extreme events to warming drought impacts Flashcards
extreme events become more frequent with climate change because of an increase in…
mean - warmer temps overall = hot weather more likely
variance - more variance in climate means more extremes are more likely
abruptness
magnitude/duration
winter trophic system
3 herbivores: - svalbard reindeer - svalbard rock ptarmigan - sibling vole 1 consumer - arctic fox large population fluctuation
natural external influences on climate
changes in amount of particles in the atmosphere from volcanoes
sun’s energy
both have influenced past climate
internal influences on climate
interactions between ocean and atmosphere e.g. el nino
north atlantic oscillation
north atlantic oscillation
dominant driver of winter climate in the north atlantic hemisphere
wet winters in europe
cold and dry winters in n. canada and greenland
liquidity
water molecules stick together vie weak hydrogen bonds
water is liquid at unusually high temperatures
marine photoautotrophs
capture about 3% of the sun’s energy that hits the sea
macrophytes (seaweeds)
benthic autotrophs (live at bottom layer of ocean/lake)
need to be attached to seabed
need light
phytoplankton
single floating cells
occur throughout oceans
produce about half the oxygen in the atmosphere
4 major classes of marine phytoplankton
cyanobacteria, haptophytes, dinoflagellates, diatoms
problems for phytoplankton
phytoplankton tend to sink = life threatening
bigger cells sink faster
overcoming 2 layered ocean dilemma
mixing of surface waters by wind
coriolis effect caused by earths rotation
surface currents driven by ocean to atmosphere interactions
thermohaline circulation
cold water sinks near poles and moves equatorwards through the deep oceans
tropical water is lifted, mixed or welled towards surface
at surface it is heated and moves towards poles
native plant species decline (uk)
28% native plant species have decreased
median change +7
native breeding birds decline
54% native bird species declined
median change -2
native butterfly decline
71% native butterfly species decline
median change -13
resistance
the ability of the plant community to maintain composition and biomass
resilience
rate of recovery
PCA
principle component analysis
- summarises plant community composition
- plots close together have a similar composition
wytham
early successional state
community more dynamic and prone to change
why is buxton resistant to change
infertile system - slow growing
space occupancy
major barrier to change in systems of long lived plants
climate envelope
limit of range based on tolerance to climatic variables
