ECEC - 3

Question 1

why was the environment mainly grassland in the devensian period?

Answer 1

the climate couldnt support forests - warming up led to the development of forests

Question 2

how could we know there was an ‘elm decline’?

Answer 2

pollen in bog showed a distinctive decline in elm pollen - reasons for decline are unclear

Question 3

what are landnam clearances when did they take place and what was their affect?

Answer 3

temporary forest clearances for crops and grazing- similar time as elm decline (3500 BC) - initial decline in tree pollen and increase in grasses but only temporary

Question 4

what were clearances like in the bronze age(2100 - 700 BC) ?

Answer 4

landnam clearances continued with increasing intensity - continued deforestation in well populated areas - centre of the microlithic industry

Question 5

what was deforestation like in the iron age (500 BC)?

Answer 5

climatic deterioration and increased precipitation with increasing deforestation continuing on from the bronze age

Question 6

what are 4 adaptations of grassland species to help survive grazing?

Answer 6

1) intercalary meristem - growth from mertistem at the base of the leaves so they aren’t destroyed when grazed - graminoid species
2) adpressed growth - leaves close to the ground (negatively phototrophic)
3) low palatability
4) ephemeral life history - grow during times of limited grazing and exploit bare patches of soil

Question 7

what types of soils do calcifuge and calcicole plants grow in and examples of species?

Answer 7

calcifuge = acidic soils - Nardus stricta
calcicole = calcareous soils - Scabiosa
columbaria

Question 8

why is PH a major influence on plant distribution?

Answer 8

because it influences the availability of ions

Question 9

why is species diversity much higher in the south?

Answer 9

because most limestone grasslands are there and this bedrock produces the most species rich grassland

Question 10

3 features of rendzina soils

Answer 10

1) high PH - low fertility
2) thin soil - shallow A horizon
3) immature soils

Question 11

describe the soils in the plateau, slope and valley of a limestone top sequence

Answer 11

Plateau = accumulation of acidic soils less affected by bedrock 
Slope = shallow soils with high levels of erosion 
valley = influenced by rivers bringing in organic matter increasing depth and nutrients

Question 12

what does crop litter mean?

Answer 12

the productivity of an area

Question 13

calcareous grasslands have intermediately low nutrient status but what is there alpha diversity like?

Answer 13

they have very high alpha diversity

Question 14

are low PH soils species rich or poor?

Answer 14

species poor

Question 15

what are helophile species and what effect did the development of post glacial forests have on them ?

Answer 15

sun loving - Development of the post-glacial forests
confined heliophiles to naturally open habitats- heliophiles eradicated from large areas of
shaded habitat

Question 16

when did the elm decline take place and what was happening during this time?

Answer 16

Boundary between the pollen sub-zones VIIa and VIIb ≈ Atlantic / Sub boreal boundary - Establishment of Neolithic farming in parts of Britain

Question 17

the reasons for the elm decline but what are 3 possible reasons?

Answer 17

• disease
• selective cropping
• trees pollarded to provide leaves for winter
  feed for livestock

Question 18

what are the reasons behind landnam clearances and how long did they occur for?

Answer 18

• For pasture or first cultivated and then grazed

- 50 years

Question 19

how many landnam clearance phases are there evidence for?

Answer 19

• 5 peaks of Plantago pollen between the Elm Decline and the Iron Age
• suggests 5 clearance phases, progressively larger and longer

Question 20

describe extensive neolithic clearances

Answer 20

• More extensive and ‘permanent’ deforestation in some parts of Britain
• starting after elm-decline & becoming progressively more important
• Associated with well-populated areas

Question 21

describe breckland soils?

Answer 21

• light, dry soils: quite easily cleared

- Centre of the microlithic industry

Question 22

what species grow over a wide range of PHs?

Answer 22

Festuca ovina - sheeps fescue

Question 23

which ion has low availability at high and low PHs?

Answer 23

phosphorous

Question 24

why are rendzina soils thin?

Answer 24

due to the purity of the bedrock - pure limestone provides very little insoluble residue on dissolution – little material to contribute to the development of a deep soil profile

Question 25

describe Grimes hump back curve for species richness and crop mass?

Answer 25

between crop-mass 300 - 900 g m-2 =corridor of high potential species richness however within the corridor of
300 - 900 g m-2 both species-rich and species poor vegetation can occur

Question 26

what is the reservoir effect?

Answer 26

fewer species are adapted to grow on acidic soils than

calcareous soils