17 - Ecological Dynamics Flashcards
Arctic amplification
arctic is warming faster than the global average
what month usually has the most sea ice?
march
T/F freeze up is occurring earlier
implications?
False
ice has less time to thicken TF leads to thinner ice cover that is prone to melting earlier
sea ice loss ____ warming
amplified
what current trends are shown by the normalized difference vegetation index?
seeing more greenness!
- longer growing season
- increasing shrub abundance
T/F longer growing season increases marine primary production
True
how does an increase in marine primary production impact benthic prey populations?
reduction in prey populations bc an increase in pelagic fish
- gray whales, walrus, sea ducks
how does rain impact ringed seals?
rain collapses their birth layers, exposing pups to predators and hypothermia
T/F boreal and arctic lakes experience dimictic thermal stratification
False - arctic monomictic
What months do monomictic lakes experience stratification
winter
- constant mixing in summer
increase in _____ can cause summer stratification
temperatures
what are the effects of increased stratification?
- 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
how will warming benefit some animals?
easier access to forage for the svalbard reindeer
what has ablation associated with winter warming resulted in for svalbard reindeer?
reduced mortality,
increased fecundity,
increased abundance
T/F there has been a range decrease of winter month outbreaks in sweden
False - expansion
T/F responses to climate change may be masked by species interactions
True
how do warmer temperatures impact nutrient, phytoplankton and zooplankton abundance
more nutrients
higher abundance of phyto, zoo, MOST crustaceans
T/F primary productivity response to warming if affected by trophic interactions
True
- higher productivity in lakes with fish than without
presence of fish affecting the phytoplankton response to warming is an example of a ____ ____
trophic cascade
implications of higher precipitation in winter
more snow –> later ice melt
lower nutrient input, limits productivity
implications of higher precipitation in summer
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
list 4 arctic predators that are strongly tied to lemming cycles
lon-tailed skua
snowy owl
arctic fox
stoat
provide an example of a phenological event
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
greatest changes in climate will likely occur at ____ latitudes
higher
