4 of the ESS glossary’s terms, each with the part of the syllabus where you first meet it.
A cultivation technique in which crops are sown directly into the undisturbed soil and residue of the previous crop, without ploughing.
The change in community composition along an environmental gradient, such as altitude, latitude, tidal level or distance from a water source.
Small, mostly microscopic animals and animal-like organisms that drift in water, many of which feed on phytoplankton and are in turn eaten by fish and other consumers.
Single-celled photosynthetic algae that live inside the tissues of reef-building corals in a mutualistic relationship, supplying most of the coral's food and its colour.