Short answer: Biodiversity is a recurring theme in Writing Task 2 and Speaking, so precise words such as habitat, endangered, invasive and resilience are among the quickest ways to raise your Lexical Resource band. The 30 words below give meanings, natural collocations and example sentences ready to adapt into an essay or Speaking answer.
Biodiversity questions appear regularly under the wider environment theme: species loss, deforestation, conservation, and whether protecting wildlife should come before economic growth.
Because the subject is so predictable, its vocabulary is learnable in advance — and a candidate who reaches for habitat, extinction and fragmentation instead of “homes for animals”, “dying out” and “breaking up land” reads immediately as a higher-band writer.
This guide gives you 30 genuine Band 7+ words on biodiversity, each with the collocation that makes it usable and an example sentence in an essay-style context.
Why topic vocabulary lifts your Lexical Resource band
In both Writing and Speaking, Lexical Resource is one of four marking criteria, each carrying equal weight — so it accounts for a full quarter of your mark on those papers.
The public band descriptors state that Band 7 requires a range of vocabulary used with "flexibility and precision" and the use of "less common lexical items… with some awareness of style and collocation", as set out in the official IELTS Writing Task 2 band descriptors.
Preparing topic vocabulary in advance is the most efficient way to reach that standard on a predictable subject like biodiversity.
The honest caveat is that the descriptors reward accuracy, not decoration. A less common word dropped into the wrong collocation — “do a conservation”, “many biodiversities” — reads as reach without control and can pull your band down rather than up.
That is why every entry below pairs the word with its natural partners. For a structured month of building this kind of active, in-context vocabulary across topics, follow our 30-day vocabulary plan.
30 Band 7+ biodiversity words
Read down the table for the meaning, then across to the collocation and the example, which shows the word doing the job it would do in a real answer.
| Word | Meaning | Collocation / common usage | Example sentence |
|---|---|---|---|
| biodiversity | the variety of plant and animal life in a habitat or on Earth | rich biodiversity, loss of biodiversity | The rainforest supports a level of biodiversity found almost nowhere else on Earth. |
| ecosystem | a community of living organisms together with their physical environment | a fragile ecosystem, a marine ecosystem | Removing a single predator can destabilise an entire ecosystem. |
| habitat | the natural home or environment of a species | natural habitat, habitat loss | Habitat loss is the single greatest threat to the world’s wildlife. |
| species | a group of organisms capable of interbreeding | a native species, a threatened species | Thousands of species are thought to disappear before they are even discovered. |
| endangered | at serious risk of extinction | an endangered species, critically endangered | The mountain gorilla remains critically endangered despite decades of protection. |
| extinction | the dying out of a species | face extinction, driven to extinction | Many amphibians now face extinction because of a spreading fungal disease. |
| conservation | the protection of the natural world and its species | wildlife conservation, conservation efforts | Conservation efforts have brought several bird species back from the edge of extinction. |
| indigenous | originating naturally in a particular place; native | indigenous species, indigenous to | The lake is home to several fish species that are indigenous to the region. |
| invasive | of a non-native species that spreads harmfully | an invasive species, invasive plants | An invasive species with no natural predators can quickly overwhelm native wildlife. |
| pollinator | an animal that transfers pollen so that plants can reproduce | pollinators such as bees, decline of pollinators | The decline of pollinators such as bees threatens the crops that depend on them. |
| resilience | the ability to recover from disturbance or damage | ecological resilience, build resilience | A diverse forest has greater resilience to disease than a plantation of a single tree. |
| deplete | to reduce a resource to a critically low level | deplete stocks, severely depleted | Overfishing has severely depleted stocks that once seemed inexhaustible. |
| degradation | a decline in the quality or condition of the environment | habitat degradation, environmental degradation | Habitat degradation from mining has left many species with nowhere to breed. |
| fragmentation | the breaking up of a habitat into isolated patches | habitat fragmentation | Road building causes habitat fragmentation that traps animals in shrinking pockets of land. |
| ecological | relating to organisms and their environment | ecological balance, ecological collapse | Draining the marsh would upset the ecological balance of the whole area. |
| niche | the role and position a species occupies in its environment | an ecological niche, occupy a niche | Each species evolves to fill a particular niche within its habitat. |
| abundance | the quantity or plentifulness of something | species abundance, in abundance | Scientists measure the abundance of insects to gauge the health of a habitat. |
| thrive | to grow and develop vigorously | species thrive, thrive in | Certain plants thrive in the poor soils where nothing else will grow. |
| sustainable | able to continue long-term without depleting resources | sustainable use, sustainable management | Sustainable management of forests allows timber to be harvested without destroying wildlife. |
| threatened | at risk of becoming endangered | a threatened species, globally threatened | One in four mammal species is now classed as threatened. |
| keystone species | a species on which the structure of an ecosystem largely depends | a keystone species | Sea otters are a keystone species whose loss allows urchins to destroy kelp forests. |
| genetic diversity | the variety of genes within a species or population | genetic diversity, loss of genetic diversity | A small population loses genetic diversity, leaving it vulnerable to disease. |
| flora | the plants of a particular region or period | native flora, alpine flora | Grazing by livestock has damaged much of the region’s native flora. |
| fauna | the animals of a particular region or period | native fauna, diverse fauna | The wetlands support an unusually diverse fauna, from otters to wading birds. |
| reintroduce | to return a species to an area where it once lived | reintroduce a species, a reintroduction programme | Conservationists plan to reintroduce beavers to rivers they vanished from centuries ago. |
| overexploitation | using a resource so heavily that it cannot recover | overexploitation of resources | The overexploitation of tropical hardwoods has pushed several tree species towards extinction. |
| biome | a large community of vegetation and wildlife adapted to a climate | a desert biome, terrestrial biomes | Coral reefs are among the most productive biomes on the planet. |
| vulnerable | exposed to the risk of harm or decline | vulnerable species, particularly vulnerable | Species with a limited range are especially vulnerable to changes in climate. |
| proliferate | to increase rapidly in number | algae proliferate, rapidly proliferate | When nutrients pollute a lake, algae proliferate and starve other life of oxygen. |
| equilibrium | a state of natural balance between opposing forces | ecological equilibrium, maintain equilibrium | Predators help maintain the equilibrium that keeps prey populations in check. |
How to turn these words into marks
The rule that turns a word list into marks is simple: use the collocation, not the isolated word. Memorising resilience is close to useless; memorising ecological resilience gives you a ready-made phrase you can drop into an essay without a grammar risk.
Use one or two precise items per paragraph where they are natural, keep everything else plain and correct, and practise the words in context rather than on a flashcard.
Meet them again in genuine reading with our biodiversity reading practice, and build them into daily active recall with the Word Coach — that recognise-then-produce loop is what makes vocabulary available under exam pressure.