Lecture 4 - Heaths & moors

Question 1

define heathland

Answer 1

distinct vegetation, dominated by ericoid dwarf shrubs

- Ericaceae family

Question 2

what is heather

Answer 2

most characteristic ericoid in British heaths
Calluna wigaris
- also bell heather, cross leaved

Question 3

why is there low floristic diversity and high conservation status

Answer 3

low nutrient status, acidic soil
much veg. restricted to UK
uncommon animals - smooth snake, Dartford warbler

Question 4

upland heath characteristics

Answer 4

above upper edge enclosed agricultural land
300-400m above sea level
up to montane zone (treeline)
2-3 mil ha UK - 75% world total

Question 5

lowland heath characteristics

Answer 5

58,000 ha UK - 20% total

<300m altitude

Question 6

Podsol soils

Answer 6

cool wet climate
intense eluviation of surface (loss material = rainfall > evaporation)
nutrients, bases leached from upper horizons

Question 7

soil zones

Answer 7

O = litter, acid humus/peat layer
A = dark grey, bleached sand - hard impermeable iron
B = clay, iron oxides
C = parent material, bedrock

Question 8

why is it a major carbon store

Answer 8

• iron + aluminium (B) accumulate, form thin layer hardpan - impedes drainage
• water logging upper horizons = simulate peat surface formation
• delayed decomposition = build up organic matter
• peatlands = largest carbon reserve UK, 3bn/t
  (more than UK + France forests)

Question 9

Heathland origin

Answer 9

• in/after bronze age
• brown earth soils beneath barrows in N. Yorkshire
• podsolisation = due to forest clearance, cultivation

Question 10

Heather dominance west Sheffield

Answer 10

• variation in onset, grazing suppresses
• dominance 400AD
• after long pastoral period back to Neolithic
• current recent dominance from 1800

Question 11

Red grouse management

Answer 11

• shooting £100bn/yr
• abundance affected by food availability = young shoots
• rotational burning 8-15 yrs = maximises biomass, provides more mature heather nesting patches

Question 12

why is burning bad for nutrients

Answer 12

• further nutrient loss via ash (leaching)
• smoke = loss of nitrogen
• elements of leached nutrients remain in upper, loss balanced by rainfall input
• ## N,P,S risk of depletion

Question 13

Reforestation

Answer 13

• may be lucrative
• most use exotic species e.g. sitka spruce (N.America)
• diversity loss, loss visual appeal
• depends on age of plantation
• conifer = species poor (evergreens)

Question 14

Broxa re-establishing birch (deciduous)

Answer 14

north Yorkshire

• small, contorted after 70 yrs
• no real commercial value
• no greater biodiversity than conifers on same soils

Question 15

Tulchan re-establishing birch

Answer 15

Scotland

• successful, important soil changes
• increased earthworms
• gradual old humus breakdown - conversion to brown forest soil
• decrease in H
• increase pH, Ca + P