What exactly are ‘ecosystem services’?
- Supporting services: underpin the other service and include soil formation, primary production (plants making sugars and carbohydrates via photosynthesis) oxygen production (from plants, see graph below) and nutrient cycles (fungi, bugs and the microorganisms in the soil that produce the essential nutrients we get from food).
- Provisioning services: food, water, medicines, raw materials
- Regulation: climate, waste removal, disease control
- Cultural: social, recreational, spiritual, sense of well-being
The following are just a few examples. Figure 2 summarises a more comprehensive list.
Food: Imagine a world without coffee or chocolate? Almost 90% of flowering plants rely on animals for pollination, and around 75% of our food crops rely on them. Pollinators, including bees and certain kinds of flies, wasps, butterflies, and birds are ‘keystone species’—species that have a disproportionately large effect on their natural environment. If keystone species vanish then entire ecosystems—including food production—collapses. While there may be technological solution in some instances, for example hand pollinating food crops or adding ever increasing amounts of fertiliser to deteriorating soils, they are time consuming, costly, and can have a destructive and dangerous side-effects, for example nitrogen fertiliser, know for its association with bowel cancer, entering waterways.
Think you can just eat seafood? 90% of global warming has been absorbed by the ocean. That’s causing the water to warm and that’s killing plants and animals. While some species are moving to cooler waters, the ocean is also absorbing a lot more carbon dioxide.
Photosynthesis (declining oxygen): More carbon dioxide is leading to a warming climate and ocean acidification, which is threatening oceanic plants and animals; this includes the tiny plants in the ocean that produce around half the oxygen in the atmosphere that we need to breathe.
“…at higher biodiversity, the impact of acidification on otherwise highly vulnerable key organisms can be reduced by 50 to >90%, depending on the species.” – Rastelli et al
Clean drinking water: doesn’t just appear from taps. It falls as rain or snow, flows over the ground as rivers or underground as aquifers, and then is pumped out, stored, and delivered to our homes.
Once upon a time the water in Canterbury was so clean you could drink it straight from the rivers and wells. But today, thanks to intensive dairy farming, Canterbury and Southland’s rivers are the most polluted in the country. Taking massive amounts of water from rivers, using it for irrigation and then allowing tonnes of fertiliser to flow back into the river means that what was once a free ecosystem service has been polluted for generations to come.
The cost of filtering and cleaning water is now something we have to pay for through rates or rent, and possibly with our health, as much of our water doesn’t meet the World Health Organisation’s standards for nitrates (which come from fertiliser and cow effluent).
‘Contaminant levels are on the rise in groundwater, rivers and lakes, with nitrate levels in particular emerging as a huge red flag. In the past 100 years, globally we have doubled the inputs of reactive nitrogen going into our natural environment. We have done this by using fossil gas to create synthetic nitrogen fertiliser, industrialising a job that used to be done for us by plants.“ – Dr Mike Joy, Victoria University of Wellington.
Medicines don’t just come from bottles: In March, the IUCN Red List declared the smooth handfish, Sympterichthys unipennis, extinct. It’s the first marine fish in modern times to be declared gone forever.
‘It might be hard to imagine why a little organism occupying a small niche in a place few humans ever visit might be important. But an enzyme from an extremophile microbe is being used in tests to diagnose COVID-19. Biodiversity matters, even if you can’t see it with your own eyes.’ – Katie Matthews, conservation scientist.
Climate control: carbon is the control nob on the planet’s thermostat (Fig. 3). Find out how carbon does this here (this website).
Diseases: Destroying ecosystems changes the way that diseases interact between people and animals. Deforestation and extinctions make pandemics more likely as diseases jump from animal hosts to humans in a process called zoonosis. Covid-19 wasn’t the first, and it’s unlikely to be the last.