W2 Flashcards
What is an ecosystem?
A community of living organsims, interacting with one another and the non-living components of their environment
What is the material flow in ecosystems?
Atmosphere - 820 Pg of carbon - mostly as Co2
Vegitation - 560 pg of carbon
soils 1500 pg of carbon
cycles of matter and energy - cycling of carbon - carbon fixation through photosynthesis
litterfall - organisms die and go into the soil
exchange of carbon dioxide as a byproduct of repsiration - exchange carbon with atmosphere
Where is the most carbon stored in organisms?
bodies of plants
animals are less that 2% of living biomass of things - tend to ignore animals in considerations of the exchange of carbon
Where does the engery from ecosystems orginate from and how is it cycled through the food chain
The sun -photosynthesis of plants and primary producers like algae
herbivores eat that and then they are eaten by preditors
How many species are there on earth>
8.7 million multi-cellular species and only 1.2 m have been discovered
Can you speak to the global distribution of species diversity?
Uneven global distribution - move towards the equator the taxon get more diverse
not really sure why - scientific gap
What are biomes?
communities that experience a similar climate so veg tends to look similar and have similar species
eg. tundra, tropical forests, temperate grassland, desert
biomes are defined by climate
What are the options for species in the context of cc?
Move - towards the poles noth and south - gets cooler to find a climate more suitable
Adapt - evolutionary - process of natural selection will generate a population that is better adapted to the current climate
or behavioural adaption like shade seeking behaviour
Go extent - limits to adaption or cant move
Can you speak to spruce pollen changes?
do poorly when temrpature is too high - adapted to cool climates
moving abundance further north
What might limit species shifts under climate change?
limits to how fast and how far species can migrate
i.e difference between trees and split-hooved animals
most animals and plants wont or cant move through a homogenous landscape like a city
What is assisted mitgation?
a conservation philsophy - introducing species to another community
but the potential to drive other species in that community to extinction
transfer of disease
What determins the disperal of plants?
Wind
animals
water
bursting
humans
- vast majority of trees seeds are found a couple of meters away from the mother tree
animal eating accelerates seed disperal but these tend to be outliers
this makes the modeling of seed dispersal v difficult
How does a cow dissipate heat and how is this affected by higher temperatures
around 30oc
- radiation
-convection
-conduction
-radiation
many ways of dissipating heat - but depdent on the relative heat of the cow to surrounding area
when it reaches 40o
only dissipate heat through breath evaporation and evporative sweating
can overheat and die
idea that every organism has a max level of heat or drought that they can stand
Can we observe real-time evolution in response to cc?
Elephants with smaller tusks are not being hunted for their ivory - elephants with smaller tusks survive
ocean - fish that are too small tend to get thrown back - big fish don’t survive
selective breeding - driven by people choices is the same underlying mechanism
Spring is happening earlier - plants have changed then they leaf and flow - happens earlier
What is phenological mismatch?
Birds like the blue tit - require a large amount of caterpillars between mid-may and june for the hatching of their offspring and fledging
blue tit has not changed their behaviour
however, peak abundance of caterpillars are occurring earlier -
Why is exintction difficult to model?
Difficult to know the exact cause of historical extinctions
models that give estimates may not account for phenological mistmatchs, adaptive potential of species and migratory potential of species
What is the global expectations for species extinction
Highest in south america
high in australia and agrica
less impact in Europe and north America
What are the main pressures on the amazon ecosystem?
Amazon is being deforested
fragmentation of the ecosystem - changes behaviours within
hotspot of forest loss and hotposts of wildfires
- intensifies fire related disturbances
- fires have an impact don’t the re-growth of the canopy depending the number of fires
fires coupled with droughts - big impact on mortality rates of tres
amazon die back
How does a coral reef become bleached?
Healthy coral gets stressed from changes in the environment
algea leave which the coral is dependent on - algead give the colour
corals like warm water but not too warm
What was the impact of the 2016 heatwave on coral?
Huge loss of coral - v converning - improtant specieis
sea temperatures going up so likely to happen again - especially with predicted increase in heat wave intensity
What are three impacts humans have on the climate that particularly impact ecosystem?
Human activities cause
- warming
-changes in precipitation
-ocean acidification
What have been species responses to cc?
- observed to alter their ranges
- adapt - physiologically or evolutionary
- climate-related extinction in this century
What is the carbon climate feedback?
If climate changes or changes preciptation alter the balance between photosynthesis and respiration there is a carbon climate feedback
positive - if it favours carbon loss from the ecosystem into the atmosphere
negative - when cc alters in such a way that land absorbs more Co2 from the atmosphere and this slows it down
Can /you talk about the feedback of amazon die-back
Temperature rises –> drought and wildires in the amazon –> more trees die and decompose or burn releasing CO2 –> fewer rainforests trees means less water is pumped into the atmosphere –> rainfall decreases –> droughts
Is soil carbon being lost to warming?
Postive cliamte feedbacks
on average when the soil is warmed it releases carbon dioxide back into the atmosphere
What is a free air Co2 experiment? what were the results?
direct fertilisation of plants using carbon dioxide
pipe pumping Co2 out to the trees and measure the growth of the trees to see if they get bigger
Results
- growth was higher when CO2 was supplied to the trees
but the difference disappeared as time went on
at this point when it had little effect nitrogen was added - growth boost was maintained
Might CO2 fertilisation effect have the potential to fully offset emissions - why or why not?
Younger trees are not as effective at sequestering carbon as older trees
not good at storing carbon
rely on temperature and sunlight - not enough to plant trees also have to be in the right environment
are there sufficient nutrients for the plants to grow - not just about sunlight, temperature and co2
nitrogen is a limited nutrient - need to have the right proportion of elements
What is the impact of postive feedback in GHG?
ecosystems emit more ghg
include veg dieback and loss of soil carbon
What is the impact of a negative feedback in ghgh?
ecosystems absorb more ghg
Co2 fertilisation
nutrients, water and temperature will still ultimately limit the Co2 fertilisation effect
What are the implications of the impacts on ecosystems on humans?
Direct impact on how crop plants are responding to cc - reduction in yield due to it being too dry or to hot
some areas will have a reduction or increase in agricultural yields - complexity of ecosystems
What is the potential impact of diseases as a result of cc?
Future distributions of misquittos - carry denge fever
currently mainly impacts tropical countries but increasingly will move to northern latitudes
What is the disease diluation hypothesis?
the more diverse your ecosystems the more potential hosts there are for any particular type of disease
What is the esimated value of nature for people?
£97 trillion
What are the four cateogories of ecosystem services?
- Provisioning services
-Reulgating services
-Cultural services
-Supporting services
What are some examples of provisioning services?
- Food
-water
-raw mterials
-medicinal resources and biochemicals - ornamental and genetic resources
What are some examples of regulating services?
- Cliamte regulation
- natural hazard
-purification and detoxification of water - air and soil
- water and water flow
-eroion and soil fertility - pollination
-pests and disease control
What are some examples of cultural services?
- opp for recreation and tourism
- aesthetic value
-inpiration for arts - information for education and research
- spiritual and reglisious experience
-cultural identity and heritage
What are some examples of supporting services?
- Ecosystem process maintenance
- lifecycle maintenance
-biodiversity maintanence and provision
Can you speak about the horseshoe crab?
Blood of the horse shoe crab is a diagnostic tool for finding pathogens in human blood
no synthetic alternative to it
previous unaware
worth £46,000 per gallon
What are the long and short term implications of climate induced changes to ecosystems?
SHORT
- impact agricultural productivity and influence the spread of disease
LONG
- climate-related extinctions will harm humanity in unpredictable ways
What are four different types/examples of nature-based solutions
- constructed wetlands
- green urban spaces
- bioswales
- natural wetlands
-mangroves
-reforestation
Globally where is the there most potential for aboveground sequestration?
the same areas where there is the most biodiversity
need to choose where max of biodiversity for min cost
crate a blue print target
What is the impact of agriculture on soil carbon?
distrubed in agricultre and released back into the atmosphere
carbon accumulates in the top of the soil
potential to change agricultural strategies to better manage how soil is stored and managed in the soil
in line with regenerative agriculture - more carbon at the top
but this is v. dependent on soil type and whether the soil is gaining or losing carbon
challenging to measure the amount of soil carbon - cant count in the same way you can trees
How can natural ecosystems absorb and store CO2?
photosynthesis
can protect carbon already locked away in the atmosphere - like in wood, soil and sediment
What do nature based solutions offer?
important ecological co-benefits but these are insufficient to offset anthropologenic impacts without emissions reductions
