lecture 33 - terrestrial ecosystems: deserts, tundra and peatlands

Question 1

characteristics of a desert

Answer 1

low rainfall, high evaporation, hot or cold, large variation in diurnal temp

Question 2

plant adaptations in Deserts

Answer 2

avoid or tolerate drought

Question 3

how have plants adapted to tolerate drought

Answer 3

intensification of water absorption
reduce transpiration

Question 4

how do plants intensify water absorption

Answer 4

shallow spreading roots or deep roots dew or fog traps

Question 5

how do plants reduce transpiration

Answer 5

sunken stomata
reduced stomata
scaly/hairy leaves
rolled leaves
retain leaves around the stem

Question 6

what is CAM

Answer 6

crassulacean acid metabolism photosynthesis

Question 7

how does CAM work

Answer 7

stomata closed during the day
during the night acids are accumulated in chlorophyll containing part of plant and converted to CO2 during the day

Question 8

physical characteristics of the tundra

Answer 8

cold, low precipitation, permafrost, short growing season

Question 9

botanical characteristics of the tundra

Answer 9

botanical diversity is low, shallow roots, perennial with vegetative reproduction

Question 10

why is the nutrients cycling system low

Answer 10

slow weathering, low N fixation, shallow soil due to permafrost, minimal input of nutrients

Question 11

what is peat

Answer 11

partially decayed organic matter of plant origin formed under wet, anaerobic conditions

Question 12

how is peat formed -succession 1

Answer 12

lake- reed swamp- fen-raised bog

Question 13

how is peat formed succession 2

Answer 13

forest - pasture/arable - heath- blanket bog

Question 14

what is the pH of a bog

Answer 14

<4 very acidic very low in bases

Question 15

ombrotrophic bog characteristics

Answer 15

low in nutrients, water logged acidic

Question 16

plant strategies in an ombrotrophic bog

Answer 16

mycorrhizae
efficient recycling
Xeromorphs
carnivorous habit
efficient ion exchange