Ecosystem services are the many ways that people benefit from nature. The living and non-living parts of the environment provide important services, such as helping plants grow by pollinating them, keeping air and water clean, breaking down waste, and controlling floods. These services are essential for people’s health and happiness. They give direct benefits, like food and clean water, and indirect benefits, such as helping to regulate the climate.

Ecosystem services are divided into groups, a system first widely used in the early 2000s by the Millennium Ecosystem Assessment (MA), a project started by the United Nations. How these groups are described depends on the classification system used. The MA divides services into four main categories. These include:
1. Provisioning services, such as providing food and water.
2. Regulating services, such as controlling the climate and preventing diseases.
3. Supporting services, such as recycling nutrients and producing oxygen.
4. Cultural services, such as offering opportunities for recreation, tourism, and spiritual fulfillment.

For example, estuarine and coastal ecosystems, which are types of marine environments, provide all four categories of ecosystem services. Their provisioning services include resources like fish and genetic material. Their supporting services include recycling nutrients and producing food through plants. Their regulating services include storing carbon (which helps reduce climate change) and controlling floods. Their cultural services include activities like tourism and recreation. Scientists sometimes calculate the economic value of these services to better understand their importance.

Definition

Ecosystem services, also called eco-services, are the goods and services that ecosystems provide to humans. According to the 2006 Millennium Ecosystem Assessment (MA), ecosystem services are "the benefits people obtain from ecosystems."

Gretchen Daily's original definition separated ecosystem goods from ecosystem services. However, later work by Robert Costanza and his team, as well as the MA, combined all of these into one category called ecosystem services.

Categories

Ecosystem services are grouped differently based on the classification system used. The Millennium Ecosystem Assessment (MA) divides these services into four categories: regulating services, provisioning services, cultural services, and supporting services. Supporting services are considered the foundation for the other three types.

An ecosystem may not provide all four types of services at the same time. However, because ecosystems are complex, it is common for humans to benefit from a mix of these services. Different ecosystems, such as forests, seas, coral reefs, and mangroves, offer services that vary in type and impact. Some services directly affect human livelihoods, such as providing fresh water, food, or aesthetic value. Other services influence the environment indirectly, such as managing climate change, controlling erosion, or reducing natural hazards.

By 2010, many definitions of ecosystem services had been developed. To avoid counting services twice in studies, The Economics of Ecosystems and Biodiversity (TEEB) replaced "Supporting Services" from the MA with "Habitat Services" and introduced the term "ecosystem functions," which describe interactions within an ecosystem that enable it to provide goods and services. The Common International Classification for Ecosystem Services later grouped "Regulatory" and "Habitat" services into a single category called "Regulation and maintenance services."

Provisioning services include all products obtained from ecosystems. These are also called ecosystem goods and include:
– Food (such as seafood, crops, wild foods, and spices)
– Raw materials (like lumber, fuelwood, and fertilizer)
– Genetic resources (such as genes for crop improvement and healthcare)
– Biogenic minerals
– Medicinal resources (including pharmaceuticals and test organisms)
– Energy (like hydropower and biomass fuels)
– Ornamental resources (such as fashion items, jewelry, and souvenirs)

Forests and their management produce a wide variety of timber products, such as roundwood, sawnwood, panels, and engineered wood like cross-laminated timber. They also provide less processed products like firewood and charcoal. In 2018, global production and trade of major wood-based products reached their highest levels since 1947. Growth in production ranged from 1% (wood-based panels) to 5% (industrial roundwood), with the fastest increases in the Asia-Pacific, North America, and Europe. Over 40% of the European Union’s land is covered by forests, and about 60% of the yearly forest growth is harvested.

Forests also provide non-wood products, such as fodder, medicinal plants, and wild foods. Around 1 billion people worldwide rely on wild foods like meat, insects, mushrooms, and fish, which are rich in nutrients. In the European Union, over 100 million people regularly consume wild food. More than 2.4 billion people use wood-based energy for cooking.

Regulating services are the benefits gained from the regulation of ecosystem processes. These include:
– Purifying water and air
– Storing carbon (which helps reduce climate change)
– Breaking down waste and removing toxins
– Controlling predator and prey populations
– Managing pests and diseases
– Pollinating plants
– Reducing the impact of natural disasters like floods

An example of water purification is New York City’s restoration of the Catskill Watershed. After reducing pollution from sewage and pesticides, water quality improved naturally. This cost $1–1.5 billion, which was much less than the $6–8 billion cost of building a water filtration plant and the $300 million annual operating costs.

Pollination by bees is essential for 15–30% of U.S. food production. Many farmers use non-native honey bees for this. A 2005 study found that wild bees in California could pollinate crops or improve honey bee efficiency. However, intensive farming can harm pollination by reducing species diversity. Preserving habitats like chaparral and oak woodlands near farms helps maintain pollination services.

Increasing native flowering plants near farms or in urban areas can also support pollination by providing food for wild bees.

Coastal and estuarine ecosystems protect against natural hazards like floods, cyclones, and storms. Wetlands and their vegetation absorb and slowly release water, reducing flood risks. Mangrove forests shield coastlines from erosion, as seen after a 1999 cyclone in India. Villages with mangroves suffered less damage than those without.

Supporting services are those that enable other ecosystem services to exist. They have long-term, indirect effects on humans. Examples include nutrient cycling, primary production, soil formation, and habitat provision. These services allow ecosystems to continue providing goods and services. Some services can be classified as both supporting and regulating, cultural, or provisioning services.

Estuarine and coastal ecosystem services

Estuarine and marine coastal ecosystems are types of marine ecosystems. These ecosystems provide four types of services in different ways: Provisioning services include items such as forest products, marine life, fresh water, raw materials, biochemical resources, and genetic resources. Regulating services include absorbing carbon dioxide from the air (which helps reduce climate change), treating waste, controlling diseases, and creating natural barriers. Supporting services include processes like recycling nutrients, creating habitats for living things, and producing energy through plants. Cultural services include activities like inspiring people, offering places for recreation and tourism, and supporting science and education.

Coasts and the areas near them, both on land and in the ocean, are important parts of local ecosystems. Estuaries, where fresh water and salt water mix to form brackish water, provide many nutrients that support marine life. Salt marshes, mangroves, and beaches also support a wide variety of plants, animals, and insects that are important for the food chain. The high number of different species leads to a lot of biological activity, which has drawn human activity for thousands of years. Coasts also provide essential living spaces for many organisms, such as estuaries, wetlands, seagrass beds, coral reefs, and mangroves. These areas are homes for migratory birds, sea turtles, marine mammals, and coral reefs.

Economics

There are questions about the environmental and economic importance of ecosystem services. Some people may not fully understand the environment or how humans are connected to it, which can lead to misunderstandings. While awareness of the environment is growing, many people still do not understand how ecosystem services work or how they are affected by human actions. Problems continue to harm ecosystems, and the "tragedy of the commons" remains a challenge. Efforts to help decision-makers compare the costs and benefits of choices now include organizing scientific information into economic terms. This helps explain the effects of decisions in ways that relate to human well-being. One challenge is that information about ecosystems collected in one place or time may not apply to another. Understanding how ecosystems function is important for making economic decisions. Factors like whether a service is hard to replace or part of a group of services can help assign economic value more effectively.

Valuing ecosystem services also involves sharing information with people, which is difficult but studied by many researchers. In general, people make choices for different reasons, but patterns in their choices can show what a society values overall. This helps estimate the economic value of services. Six main methods are used to assign monetary value to ecosystem services:

• Avoided cost: Services help society save money that would have been spent without them (e.g., wetlands reduce health costs by treating waste).
• Replacement cost: Services can be replaced by human-made systems (e.g., restoring the Catskill Watershed cost less than building a water purification plant).
• Factor income: Services improve income (e.g., better water quality increases fishery profits and fishers' earnings).
• Travel cost: The cost of traveling to use a service can show its value (e.g., ecotourism visitors pay to experience nature).
• Hedonic pricing: Prices people pay for goods linked to a service can reflect its value (e.g., homes near coasts cost more than inland homes).
• Contingent valuation: People are asked how much they would pay for a service in hypothetical situations (e.g., visitors might pay to visit national parks more often).

A study published in 1997 estimated the value of global ecosystem services and natural capital to be between $16 and $54 trillion each year, with an average of $33 trillion. However, another expert in 2011 said, "The total value of biodiversity is infinite, so trying to assign a total value to nature is pointless because we cannot live without it."

By 2012, many companies did not fully understand how much they relied on ecosystems or the effects of their actions. Tools for managing the environment often focus on pollution and resource use, not on how businesses depend on ecosystems. Some tools help companies assess ecosystem services, such as Our Ecosystem, the 2008 Corporate Ecosystem Services Review, the 2007 Artificial Intelligence for Environment & Sustainability (ARIES) project, the 2012 Natural Value Initiative, and the 2012 InVEST program.

An example of a cost comparison: The land owned by the United States Department of Defense provides ecosystem services like carbon storage, climate resilience, and habitat for endangered species. In 2020, the Eglin Air Force Base was estimated to provide about $110 million in ecosystem services each year, which is $40 million more than if the base had not existed.

Payments for ecosystem services (PES), also called payments for environmental services, are rewards given to farmers or landowners for managing their land in ways that benefit the environment. These programs are described as "a clear system for encouraging environmental services through payments to people who choose to help protect nature." They support the conservation of natural resources in the marketplace.

Management and policy

Although money-based pricing is still used to value ecosystem services, challenges in creating and managing policies are large and difficult. Managing shared natural resources has been studied a lot by experts. From identifying problems to finding practical and lasting solutions, many obstacles remain. Choosing options must balance needs now and in the future, and leaders often work with information that is not complete. Current laws are often seen as not enough because they focus on human health standards that do not match the needs to protect ecosystems and their services. In 2000, an idea called the Ecosystem Services Framework (ESF) was suggested to improve information. This framework combines the physical and social aspects of protecting the environment and helps institutions use information from different fields to guide decisions.

By 2005, local and regional efforts to manage services like pollination or resources like water were considered useful. Another idea that became popular in the 1990s is selling ecosystem services. Paying for or trading ecosystem services is a growing solution worldwide, where people can buy credits for actions like protecting carbon sources or restoring ecosystems. In some places, banks for these credits exist, and conservation companies have even sold shares on stock markets, showing a link between environmental work and economic opportunities. However, clear land ownership rules are essential for these efforts, but they are often missing in many developing countries. In particular, countries with forests that are being cut down often have conflicts among people who use or manage the forests. Global efforts also face problems, such as unequal pay for services or misuse of resources. In 2001, a new approach focused on protecting areas with high biodiversity. Recognizing that conserving ecosystem services matches traditional goals like saving species, experts suggested combining these goals. This could be helpful when using networks that allow services to move across areas and when finding money from different investors to protect services.

For example, by 2013, there was interest in valuing ecosystem services from shellfish like oysters. These shellfish are important species low in the food chain and support many other species by doing tasks that help the environment. Some shellfish also affect ecological processes so much that they are called "ecosystem engineers"—organisms that change their environment in ways that affect other life. The work shellfish do, like cleaning water and reducing harmful nutrients, helps humans by providing long-term benefits. As of 2018, the idea of ecosystem services had not yet been fully included in international or regional laws.

Despite this, the United Nations Sustainable Development Goal 15 includes a target to protect, restore, and use ecosystem services wisely. It is estimated that ecosystem services add about $125 trillion to $140 trillion to the global economy each year. However, many of these services are at risk because of climate change and other human activities. Scientists predict that climate change could reduce ecosystem services by about 9% globally by 2100.

Ecosystem-based adaptation (EbA) includes many ways to help people deal with climate change. These methods involve managing ecosystems and their services to reduce the harm climate change causes to human communities. The Convention on Biological Diversity (CBD) defines EbA as using biodiversity and ecosystem services as part of plans to help people adapt to climate change effects.

EbA includes protecting, managing, and restoring ecosystems like forests, grasslands, wetlands, mangroves, or coral reefs to reduce the harm from climate problems, such as changes in rainfall, temperature extremes, stronger storms, and unpredictable weather. EbA methods can be used alone or with other solutions, like building water reservoirs or artificial reefs, or by helping people and groups prepare for climate risks, such as using early warning systems.

Decisions about ecosystem services involve complex choices that connect ecology, technology, society, and the economy. These decisions must consider many types of information, respect all viewpoints from groups like regulators, planners, residents, and organizations, and measure effects on all parts of this connection. These decisions are often about places, always aim to balance many goals, and rely on uncertain data, models, and estimates. Usually, the best scientific information combined with the values and opinions of people involved guides the process.

One study used a model to show how people involved in water management in New Mexico made decisions, but it did not include uncertainty. Another study used a method called Monte Carlo to analyze how landowners make decisions about land use changes. This study treated people's opinions as random to show uncertainty. A third study used a system called Bayesian to model uncertainty in scientific information and help collect and combine people's input. This study focused on placing wave energy devices off the Oregon Coast but shows a general way to handle uncertain information in decisions. Remote sensing data can also help track the health and size of areas that provide ecosystem services, which supports planning, monitoring, and communication among people involved.

In the Baltic countries, scientists, conservationists, and local leaders are using a combined planning method for grassland ecosystems. They are creating a tool based on GIS (geographic information system) technology and putting it online to help planners choose the best way to manage grasslands. This tool looks at natural and social factors in an area to find the best management solutions for grasslands.

History

The idea that humans rely on Earth's ecosystems dates back to the beginning of human history. However, the term "natural capital" was first used by E. F. Schumacher in 1973 in his book Small is Beautiful. People have understood for a long time that ecosystems provide important services. For example, Plato, around 400 BC, recognized that cutting down trees could cause soil erosion and dry up water sources. In 1864, George Perkins Marsh argued that Earth's natural resources are not endless, using examples of changing soil fertility in the Mediterranean. It was not until the late 1940s that three authors—Henry Fairfield Osborn, Jr., William Vogt, and Aldo Leopold—helped people see the importance of depending on the environment.

In 1956, Paul Sears highlighted how ecosystems help process waste and recycle nutrients. In 1970, Paul Ehrlich and Rosa Weigert wrote about "ecological systems" in their textbook, warning that human actions could destroy the systems humans depend on for survival. A 1970 report titled Study of Critical Environmental Problems introduced the term "environmental services," listing examples like insect pollination, fishing, climate control, and flood prevention. Over time, variations of the term were used, but "ecosystem services" became the most common term in scientific writing.

In the 1990s, two important books were published: Nature's Service by Gretchen Daily, which influenced discussions about ecosystem services, and The Value of the World's Ecosystem Services and Natural Capital by Costanza et al., which was the first study to assign an economic value to ecosystem services. Today, the concept of ecosystem services includes goals related to society, the economy, and protecting nature.