Ecosystem services

What are ecosystem services?

Ecosystem services are the benefits people draw from ecosystems. Some of them can be held in the hand: grain, fruit, timber, fibre, fresh water. Others work in the background and are noticed only when they fail. Bees and other insects pollinate crops. Soil and plants take in the winter rain and release it slowly. Roots hold a slope in place. Trees shade the ground and cool the air through their leaves. Woods, meadows and coasts give people rest, beauty and a sense of belonging.

Most of these benefits are never paid for. A farmer pays for seed and diesel, but not for the earthworms that loosen the soil or for the wild bees in the orchard. That is the core of the idea: it makes visible what the economy takes for granted, so that it is not destroyed by accident.

Where the term comes from

The thought is old; the term is young. In 1977 the ecologist Walter Westman asked in the journal Science how much nature's services were worth. Paul and Anne Ehrlich are usually credited with the exact phrase ecosystem services, which they used in 1981. In 1997 two publications made the concept widely known: the book Nature's Services, edited by Gretchen Daily, and a first attempt by Robert Costanza and colleagues to put a global value on these services.

The breakthrough in policy came with the Millennium Ecosystem Assessment, a study called for in 2000 by the Secretary-General of the United Nations, Kofi Annan, and carried out by more than 1,360 experts from 2001 to 2005. Its synthesis report of 2005 found that about 60 percent of the ecosystem services it examined, 15 of 24, were being degraded or used unsustainably.

How ecosystem services are classified

Millennium Ecosystem Assessment (2005). The assessment sorted services into four groups. Provisioning services are the products of ecosystems: food, water, wood, fibre, medicinal plants. Regulating services keep conditions stable: pollination, the control of floods, erosion and pests, the purification of water, the local climate. Cultural services are non-material benefits such as recreation, beauty, spiritual value and knowledge. Supporting services, finally, make all the others possible: soil formation, nutrient cycling, the growth of plants.

CICES. The Common International Classification of Ecosystem Services grew out of work for the European Environment Agency, which today acts as its custodian. Version 5.1, written by Roy Haines-Young and Marion Potschin, appeared in 2018, and version 5.2 followed in 2025. CICES keeps three sections: provisioning, regulation and maintenance, and cultural services. It deliberately leaves out the supporting services and treats them as the structures and processes underlying the others. The reason is practical: anyone who wants to link nature to economic accounts must avoid counting soil formation once on its own and again in every harvest.

IPBES. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services speaks of nature's contributions to people. The concept, set out by Sandra Díaz and colleagues in 2018, covers the same ground but places more weight on culture and on the knowledge of indigenous peoples and local communities. It also admits that nature's effects can be harmful, for example through pests or diseases. IPBES distinguishes 18 categories in three overlapping groups: material, non-material and regulating contributions. Its global assessment of 2019 found that material contributions such as food and timber had increased since 1970, while 14 of the 18 categories, mostly regulating and non-material ones, had declined.

Examples from the land

Pollination. According to the IPBES assessment of 2016, more than three quarters of the world's food crops depend at least in part on pollination by insects and other animals, and so do nearly 90 percent of wild flowering plants. The page on bees and pollinators describes who does this work.

Holding water. Soil rich in humus and covered by plants takes in rain like a sponge and releases it slowly to roots, springs and streams. The same rain on bare, crusted ground runs off, carries soil away and is missing in summer. The pages on infiltration and the water cycle explain the mechanism.

Soil formation. Roots, fungi, earthworms and bacteria turn rock and dead plant matter into living soil. It is the slowest of all services and the hardest to replace, which is why its loss weighs so heavily.

Erosion control. Plant cover breaks the force of the rain, and roots tie the soil together. Where cover is lost, soil erosion follows, often in a single storm.

Cooling. Trees shade the ground and evaporate water through their leaves, which cools the air beneath their crowns. In a dry Mediterranean summer this difference can decide whether young plants survive.

Recreation and meaning. A shady path, a view over an old olive grove, a place where a family has worked for generations: cultural services are hard to measure, but people often defend them most fiercely.

Putting a price on nature

The best-known attempt at a price came from Robert Costanza and colleagues. In 1997 they estimated in Nature that the services of the world's ecosystems were worth an average of 33 trillion US dollars a year, in dollars of 1995. An update in 2014 arrived at 125 trillion dollars a year for 2011, in dollars of 2007, and estimated that changes in land use between 1997 and 2011 had cost between 4.3 and 20.2 trillion dollars a year in lost services. The authors themselves stress that such global figures show the scale of what is at stake but do not answer any concrete decision. The IPBES pollination assessment offers a more tangible figure: between 235 and 577 billion US dollars' worth of annual global food production relies directly on pollinators.

The approach has met strong criticism. In 2006 the ecologist Douglas McCauley argued in Nature that conservation based on market value stands on weak ground and that nature should be protected for its own sake. Erik Gómez-Baggethun and Manuel Ruiz-Pérez warned in 2011 that economic valuation can pave the way for turning nature into a commodity, with risks for conservation and for fair access to its benefits. Defenders reply that a value is information, not a price tag, and that it does not replace ethics. The debate is still open. What it shows is that the language of services is a tool for seeing, and that it becomes dangerous where it is taken for the whole truth about a landscape.

Ecosystem services, restoration and permaculture

Ecological restoration can be read as the repair of services that degradation has switched off. A slope that is covered again holds its rain, its soil begins to form again, flowers return and with them pollinators. Regreening in dry regions follows the same path. The order matters: water and soil first, because every other service depends on them.

Permaculture arrived at the same idea from the practical side. David Holmgren's fifth principle asks us to use and value renewable resources and services, letting living things do work that would otherwise cost fuel and money. The third principle, obtain a yield, counts shade, cooler air, fertile soil and beauty among the yields of a design. Both describe returns of the land that no market pays for. Economic models such as community supported agriculture, in which members fund a farm as a whole rather than buying single products, can make room for these returns.

How Terra Humana understands ecosystem services

For Terra Humana the concept is useful because it names what a degraded landscape has lost and what renaturation can give back: water held in the slope, soil that grows again, shade, flowers and the creatures that live on them. We use the language of services to make these returns visible, not to put a price on land. Some of what a place gives, its quiet, its beauty, its meaning to the people who care for it, cannot be expressed in money, and it need not be. We describe the services of our own land only as far as we have observed them.