L9 Flashcards
What is heathland and what is it dominated by?
- Refers to a distinct type of vegetation dominated by ericoid dwarf shrubs
- Normally dominated by Calluna vulgaris
What are the two types of heathland?
Upland heathland and lowland heaths
Upland heaths (moors)
- 300-400m above sea level
- up to montane zone (the tree-line)
- 2-3 million hectares in the UK, which represents 75% of the global upland heath
Lowland heaths
- altitudes less than 300m
- 58,000 ha in the UK
- 20% of the worlds total
Is heathland dry or wet?
Neither - it can be both
Eluviation definition
The transport of soil material from upper layers of soil to lower levels by downward precipitation of water across soil horizons
Podzol soils
- characteristic of cool, wet climates
- typical of boreal forests and heathland
- intense eluviation of surface horizons
- nutrients and bases leached from upper horizons
- low nutrient, acidic soil
Podzol soil structure
- Iron layer is characteristic
- Iron oxides precipitates out and make it impermeable
- Prevents water loss
Origins of heathland
Post glacial
- Tundra-type vegetation included dwarf shrubs such as heather
- Survived woodland development in glades, clearings, cliffs, above the treeline
Forest clearances
Occurred from 5000 y BP
-On poor soils … increased acidity and nutrient leaching
-good for heathers, gorse
-poor for for grassland / crops
-Heather pollen increases in the pollen record at this time
Bronze age onwards (3000 y BP)
- Heathland established over significant areas
Why did heaths persist?
Poor soils, not converted to permanent agriculture - why don’t they become forest again?
Continued exploitation:
grazing / browsing (& fertilisation of fields)
heather thatch
turf fuel (turbary)
bracken: bedding, potash
gorse: fuel, fodder
sand & gravel
Coexisted with, and complementary to, agriculture
