climate change 5 Flashcards
impact of extreme temperature (23 cards)
impact of CO2 on corals
structural component is CaCO3 (aragonite shells)
CO3 is in equilibrium with CO2, more CO2 above ocean forms more CO3 (corals)
this relationship is dependant on PH
pH is also dependent on CO2 conc in water
inc CO2 decreases aragonite volume
measured impact of CO2 on corals
decreased calcification of corals
decreased coral growth rates
decreased coral skeleton density
impacts other organisms living in corals
effect of ocean CO2 on sea urchin
decreased ocean pH due to increase CO2
lower speed and motility of ocean sperm
effect of CO2 on temperature
strong correlation
CO2 absorb infrared: GHG effect
effect of global warming in artic
glacier melt
temperature increase is largest in artic
sea ice loss in the artic
ecosystem loss
impact of climate change on phenology
global warming interrupting phenology
e.g. day of first cherry blossom in Kyoto
e.g. grape harvest in France is become earlier
understanding the impact of global warming on biota
in the context of biotic responses: mean global temperature increase is likely not the best indicator of climate change
the spatial and temporal pattern of warming, particularly of extreme events, is probably more important
extreme events have bigger impacts on organisms
variation globally and seasonally
how extreme weather events impacts biota
mean temp increases slightly due to global warming
less cold, more hot, more extreme hot
the extremes are more impactful on organism survival: extreme events are above the lethal temperature limit for population
bleached coral
as corals get stressed symbionts (algea) are expelled from coral
okay as a short erm stress response, long term kills coral
location of coral bleaching hotspots
data from NOAA Jan-Feb 2025
in southern hemisphere, critically warm waters (summer)
many coral bleaching events in Great barrier reef
increasing frequency
first mass bleaching of entire reef from North to South
now added new alert levels (AL3-AL5) due to new severity
frequency of severe heat events with corals
at the great barrier reef (GBR)
DHW (degree heating week): measure of severity of exposure, both temp and exposure time
above DHW 4 is bleaching threshold
DHW 16 is coral death
more mass bleaching events, less recovery time
resultant coral decline
ecosystem impact of coral loss
less coral
replace by algae mats
less biodiverse
restoring coral reef
many strategies in place
regrowing coral on artificial structures and then replanted
small scale, is it feasible repopulation strategy
bleaching still occurs at the nursery
restoration is not feasible due to scale and still vulnerable to high temperature
must focus on preventing increasing sea surface temperature
effect of extreme temperature on food plants: rice leaf yeild
leaf temperature increases during the day in pattern with day temperature
rice leaf are exceeding the heat sterility threshold: above 33 degrees no seeds is produced
result: lower yield
effect of extreme temperature on food plants: rice leaf transpiration
high CO2
stomata close
less transpiration
less cooling
lower yield
lodgepole pine impact of temp
high temp causes more death due to bark beetles bc trees more susceptible
drier and hotter also kills trees
extreme heat and penguin
higher temp causes lower survival of king penguin chick
due to food source decline
downstream effects of inc CO2 on plants
stress tolerance
starch resources
biomass
leaf area
mycorrhizal infection
nitrogen fixation
effect: mortality, competitive ability, soil fertility, population dynamics, mutualistic interactions, decomp rate
how to study the effect of elevated CO2
feasibility
cost
reliability
artifacts (other things impacting study)
hypothesis
what will be the effect of the study
can CO2 enrichment study realistically show impacts of high CO2 environment
ways to study elevated CO2
plant growth chambers: highly controlled but limited to size
glasshouses: less prone to mechanical chamber, less environmental controls, more plants can be studied
open top chambers for field work: can be measured in environment
FACE: more realistic, covers entire communities but cost and low environmental control and limited replicability and flexibility
effect of simulated elevated CO2 on soy crop
done using FACE
free air CO2 enrichment
causes plants to close stomata
therefore effect on crop yield increase was less than expected
global increase in plant biomass due to high CO2
climatic feedback of elevated CO2
sea ice decrease
decreased albedo (amount of sunlight relucted)
positive feedback
higher rates of plant growth further decreases albedo
effect of CO2 on plant competition
other variables e.g. nitrogen, soil, water abundance
also impacts competition between plants
effect of elevated CO2 is highly complex
