2.2 - Ecosystem Services
Learning Objectives
The main objective is describing ecosystem services and detailing how human activities can degrade or disrupt them. The associated skill is explaining an environmental concept or process.
Introduction to Ecosystem Services
Ecosystem services are the products (goods) taken from natural resources, or the functions (services) that ecosystems perform. These services have a measurable economic or financial value to humans and can be quantified in dollars.
The Four Categories of Ecosystem Services
Ecosystem services fall into four core categories: provisioning, regulating, supporting, and cultural.
1. Provisioning Services
These are the goods or products taken directly from natural resources.
Service Type | Examples | Products Made from Natural Resources | Disruption by Humans |
Direct Goods | Wild foods, fish and hunted animals, lumber, apples. | Paper (from lumber), medicines (from plants or plant compounds), and rubber. | Over harvesting, like fishing faster than populations can regenerate. Pollution, which leaves fish unable to survive. Clearing land for agriculture or urbanization. |
2. Regulating Services
These relate to regulating conditions like climate and air quality, and they often result in money saved for human society.
Regulation Example | Ecosystem Mechanism | Economic Benefit (Money Saved) |
Climate Regulation | Trees sequester from the atmosphere via photosynthesis and store it in their tissues, which decreases atmospheric . | Decreased repair costs for storm damage, less property loss from rising sea levels, and fewer losses for farmers due to drought. |
Air Quality | Trees trap air pollutants in their leaves. | Decreased healthcare costs related to respiratory diseases like asthma or bronchitis. |
Water Filtration | Wetlands have dense plant roots that trap pollutants as water seeps into the soil, which recharges clean groundwater and surface water. | Humans pay less to purify water, avoiding the cost of building water treatment plants. |
Pollination | Bees and other insects pollinate agricultural crops. | Increases crop productivity, which means higher yields and more revenue for farmers, plus lower prices at grocery stores. |
Disruption: The main disruptor of regulating services is deforestation, meaning clearing land for logging, agriculture, or cities. When trees are cut down, the amount of stored in trees decreases, atmospheric increases, and the rate of climate change goes up. Filling in wetlands for agriculture or cities decreases water filtration, which leads to higher future water purification costs, and destroying the habitats pollinators rely on, like prairie ecosystems, lowers crop yields.
3. Supporting Services
These are the background processes done by natural ecosystems that all the other services depend on. They make what humans do, like farming, possible and less costly.
Supporting Service | Ecosystem Mechanism | Economic Benefit | Disruption by Humans |
Nutrient Cycling | Decomposers break down dead plants, animals, and waste and return nitrogen and phosphorus to the soil, where plants take them up again (1.5, 1.6). | Farmers need less fertilizer, since healthy soil keeps recycling its own nutrients. | Clearing forests and leaving fields bare, so rain washes nutrients away, and adding so much fertilizer that the extra runs off into waterways. |
Soil Formation | Weathering breaks rock into small particles, and decaying organic matter mixes in to slowly build topsoil (4.2). | Fertile topsoil grows crops, pasture, and timber. | Erosion from overgrazing, deforestation, and plowing strips topsoil away far faster than it forms. |
Primary Production | Plants, algae, and phytoplankton use photosynthesis to make the biomass at the base of every food web (1.8). | Every provisioning service (crops, timber, fish, and livestock) depends on it. | Paving over land, clearing forests, and pollution that kills producers, like algal blooms that block sunlight. |
4. Cultural Services
This category includes revenue generated from recreational activities and the economic profits from scientific discoveries.
Cultural Service | Examples of Revenue / Value | Key Condition |
Recreation and Tourism | Money generated by tourism, entrance fees at national parks, hunting or fishing licenses, and local spending at restaurants and hotels. | The landscape has to be intact and healthy to draw tourists. Fishing licenses only get purchased if the waters are clean and provide healthy fish. |
Scientific Knowledge | Scientific discoveries, like new treatments for diseases or new agricultural techniques, based on naturally occurring compounds found in ecosystems. | Companies generate revenue from these medical or agricultural advances. |
Disruption: Cultural services are degraded by deforestation (tourists won’t pay to see stumps), pollution (people won’t fish or canoe in polluted waters), and urbanization (clearing natural spaces makes people less interested in visiting).
Consequences of Disrupting Services
When humans do things like clear land for cities or overfish, the value of ecosystem services decreases.
- The loss results in ecological consequences for the organisms in the ecosystem.
- It also results in significant economic consequences, like lost jobs or lost tourism revenue.
- For example, overfishing may increase short term profits, but it leads to a collapse in fish populations, which means lost fishing jobs and lost revenue in the future.
- Real example (Atlantic cod): Decades of overfishing collapsed the northern cod stock off Newfoundland, and Canada closed the fishery in 1992. About 30,000 to 40,000 people lost fishing and fish plant jobs, one of the largest layoffs in Canadian history. Losing that provisioning service had ecological consequences (a top predator removed from the food web) and economic ones.
- Real example (New York City's water): Most of New York City's drinking water comes from reservoirs in the Catskill Mountains and the upper Delaware River watershed. Since the 1990s, the city has spent well over $1 billion buying and protecting forest and land around those reservoirs so the ecosystem keeps filtering the water. If development degraded that land, the city would have to build a filtration plant, and the city's own early 1990s estimate was about $6 billion to build plus more than $300 million a year to run.
- Quick calculation: Using that estimate, a plant would cost $6 billion + ($300 million/year × 20 years) = $6 billion + $6 billion = $12 billion over 20 years, several times what the city has spent protecting the watershed.
- Real example (pollinators): Crops that depend on animal pollinators make up an estimated $235 billion to $577 billion of global food production each year (IPBES, 2016). Habitat loss and pesticides that reduce bee populations put that value at risk, which means lower yields for farmers and higher food prices.
Big picture: Ecosystem services are basically the “free labor” Earth provides, from the forest acting as a cheap scrubber (regulating) to bees providing efficient crop fertilization (also regulating). When humans degrade these services, it’s like firing all the unpaid workers. We save a little money initially (short term profit), but then we have to immediately hire expensive alternatives, like building water purification plants or paying massive climate disaster repair bills (long term economic consequence).