L3 Post-Glacial History of British Flora

Question 1

what time period is he ice age in

Answer 1

quaternary

Question 2

What is the name for the current interglacial period and how long has it been going on for

Answer 2

The Holocene
11,700 years

Question 3

Which direction was the movement of continental land mass in the Quaternary period

Answer 3

Migration towards polar regions

Question 4

What mountainous region formed in the Quaternaty period and what did it cause

Answer 4

Himalayas
Led to significant cooling

Question 5

3 main events that occured in the Quaternary period

Answer 5

Migration of continental mass towards poles
Uplift of Himalayas
Closing of the Isthmus of Panama

Question 6

What change did the closing of the Isthmus of Panema bring about

Answer 6

Changes to ocean circulation

Question 7

What causes repeated glaciations

Answer 7

Milankovitch cycles

Question 8

What is involved in the Milankovitch cycles that causes glaciations

Answer 8

Eccentricity
Obliquity
Precession of the equinox

Question 9

What is eccentricity

Answer 9

Shape of earth’s orbit around the sun
Changes over time: sometumes circular, sometimes more eliptical

Question 10

What is obliquity

Answer 10

The tilt of the earth in relation to its plane of orbit

Question 11

What is meant by precession of the equinox

Answer 11

The season during which the earth is closest to the sun varies over time

Question 12

What happened to plants in the glaciated regions

Answer 12

Wiped out
Only species in the refuga survivef and repopulated

Question 13

What was the last major tree to migrate back after the ice age and why

Answer 13

Beech
Has very large seeds so is much slower a spreading

Question 14

What is studied in palaeoecology

Answer 14

Ecology of the past

Question 15

Ways to study palaeoecology

Answer 15

Terrestrial sediment cores
Ice cores
Sediments
Tree rings
Fossil pollen
Macrofossils (plant parts)
Charcoal
Fossil beetles
Stable isotopes

Question 16

How is sediment used in palaeoecology

Answer 16

Sediment is extracted as a tube of earth
Take samples along different points of the tube = different points in time

Question 17

What is the benefit of takinf samples from an anoxic environment

Answer 17

Preserves fossils

Question 18

How are the sediment tube samples processed in the lab (what is added to them and what does it do)

Answer 18

Hydrochloric acid added - breaks down everything except pollen as pollen contains highly resistant sporopollenin

Question 19

What is the Clements Gleason debate about
What is Gleasons’ view point and is it supported by palaeoecology

Answer 19

Wheterh plants behave as one organism
Gleason argues that species are individualistic and just happen to occur together at certain points in time
This is supported by palaeoecology as it shows species arrive and dominate at different times and different rates

Question 20

What is the possible origin of pine in Scotland

Answer 20

Glacial refuge off coast of Scotland which reestablished species

Question 21

What was the woodland structure of Britain in the early postglacial period

Answer 21

Treeless steppe-tundra flora with Arctic/Alpine flora

Question 22

What was the woodland structure of British woodlands 11000-10000 YA and what was the climate

Answer 22

Increase in juniper, birch, pine
Climate cold, becoming continental

Question 23

what was the climate in the pre-boreal period

Answer 23

cold but becoming continental

Question 24

explain what changes were seen in vegetation 10000-8000 BP

Answer 24

rapid rise in hazel
appearance of oak and elm

Question 25

what was the climate 10000-8000BP

Answer 25

continental

Question 26

How many years ago did Britain seperate from the European continent

Answer 26

8000-6000

Question 27

What was the climate 8000-6000BP and what plant structure dominated

Answer 27

Climate warm and wet, oceanic Wildwood forests

Question 28

At what time was the most complete wildwood development

Answer 28

5000BP

Question 29

What percentage of the UK is covered by woodland and how much of this is ancient

Answer 29

13%, majority conifer plantation Only 1.2% ancient

Question 30

7 main trees dominating wildwood uk

Answer 30

Alder Ash Lime Hazel Oak Pine Birch

Question 31

Where was Alder found 5000YA

Answer 31

Major river valleys and wetlands

Question 32

Where was Ash found 5000YA

Answer 32

Calcerous soils in S and E England

Question 33

Where was Lime found 5000YA

Answer 33

Fertile, non-calcerous soil in England and Wales

Question 34

Where was hazel found 5000YA

Answer 34

Calcerous soils beyond the range of Ash

Question 35

Where was Oak found 5000YA

Answer 35

Acidic infertile soil

Question 36

Where was pine found 5000YA

Answer 36

Western and Northern Ireland and Scotland

Question 37

Where was Birch found 5000YA Why was it often out-competed

Answer 37

Extreme limits of woodland growth (Northern Scotland) Low shade tolerance

Question 38

What events occured after 5000BP

Answer 38

Forest clearance Easy agriculture Blanket bog spread

Question 39

What types of pollen increased and decreased

Answer 39

Decrease in tree pollen Increase in graminoid pollen (grasses, cereals)