Unit 8: Ecosystems - Stability, Change and Conservation Flashcards

Question

positive feedback cycles in global warming

Answer 1

1. less snow --> less sunlight reflection --> more radiation absorbed --> more ice melting 2. more heat --> more permafrost --> more decay and more methane 3. warmer oceans --> less dissolved co2 --> more co2 in atmosphere --> more heat 4. warmer temps --> more drought more fires --> more carbon release

Answer 2

emperor penguins use ice for breeding distance to/from sea is important early icebreak can kill chicks walruses use ice for resting lack of ice --> energy expenditure finding ice

Answer 3

warmer surface water decreases ocean currents, leading to stratification (stable layers instead of mixing) less current also leads to less upwelling of nutrients and altered timing, reducing nutrient cycling and primary production and energy flow

Answer 4

UPSLOPE animals live at top of mountain only them because niches if warmer, species move upslope to find optimal temp compete for niches with species already living up there POLEWARD same as before, but instead of up, they move to the poles

Answer 5

co2 absorption causes water to become acidic more difficult for corals to absorb carbon from water calcium carbonate shells of marine organisms dissolve warm water also causes coral to expel mutualistic algae (bleaching) thus, coral reef ecosystem collapses

Answer 6

capturing and storing carbon (making a carbon sink) --> photosynthesis --> plant growth --> building of shells of marine organisms --> fossilisation and peat formation

Answer 7

planting trees in areas w/ no trees

Answer 8

planting trees that have been cut down

Answer 9

usually fast growing species that do not occur naturally adv: positively affects carbon sequestration disadv: monoculture may have neg. impacts on other factors that affect ecosystem stability

Answer 10

peat = partially decomposed organic matter trapped under acidic, waterlogged soil (anoxic) can happen quickly in tropical environments restoring previously drained wetlands and reintroducing native species helps reestablish these areas as carbon sinks

Answer 11

study of seasonal timing of event in plants and animals changes in timing can indicate climate change 2 major factors: temp and photoperiod (daylight hours)

Answer 12

temp: bud burst (new leaves) photoperiodism bud set (growth stoppage) flowering (short day vs long day plants) bird migration

Answer 13

Temps are changing Two interacting species need to synch their timing if one is cued by photoperiods, and another by temps a disruption in temp may throw off the timing of events necessary for successful interaction i.e. caribou eat arctic mouse ear and time their spring migration to match the peak development of the arctic mouse ear -mismatch between migration timing and plant development-> not enough food supply i.e.2 great tit eat caterpillars need lots of food during breeding season caterpillar population peak earlier due to warmer weathers great tit breeding season stayed the same fewer surviving chicks

Answer 14

spruce bark beetle (pest) -develops in weak trees -healthy trees limit spruce bark beetle population -drought and warm temps stress trees -more spruce bark beetles 2 year generation time has reduced to 1 trees are now more susceptible and there are more beetles

Answer 15

tawny owl -overpopulation and competition = food shortage -variation = feather colour (gray vs brown) - survival of the fittest (less snow cover changes the ability to blend in) - increase in trait frequency = brown colour more common

Answer 16

ecosystem varied environments and species (i.e desert vs coral reef) species many diff species (i.e. fungus vs polar bear) genetic gene pool within species vary (poodle vs great dane)

Answer 17

many more now than then

Answer 18

1. overharvesting 2. habitat destructions 3. invasive species 4. pollution 5. global climate change

Answer 19

1. land use for agriculture 2. urbanisation 3. overexploiting resources 4. mining 5. dams and water extraction 6. diversion of water 7. fertilisers and eutrophication 8. climate change

Answer 20

biodiversity crisis: unprecendented loss of ecosystems, species, and genetic diversity 1. population sizes 2. ranges 3. species diversity in an ecosystem 4. richness and evenness 5. area 6. degradation extent etc etc simpson's diversity index: D = diversity index N = total number of organisms in all species n = total number of individuals in a specific species D = (N(N-1))/(∑(n(n-1))) high index when you have a high richness and evenness of species

Answer 21

overpopulation

Answer 22

in situ: conservation in the natural environment - no disruption to behaviour/evolution -cost-effective -active management ex situ: outside the natural habitat - captive breeding and release - preservation of endangered species - preservation of eggs/sperm/seeds

Answer 23

you cannot save them all EDGE of existence prioritises conservation efforts based on - uniqueness - likelihood of extinction)