Plant biogeography

Question 1

plate tectonics

Answer 1

• convection currents in fluid move the crust
• crust is formed where convection currents move plates away from each other
• crust melts in subduction zones - pushed down under other crust
• continents ‘drift’ w/ crust over surface of earth
• from Pangea to today

Question 2

event-based biogeography

Answer 2

estimating no. of dispersal events by computing the most likely events that led to observed species distribution patterns

Question 3

6 floristic kingdoms

Answer 3

• holarktis
• palaeotropis
• neotropis
• australis
• antarctic
• capensis

Question 4

holarktis

Answer 4

• North America & Eurasia were joined in a single continent = Laurasia
• Atlantic opened up & continents connected periodically via land bridges between Alaska and Siberia
• contains temperate climate species

Question 5

palaeotropis

Answer 5

• comprises of tropical areas of Africa, Asia and oceania
• part of flora inherited from supercontinent Gondwana

Question 6

neotropis

Answer 6

• comprises of tropical areas of central and South America
• wetter and warmer climate millions of years ago supported tropical adapted flora

Question 7

australis

Answer 7

• flora has strong affinities with flora of gondwana
• below family level, highly endemic angiosperm flora, diversity shaped by effects of continental drift and climate change since cretaceous
• prominent adaptations to aridity and fire

Question 8

antarctic

Answer 8

• includes Antarctica, Patagonia, most of New Zealand and its subantarctic island
• dates back to time of gondwana

Question 9

cape floristic region

Answer 9

• greatest non-tropical concentration of plant species in world
• smallest of six kingdoms
• home to over 9000 vascular plant species

Question 10

succulent karoo

Answer 10

• 116,000km
• coastal strip of southwestern Namibia and south Africas cape province
• worlds richest flora of succulent plants
• harbours 1/3 of worlds 10,000 succulent species
• biodiversity due to extensive array of habitat types, massive speciation of arid-adapted biota in response to unique climate conditions

Question 11

plant poaching

Answer 11

• poaching of succulents is increasing
• huge demand in areas such as South Korea - small apartments, move a lot, not much time to care for plants

Question 12

CAM

Answer 12

• crassulacean acid metabolism
• involves nocturnal stomatal opening
• starch metabolism plays a key role in both