Start here · Essential guide
What Is an Ecosystem?
An ecosystem is a community of living things and the non-living parts of their habitat, linked by energy and nutrients. Learn how the pieces interact.
Earth and Life
Ecosystems and Wildlife
How living things depend on each other and on their environment.
Food Chains and Food Webs
Food chains show who eats whom in a straight line; food webs show the tangled reality. See how energy flows from producers to top predators and why it thins.
How and Why Animals Migrate
Why do birds, whales, butterflies and wildebeest make huge seasonal journeys? Explore the reasons, the cues that trigger them and the open questions on navigation.
How Bees and Other Insects Pollinate Plants
Pollination moves pollen between flowers so plants can make seeds and fruit. See how bees, flies, beetles and others do it and why many food crops depend on them.
How Photosynthesis Works
Photosynthesis lets plants, algae and some bacteria turn light, water and carbon dioxide into sugar and oxygen. Here is how the two stages work in plain terms.
How Recycling Works and What It Can Achieve
Recycling means collecting, sorting and reprocessing used materials into new products. See how it works for metal, glass, paper and plastic, and where its limits lie.
Rainforests and Their Role in the World
Rainforests have layered structures, huge numbers of species and a role in regional climate and carbon storage. Learn how they work and why they matter.
What Causes Species to Go Extinct
Extinction is a natural process, but habitat loss, invasive species, overharvesting, pollution and climate change have raised its pace. See how the pressures work.
Why Biodiversity Matters
Biodiversity is the variety of life at the level of genes, species and ecosystems. Learn why that variety helps ecosystems cope with change and supports people.
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