APS 124 Gareths Lectures Flashcards
What is meant by a complementary distribution?
Where two species fill similar niches but in different parts of an environment
E.g. Crowberry vs dogwood in the UK
Similar plants but dogwood more common in south and crowberry common in south
What are the three factors that determine species distribution?
Climactic factors - global and regional patterns of distribution
2 physiographic factors - landscape more local scale
- e.g. Lapse rate -6.5 degrees for 1000 meter increase in altitude
- aspect - direction of a slope will effect the tree line
3 edaphic factors
- soil factors
Plant anchorage, water and nutrients
Define resource
Commodity that a organism consumes
Why do acidic soils often have less plant biomass?
Increases abundance of toxic ions
What are the six forms of interaction between species
Competition = both lose out
Facilitation= one species gains from another whilst having no detriment to the second species
3) parasitism = one species gains at the expense of another
4) mutualism = both benefit
5) commencsalism - similar to facilitation e.g. Bacteria living on you (no harmful)
6) ammensalism - no one benefits but one loses out e.g. Algal blooms in water
Define indirect competition
Normal competition where both organisms are competimg for the same shared resource
What is direct competition
A direct antagonism between plant soecies e.g. Strangling or parasitism
Differntiate between hemi and haloparasitic organisms
Hemi will have some chlorophyll e.g.witch weed
Halo parasitic - fully parasitic no chlorophyll e.g. Dodder
Define allelopathy
Chemical inhibit one plant by another via a release into the environment
Nitrogen depostion can be wet or dry and reduced or oxidised
Give an example of each combination
Dry oxidised - Nitrous oxide N20
Wet oxidised - No3 - (nitrate)
Wet reduced - NH4+ ammonium
Dry reduced - NH3 ammonia
What are the two major sources of anthropgenic nitrogen?
Fossil fuel combustion - NOx (oxidised emissions)
Agriculture - NHy (reduced emissions)
What is the UK N budget, how much do we export to Europe?
700 ktonnes per years
Export 321 tonnes
What are three factors effecting nitrogen deposition?
Distance from source - oxidied forms have larger dispersal distances than reduced forms
Surface roughness - faster on rough surfaces (woodland rougher than grassland)
Rainfall - more rainfall = more deposition
Describe the seeder feeder effect
A feeder cloud - orographic feeder sits above the hill and gathers pollution
Seeder cloud moves above and rains through the orographic cloud hence releasing all the pollution
Where are some N depostion hotspots? Why?
Brecon beacons and Peak District
- both agricultural land but very near industrial cities
Describe how eutrophication due to nitrogen depostion poses an ecological threat
Nitrogen accumulates in the soil and enables more nitrophillus species to grow = compeitive exclusion
Why does increased nitrogen deposition cause more acidic soil?
Depletes the quantity of cations in the soil
Increases the number of toxic metals
Is direct toxicity from nitrogen a big problem ecologically?
No
Eutrophication in dutch chalk lands caused which plant to expand?
Brachypodium pinnatum
What is the current average nitrogen deposition and what effect will this have on species richness? What about in peak district?
17kg per hectare
Reduce richness by 4/5 species
30kg per hectare
Recuce richness by half
Describe how nitrogen depositon is effecting the ecosystem service of providing clean drinking water
Looked at monoliths - rain water through monoliths Measured how much nitrogen left the soil 65-75% retained in calcareous grassland 37-16% retained acidic grassland Hence nitrogen is being kept in the water - worse quality for drinkng
How much will nitrogen depostion have increased by 2050?
Doubled
Nitrogen deposition is the ____ greatest
3rd
The ____ world biodiveristy hotspots make up ______ of the worlds global surface but contains ______ of global biodiversity
38
2.4
43
How much cooler would the earth be without the greenhouse layer
30 degrees
Define net radiative forcing
Difference in long wave radiation absorbed and radiated back into space
What was the last year in which temperatures where below global average?
1976
Describe the global climate change hiatus and why it is not accurate
Between 1998 amd 2013 there was said to be increase in global temperatures
But sea temperatures and arctic data wasnt taken into account both of which increased
What was the atmospheric carbon concentration in the 70s and 80s and what is it now?
360 70/80s
412.08 now
Give with percntages the four main greenhouse gases
CO2 65% industrial - 11% land use
CH4 - 16%
N2O - 6%
CFCs
What percentage of co2 emissions are from fossil fuels?
90%
What is the intergrated radiative forcing? Give values for CO2, N2O, CH4
The global warming potential of each gas i.e. How strong a climate change causer it is.
CO2 is 1
CH4 is 25
N2O is 298
What percentage of methane emissions is from biogenic sources? Give examples of sources, what do they have incommon
70%
E.g. Wetlands and rice crops - anerobic respiration
Give another name for extreme events such as floods and storms
Acute or pulse events
Since 1500 when have the 5 hottest summers been?
After 2000
In 2003 how many europeans died becuase of extreme heat
70,000
The extreme heat event of 2003 would have had a return time of ______ years but now it is ______ years
1000
100
Describe the Philippines super typhoon in 2013
6000 deaths
8 - 15 billion in damage
Show how the following extreme events are linked to increasing climate change
Storms - heat causes reduction in evapourative cooling
Precipitation- 1 degree warmer = 7% more saturated air
Storms - more latent heat energy and increased atmospheric pressure
What are the main ecological threats posed by extreme events
Pass lethal thresholds - climate change alone may not have a significant enough effect but extreme event may push beyond physioogical limits
Decreasing inertia to climate change - e.g. Storms destroys trees which provided a climate buffer - new ecosytem under trend climactic conditions
When is an event described as extreme?
When it is in the 95th percentile
How do you measure the ecological abundance of an event?
Abruptness describes ecological events
Magnitude/ duration
The duration is relative to the lifespan of the organism hence hard to keep consistent
- magnitude relies on the ecosytem responding
Describe the water bucket hypothesis experiments
Package water so ecosystems get more extreme precipitation with bigger gaps in between
Xeric and hydric conditions are less stressed in the more extreme conditons than ambient
But messic plants are more stressed
Describe the field manipulation study in konza prairie
Used shelters to manipulate rainfall, either 100 or 70%
And ambient or 50% gap
Lengthened interval between rainfall - more variable water content, 10% productivity reduction. altering packaging gives same response ss a 30% decrease in rainfall
Describe the effect rain no snow events can have on herbivores
Ice encasement and ice lenses
Mean food plants inaccessible in winter and could be damaged
Increase the rate at which svalnard reindeer populations decrease
Global warming will increase the rate of rain on snow events
Describe the interactions caused by rain on snow events on the svalbard ecosystems
3 producers - reindeer, ptarmigan bird, vold
1 consumer - arctic fox
The three producers are synchronised and fluxtuate
- foxes crash one year later
Rain on snow, herbivores die, carrion runs out then consumers start to die
How has climate change in the england, wales and northen ireland, since 1970?
1 degree
0.8 in wales and N.Ireland
What are three causes for uncertainty in future effects of climate change?
Natural climate variability
Incomplete understanding of the earths system as well as imperfect representation in climate models
Uncertainty in future man made emissions of GHGs
Give some examples of natural external influences on climate
Chnages in the amount of particles in the atmosphere from volcanoes
Suns energy - sunspots - 11 cycles
Haze effect - global cooling effect e.g. 1982 chichon cooled global temperatures by 0.3-0.5 ( a large volcanoe in mexico)
