L3 Post-Glacial History of British Flora Flashcards
what time period is he ice age in
quaternary
What is the name for the current interglacial period and how long has it been going on for
The Holocene
11,700 years
Which direction was the movement of continental land mass in the Quaternary period
Migration towards polar regions
What mountainous region formed in the Quaternaty period and what did it cause
Himalayas
Led to significant cooling
3 main events that occured in the Quaternary period
Migration of continental mass towards poles
Uplift of Himalayas
Closing of the Isthmus of Panama
What change did the closing of the Isthmus of Panema bring about
Changes to ocean circulation
What causes repeated glaciations
Milankovitch cycles
What is involved in the Milankovitch cycles that causes glaciations
Eccentricity
Obliquity
Precession of the equinox
What is eccentricity
Shape of earth’s orbit around the sun
Changes over time: sometumes circular, sometimes more eliptical
What is obliquity
The tilt of the earth in relation to its plane of orbit
What is meant by precession of the equinox
The season during which the earth is closest to the sun varies over time
What happened to plants in the glaciated regions
Wiped out
Only species in the refuga survivef and repopulated
What was the last major tree to migrate back after the ice age and why
Beech
Has very large seeds so is much slower a spreading
What is studied in palaeoecology
Ecology of the past
Ways to study palaeoecology
Terrestrial sediment cores
Ice cores
Sediments
Tree rings
Fossil pollen
Macrofossils (plant parts)
Charcoal
Fossil beetles
Stable isotopes