So what are ecosystem services, anyway?

If you’re wondering about what’s behind all of our stories, you’re in the right place! ‘Ecosystem services’ are all the benefits that ecosystems give to us humans: better health, food to eat, cleaner water and air, and more. The Millenium Ecosystem Assessment made the idea popular in the early 2000s (at least for scientists), and the UN’s Economics of Ecosystems and Biodiversity (TEEB) program has carried the flag since then.

There are four main types of ecosystem services: provisioning, regulating, supporting, and cultural.

Provisioning

Provisioning services are energy or materials that come from the ecosystems around us. People can use them directly, like food and water, or sell them for cash, like timber.  Either way, they rely on ecosystems.

Food can be farmed, like most crops, or wild, like fisheries. Rural people also often collect food from forests, like mushrooms, seeds, berries, and nuts.

Then there are raw materials, like timber, fodder, fertilizer, fuelwood (gotta stay warm!) and biofuels. These aren’t just for small, rural communities: wood still comes from the forest, even if you don’t have one next to you. Without the forest, there would be no wood, no timber industry, and no timber jobs. And no log cabins or ski chalets, either. So even though it’s a large, commercial industry, timber is a quintessential ecosystem service.

Collecting, moderating, and purifying freshwater is another big one. See the examples below for more.

Regulating

Always in motion is the future. Always in motion is also our planet. Ecosystems manage the changes around us, and sometimes they can even help protect us against disasters. These are regulating services, because they keep everything running smoothly in the background.

Trees make sure we have clean air to breathe by removing pollutants. Forests often attract rainfall and improve water availability and cleanliness. And wetlands have tons of little organisms that filter pollutants out of water.

Regulating services also help with natural disasters: floods, landslides, storms, waves, tsunamis, and others. Wetlands are naturally good at soaking up water, so they can help moderate heavy rains or flooding. Tree roots dig in to the soil and help to keep it in place, preventing erosion and stabilizing hillsides. And coastal ecosystems like mangroves, coral reefs, and marshes can buffer storm surges and high waves.

Lastly, ecosystems host wild birds, bees, and other animals. These can reduce disease by feeding on bugs, and many of them also pollinate the crops we rely on for food. That’s a regulating service that supports the provisioning service.

Cultural

We don’t talk too much about cultural ecosystem services, but they’re still important. There’s recreation (skiing, fishing, hunting, hiking) and tourism. Often, they’re closely related – think safaris or scuba diving trips. And regulating or provisioning services can support cultural services, like the coral reef protecting the beach.

Then there’s art, spirituality, creativity, history, science, and just getting out into nature to relax, which can improve health: lower stress, better attention, and happier people.

Supporting

Supporting services don’t get a lot of glory, because they’re hard to research and measure. But they make all the other ones possible.

Habitats give plants and animals a place to live. And as we’ve seen above, people depend on those plants and animals for food, materials, protection, and others.

Biodiversity may be the most difficult to measure. But just like you might hedge your bets by having many lines of business or buying insurance, a healthy ecosystem will have a large number of different species. All of them play a different role, so it’s smart to keep multiple options around, just in case. You probably won’t see it directly, but it may be the most critical ecosystem service of all.

Measuring ecosystem services

We hope this makes sense to you! (Please email hidden; JavaScript is required if it doesn’t.) But now that we’ve explained what ecosystem services are, we can add the last piece of the puzzle: measuring them.

First, though, we should note that we aren’t suggesting that ecosystem services should be the only way we value nature. Nature can be priceless regardless of the service or services it provides. But because ecosystems do provide so many physical services like food, building materials, or flood protection, we can track how they affect life. We can measure the amount of food they produce, the amount of flood damages they prevent, and so on.

Sometimes, that’s all we need. Other times, we might turn this into a cash value. We could say a healthy forest feeds a percentage of the population and supports jobs, and we could also say how much those jobs and food are worth in cash. But whether they’re making us money or keeping us safe, the idea is the same: ecosystems make our lives better.

Read on below for a few examples of exactly how they work.

A Few Examples

Forests and Water

Trees’ leaves and branches intercept water as it falls. Some evaporates, soils soak up more, and roots take up some of what reaches the soil. Obviously this means that forests use up some of the water – but it also means all that water doesn’t go straight downhill or into a stream, which could cause a flood. And during the dry season, even though forests use more water, they can also slowly release it. The result is that forests can regulate water flows over the year, which is especially important in the dry season.

Of course, a massive flood can overwhelm a forest’s ability to buffer water. And in some places or at some times of the year, forests may actually decrease water yield by letting it evaporate or using it internally. But even then, the moisture lost to the air helps to create rainfall.

So there’s some uncertainty about how much of an effect forests can have on water, and what the tradeoffs might be. But overall, these effects do exist; see the story on drinking water in Chile for an example. They’re just usually very specific to a location.

Watersheds

‘Watershed’ can be a slightly confusing term depending on where in the world you are, but often, it means a large area that collects precipitation and drains it into a (common) water body. Watersheds are often mountainous and forested, and these areas are especially well suited to catching water. Mountains often receive a lot of rainfall, snowfall, or other precipitation), and their trees intercept water and release it to soils and eventually to groundwater or rivers.

Whether mountainous or not, the rivers that flow out of watersheds often merge with others, getting bigger and bigger as they flow towards the ocean. And sometimes, they become or join major rivers like the Amazon, Nile, Mississippi, or Congo. So you could say watersheds and their ecosystems create your water supply.

Seagrasses and Coastal Protection

Seagrasses have been called the ‘lungs of the sea‘ because they produce so much oxygen. Like normal plants, they use photosynthesis to convert light to energy, so they usually live in shallow waters, where light still reaches the ocean floor. These are also often areas close to the coast.

And just like tree or plant roots, seagrass roots worm their way into the soil. But they also have a horizontal stem that adds extra stability, which helps lock down sediment on the ocean floor. They grow over large, continuous areas (called ‘seagrass meadows’), and even though they’re floppy, all together their leaves create a lot of resistance to water. So both their roots and leaves can help buffer coasts against strong waves, currents, and soil erosion.

Seagrass leaves also attract particles and sediments floating around in the water, keeping the water clean for your enjoyment. And they manage to absorb and recycle nutrients, which is especially important near industrial areas. These often have high pollution levels, and seagrasses can filter some of it before it affects delicate ecosystems like coral reefs.

Seagrasses and Fish

We’re not quite done with seagrasses and their services yet: there’s also nursery habitat. We covered some of this in the story on South Australia, but there are many more species that live in seagrass for at least part of their lives. These could be species caught by commercial or recreational fishers, or they could be species that aren’t caught at all – but which are a critical food supply for the bigger ones that are.

Even fish that live in other habitats like coral reefs spend some time in seagrasses. There’s evidence that fish grow faster on reefs, but survive better in seagrass because they are able to hide from predators. Fish and shellfish also take shelter from strong currents, thanks to the grasses’ intricate root systems and water buffering ability.

So, seagrasses are critical to marine life, and to marine economies that rely on fishing or live near the coast. They provide a huge range of ecosystem services. And they have such a large impact on life around them that they are often called ecosystem engineers.

By the way, fish habitat could be either a provisioning or a supporting service. But supporting services get much less attention, so we had to give them some.

More Coming Soon

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