONS AND UNITS ................................................................................................................................................ 63
REFERENCES .......................................................................................................................................................................... 65
TABLES
Table 1. Ideal Indicators of Grassland Condition ............................................................................................................. .8
Table 2. Grassland Extent, Goods and Services, and Indicators ....................................................................................... .9
Table 3. Extent of the World’s Grasslands ........................................................................................................................ 12
Table 4. Ecosystem Area and Population ......................................................................................................................... 13
Table 5. Grassland Types of the World ............................................................................................................................. 14
Table 6. World Regions, PAGE Grassland Area, and Population ..................................................................................... 15
Table 7. Top Countries for Grassland Area ....................................................................................................................... 16
Table 8. Top Countries for Percent of Grassland Area ...................................................................................................... 17
Table 9. Grasslands within Aridity Zones ........................................................................................................................ 18
Table 10. Conversion of Historical Grassland Areas ........................................................................................................ 20
Table 11. Conversion of Grassland Ecoregions ................................................................................................................ 21
Table 12. Decline in Prairies of Central North America ................................................................................................... 22
Table 13. PAGE Grasslands and Soil Degradation Using Extent and Degree Classes from GLASOD .............................. 31
Table 14. Livestock in Developing Countries with Extensive Grassland .......................................................................... 34
Table 15. Two Views of Grassland Degradation in Mongolia ............................................................................................ 36
Table 16. Ecosystems and Protected Area ....................................................................................................................... 44
Table 17. Estimated Range of Total Carbon Storage by Ecosystem .................................................................................. 51
Table 18. Global Estimates of Annual Amounts of Biomass Burning ............................................................................... 52
Table 19. International Inbound Tourists in Countries with Extensive Grassland ............................................................ 57
Table 20. International Tourism Receipts in Countries with Extensive Grassland ........................................................... 58
FIGURES
Figure 1. Goods and Services Provided by Grasslands .................................................................................................... .8
Figure 2. Grassland Watersheds of the World .................................................................................................................. 18
Figure 3. Percent Woody Vegetation in Grasslands .......................................................................................................... 19
Figure 4. Untilled Landscapes in the Great Plains ........................................................................................................... 23
Figure 5. General Representation of the Rain-Use Efficiency Index .............................................................................. 32
Figure 6. Trends in Rain-Use Efficiency in Southern Africa ........................................................................................... 33
Figure 7. Inner Asia ......................................................................................................................................................... 35
Figure 8. Two Perceptions of Grassland Degradation in Mongolia ................................................................................... 37
Figure 9. Biologically Distinct Grassland Ecoregions ...................................................................................................... 41
Figure 10. Key Threatened Bird Areas in the Neotropics ................................................................................................ 46
Figure 11. Habitats of Key Threatened Bird Areas .......................................................................................................... 47
Figure 12. Principal Pools in a Savanna Carbon Cycle .................................................................................................... 50
Figure 13. An International Perspective on Trophy Hunting ............................................................................................ 59
BOXES
Box 1. Caribou Migrations and Calving Grounds: Globally Outstanding Ecological Phenomena ..................................... 42
Box 2. Threatened Tall-Grassland Birds of Continental North America ........................................................................... 45
Box 3. Valuing a Fynbos Ecosystem ................................................................................................................................. 48
Box 4. Miombo Woodlands and Carbon Sequestration ..................................................................................................... 53
Box 5. Ecotourism and Conservation: Are They Compatible? .......................................................................................... 60
vi P I L O T A N A LY S I S O F G L O B A L E C O S Y S T E M SMAPS .......................................................................................................................................................................................... 70
Map 1. Global Extent of Grassland
Map 2. Grasslands and Aridity Zones
Map 3. Percent Woody Vegetation in Grasslands
Map 4. Major Grassland Habitat Types
Map 5. Agricultural Mosaics and Grasslands
Map 6. Fires and Grasslands
Map 7. Central and North America: Fragmentation and Wildlife Exploitation
Map 8. Global Net Primary Productivity of Grasslands (1982-1993)
Map 9. Global Variation in Grassland Net Primary Productivity (1982-1993)
Map 10. Southern Africa: Rain-Use Efficiency (1981-1993)
Map 11. Global Livestock Density
Map 12. Africa: Cattle Density
Map 13. Endemic Bird Areas and Centers of Plant Diversity in Grasslands
Map 14. Global 200: Grassland Ecoregions
Map 15. Protected Areas and Grasslands
Map 16. North America: Non-Native Plant Species in Grasslands
Map 17. Grassland Bird Populations: Density and Trends
Map 18. Botswana: Grassland Fragmentation
Map 19. The Great Plains: Grassland Fragmentation
Map 20. Global Carbon Storage in Above- and Below-Ground Live Vegetation
Map 21. Global Carbon Storage in Soils
Map 22. Global Carbon Storage in Above- and Below-Ground Live Vegetation and Soils
Grassland Ecosystems viiForeword
Earth’s ecosystems and its peoples are bound together in a broad array of ecosystem goods and services that people need,
grand and complex symbiosis. We depend on ecosystems to or enjoy, but do not buy in the marketplace.
sustain us, but the continued health of ecosystems depends, The five PAGE reports show that human action has pro-
in turn, on our use and care. Ecosystems are the productive foundly changed the extent, condition, and capacity of all
engines of the planet, providing us with everything from the major ecosystem types. Agriculture has expanded at the ex-
water we drink to the food we eat and the fiber we use for pense of grasslands and forests, engineering projects have
clothing, paper, or lumber. Yet, nearly every measure we use altered the hydrological regime of most of the world’s major
to assess the health of ecosystems tells us we are drawing on rivers, settlement and other forms of development have con-
them more than ever and degrading them, in some cases at verted habitats around the world’s coastlines. Human activi-
an accelerating pace. ties have adversely altered the earth’s most important bio-
Our knowledge of ecosystems has increased dramatically geochemical cycles — the water, carbon, and nitrogen cycles
in recent decades, but it has not kept pace with our ability to — on which all life forms depend. Intensive management
alter them. Economic development and human well-being will regimes and infrastructure development have contributed
depend in large part on our ability to manage ecosystems positively to providing some goods and services, such as food
more sustainably. We must learn to evaluate our decisions on and fiber from forest plantations. They have also led to habi-
land and resource use in terms of how they affect the capac- tat fragmentation, pollution, and increased ecosystem vul-
ity of ecosystems to sustain life — not only human life, but nerability to pest attack, fires, and invasion by non-native
also the health and productive potential of plants, animals, species. Information is often incomplete and the picture con-
and natural systems. fused, but there are many signs that the overall capacity of
A critical step in improving the way we manage the earth’s ecosystems to continue to produce many of the goods and
ecosystems is to take stock of their extent, their condition, services on which we depend is declining.
and their capacity to provide the goods and services we will The results of the PAGE are summarized in World Resources
need in years to come. To date, no such comprehensive as- 2000–2001, a biennial report on the global environment pub-
sessment of the state of the world’s ecosystems has been un- lished by the World Resources Institute in partnership with
dertaken. the United Nations Development Programme, the United Na-
The Pilot Analysis of Global Ecosystems (PAGE) begins tions Environment Programme, and the World Bank. These
to address this gap. This study is the result of a remarkable institutions have affirmed their commitment to making the
collaborative effort between the World Resources Institute viability of the world’s ecosystems a critical development pri-
(WRI), the International Food Policy Research Institute ority for the 21st century. WRI and its partners began work
(IFPRI), intergovernmental organizations, agencies, research with a conviction that the challenge of managing earth’s eco-
institutes, and individual experts in more than 25 countries systems — and the consequences of failure — will increase
worldwide. The PAGE compares information already avail- significantly in coming decades. We end with a keen aware-
able on a global scale about the condition of five major classes ness that the scientific knowledge and political will required
of ecosystems: agroecosystems, coastal areas, forests, fresh- to meet this challenge are often lacking today. To make sound
water systems, and grasslands. IFPRI led the agroecosystem ecosystem management decisions in the future, significant
analysis, while the others were led by WRI. The pilot analy- changes are needed in the way we use the knowledge and
sis examines not only the quantity and quality of outputs but experience at hand, as well as the range of information brought
also the biological basis for production, including soil and to bear on resource management decisions.
water condition, biodiversity, and changes in land use over A truly comprehensive and integrated assessment of glo-
time. Rather than looking just at marketed products, such as bal ecosystems that goes well beyond our pilot analysis is
food and timber, the study also analyzes the condition of a necessary to meet information needs and to catalyze regional
viii P I L O T A N A LY S I S O F G L O B A L E C O S Y S T E M Sand local assessments. Planning for such a Millennium Eco- We deeply appreciate support for this project from the
system Assessment is already under way. In 1998, represen- Australian Centre for International Agricultural Research,
tatives from international scientific and political bodies be- The David and Lucile Packard Foundation, The Netherlands
gan to explore the merits of, and recommend the structure Ministry of Foreign Affairs, the Swedish International Devel-
for, such an assessment. After consulting for a year and con- opment Cooperation Agency, the United Nations Develop-
sidering the preliminary findings of the PAGE report, they ment Programme, the United Nations Environment
concluded that an international scientific assessment of the Programme, the Global Bureau of the United States Agency
present and likely future condition of the world’s ecosystems for International Development, and The World Bank.
was both feasible and urgently needed. They urged local, A special thank you goes to the AVINA Foundation, the
national, and international institutions to support the effort Global Environment Facility, and the United Nations Fund
as stakeholders, users, and sources of expertise. If concluded for International Partnerships for their early support of PAGE
successfully, the Millennium Ecosystem Assessment will gen- and the Millennium Ecosystem Assessment, which was in-
erate new information, integrate current knowledge, develop strumental in launching our efforts.
methodological tools, and increase public understanding.
Human dominance of the earth’s productive systems gives JONATHAN LASH
us enormous responsibilities, but great opportunities as well. President
The challenge for the 21st century is to understand the vul- World Resources Institute
nerabilities and resilience of ecosystems, so that we can find
ways to reconcile the demands of human development with
the tolerances of nature.
Grassland Ecosystems ixAcknowledgments
The World Resources Institute and the International Food (CIESIN); Environmental Systems Research Institute (ESRI);
and Research Institute would like to acknowledge the mem- European Space Agency (ESA); Food and Agriculture Orga-
bers of the Millennium Assessment Steering Committee, who nization of the United Nations (FAO); International Livestock
generously gave their time, insights, and expert review com- Research Institute (ILRI); International Soil Reference and
ments in support of the Pilot Analysis of Global Ecosystems. Information Centre (ISRIC); IUCN- The World Conservation
Edward Ayensu, Ghana; Mark Collins, United Nations Union; National Oceanic and Atmospheric Administration -
Environment Programme-World Conservation Monitoring National Geophysical Data Center (NOAA-NGDC); The Na-
Centre (UNEP-WCMC), United Kingdom; Angela Cropper, ture Conservancy (TNC); Patuxent Wildlife Research Labo-
Trinidad and Tobago; Andrew Dearing, World Business Coun- ratory; Safari Club International; United Nations Environment
cil for Sustainable Development (WBCSD); Janos Pasztor, Programme (UNEP); United States Geological Survey (USGS),
UNFCCC; Louise Fresco, FAO; Madhav Gadgil, Indian In- Earth Resources Observation Systems (EROS) Data Center;
stitute of Science, Bangalore, India; Habiba Gitay, Austra- University of Maryland, Geography Department; The World
lian National University, Australia; Gisbert Glaser, UNESCO; Bank; World Conservation Monitoring Centre (WCMC); World
Zuzana Guziova, Ministry of the Environment, Slovak Re- Wildlife Fund – U.S. (WWF-U.S.).
public; He Changchui, FAO; Calestous Juma, Harvard Uni- The authors also would like to express their gratitude to
versity; John Krebs, National Environment Research Coun- the many individuals who contributed information and ad-
cil, United Kingdom; Jonathan Lash, World Resources Insti- vice, attended expert workshops, and reviewed successive
tute; Roberto Lenton, UNDP; Jane Lubchenco, Oregon State drafts of this report.
University; Jeffrey McNeely, World Conservation Union Niels Batjes, International Soil Reference and Information
(IUCN), Switzerland; Harold Mooney, International Council Centre;
for Science (ICSU); Ndegwa Ndiangui, Convention to Com- Roy H. Behnke, Overseas Development Institute;
bat Desertification; Prabhu L. Pingali, CIMMYT; Per Pinstrup- Daniel Binkley, Colorado State University;
Andersen, Consultative Group on International Agricultural Jesslyn Brown, USGS, EROS Data Center;
Research; Mario Ramos, Global Environment Facility; Peter Virginia Dale, Oak Ridge National Laboratory;
Raven, Missouri Botanical Garden; Walter Reid, Secretariat; Ruth DeFries, University of Maryland, Geography Department;
Cristian Samper, Instituto Alexander Von Humboldt, Colom- Andre DeGeorges, Safari Club International;
bia; José Sarukhán, CONABIO, Mexico; Peter Schei, Direc- Eric Dinerstein, WWF-US;
torate for Nature Management, Norway; Klaus Töpfer, UNEP; James E. Ellis, Natural Resource Ecology Laboratory;
José Galízia Tundisi, International Institute of Ecology, Bra- Colorado State University;
zil; Robert Watson, World Bank; Xu Guanhua, Ministry of Chris Elvidge, NOAA-NGDC;
Science and Technology, People’s Republic of China; A.H. Hari Eswaran, USDA, Natural Resources Conservation Service;
Zakri, Universiti Kebangsaan Malaysia, Malaysia. Robert Friedman, The Heinz Center;
The Pilot Analysis of Global Ecosystems would not have Peter Gilruth, UNSO, United Nations Environment Program;
been possible without the data provided by numerous insti- Scott Goetz, University of Maryland, Geography Department;
tutions and agencies. The authors of the grassland ecosystem Patrick Gonzalez, USGS, Desertification and Climate Change;
analysis wish to express their gratitude for the generous co- Paul Goriup, Nature Conservation Bureau, UK;
operation and invaluable information we received from the Jon Haferman, The Nature Conservancy;
following organizations. David Hall, Kings College, London;
BirdLife International; Carbon Dioxide Information Analy- Jeremy Harrison, World Conservation Monitoring Centre;
sis Center (CDIAC), Oak Ridge National Laboratory(ORNL); Richard Houghton, Woods Hole Research Center;
Center for International Earth Science Information Network JoAnn House, Kings College, London;
x P I L O T A N A LY S I S O F G L O B A L E C O S Y S T E M SJohn Kartesz, University of North Carolina, Chapel Hill; Manuel Winograd, International Center for Tropical Anthony King, Oak Ridge National Laboratory; Agriculture. James Martin-Jones, World Wildlife Fund-US; We also wish to thank the many individuals at WRI and Robin O’Malley, The Heinz Center; IFPRI who were generous with their help as this report pro- Wayne Ostlie, Weather Creek Conservation Consultants; gressed: Elizabeth Berendt, Jake Brunner, Lauretta Burke, Eric Rodenburg, USGS, Minerals and Materials Analysis; Allen Hammond, Lori Han, Tony Janetos, Ken Kassem, Emily Osvaldo Sala, Ecology Department, University Buenos Aires; Matthews, Kenton Miller, Becky Milton, Gregory Mock, Chris- Fred Samson, US Forest Service; tian Ottke, Janet Overton, Carmen Revenga, Carol Rosen, David Sneath, University of Cambridge; Kate Sebastian,Valerie Thompson, Amy Wagener, and Stan Alison Stattersfield, Birdlife International; Wood; as well as Armin Jess, Johnathon Kool, Yumiko Kura, Bruce Stein, The Nature Conservancy; and Wendy Vanasselt for their contibutions to maps, text boxes, Larry Tieszen, USGS, EROS Data Center; and figures. We are particularly grateful to Arwen Gloege, Emma Underwood, World Wildlife Fund-US; Norbert Henninger, Walter Reid, and Dan Tunstall for their Thomas R. Vale, University of Wisconsin-Madison, dedication and guidance throughout the project. Special Geography Department; thanks goes to Oretta Tarkhani for coordinating meetings and David Wege, Birdlife International; workshops, Melissa Edeburn for her editorial guidance, and Keith L. White, University of Wisconsin-Green Bay, to Hyacinth Billings, Kathy Doucette, and Maggie Powell for Environmental Sciences; their production expertise. Grassland Ecosystems xi
I n t r o d u c t i o n t o t h e P A G E
Introduction to the Pilot Analysis of
Global Ecosystems
PEOPLE AND ECOSYSTEMS may not know of each other’s relevant the extent and distribution of the five
The world’s economies are based on the findings. major ecosystem types and identifies
goods and services derived from ecosys- ecosystem change over time. It analyzes
tems. Human life itself depends on the OBJECTIVES the quantity and quality of ecosystem
continuing capacity of biological pro- The Pilot Analysis of Global Ecosystems goods and services and, where data
cesses to provide their multitude of ben- (PAGE) is the first attempt to synthesize exist, reviews trends relevant to the pro-
efits. Yet, for too long in both rich and information from national, regional, and duction of these goods and services over
poor countries, development priorities global assessments. Information sources the past 30 to 40 years. Finally, PAGE
have focused on how much humanity include state of the environment re- attempts to assess the capacity of eco-
can take from ecosystems, and too little ports; sectoral assessments of agricul- systems to continue to provide goods
attention has been paid to the impact of ture, forestry, biodiversity, water, and and services, using measures of biologi-
our actions. We are now experiencing fisheries, as well as national and glo- cal productivity, including soil and
the effects of ecosystem decline in nu- bal assessments of ecosystem extent water conditions, biodiversity, and land
merous ways: water shortages in the and change; scientific research articles; use. Wherever possible, information is
Punjab, India; soil erosion in Tuva, Rus- and various national and international presented in the form of indicators and
sia; fish kills off the coast of North Caro- datasets. The study reports on five ma- maps.
lina in the United States; landslides on jor categories of ecosystems: A second objective of PAGE is to
the deforested slopes of Honduras; fires ♦ Agroecosystems; identify the most serious information
in the forests of Borneo and Sumatra in ♦ Coastal ecosystems; gaps that limit our current understand-
Indonesia. The poor, who often depend ♦ Forest ecosystems; ing of ecosystem condition. The infor-
directly on ecosystems for their liveli- ♦ Freshwater systems; mation base necessary to assess ecosys-
hoods, suffer most when ecosystems are ♦ Grassland ecosystems. tem condition and productive capacity
degraded. These ecosystems account for about has not improved in recent years, and
A critical step in managing our eco- 90 percent of the earth’s land surface, may even be shrinking as funding for
systems is to take stock of their extent, excluding Greenland and Antarctica. environmental monitoring and record-
their condition, and their capacity to PAGE results are being published as a keeping diminishes in some regions.
continue to provide what we need. Al- series of five technical reports, each cov- Most importantly, PAGE supports the
though the information available today ering one ecosystem. Electronic versions launch of a Millennium Ecosystem As-
is more comprehensive than at any time of the reports are posted on the Website sessment, a more ambitious, detailed,
previously, it does not provide a com- of the World Resources Institute [http:/ and integrated assessment of global eco-
plete picture of the state of the world’s /www.wri.org/wr2000] and the systems that will provide a firmer basis
ecosystems and falls far short of man- agroecosystems report also is available for policy- and decision-making at the
agement and policy needs. Information on the Website of the International Food national and subnational scale.
is being collected in abundance but Policy Research Institute [http://www/
efforts are often poorly coordinated. ifpri.org]. A N I N T E G R AT E D A P P R O A C H T O
Scales are noncomparable, baseline The primary objective of the pilot ASSESSING ECOSYSTEM GOODS
data are lacking, time series are incom- analysis is to provide an overview of eco- AND SERVICES
plete, differing measures defy integra- system condition at the global and con- Ecosystems provide humans with a
tion, and different information sources tinental levels. The analysis documents wealth of goods and services, including
Grassland Ecosystems Introduction / 1I n t r o d u c t i o n t o t h e P A G E
food, building and clothing materials, the current provision of goods and ser- and discussed at a Millennium Assess-
medicines, climate regulation, water pu- vices and the likely capacity of the eco- ment planning meeting in Winnipeg,
rification, nutrient cycling, recreation system to continue providing those Canada, (September, 1999) and at the
opportunities, and amenity value. At goods and services. Goods and services meeting of the Parties to the Conven-
present, we tend to manage ecosystems are selected on the basis of their per- tion to Combat Desertification, held in
for one dominant good or service, such ceived importance to human develop- Recife, Brazil (November, 1999).
as grain, fish, timber, or hydropower, ment. Most of the ecosystem studies ex-
without fully realizing the trade-offs we amine food production, water quality KEY FINDINGS
are making. In so doing, we may be sac- and quantity, biodiversity, and carbon Key findings of PAGE relate both to eco-
rificing goods or services more valuable sequestration. The analysis of forests system condition and the information
than those we receive — often those also studies timber and woodfuel pro- base that supported our conclusions.
goods and services that are not yet val- duction; coastal and grassland studies
ued in the market, such as biodiversity examine recreational and tourism ser-
T h e C u r re n t S t a t e o f
and flood control. An integrated ecosys- vices; and the agroecosystem study re-
tem approach considers the entire range views the soil resource as an indicator Ecosystems
of possible goods and services a given of both agricultural potential and its cur- The PAGE reports show that human ac-
ecosystem provides and attempts to op- rent condition. tion has profoundly changed the extent,
timize the benefits that society can de- distribution, and condition of all major
rive from that ecosystem and across eco- PARTNERS AND THE RESEARCH ecosystem types. Agriculture has ex-
systems. Its purpose is to help make PROCESS panded at the expense of grasslands and
trade-offs efficient, transparent, and sus- The Pilot Analysis of Global Ecosys- forests, engineering projects have al-
tainable. tems was a truly international collabo- tered the hydrological regime of most of
Such an approach, however, presents rative effort. The World Resources In- the world’s major rivers, settlement and
significant methodological challenges. stitute and the International Food other forms of development have con-
Unlike a living organism, which might Policy Research Institute carried out verted habitats around the world’s coast-
be either healthy or unhealthy but can- their research in partnership with nu- lines.
not be both simultaneously, ecosystems merous institutions worldwide (see Ac- The picture we get from PAGE re-
can be in good condition for producing knowledgments). In addition to these sults is complex. Ecosystems are in good
certain goods and services but in poor partnerships, PAGE researchers relied condition for producing some goods and
condition for others. PAGE attempts to on a network of international experts services but in poor condition for pro-
evaluate the condition of ecosystems by for ideas, comments, and formal re- ducing others. Overall, however, there
assessing separately their capacity to views. The research process included are many signs that the capacity of eco-
provide a variety of goods and services meetings in Washington, D.C., attended systems to continue to produce many of
and examining the trade-offs humans by more than 50 experts from devel- the goods and services on which we de-
have made among those goods and ser- oped and developing countries. The pend is declining. Human activities
vices. As one example, analysis of a meetings proved invaluable in devel- have significantly disturbed the global
particular region might reveal that food oping the conceptual approach and water, carbon, and nitrogen cycles on
production is high but, because of irri- guiding the research program toward which all life depends. Agriculture, in-
gation and heavy fertilizer application, the most promising indicators given dustry, and the spread of human settle-
the ability of the system to provide clean time, budget, and data constraints. ments have permanently converted ex-
water has been diminished. Drafts of PAGE reports were sent to over tensive areas of natural habitat and con-
Given data inadequacies, this sys- 70 experts worldwide, presented and tributed to ecosystem degradation
tematic approach was not always fea- critiqued at a technical meeting of the through fragmentation, pollution, and
sible. For each of the five ecosystems, Convention on Biological Diversity in increased incidence of pest attacks,
PAGE researchers, therefore, focus on Montreal (June, 1999) and discussed fires, and invasion by non-native spe-
documenting the extent and distribution at a Millennium Assessment planning cies.
of ecosystems and changes over time. meeting in Kuala Lumpur, Malaysia The following paragraphs look
We develop indicators of ecosystem con- (September, 1999). Draft PAGE mate- across ecosystems to summarize trends
dition — indicators that inform us about rials and indicators were also presented in production of the most important
Introduction / 2 P I L O T A N A LY S I S O F G L O B A L E C O S Y S T E M SI n t r o d u c t i o n t o t h e P A G E
goods and services and the outlook for ecosystems. Water engineering has pro- and mortality in the developing world.
ecosystem productivity in the future. foundly improved living standards, by Pollution and the introduction of non-
providing fresh drinking water, water for native species to freshwater ecosystems
Food Production irrigation, energy, transport, and flood have contributed to serious declines in
Food production has more than kept control. In the twentieth century, water freshwater biodiversity.
pace with global population growth. On withdrawals have risen at more than
average, food supplies are 24 percent double the rate of population increase Carbon Storage
higher per person than in 1961 and real and surface and groundwater sources in The world’s plants and soil organisms
prices are 40 percent lower. Production many parts of Asia, North Africa, and absorb carbon dioxide (CO2) during pho-
is likely to continue to rise as demand North America are being depleted. tosynthesis and store it in their tissues,
increases in the short to medium term. About 70 percent of water is used in ir- which helps to slow the accumulation
Long-term productivity, however, is rigation systems where efficiency is of- of CO2 in the atmosphere and mitigate
threatened by increasing water scarcity ten so low that, on average, less than half climate change. Land use change that
and soil degradation, which is now se- the water withdrawn reaches crops. On has increased production of food and
vere enough to reduce yields on about almost every continent, river modifica- other commodities has reduced the net
16 percent of agricultural land, espe- tion has affected the flow of rivers to the capacity of ecosystems to sequester and
cially cropland in Africa and Central point where some no longer reach the store carbon. Carbon-rich grasslands
America and pastures in Africa. Irri- ocean during the dry season. Freshwa- and forests in the temperate zone have
gated agriculture, an important compo- ter wetlands, which store water, reduce been extensively converted to cropland
nent in the productivity gains of the flooding, and provide specialized and pasture, which store less carbon per
Green Revolution, has contributed to biodiversity habitat, have been reduced unit area of land. Deforestation is itself
waterlogging and salinization, as well as by as much as 50 percent worldwide. a significant source of carbon emissions,
to the depletion and chemical contami- Currently almost 40 percent of the because carbon stored in plant tissue is
nation of surface and groundwater sup- world’s population experience serious released by burning and accelerated
plies. Widespread use of pesticides on water shortages. Water scarcity is ex- decomposition. Forests currently store
crops has lead to the emergence of many pected to grow dramatically in some re- about 40 percent of all the carbon held
pesticide-resistant pests and pathogens, gions as competition for water grows be- in terrestrial ecosystems. Forests in the
and intensive livestock production has tween agricultural, urban, and commer- northern hemisphere are slowly increas-
created problems of manure disposal cial sectors. ing their storage capacity as they regrow
and water pollution. Food production after historic clearance. This gain, how-
from marine fisheries has risen sixfold Water Quality ever, is more than offset by deforesta-
since 1950 but the rate of increase has Surface water quality has improved with tion in the tropics. Land use change
slowed dramatically as fisheries have respect to some pollutants in developed accounts for about 20 percent of anthro-
been overexploited. More than 70 per- countries but water quality in develop- pogenic carbon emissions to the atmo-
cent of the world’s fishery resources for ing countries, especially near urban and sphere. Globally, forests today are a net
which there is information are now fully industrial areas, has worsened. Water is source of carbon.
fished or overfished (yields are static or degraded directly by chemical or nutri-
declining). Coastal fisheries are under ent pollution, and indirectly when land Biodiversity
threat from pollution, development, and use change increases soil erosion or re- Biodiversity provides many direct ben-
degradation of coral reef and mangrove duces the capacity of ecosystems to fil- efits to humans: genetic material for crop
habitats. Future increases in production ter water. Nutrient runoff from agricul- and livestock breeding, chemicals for
are expected to come largely from ture is a serious problem around the medicines, and raw materials for indus-
aquaculture. world, resulting in eutrophication and try. Diversity of living organisms and the
human health hazards in coastal regions, abundance of populations of many spe-
Water Quantity especially in the Mediterranean, Black cies are also critical to maintaining bio-
Dams, diversions, and other engineer- Sea, and northwestern Gulf of Mexico. logical services, such as pollination and
ing works have transformed the quan- Water-borne diseases caused by fecal nutrient cycling. Less tangibly, but no
tity and location of freshwater available contamination of water by untreated less importantly, diversity in nature is
for human use and sustaining aquatic sewage are a major source of morbidity regarded by most people as valuable in
Grassland Ecosystems Introduction / 3I n t r o d u c t i o n t o t h e P A G E
its own right, a source of aesthetic plea- of indicators that quantify the degree of Ecosystem Condition and Capacity
sure, spiritual solace, beauty, and won- human modification but more informa- to Provide Goods and Services
der. Alarming losses in global tion is needed to document adequately In contrast to information on spatial
biodiversity have occurred over the past the nature and rate of human modifica- extent, data that can be used to analyze
century. Most are the result of habitat tions to ecosystems. Relevant data at the ecosystem condition are often unavail-
destruction. Forests, grasslands, wet- global level are incomplete and some able or incomplete. Indicator develop-
lands, and mangroves have been exten- existing datasets are out of date. ment is also beset by methodological
sively converted to other uses; only tun- Perhaps the most urgent need is for difficulties. Traditional indicators, for
dra, the Poles, and deep-sea ecosystems better information on the spatial distri- example, those relating to pressures on
have experienced relatively little bution of ecosystems and land uses. Re- environments, environmental status, or
change. Biodiversity has suffered as mote sensing has greatly enhanced our societal responses (pressure-state-
agricultural land, which supports far less knowledge of the global extent of veg- response model indicators) provide only
biodiversity than natural forest, has ex- etation types. Satellite data can provide a partial view and reveal little about the
panded primarily at the expense of for- invaluable information on the spatial underlying capacity of the ecosystem to
est areas. Biodiversity is also diminished pattern and extent of ecosystems, on deliver desired goods and services.
by intensification, which reduces the their physical structure and attributes, Equally, indicators of human modifica-
area allotted to hedgerows, copses, or and on rates of change in the landscape. tion tell us about changes in land use or
wildlife corridors and displaces tradi- However, while gross spatial changes in biological parameters, but do not nec-
tional varieties of seeds with modern vegetation extent can be monitored us- essarily inform us about potentially posi-
high-yield, but genetically uniform, ing coarse-resolution satellite data, tive or negative outcomes.
crops. Pollution, overexploitation, and quantifying land cover change at the Ecosystem conditions tend to be
competition from invasive species rep- national or subnational level requires highly site-specific. Information on rates
resent further threats to biodiversity. high-resolution data with a resolution of of soil erosion or species diversity in one
Freshwater ecosystems appear to be the tens of meters rather than kilometers. area may have little relevance to an ap-
most severely degraded overall, with an Much of the information that would parently similar system a few miles away.
estimated 20 percent of freshwater fish allow these needs to be met, at both the It is expensive and challenging to moni-
species becoming extinct, threatened, or national and global levels, already ex- tor and synthesize site-specific data and
endangered in recent decades. ists, but is not yet in the public domain. present it in a form suitable for national
New remote sensing techniques and im- policy and resource management deci-
Information Status proved capabilities to manage complex sions. Finally, even where data are avail-
and Needs global datasets mean that a complete able, scientific understanding of how
satellite-based global picture of the changes in biological systems will affect
Ecosystem Extent and Land Use earth could now be made available, al- goods and services is limited. For ex-
Characterization though at significant cost. This informa- ample, experimental evidence shows
Available data proved adequate to map tion would need to be supplemented by that loss of biological diversity tends to
approximate ecosystem extent for most extensive ground-truthing, involving ad- reduce the resilience of a system to per-
regions and to estimate historic change ditional costs. If sufficient resources turbations, such as storms, pest out-
in grassland and forest area by compar- were committed, fundamentally impor- breaks, or climate change. But scien-
ing current with potential vegetation tant information on ecosystem extent, tists are not yet able to quantify how
cover. PAGE was able to report only on land cover, and land use patterns around much resilience is lost as a result of the
recent changes in ecosystem extent at the world could be provided at the level loss of biodiversity in a particular site
the global level for forests and agricul- of detail needed for national planning. or how that loss of resilience might af-
tural land. Such information would also prove in- fect the long-term production of goods
PAGE provides an overview of hu- valuable to international environmental and services.
man modifications to ecosystems conventions, such as those dealing with Overall, the availability and quality
through conversion, cultivation, wetlands, biological diversity, desertifi- of information tend to match the recog-
firesetting, fragmentation by roads and cation, and climate change, as well as nition accorded to various goods and ser-
dams, and trawling of continental the international agriculture, forest, and vices by markets. Generally good data
shelves. The study develops a number fishery research community. are available for traded goods, such as
Introduction / 4 P I L O T A N A LY S I S O F G L O B A L E C O S Y S T E M SI n t r o d u c t i o n t o t h e P A G E
grains, fish, meat, and timber products fundamental importance in maintaining tems provide. We conclude that we lack
and some of the more basic relevant pro- living systems. much of the baseline information nec-
ductivity factors, such as fertilizer ap- Although the economic value of ge- essary to determine ecosystem condi-
plication rates, water inputs, and yields. netic diversity is growing, information tions at a global, regional or, in many
Data on products that are exchanged in on biodiversity is uniformly poor. instances, even a local scale. We also
informal markets, or consumed directly, Baseline and trend data are largely lack- lack systematic approaches necessary to
are patchy and often modeled. Examples ing; only an estimated 15 to 20 percent integrate analyses undertaken at differ-
include fish landings from artisanal fish- of the world’s species have been identi- ent locations and spatial scales.
eries, woodfuels, subsistence food crops fied. The OECD Megascience Forum Finally, it should be noted that PAGE
and livestock, and nonwood forest prod- has launched a new international pro- looks at past trends and current status,
ucts. Information on the biological fac- gram to accelerate the identification and but does not try to project future situa-
tors that support production of these cataloging of species around the world. tions where, for example, technological
goods — including size of fish spawn- This information will need to be supple- development might increase dramati-
ing stocks, biomass densities, subsis- mented with improved data on species cally the capacity of ecosystems to de-
tence food yields, and forest food har- population trends and the numbers and liver the goods and services we need.
vests — are generally absent. abundance of invasive species. Devel- Such considerations were beyond the
The future capacity (long-term pro- oping databases on population trends scope of the study. However, technolo-
ductivity) of ecosystems is influenced by (and threat status) is likely to be a ma- gies tend to be developed and applied
biological processes, such as soil forma- jor challenge, because most countries in response to market-related opportu-
tion, nutrient cycling, pollination, and still need to establish basic monitoring nities. A significant challenge is to find
water purification and cycling. Few of programs. those technologies, such as integrated
these environmental services have, as The PAGE divides the world’s eco- pest management and zero tillage culti-
yet, been accorded economic value that systems to examine them at a global vation practices in the case of agricul-
is recognized in any functioning market. scale and think in broad terms about the ture, that can simultaneously offer mar-
There is a corresponding lack of sup- challenges of managing them ket-related as well as environmental
port for data collection and monitoring. sustainably. In reality, ecosystems are benefits. It has to be recognized, none-
This is changing in the case of carbon linked by countless flows of material and theless, that this type of “win-win” so-
storage and cycling. Interest in the pos- human actions. The PAGE analysis does lution may not always be possible. In
sibilities of carbon trading mechanisms not make a distinction between natural such cases, we need to understand the
has stimulated research and generated and managed ecosystems; human inter- nature of the trade-offs we must make
much improved data on carbon stores vention affects all ecosystems to some when choosing among different combi-
in terrestrial ecosystems and the dimen- degree. Our aim is to take a first step nations of goods and services. At present
sions of the global carbon cycle. Few toward understanding the collective im- our knowledge is often insufficient to tell
comparable datasets exist for elements pacts of those interventions on the full us where and when those trade-offs are
such as nitrogen or sulfur, despite their range of goods and services that ecosys- occurring and how we might minimize
their effects.
Grassland Ecosystems Introduction / 5E x e c u t i v e S u m m a r y
G R A S S L A N D S:
E X E C U T I V E S U M M A RY
Scope of Analysis in this report address the condition of the following goods and
services provided by grasslands:
This study, or Pilot Analysis of Global Ecosystems (PAGE), ex-
amines grassland ecosystems of the world using a large collec- ♦ Food, forage, and livestock;
tion of spatial and temporal data. We analyze datasets primarily ♦ Biodiversity;
at the global level, presenting quantitative indicators and quali- ♦ Carbon storage; and
tative information on the condition of the world’s grasslands. ♦ Tourism and recreation.
Grassland condition is defined in terms of the current and fu- Each good or service is discussed in terms of its current sta-
ture capacity of these ecosystems to provide goods and services tus, trends over time, and modifications that have changed its
important to humans. condition. The good or service also is discussed in terms of the
type of data required to expand our knowledge about the
G R A S S L A N D E X T E N T, C H A N G E , A N D H U M A N ecosystem’s ability to provide the service. When quantitative
M O D I F I C AT I O N indicators are available, we explore the potential to use them to
PAGE analysts define grasslands as terrestrial ecosystems domi- evaluate the condition of grasslands. In other cases we present
nated by herbaceous and shrub vegetation and maintained by qualitative measures of condition, sometimes based entirely on
fire, grazing, drought and/or freezing temperatures. This defini- expert opinion.
tion includes vegetation covers with an abundance of non-woody This study attempts to locate and draw together global, spa-
plants and thus lumps together some savannas, woodlands, tially represented databases on grassland ecosystems. It is not
shrublands, and tundra, as well as more conventional grass- an exhaustive review of literature available on grassland types.
lands. Our comprehensive view of grasslands allows us to make Nor is it complete in its search for spatial datasets related to
use of a variety of global datasets and to avoid somewhat arbi- grassland ecosystems. Some important goods and services pro-
trary distinctions among different land cover types. We exam- vided by grasslands also have not been covered. For example,
ine the spatial extent of grasslands and modifications that have woodfuel, often collected from shrublands or savannas, is not dis-
altered their extent, structure, and composition over time. Modi- cussed in this report (but see the PAGE analysis on forest ecosys-
fications include human-induced changes such as cultivation, tems), nor are the important services that grasslands provide in
urbanization, desertification, fire, livestock grazing, fragmen- terms of water and nutrient cycling. Rather, we present an exami-
tation, and introduction of invasive species. nation of many of the global datasets most readily accessible, and
of quantitative and qualitative indicators that can be used as start-
GRASSLAND GOODS AND SERVICES ing points for a more comprehensive, international effort to evalu-
This analysis focuses on a selected set of grassland goods and ate the condition of grassland ecosystems worldwide.
services. Our choice was determined partly in consultation with
grassland experts worldwide and partly by availability of data.
Our goal was to use global datasets, preferably in electronic Key Findings and Information Issues
form, available spatially and with time-series. Where global The following tables (pp. 2-5) summarize key findings of the
data were not available, we used regional, national, and some- study regarding grassland condition and trends and the quality
times sub-national studies. The data and indicators presented and availability of data.
Grassland Ecosystems 1You can also read
