Key Terms: Ecosystems & Sustainability (AQA A Level Geography): Revision Note

Biodiversity - key terms

Biodiversity – The variety of life in all its forms, including the diversity of species, ecosystems, and genetic material.

Biome – A large ecological area characterised by specific climate, vegetation, and animal life (e.g. tropical rainforest, tundra).

Blanket bog – A type of wetland ecosystem found in cool, wet upland areas of the UK; important for biodiversity and carbon storage.

Climatic climax community – The final stage in ecological succession where the ecosystem reaches a stable and balanced mix of species.

Ecosystem – A community of living organisms interacting with each other and their physical environment (e.g. soil, light, water).

Ecosystem succession – The natural process by which ecosystems develop and change over time, often moving from simple to more complex communities.

Evenness index – A measure of how evenly individuals are distributed among the different species in an ecosystem.

Genetic diversity – The range of genetic characteristics within a species, which increases adaptability and survival chances.

Indicator species – Species whose presence, absence, or abundance indicates particular environmental conditions or ecosystem health.

Living Planet Index (LPI) – A measure of global biodiversity based on the population trends of selected vertebrate species.

Population number – The size of a distinct population of a species in a given area.

Species richness – The total number of different species present in a given area or ecosystem.

Biodiversity and humans - key terms

Agriculture – A major cause of biodiversity loss due to habitat destruction, monoculture, and use of fertilisers and pesticides.

Cultural services – Non-material benefits people obtain from ecosystems, such as recreation, aesthetic value, and spiritual meaning.

Deforestation – The removal of forest cover, usually for farming or development, which leads to habitat and species loss.

Ecosystem degradation – The decline in the quality and function of ecosystems due to human impact, making them less able to support biodiversity.

Ecosystem services – The benefits people gain from ecosystems, including provisioning, regulating, supporting, and cultural services.

Environmental Kuznets Curve (EKC) – A model suggesting environmental degradation increases with economic development until a certain point, after which improvements occur.

Exploitation – Unsustainable use of natural resources, such as overfishing or hunting, which reduces species populations and genetic diversity.

Footpath erosion – Damage to sensitive environments like peatlands caused by trampling, leading to vegetation loss and soil exposure.

Globalisation – Increases connectivity and trade, but can spread invasive species, pollutants, and unsustainable resource use.

Green policies – Government strategies aimed at protecting biodiversity, including laws, education, protected areas, and conservation programmes.

Invasive species – Non-native organisms introduced by humans that outcompete native species and disrupt ecosystem balance.

Overgrazing – Excessive grazing by livestock that depletes vegetation, leads to soil erosion, and reduces habitat quality.

Pollution – Contaminants like fertilisers, pesticides, and industrial waste that degrade habitats and harm wildlife.

Provisioning services – Ecosystem products such as food, fuel, water, and medicinal resources used directly by humans.

Regulating services - Benefits that ecosystems provide by controlling natural processes such as water purification.

Rewilding – The process of restoring ecosystems to a more natural state, often including the reintroduction of key species.

Socio-political factors – Human values, governance, policies, and institutions that influence how biodiversity is managed or exploited.

Sustainable development – Economic and social development that meets current needs without compromising the environment for future generations.

Supporting services - Ecosystem processes that ensure the survival of plants and animals such as photosynthesis and nutrient cycling.