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Ecosystem Services: A Primer

Ecological Society of America


Natural ecosystems produce services upon which we are dependent. For example, they:

  • provide us with clean water and air
  • pollinate our crops and disperse seeds
  • protect us from extreme weather and ultraviolet light
  • control pests and disease-carrying organisms

August 2000


Natural ecosystems perform fundamental life-support services. The Elora Gorge, Ontario, Canada. Photo: Oksana Hlodan.

From the Ecological Society of America (ESA)

Human civilization depends on healthy ecosystems.

Have you ever considered that the cereal you eat is brought to you each morning by the wind, or that the glass of clear, cold, clean water drawn from your faucet may have been purified for you by a wetland or perhaps the root system of an entire forest? Trees in your front yard work to trap dust, dirt, and harmful gases from the air you breathe. The bright fire of oak logs you light to keep warm on cold nights and the medicine you take to ease the pain of an ailment come to you from Nature’s warehouse of services. Natural ecosystems perform fundamental life-support services upon which human civilization depends. Unless human activities are carefully planned and managed, valuable ecosystems will continue to be impaired or destroyed.

What are ecosystem services?

Ecosystem Services: processes by which the environment produces resources.

Ecosystem Services are the processes by which the environment produces resources that we often take for granted such as clean water, timber, and habitat for fisheries, and pollination of native and agricultural plants. Whether we find ourselves in the city or a rural area, the ecosystems in which humans live provide goods and services that are very familiar to us.

Ecosystems provide “services” that:

These services are extensive and diverse … affecting the quality of our land, water, food, and health.
  • moderate weather extremes and their impacts
  • disperse seeds
  • mitigate drought and floods
  • protect people from the sun’s harmful ultraviolet rays
  • cycle and move nutrients
  • protect stream and river channels and coastal shores from erosion
  • detoxify and decompose wastes
  • control agricultural pests
  • maintain biodiversity
  • generate and preserve soils and renew their fertility
  • contribute to climate stability
  • purify the air and water
  • regulate disease carrying organisms
  • pollinate crops and natural vegetation

What is an ecosystem?

Ecosystems are nature’s support systems for life.

An ecosystem is a community of animals and plants interacting with one another and with their physical environment. Ecosystems include physical and chemical components, such as soils, water, and nutrients that support the organisms living within them. These organisms may range from large animals and plants to microscopic bacteria. Ecosystems include the interactions among all organisms in a given habitat. People are part of ecosystems. The health and wellbeing of human populations depends upon the services provided by ecosystems and their components — organisms, soil, water, and nutrients.

What are ecosystem services worth?

Nature’s services have financial value.

Natural ecosystems and the plants and animals within them provide humans with services that would be very difficult to duplicate. While it is often impossible to place an accurate monetary amount on ecosystem services, we can calculate some of the financial values. Many of these services are performed seemingly for “free,” yet are worth many trillions of dollars, for example:

About 78% of the top medicines used in the U.S. come from nature.
  • Much of the Mississippi River Valley’s natural flood protection services were destroyed when adjacent wetlands were drained and channels altered. As a result, the 1993 floods resulted in property damages estimated at twelve billion dollars partially from the inability of the Valley to lessen the impacts of the high volumes of water.

  • 80% of the world’s population relies upon natural medicinal products. Of the top 150 prescription drugs used in the U.S., 118 originate from natural sources: 74% from plants, 18% from fungi, 5% from bacteria, and 3% from one vertebrate (snake species). Nine of the top 10 drugs originate from natural plant products.

  • Over 100,000 different animal species — including bats, bees, flies, moths, beetles, birds, and butterflies — provide free pollination services. One third of human food comes from plants pollinated by wild pollinators. The value of pollination services from wild pollinators in the U.S. alone is estimated at four to six billion dollars per year.

It would cost New York City billions to duplicate nature’s water filtration system.

New York City is a case in point. Before it became overwhelmed by agricultural and sewage runoff, the watershed of the Catskill Mountains provided New York City with water ranked among the best in the Nation by Consumer Reports. When the water fell below quality standards, the City investigated what it would cost to install an artificial filtration plant. The estimated price tag for this new facility was six to eight billion dollars, plus annual operating costs of 300 million dollars — a high price to pay for what once was free. New York City decided instead to invest a fraction of that cost ($660 million) in restoring the natural capital it had in the Catskills watershed. In 1997, the City raised an Environmental Bond Issue and is currently using the funds to purchase land and halt development in the watershed, to compensate property owners for development restrictions on their land, and to subsidize the improvement of septic systems.

How are ecosystem services “cut off”?

Overpopulation and overconsumption threaten ecosystems.

Ecosystem services are so fundamental to life that they are easy to take for granted and so large in scale that it is hard to imagine that human activities could destroy them. Nevertheless, ecosystem services are severely threatened through

  1. growth in the scale of human enterprise (population size, per-capita consumption, and effects of technologies to produce goods for consumption)
  2. a mismatch between short-term needs and long-term societal well-being

Many human activities disrupt, impair, or reengineer ecosystems every day including:

  • runoff of pesticides, fertilizers, and animal wastes
  • pollution of land, water, and air resources
  • introduction of non-native species
  • overharvesting of fisheries
  • destruction of wetlands
  • erosion of soils
  • deforestation
  • urban sprawl

Ecology and ecosystem services

Many questions remain unanswered about the workings of ecosystem services.

Ecologists work to help us understand the interconnection and interdependence of the many plant and animal communities within ecosystems. Although substantial understanding of many ecosystem services and the scientific principles underlying them already exists, there is still much to learn. The tradeoffs among different services within an ecosystem, the role of biodiversity in maintaining services, and the effects of long and short-term perturbations are just some of the questions that need to be further explored. The answers to such questions will provide information critical to the development of management strategies that will protect ecosystems and help maintain the provisions of the services upon which we depend.

Conclusion: The future depends on wise eco choices today.


The choices we make today in how we use land and water resources will have enormous consequences on the future sustainability of earth’s ecosystems and the services they provide.

The Ecological Society of America (ESA) is a non-partisan, nonprofit organization of scientists founded in 1915 to promote ecological science, raise the public’s level of awareness of ecological science, increase resources available for ecology study, and ensure the appropriate use of ecological science in environmental decision making.

Ecosystem Services: A Primer

More articles on the value of ecosystems

The article you have just read on ecosystem services is a good primer for the following articles on our site:

BioScience Article

“Ecology in Times of Scarcity.”
In an energy-scarce future, ecosystem services will become more important in supporting the human economy, according to John W. Day Jr. et al. (BioScience, April 2009). Moreover, they state that the primary role of ecology will be the sustainable management of ecosystems. Energy scarcity will affect ecology in a number of ways. Ecology will become more expensive, which will be justified by its help in solving societal problems, especially in maintaining ecosystem services. Read the abstract, or log in to purchase the full article.

Valuing ecosystem services

The World Resources Institute looks at the economic valuation of ecosystems.

“Putting the Right Price on Nature”

Transcript of a Radio National interview (8/9/01) with Thomas Lovejoy and Gretchen Daily about the value of ecosystem services.

“The New Economy of Nature”

Summary of a book that examines the economic value of nature.

Millennium Ecosystem Assessment

Designed by a partnership of UN agencies, international scientific organizations, and development agencies, this ongoing study assesses the capacity of ecosystems worldwide to provide goods and services that are important for human development.

Ecology quiz

Test your ecology IQ.

Scorecard: your community’s pollution

“Enter your [U.S.] zip code and find out what pollutants are being released into your community — and who is responsible.” Part of the Environmental Defense Network, the second link below.

Read a book

Biosphere reserves — Special places for people and nature (UNESCO Publishing, 2003): Anyone involved or interested in conservation will find useful, well-illustrated information on issues such as biodiversity, natural resources, and sustainable development. The book includes a history of the concept’s development, from the first preserve to the current network of 394 reserves in 94 countries. View the book’s table of contents and ordering information at

Communicating with the media about ecosystems

The Ecological Society of America offers tips to the public and organizations involved in ecosystem conservation on how to get a message in the media. Includes resources to help organize and write a media story.

Ask a scientist about nature

Choose from several categories to ask scientists questions about animals, habitats, and conservation.

The National Biological Information Infrastructure

The National Biological Information Infrastructure (NBII) is a broad, collaborative program to provide increased access to data and information on the nation’s biological resources. It includes a whole page dedicated to Ecological Topics. It also has a “Toolkit” with important links.

Emergency help for wildlife

Wildlife International offers suggestions for wild animal rehabilitation. On the home page, individuals can find a nearby wildlife rehabilitator to contact about a wild animal in need. Also, wildlife rehabilitators can learn about “everything from administration to wildlife care.”

Best Practices for Environmental Education: Guidelines for Success

This is “a guide written for the providers of environmental education (EE) — the people in the classrooms, nature centers, parks, zoos, museums, agencies, businesses, & organizations. It is designed to help EE providers develop and implement the highest quality EE programs.”

For educators: ecology education resources

  • » The Teaching Issues and Experiments in Ecology (TIEE) website, a project of the Ecological Society of America, offers peer-reviewed ecological education classroom activity ideas and labs that educators can adapt and use freely.
  • » The Ecological Society of America’s EcoEd Digital Library (EcoEdDL) offers a collection of ecology education resources including photos, videos, figures, labs and classroom activity (also without restrictions for educational use).

Information for Action

“This website explains the environmental problems & offers solutions to fix them. There are many valuable resources available” including lobbying info, contacts database, & news updates. original lesson

This lesson has been written by a science educator to specifically accompany the above article. It includes article content and extension questions, as well as activity handouts for different grade levels.

Lesson Title: How Much Is an Ecosystem Worth?
Levels: upper middle school - undergraduate
Summary: This lesson engages students in critical thinking about the value of ecosystems. Students assess ecosystem services, consider the benefits of biomonitors, explore ecosystem databases, brainstorm “What if?” scenarios…and more!

Download/view lesson.
(To open the lesson’s PDF file, you need Adobe Acrobat Reader free software.)

Useful links for educators

Useful links for student research

In addition to the links in the “learn more” section above:

  • » This site provides searchable online field guides to over 5,500 species of plant and animal life. This is a very student-friendly site for research.
  • » Earth Force website This site provides a framework for students of all ages to discover and implement solutions to environmental problems in their communities. Free resources, newsletters, and links are available from this site.
  • » Ecological Risk Assessment glossary
  • » The Ecosystem Services Database The Ecoinformatics Collaboratory at the University of Vermont runs this database that spans fields from biodiversity conservation to the economic valuation of ecosystem services.

General References:

  • » Ecological Society of America. 1997. “Ecosystem Services: Benefits Supplied to Human Societies by Natural Ecosystems.” Issues in Ecology No. 2, Spring 1997. (URL updated 12/03)
  • » Gretchen C. Daily, ed. 1997. Nature’s Services, Societal Dependence on Natural Ecosystems. Island Press.
  • » President’s Committee of Advisors on Science and Technology. March 5, 1998. “Teaming with Life: Investing in Science to Understand and Use America’s Living Capital.” (no longer accessible online as of 11/03)
  • » R. Costanza et al. 1997. “The Value of the World’s Ecosystem Services and Natural Capital.” NatureVol. 387.


Understanding Science