What are ecosystems?
An ecosystem is a community of living organisms, from the smallest microorganisms to the largest mammals, together with the non-living environment they interact with: the air, water, soil, and sunlight around them. Everything in an ecosystem is connected, and each part depends on the others to keep the whole system functioning.
Ecosystems exist in virtually every corner of the planet, from the deep ocean to the highest mountains, and they vary enormously in scale and character. They are usually grouped into a few broad types of ecosystems.
Flora and fauna at Raja Ampat Island, Indonesia.
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Terrestrial ecosystems: land-based systems such as forests, grasslands, deserts, and tundra, which regulate the climate and provide much of our food and fresh water.
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Aquatic ecosystems: freshwater systems such as rivers, lakes, and wetlands, and marine systems such as oceans and coral reefs. The ocean alone covers more than 70% of the Earth's surface, making it the planet's largest living system.
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Specialised ecosystems: systems shaped by extreme or unusual conditions, including polar regions, hot deserts, and even urban ecosystems shaped by human activity.
Together these systems support an extraordinary variety of life. According to a landmark study, there are an estimated 8.7 million species on Earth, of which around 86% have yet to be formally described, a reminder of how much of the living world we are still discovering.
Read more: The ecosystems of Africa
Why it matters
Ecosystems hold the natural world together. Every part is connected to the others, and the whole depends on that balance: when one part is damaged, the effects spread and the entire system is weakened. Their value is, first and foremost, the life they sustain. Ecosystems are home to the world's wildlife (including many endangered species), from the largest mammals to the smallest insects, and the loss of habitat is the single biggest reason so many species are now at risk of extinction. They are the living framework that holds up biodiversity, the variety of species, genes, and habitats that keeps nature resilient. And they are built on forests, wetlands, and other vital habitats that store carbon, regulate water, and shelter much of life on Earth. Harm one part, and the whole web feels it.
People are part of this web too, and depend on it just as completely. The benefits ecosystems provide to us are known as ecosystem services, usually grouped into four kinds:
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Provisioning: the tangible goods we take from nature, such as food, fresh water, timber, and medicine.
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Regulating: the processes that keep conditions stable, such as climate regulation, clean air and water, flood protection, and pollination.
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Cultural: the recreational, spiritual, and aesthetic value people find in nature.
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Supporting: the underlying processes such as soil formation, nutrient cycling, and photosynthesis that make all the others possible.
The scale of that dependence is striking even in narrow economic terms. According to the World Economic Forum, more than half of global GDP, around 44 trillion US dollars of economic value, is moderately or highly dependent on nature and its services. Seen another way, BCG estimates the services ecosystems provide for free to be worth more than 150 trillion US dollars a year, around twice global GDP. The greater the variety of life an ecosystem holds, the more resilient and productive it tends to be, which is why protecting the whole web matters for every part of it, ourselves included.
Read more: 10 Vital ecosystem services: sustaining life on Earth
Beekeeper removing honeycomb from beehive.
Read more: Sweet solutions: the role of bees and Impact Investments in environmental restoration
What threatens ecosystems
Ecosystems around the world are under growing pressure, almost all of it from human activity. The main threats are connected, and often make one another worse.
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Habitat destruction: Clearing land for agriculture, logging, and urban development is the single biggest threat, destroying and fragmenting the habitats that species depend on. Deforestation alone removes vast areas of forest ecosystem every year.
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Overexploitation: Using natural resources faster than they can recover, through overfishing, overhunting, and the depletion of soils and groundwater, exhausts ecosystems and the resources that local economies rely on.
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Pollution: Chemicals, waste, and plastics contaminate soil, water, and air, harming wildlife, destroying habitats, and damaging human health along the way.
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Invasive species: Species introduced into ecosystems where they have no natural predators can outcompete native life, disrupt food chains, and spread disease.
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Changing environmental conditions: Rising temperatures and shifting weather patterns alter ecosystems faster than many species can adapt, shifting where species can live, degrading habitats, and driving more frequent droughts, floods, and storms.
Read more: How biodiversity loss impacts ecosystems and what we can do to help
Tree researcher measuring a gum tree, Australia.
Protecting our ecosystems
Protecting ecosystems means both defending what remains and repairing what has been damaged. The most effective efforts combine a few complementary approaches, and work best when local communities are at the centre of them.
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Conservation: protecting intact ecosystems through national parks, reserves, and protected areas, and enforcing the laws that safeguard wildlife and habitats. Preventing damage is always more effective than repairing it.
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Restoration: repairing degraded ecosystems through reforestation, wetland and peatland restoration, and removing invasive species, helping nature and its services recover.
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Sustainable use: managing resources responsibly, through sustainable farming, fishing, and forestry, so that people can benefit from ecosystems without depleting them.
Rescued tortoise holding its flippers with human hands. The Sea Turtles Conservation Research Project in Bentota, Sri Lanka.
Together, these approaches can turn the tide on ecosystem decline, protecting biodiversity and the services that all of us depend on.
Read more: Peatland restoration: why it's crucial and how to pay for it
How Green Earth helps with ecosystem restoration
Ecosystems are vital for human wellbeing and survival, providing a range of specific ecosystem services, such as clean water, food, and air, as well as supporting cultural and recreational values. Ecosystems also support biodiversity, providing habitats for millions of species and playing a critical role in regulating the Earth's climate and biogeochemical cycles.
However, ecosystems are facing significant threats from human activities, including overexploitation, pollution, and environmental instability, which are causing the loss of biodiversity, ecosystem functioning, and ecosystem services. Protecting and restoring ecosystems is therefore vital for maintaining human wellbeing and ensuring the sustainability of our planet.
Given the importance of ecosystems for human wellbeing and the significant threats facing them, we must take action to protect and restore them. We can do this with a range of measures, such as reducing our use of natural resources, promoting sustainable practices, and supporting conservation and restoration efforts.
At Green Earth, we are committed to supporting nature to flourish and prosper. We implement actionable strategies in support thereof with every project we undertake. We believe these efforts will benefit us all—and ensure that future generations will be given a chance to enjoy the wonders of nature as we do.
There are also individual actions each of us can take, like reducing our carbon footprint, supporting sustainable businesses, and advocating for policies that protect ecosystems. Protecting and restoring ecosystems is not only necessary for preserving biodiversity and supporting human wellbeing, but also for ensuring the sustainability of our planet and future generations. We all have a role to play in protecting ecosystems, and it is up to each of us to take action to secure a healthy future for ourselves and the planet.
The time to take action is now
