The main terrestrial ecosystems in the UK

The United Kingdom hosts a variety of terrestrial ecosystems, each with distinct characteristics shaped by geography, climate, and altitude. These land-based ecosystems include heaths, moorlands, wetlands, and woodlands, which are distributed across different regions of the country.

Distribution of terrestrial ecosystems

• Heaths - Found in lowland areas below 900 metres, predominantly in southern England with extensive coverage in various southern regions.
• Moorlands - Located in upland areas, mainly in Scotland, northern England, and Wales.
• Wetlands - Often situated on floodplains, near lakes, or in some upland zones, with significant areas in East Anglia.
• Woodlands - Once covered most of the UK, now limited to small patches in lowlands and larger regions in southern and northern England.

Characteristics of heaths and moorlands

Heaths and moorlands share several features due to their environmental conditions, yet they differ primarily in their altitude and the species they support.

Similarities between heaths and moorlands

• Open landscapes - Both ecosystems feature sparse tree cover and poor, often acidic soils due to high rainfall.
• Dominant vegetation - Heather, gorse, and grasses are the primary plants, adapted to the challenging soil conditions.
• Waterlogged areas - On flatter terrain, soils can become saturated, forming bogs where vegetation decomposes slowly, creating peat layers that store water and carbon.

Differences between heaths and moorlands

• Heaths:
  • Lowland ecosystems with varied soils, from dry and sandy in the south and east to wet and peaty in the north and west.
  • They support rare wildflowers with vibrant purple blooms, which attract numerous insects and provide food for birds and rare reptiles like brightly coloured lizards.
• Moorlands:
  • Upland ecosystems hosting important wildlife such as wild rabbits in highland areas, ground-nesting birds, and wading birds.
  • Many areas are used for grazing sheep and raising game birds, which feed on heather shoots and nest within the plants.
  • Heather moorlands are often burnt annually to promote new growth for these birds.

Features of wetlands and woodlands

Wetlands and woodlands represent two contrasting ecosystems in the UK, each with unique environmental conditions and biodiversity.

Characteristics of wetlands

• Waterlogged conditions - Found in areas like marshes, fens, and bogs where soils are saturated for most or all of the year, including seasonally flooded regions.
• Soil properties - Anaerobic soils due to water preventing oxygen penetration; bogs have acidic soils, while marshes often have neutral or alkaline soils.
• Vegetation types - Only specific plants like reeds and mosses can thrive in these wet, low-oxygen conditions. Vegetation in bogs decomposes slowly, forming peat.
• Wildlife habitats - Support mammals such as swimming species and aquatic rodents, as well as birds including wading and marsh species. Wetlands offer ideal breeding grounds for flying insects with large, transparent wings, which serve as food for nocturnal flying mammals.

Characteristics of woodlands

• Deciduous dominance - Most native UK woodlands are deciduous, with trees like oak, ash, and beech losing leaves in autumn. Fallen leaves decompose into fertile brown earth soils, supporting smaller plants such as lichens and spring-flowering bulbs.
• Coniferous presence - Evergreen coniferous woodlands, often commercial plantations of native pine species, are also widespread and grown for timber production.
• Animal diversity - Home to burrowing mammals, predatory mammals, and tree-climbing rodents, alongside birds like nocturnal hunters and those that drill into trees for food.

Diversity of marine ecosystems around the UK

The UK is surrounded by a range of marine ecosystems, including salt marshes, estuaries, cold-water coral reefs, and deep-sea habitats. These environments provide essential resources and support coastal economies while hosting rich biodiversity.

Resources provided by marine ecosystems

• Recreation and tourism - Estuaries and coastal areas are popular for activities like swimming, fishing, and boating, generating income and livelihoods through tourism.
• Energy production - Deep-sea platforms extract oil and natural gas for transport and industrial use, while marine sites also support renewable energy generation through tidal, wave, and wind technologies.
• Fishing industry - Marine ecosystems supply fish as a food source, supporting jobs and providing feeding and breeding grounds for key commercial fish species.

Human impacts on marine ecosystems

Human activities significantly affect the health of marine ecosystems around the UK, often leading to degradation through pollution, physical damage, and overexploitation.

Forms of degradation in marine ecosystems

• Pollution challenges:
  • Marine animals ingest plastic waste, mistaking it for food, which accumulates in their bodies and can be fatal.
  • Industrial waste, such as residues from pharmaceutical manufacturing, harms the health of marine organisms.
  • Agricultural run-off causes eutrophication, where excess fertilisers lead to rapid algae growth in estuaries, reducing oxygen and light to seabed habitats and killing organisms.
• Seabed damage:
  • Dredging for shipping routes removes vital nutrients and damages seabed plants, reducing food availability for marine life.
  • Trawl net fishing harms delicate habitats like coral reefs, which recover slowly.
  • Construction of marine infrastructure, such as offshore wind farms and oil platforms, physically damages the sea floor and affects seabed organisms.
• Overfishing issues:
  • Demand for fish exceeds the natural supply, leading to overfishing where species are caught faster than they can reproduce, causing population declines.
  • This impacts other marine life, including birds and seals, by reducing food availability and increasing risks of entanglement in fishing nets.