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

Urban wasteland ecosystems - key terms

Adaptation – The process by which plants and animals adjust to the harsh, often polluted and nutrient-poor conditions of urban wastelands.

Brownfield site – Previously built-on land that has been abandoned and is now colonised by natural vegetation; also known as urban wasteland.

Microclimate – Small-scale climate variations caused by urban features such as buildings, rubble, or shade, affecting colonisation.

Pioneer species – The first species to colonise wastelands, often tolerant of poor soils and pollution, e.g. mosses, lichens.

Plant succession – The natural sequence of colonisation and ecosystem development on urban wastelands, from bare ground to scrub woodland.

Secondary succession – Ecological succession that occurs on previously disturbed land where soil is still present (e.g. urban wastelands).

Urban heat island effect – The increased temperature in urban areas due to concrete surfaces and human activity, which affects plant and animal behaviour.

Urban wasteland – An abandoned area within the city where buildings or infrastructure have fallen into disuse, now undergoing natural colonisation.

Factors affecting development - key terms

Colonisation – The establishment of plant and animal species on a previously uninhabited or disturbed site.

Impermeable surfaces – Concrete and tarmac restrict water absorption and root penetration, influencing which species can grow.

Pollution tolerance – The ability of certain species to survive in contaminated soils, common in areas with industrial waste.

Porosity – Porous surfaces retain water and dust, providing better conditions for seed germination and rooting.

Seed dispersal – Can occur by wind, water, birds, or humans; influences the rate and variety of plant colonisation.

Shade – Shady areas restrict light availability, favouring shade-tolerant plants such as ferns and mosses.

Soil pH – Influences nutrient availability and plant diversity; varies depending on previous land use.

Soil water budget – Balance between precipitation and evaporation; wastelands typically have low moisture retention.

Stage 1: Pioneers – Colonisers like mosses and lichens that tolerate exposed, nutrient-poor conditions.

Stage 2: Herbaceous plants – Plants like Oxford ragwort and willow herb that root in cracks and shallow soils.

Stage 3: Tall herbs – Taller plants such as rosebay willow herb and fennel establish, outcompeting smaller species.

Stage 4: Grassland – Grasses become dominant as soil develops; biodiversity increases.

Stage 5: Scrub woodland – Shrubs and trees like birch and sycamore appear, forming the climax vegetation if undisturbed.

Topography – Uneven terrain creates varied microhabitats, supporting diverse plant and animal life.

Issues and management of change - key terms

Conservation – The protection and sustainable management of urban wastelands for ecological, educational, or recreational purposes.

Deforestation (urban) – The clearing of natural vegetation during redevelopment, leading to loss of habitats.

Invasive species – Non-native plants or animals (e.g. Japanese knotweed) that outcompete native species and alter natural succession.

Japanese knotweed – A fast-growing invasive plant that damages concrete, spreads rapidly, and requires chemical treatment for removal.

Plagioclimax – A stable ecosystem maintained by human interference (e.g. grazing, burning, or urban management) that halts natural succession.

Redevelopment – Urban regeneration activities that may threaten or destroy existing wasteland ecosystems (e.g. draining ponds, removing rubble).

Regreening – Transforming derelict land into green spaces, often through planting or natural succession, to improve urban environments.

Rewilding – Allowing nature to reclaim and restore ecological functions in urban areas with minimal human interference.

SSSI (Site of Special Scientific Interest) – A legally protected area in the UK due to its unique wildlife or geology, including some brownfield sites.

Sustainable use – Utilising urban wasteland for recreation, education, and nature conservation while preserving ecological value.

Urban biodiversity – The variety of plant and animal life found in cities; urban wastelands can serve as key biodiversity hotspots.

Wildlife charities – Organisations such as Buglife, the Wildlife Trust, and RSPB advocate for the conservation of urban wastelands.