Threatened habitats in the UK

Traditional woodland management:

-Mature trees- used to product large timbers for house/ship construction. Valuable for nesting birds and roosting bats

-Coppicing- trees cut to ground level on rotation every 7/12 years. As re-grow thin, straigh branches are produced used for fencing and wall panels. Mixed habitat produced and very valuable for many species like butterflies, insects and dormice

-Pollarding- similar to coppicing but trees cut down to around 1.8m. This protects the new growth from grazing livestock, deer and rabbits

These methods had few harmful effects on wildlife. Easy for species to recolonise and also can create a bi-product

The importance of native woodlead

- Its the terrestrial habitat with the highest biodiversity

- Range of recreational activites are possible

- Regulated water flow catchment areas around rivers and reservoirs

- Trees reduce soil erosion

- Growing forests act as a Carbon sink limiting global climate change

- Trees return water back to the atmosphere by evapo-transpiration and maintain rainfall downwind

- Woodland can provide a sustainable supply of fuel for domestic and industrial use as wood or charcoal

- The timber from particular species was used for house construction, carts, barrels, tools, ship building and bark for leather tanning

Modern conifer plantations are very different from native decidous woodland:

- Large area cleared and planted with small range of conifer species grown in monocultures

- Imported species used (Sitka spruse) to suffer less pest damage but used by fewer native wildlife species

- Close planting makes tall straight trunks, little/no undergrowth

- Herbicides are often used to clear weeds

- Don't provide varied habitat that supports a range of wildlife

- Recently trended towards more wildife-friendly plantations with more species and creation of more wildlife habitats such as small clearings

Areas of shallow water for example: Lakes, ponds, marshes, rivers and flooded gravel pits. Very important as relatively rare. Usually silt up or go through ecological succession to lose wetlands. Importat for migratory birds as they remain ice free

Threats:

- Drainage to produce more productive farmland

- Urban expansion onto flood-plains

- Straightening of rivers speeding up drainage and reduce flooding risk

- Excessive recreation pressure

- Bank reinforvement to reduce flooding risk

- Pollution from industry, sewage and agriculture

The richest and most varied freshwater habitat in the UK with unique fisheries, wildfowl, marsh birds, insects and plants. As well as historical and landscape value

Threats:

- Eutrophication caused by phosphates from sewage and nitrates from fertiliser runoff encouraged the growth of algae and the devline of natural foodwebs

- Introduced species such as the coypu caused problems. Escaped fur farms and their burrows damage banks causing flooding. They were all caught and killed.

- Recreation pressure; litter, noise, trampling, fuel pollution, wash from boats

- Global climate change and sea level rise may cause flooding and saltwater incursions

Management strategies:

- Sediment removal from Broads and rivers- remove phosphates

- Phosphate removal from liquid effluents at sewage works

- Coypu eradication

- Carr woodland and reed bed clearance followed by the re-establishment of commercial reed cutting

- Bank protection

- Better boat designs to reduce wash

- Boat speed limits

- Path maintenance

- Public education

A plagioclimax habitat, found on sand and gravel soils. The soils are naturally infertile because heathlands have not usually been farmed intenseively. Low use of fertilisers and pesticides allowed many species to remain. Grazing and burning prevent woodland re-establishment. Smaller plants thrive off the lack of woodland. Animals include: Sand lizards, smooth snakes, nightjars and Dartford warbler.

Threats:

- Urban expansion

- Conifer plantations

- Golf courses

- Stopping the use of burning, technique used in the management of heathland

Species that live in hedgerows are often the species found in woodlands, particularly around the edges or next to clearings

Types of hedgerows:

- Woodland relic hedges- strips of woodland left between fields as woodland was cleared. Usually rich in plant-life and animal-life so great wildlife value

- Planted hedges- planted to divide up Common Land on the open farming landscape, often as part of the 'enclosure movement', since the Middle Ages. Some were planted to provide barriers to keep livestock in. They usually have fewer plant species so they are of lower wildlife value than woodland relic hedges

Hedgerows act as biological corridors linking other habitats such as isolated woodland for species such as mice, squirrels, weasels, stoats and dormice.

Reasons for hedgerow loss:

- increase in the size of arable fields for the easier use of machinery

- increase in the farmable area and food harvests

- road widening

- Replacement by fences, easier to maintain

- Damage by vehicles, which creates gaps

- Neglect by ceasing traditional management such as hedge-laying

Threats to the environments through Hedgerow loss:

- Loss of wildlife

- Loss of habitats for predators that control agricultural pests

- Increased wind erosion in neighbouring field

- Reduction in the scenic quality of the countryside

 Originally covered with woodland but cleared for farmland. Farming led to serious soil erosion meaning crop growing had to stop. Then used for sheep grazing allowing the grass to protect the thin soil but prevented ecological succession which would have re-established the woodland. Species include: Cowslips and monkey orchids, the chalkhill blue butterfly and birds including the stone curlew and skylark

Threats:

- Intensive farming with ploughing and use of fertilisers to substitute for fertile soil

- 'Improvement' of the grassland using fertilisers, pesticides and re-seeding with more productive grass varieties

- Urban expansion and road building

- Abandonment of grazing when sheep farming is not profitable. Leading to secondary succession where thorn and scrub woodland replaces the grassland

Rare species that live in meadows include plants such as the fritillary and greater butterfly orchid and birds such as the corncracke

Threats to hay meadows unclude the following:

- 'Improved' grassland- the ground sprayed with weedkiller, then ploughed and re-seeded with fast-growing varieties of grass that provide a higher crop yield. The wildflowers are killed and the reduced plant divercity means there are fewer insects and birds that feed of them

- A change in grassland management to silage cutting- the grass is cut several times during the summer and stored wet in silage clamps. Regular cutting kills wildflowers before can produce seeds and destroys the nests of ground nesting birds

 When the woodlands of upland Britain were cleared for fuel, the land was often used for sheep grazing, which produced a heather and grass community of great wildlife value

Regular burning helps to maintain the moorland plagioclimax, which may be used for grouse shooting

Threats:

- Conversion to 'improved' grassland where high yielding grass varieties are planted

- Afforestation with connifers

- Reservoir construction

- Abandonment of grazing or grous shooting, allowing secondary succession

- Increased visitor pressure as result of the Countryside and Rights of Way Act (2000)

Important moorland species include the hen harrier, golden eagle and black grouse

 Very biologically productive because of the large amounts of dead organic matter carried downstream by rivers or brought in by the incoming tides. Shallow, warm conditions also allow rapid algae growth

Abiotic factors in estuaries

- Salinity- ranging from pure seawater to freshwater where the river flows in

- Depth

- Turbidity- ranging from clear water to water with fine suspended solids brough in by river or sea

- Water flow rates- from very slow movement to speeds over 10 mph

- Period of exposure to air- from almost never covered with water to almost never exposed to the air

Threats

- Port developments

- Pollution from rivers that drain into estuaries

- Land reclamation

- Pollution from industrial developments such as oil terminals