Biodiversity Vocabulary in English

Biodiversity refers to the variety of life on Earth at all levels — from genetic variation within a species to the diversity of ecosystems across the planet. It matters for several interconnected reasons. Diverse ecosystems are more resilient and better able to recover from disturbances such as drought or disease. Many of the things humans depend on — food, clean water, medicines, climate regulation — come from healthy, biodiverse ecosystems. Biodiversity also has intrinsic value: most people agree that other species have a right to exist regardless of their usefulness to humans. Scientists estimate that we are currently experiencing a “sixth mass extinction” driven by human activities, making the protection of biodiversity one of the most urgent environmental challenges of our time.

A keystone species is one that has a disproportionately large effect on its ecosystem relative to its population size. Remove a keystone species and the ecosystem can change dramatically or even collapse. The classic example is the wolf in Yellowstone National Park: when wolves were reintroduced in 1995 after decades of absence, they reduced deer overgrazing, which allowed riverbank vegetation to recover, which in turn changed river flow patterns — a cascade of effects known as a “trophic cascade.” Other keystone species include sea otters (which control sea urchin populations that would otherwise destroy kelp forests), elephants (which create water holes and clearings used by many other species), and certain fig trees in tropical forests.

An endangered species is one that faces a very high risk of extinction in the wild if threats are not addressed. The IUCN Red List classifies species by their extinction risk across several categories: least concern, near threatened, vulnerable, endangered, critically endangered, extinct in the wild, and extinct. An extinct species no longer exists anywhere on Earth. The distinction matters because endangered species can potentially be saved through conservation action, habitat protection, captive breeding programmes, and legislation. Critically endangered species, such as the Amur leopard or the vaquita porpoise, have populations in the low tens or hundreds and require immediate intervention.

Ecosystem services are the benefits that natural ecosystems provide to humans, usually grouped into four categories. Provisioning services supply food, fresh water, timber, and medicines. Regulating services control climate, flood risk, water purification, and pollination. Cultural services provide recreation, tourism, spiritual values, and educational opportunities. Supporting services — such as nutrient cycling and soil formation — underpin all the others. Economists have attempted to put a monetary value on these services to make their importance visible in policy decisions. Estimates suggest global ecosystem services are worth tens of trillions of pounds annually. When ecosystems are degraded, these services are lost, often at great economic and social cost.

Rewilding is an approach to conservation that focuses on restoring natural processes and, where appropriate, reintroducing lost species to allow ecosystems to recover with minimal human management. Unlike traditional conservation, which often tries to maintain a fixed historic state, rewilding accepts that ecosystems will change and evolve. Notable British rewilding projects include the Knepp Estate in West Sussex, where former farmland has been transformed into a thriving mosaic of habitats, and several projects reintroducing beavers, white-tailed eagles, and pine martens. Rewilding is sometimes controversial when it conflicts with farming, land use traditions, or concerns about predators near livestock.

A species is considered invasive when it is introduced — deliberately or accidentally — to a new area where it did not evolve, and spreads in a way that causes ecological, economic, or social harm. Not all non-native species are invasive; many introduced species have little impact. Invasive species often thrive because they lack the predators, parasites, or competitors that kept their populations in check in their native range. Examples in Britain include the grey squirrel (from North America), the signal crayfish (from North America), Japanese knotweed (from East Asia), and Himalayan balsam. They are estimated to cost the UK economy hundreds of millions of pounds per year in damage and management costs.

Pollinators — mainly bees, butterflies, moths, hoverflies, and some birds — transfer pollen between flowers, enabling plants to reproduce sexually. Approximately 75% of the world’s flowering plant species and around a third of global food crops depend on animal pollination. This includes fruits, vegetables, nuts, and seeds. Without pollinators, yields of many crops would fall dramatically, threatening food security. Pollinator populations have declined sharply in recent decades due to habitat loss, pesticide use, disease, and climate change. Conservation measures include creating wildflower habitats, reducing pesticide use, and supporting organic farming practices that are less harmful to insect populations.

Carbon sequestration is the process by which carbon dioxide is removed from the atmosphere and stored in biological or geological sinks. Forests, particularly old-growth forests and tropical rainforests, are among the most important natural carbon sinks: trees absorb CO2 during photosynthesis and store it in their wood and roots. Soils, wetlands, and oceans are also major carbon sinks. Carbon sequestration is central to climate change mitigation because it offsets some of the carbon dioxide released by burning fossil fuels. Protecting and restoring forests, peatlands, and seagrass beds are increasingly recognised as cost-effective natural climate solutions alongside reducing emissions from industry and energy.

Genetic diversity refers to the range of different genes and inherited traits within a species’s population. It is the raw material on which natural selection acts, allowing populations to adapt to changing conditions. Species with low genetic diversity are more vulnerable to disease, environmental change, and inbreeding depression. The cheetah is a famous example: a population bottleneck thousands of years ago left cheetahs with very low genetic diversity, making them susceptible to disease and reproductive problems. For crop plants, genetic diversity in wild relatives provides the breeding material needed to develop disease-resistant or drought-tolerant varieties. This is why seed banks and the protection of wild plant populations are important conservation priorities.

Start by grouping the words into conceptual clusters: ecological structures (ecosystem, biome, habitat, food web, trophic level), species concepts (endemic, keystone species, invasive species, endangered, extinction), processes (carbon sequestration, pollination, symbiosis, rewilding), and conservation terms (biodiversity, genetic diversity, ecosystem services, conservation). Use Flash Cards to build confident recall of definitions, then practise reading environmental news articles from sources such as the BBC, the Guardian, or National Geographic, where many of these words appear regularly. Watching nature documentaries with English subtitles is an excellent way to hear the vocabulary used in vivid, memorable contexts.