17 - Ecological Dynamics

Question 1

Arctic amplification

Answer 1

arctic is warming faster than the global average

Question 2

what month usually has the most sea ice?

Answer 2

march

Question 3

T/F freeze up is occurring earlier

implications?

Answer 3

False

ice has less time to thicken TF leads to thinner ice cover that is prone to melting earlier

Question 4

sea ice loss ____ warming

Answer 4

amplified

Question 5

what current trends are shown by the normalized difference vegetation index?

Answer 5

seeing more greenness!

• longer growing season
• increasing shrub abundance

Question 6

T/F longer growing season increases marine primary production

Answer 6

True

Question 7

how does an increase in marine primary production impact benthic prey populations?

Answer 7

reduction in prey populations bc an increase in pelagic fish

• gray whales, walrus, sea ducks

Question 8

how does rain impact ringed seals?

Answer 8

rain collapses their birth layers, exposing pups to predators and hypothermia

Question 9

T/F boreal and arctic lakes experience dimictic thermal stratification

Answer 9

False - arctic monomictic

Question 10

What months do monomictic lakes experience stratification

Answer 10

winter

• constant mixing in summer

Question 11

increase in _____ can cause summer stratification

Answer 11

temperatures

Question 12

what are the effects of increased stratification?

Answer 12

• positive feedbacks via warming of surface layer
• increase in phytoplankton and zooplankton growth rates
• increased propensity to deep water oxygen depletion
• increased retention of contaminants within arctic food webs

Question 13

how will warming benefit some animals?

Answer 13

easier access to forage for the svalbard reindeer

Question 14

what has ablation associated with winter warming resulted in for svalbard reindeer?

Answer 14

reduced mortality,
increased fecundity,
increased abundance

Question 15

T/F there has been a range decrease of winter month outbreaks in sweden

Answer 15

False - expansion

Question 16

T/F responses to climate change may be masked by species interactions

Answer 16

True

Question 17

how do warmer temperatures impact nutrient, phytoplankton and zooplankton abundance

Answer 17

more nutrients

higher abundance of phyto, zoo, MOST crustaceans

Question 18

T/F primary productivity response to warming if affected by trophic interactions

Answer 18

True

• higher productivity in lakes with fish than without

Question 19

presence of fish affecting the phytoplankton response to warming is an example of a ____ ____

Answer 19

trophic cascade

Question 20

implications of higher precipitation in winter

Answer 20

more snow –> later ice melt

lower nutrient input, limits productivity

Question 21

implications of higher precipitation in summer

Answer 21

more rain, higher runoff, higher nutrient loading

increase in phytoplankton production, leads to oxygen depletion under ice in winter

fish impacted by the primary producers as a result of increased precipitation

Question 22

list 4 arctic predators that are strongly tied to lemming cycles

Answer 22

lon-tailed skua
snowy owl
arctic fox
stoat

Question 23

provide an example of a phenological event

Answer 23

birds time their nesting so eggs hatch when insects available.
Insect emergence synchronized with leafing out in their host plants

calving by caribou in West Greenland coincides with emergence of plant growth

Question 24

greatest changes in climate will likely occur at ____ latitudes

Answer 24

higher

Question 25

T/F frequency of forest fires are expected to decrease, increasing nth total boreal forest area

Answer 25

false