APS124 Pheonix Flashcards
1
Q
What is the period between 115,000 and 10,000 BP known as?
A
“The Devensian cold stage”
2
Q
The Devensian cold stage comprised…
A
- interstadials - embedded periods of temporarily ‘warm’ condutions
- stadials - embedded periods of ‘cold’ conditions
generally ‘cold’ but considerable temperature fluctuation
3
Q
What are the cold, arctic tundra-like conditions south of glaciers called?
A
Periglacial conditions
4
Q
After the first period of cold in the Devensian cold stage, where there is likely to have been permafrost soils, what is the first interstadial period known as?
A
Chelford interstadial (~60,000 BP)
- birch, pine and spruce
- rich vertebrate fauna, inc. temperate and boreal species
- February mean of -10C
- July mean of 16C (now 17C)
5
Q
What was the warm period before the Devensian cold stage called?
A
Ipswichian interglacial
6
Q
What is the second interstadial period in the devensian cold stage?
A
Upton Warren Interstadial complex (42,000-38,000 BP)
- July mean of 16C
- Possible cold winters (-15C Jan?)
- Species-rich flora - thermophilous species
- dward willows and birch but no trees - possibly due to cold winter temps or herbivores (pressure from them)
- rich vertebrate fauna
7
Q
The Upton Warren interstadial complex was followed by…
A
the Dimlington stadial - long period of cold
- maximum expansion of Devensian ice (~21,000 BP)
- periglacial fringe south of extensive ice sheets
- large herbivores probably forced south (lemming evidence too)
8
Q
The Dimlington stadial was followed by…
A
the Windermere interstadial
- rapid climatic warming after ~13,000 BP
- July mean temps 17-18C
- Park-tundra vegetation
- more continuous woodland
- Pine woods in the south and east
- strong reduction of the ice caps
9
Q
The Windermere interstadial was followed by…
A
the Loch Lomond stadial
- return to cold conditions for about 1000 years
- july mean temps 10-12C
- caused by disruption of the gulf stream?
- ended with very rapid temperature rise, leading to the post-glacial (Flandrian period)
10
Q
So what is the order of everything then?
A
Ipswichian interglacial –> loooong cold period –> Chelford interstadial –> cold period –> Upton Warren interstadial complex –> Dimlington stadial –> Windermere interstadial –> Loch Lomond stadial –> Flandrian (~10,000 BP)
11
Q
From 10,000 BP, there is large expansion of…
A
forests
12
Q
What is the forest maximum?
A
The period where the most of the UK is covered by forest
13
Q
Godwin zonation looks at…
A
pollen taken from peatland in Hockham Mere (in East Anglia) - deeper peat core = further back in time, so can see dominance of different species
14
Q
Zones I-III equate to…
A
I. pre-windermere
II. Windermere interstadial
III. Loch Lomond stadial
15
Q
Zone IV equates to…
A
the post-glacial birch zone
- 9500 BC
- sub-arctic climate
- Birch dominant
- willows, juniper
- some pine (probably restricted to south)
16
Q
Zone V equates to…
A
the hazel-pine-birch period
- 7600-5500 BC
- Hazel expansion (esp. north and west)
- Birch still dominant despite warming
- In south, pine begins to dominate
- start to see pollen evidence for warm-loving (thermophilous) trees
17
Q
Zone VI equates to…
A
Hazel-pine period
- Pine abundant more or less everywhere
- hazel still important
- Appearances of thermophilous trees in some quantity
- expansion of elm and hazel, then oak, then lime and alder
18
Q
Zone VII equates to…
A
the forest maximum (alder/mixed oak)
- 5,500 - 3,000 BC
- rapid increase in alder (at expense of pine and birch)
- oak still relatively abundant
- lime reaches peak
- elm declines half way through
19
Q
What was the climate like during the forest maximum?
A
- warm and wet (climatic optimum)
- implies high temperatures and pronounced oceanicity
- biological evidence supports that temperatures were up to 2.5C higher than today - trees reached highest altitudes and latitudes
20
Q
Zone VIII equates to…
A
alder-birch-oak-beech period
- cooler and wetter
- lime declines
- appearance of beech and hornbeam
- brings us to about 500BC
21
Q
We can describe species distributions on…
A
local, national and global scales
22
Q
Daisies are found everywhere in the uk, so is known as…
A
cosmopolitan. - well-adapted to the UK
23
Q
Sea sandwort has a distribution determined by…
A
maritime conditions
- “salt-loving” halophyte
- grows well in sands and shingle
24
Q
Often species which favour differing climatic conditions have … distributions
A
complementary
- e.g. crowberry (northwest) and dogwood (southeast)
25
Plant distributions can be explained in terms of three groups of factors:
- climatic factors
- physiographic factors
- edaphic factors
26
Climatic factors include... and are responsible for main global and regional patterns of plant distribution.
temperature, rainfall, light, wind, humidity
27
In the uk it is warmer in the ... and wetter in the ..., and windspeeds are higher at higher ...
south, west, altitudes
28
Physiographic factors are determined by... and include...
the landforms (physiography) of the landscape,
- altitude: lapse rate ~-6.5C for each 1000m increase in altitude
- aspect (= direction of slope) influences irradiance received - south-facing slopes tend to be warmer
29
Edaphic factors are associated with..
the soil
30
for plants, the main functional features of the soils are that they provide a...
- rooting medium (anchorage)
- source of water
- source of nutrients
The soil (and other parts of the environment) tehrefore provides both conditions and resources
31
Resources are...
- commodities which are 'consumed' by plants
- essential for growth (e.g. CO2, O2, H2O, nutrients)
- Different species have different capacities to use a particularly level of resource supply
- insufficient resources give poor growth (sub-optimal)
- excess resources do not necessarily result in an increase in growth, and are sometimes detrimental (supra-optimal)
32
Conditions are..
- environmental variables to which plants respond
- not consumed
- some may help to regulate the availability of resources, e.g. pH
33
Light can be both a...
condition and a resource
34
Look at interactions pic on phone
go on do it
35
Competition occurs when...
the growth or development of an individual is adversely affected by the presence of another individual
- may be direct or indirect
36
Indirect competition is when individuals...
attempt to obtain the same, shared resource (e.g. light, water, nutrients or growing space)
- requires some resource to be of limited availability
- is dependent on the density of individuals
37
competition increases with higher...
densities
38
allocation of resources to ... is often the first to decline
reproduction
39
Direct competition is...
a form of antagonism between different plant species - less common than indirect competition between plants
e.g. strangulation (e.g. strangler fig), allelopathy (chemical warfare), parasitism (e.g. mistletoe)
40
There are over ... species of parasitic plants in 17 families. 80% are ..., meaning.... 20% are holoparasitic, meaning...
3000,
hemiparasitic - have chlorophyll but obtain some carbon, nutrients and water from their host
holoparasitic - no chlorophyll, obtain all their carbon from their host (e.g. Cuscuta/Dodder)
41
Facilitation occurs when..
a plant benefits from having a neighbour (opposite of competition)
- especially important in extreme environments (e.g. arctic, alpine, desert ecosystems) - relative neighbour effect more often positive at high elevations
42
What is dry nitrogen deposition? Wet?
in gas or aerosols
| in rain
43
Oxidised forms of N (NOx) include...
wet: NO3- (nitrate)
dry: NO2 (nitrous oxide)
44
Reduced forms of N (NHy) include...
wet: NH4+ (ammonium)
dry: NH3 (ammonia)
45
What is the main source of NOx?
fossil fuel combustion (e.g. power stations, cars)
46
What is the main source of NHy?
Agriculture (especially ammonia, NH3, from livestock manure)
47
How much nitrogen does the UK emit every year? How much falls back down?
around 720 kilotonnes
| around 400 kilotonnes
48
Nitrogen deposition velocities are faster to ... ...
rougher surfaces
49
Some upland areas have high rates of N deposition due to...
rain and seeder-feeder effect
50
How can eutrophication threaten UK ecology?
N accumulation in soils allows expansion of nitrophilous species, resulting in competitive exclusion of others and declines in biodiversity
e.g. dutch chalk grasslands
51
How can soil acidification threaten UK ecology?
Soil acidification, base cation depletion and enhanced availability of toxic metals can reduce plant health and productivity, alter community composition and cause declines in species richness
52
What are two other mechanisms of N deposition threatening UK ecology?
- increased susceptibility of plants to secondary stress (greater herbivory, reduced resistance to pathogen attack, increased susceptibility to drought and/or freezing damage)
- direct toxicity to plants
53
Grasslands accumulate up to ... of the pollutant N deposition, maintaining provision of clean ...
75%,
| groundwater
54
Global N deposition is estimated to be ... greater in 2050 than 1990
two-fold
- "3rd greatest threat to global biodiversity after land use and climate change"
- industrialisation of developing countries is a major issue
55
There are ... world biodiversity hotspots, proposed by Conservation International as regions of conservation priority. They cover only 2.4% of the earth's terrestrial area, yet contain as endemics, ... of the world's vascular plant species and ... of all terrestrial vertebrate species
36,
>50%,
43%
- many are in developing countries undergoing industrialisation
56
Climate is not...
weather
57
Climate refers to the ... conditions experienced in a region over...
average, 30 years
58
We do need some greenhouse effect, otherwise the earth's average temperature would be...
33 degrees cooler
59
Net radiative forcing =
the difference of insolation (sunlight) absorbed by the Earth and energy radiated back to space
60
when was the last year the Earth was cooler than the 20th century average?
1976
61
More than 93% of the absorption of global warming by our planet is...
by the oceans
62
Who first discovered CO2 was increasing?
Roger Revelle
63
Which scientist really made the foundations for understanding increasing CO2?
Charles Keeling
- took samples at south pole and hawaii
- classic "keeling curve"
64
What are the main greenhouse gases?
CO2 (carbon dioxide)
CH4 (methane)
N2O (nitrous oxide)
plus a number of CFCs
65
Global Warming Potential: compares the..
integrated radiative forcing over a specified period (e.g. 100 years)
- a measure of how much energy the emissions of one ton of a gas will absorb over a given period of time, relative to the emissions of one ton of carbon dioxide
- CO2 has GWP of 1, CH4 has a GWP of 25, N2O has a GWP of 298
66
... produces over 60% of nitrous oxide emissions
Agriculture
67
... sources produce >70% of the global total emissions of methane. This includes...
biogenic,
| wetlands + livestock + rice agriculture + landfills + termites
68
Climate change can be split into two types:
Trend changes - e.g. CO2, mean temperatures, mean precipitation, N deposition
Extreme events - drought, heavy rainfall, heat waves, storms, (N deposition)
69
Extreme events are short in ... but large in ...
duration, magnitude
70
Why do extreme events become more frequent with climate change?
- increase in mean - e.g. warmer temperatures overall means very hot weather more likely
- increase in variance - more variation in climate means extremes more likely
- increases in both mean and variance
71
All 5 of the warmest summers on record in europe have occured...
in the 21st century
72
How many people died in the 2003 heatwave?
70,000 people
73
Extreme hot summers ("ref 6") used to have a return time of ... years, and now the return time is every ... years, giving a ...-... frequency increase in just a decade.
52, 5, ten-fold
74
Since 1900 the frequency of heatwaves has pretty much ... globally
tripled
75
Why does global warming lead to higher precipitation in some areas?
Warmer air holds more moisture (7% more water vapour for every 1 degree increase in air temperature)
76
Increased atmospheric moisture leads to more storm events as...
there is more latent heat energy to drive storms, plus higher sea surface temperatures lead to more tropical storms
77
There will be more heatwaves. Heatwaves can take organisms past...
lethal thresholds - can send ecosystems in completely different directions and allow different species to totally dominate
78
An extreme event is climatically any event in the...
95th percentile
79
Ecologically, extreme events are described by the concept called...
abruptness
= magnitude/duration
Duration being relative to the lifespan of the organism
80
What is Knapp et al.'s "soil water bucket concept"?
Climate change is driving more extreme precipitation, less often
81
How can extreme events affect animal populations in the arctic?
It can cause ice encasement and ice lenses (due to extreme winter warming events and winter "rain on snow" events), making food plants inaccessible in winter, and damaging plants so there is less summer food as well.
82
RoS stands for..
rain on snow
83
In Svalbard there is a close relationship between RoS and ... ..., and tight control of ground ice on ... ... ...
ground ice, reindeer population size
84
In ... ..., Canada, there is a subspecies of reindeer called Peary's reindeer, and this almost suffered a complete population crash between 1982 and 1998, with population declining by...
Banks Island, 87%
85
In arctic ecosystems, the population fluctuations between herbivores are closely ..., and the foxes (predators) are too if...
synchronised, the data is advanced by one year
- foxes lag due to abundance of carrion after rainy winte - recovery of populations due to reduced competition for food and reduced predation from fox
86
The Central England Temperatures (CET) have been monitored instrumentally since...
1772
| - what we see very much reflects global temperature changes and increases
87
Temperatures have increased in england by about... since ...
1 degree, 1970s
- temps in wales, scotland and NI +0.8C since 1980
- coastal seas surface temperatures +0.7C since 1980
88
What does IPCC stand for?
Intergovernmental Panel on Climate Change
89
UK uses projections of the IPCC - refined by ...
UKCP (United Kingdom Climate Projections)
90
Why is there uncertainty in climate change projections?
- natural climate variability (internal and external influences)
- Incomplete understanding of Earth system processes and their imperfect representation in climate models (modelling uncertainty)
- Uncertainty in future man-made emissions of GHGs
91
Natural external influences on climate include
- changes in the amount of particles in the atmosphere from volcanoes
- sun's energy
- both have influenced past climates and were important drivers before man influence
- must account for in models
92
sunspots peak every ... ...
11 years
| - although intensity varies
93
natural internal processes influencing climate change include
- interactions between ocean and atmosphere, such as el nino (oscillation of ocean-atmosphere system in tropical pacific) - positive phase has unusually warm ocean temperatures in equatorial pacific
- Uk impacts less predictable - weather tends to be more extreme
- north atlantic oscillation - dominant driver of winter climate variability in North Atlantic area - wet winters in Europe - cold and dry winters in north canada and greenland
94
There are different projections from different climate models, and greater uncertainties at smaller scales (e.g. locally/regionally - data needed). Multiple models allow ... ... ..., which take account of both known ... .... and that due to ... ...
Probability Density Functions (PDFs),
modelling uncertainty,
natural variability
95
What are the future UK winter climate temperature predictions (2060-79, based on GHG emissions peaking by 2040)?
Winter increase in 1-2 degrees over most of UK
96
What are the future UK summer climate temperature predictions (2060-79, based on GHG emissions peaking by 2040)?
Summer increase 1-3 degrees (more clear north-south gradient)
+2-3 degrees for Yorkshire & Humber
Summer maxima:
+2-3 degrees in England and borders
+3-4 degrees emerging in South
97
What are the future UK precipitation predictions?
little change in annual precipitation:
- 0-10% increase in N & W
- 0-10% decrease in S & E
winters wetter
- 10-20% increase in S and coastal
summers drier
- 20-30% drier in S & W
- 10-20% drier in most of N
98
Sea level rise is caused by..
- heating and thermal expansion of ocean water
| - melting of the ice sheets, ice caps and glaciers
99
The UK range of rise to 2010 is predicted to be
0. 1-1.0 m
| - south more affected as north is bouncing back after ice sheets
100
The gulf stream (North Atlantic Ocean Circulation) could weaken by....
50% by 2100
101
RCP 6 means
emissions peak around 2080
102
Even under optimistic RCP2.6, sea level rise of at least ... by 2100
If we let GHG emissions continue to rise (RCP6.5), more than ... rise by 2100
0. 4m,
| 0. 7m
103
Greatest warming will occur at...
high northern latitudes (northern oceans and boreal and arctic ecosystems
104
Even if we peak our CO2 emissions now, by 2050 we are projected to have lost...
over half of northern hemisphere sea ice
105
How can we study climate change impacts?
- looks at past and current change by monitoring populations of ecosystems over time
- site comparisons (not often used) - compare to "pristine" sites
- predict impacts of future change - simulation through manipulation experiments and gradient studies
106
How have plants and lichens been impacted by recent climate change in the UK?
+20%
107
How have vertebrates been impacted by recent climate change in the UK?
+18%
108
How have invertebrates been impacted by recent climate change in the UK?
-39%
109
When looking at species impacted by climate change in the UK, there are clear...
```
winners and losers.
Strong to moderate declines in:
- 31% of vertebrates
- 33% of plants and lichens
- 42% of invertebrates
```
110
In the UK there has been an overall ... decline in number of species
16%
111
In the UK there has been a 35% decline in the ... of species and a 67% decline in the ... of species
occupancy,
| abundance
112
Most causes of species decline in the UK have positive and negative influences. The biggest negative cause is ... ..., and the biggest positive influence is ... ...
intensive agriculture,
| climate change
113
Impact of ... on biodiversity "intactness" is clear. UK biodiversity is harmed to similar levels...
urbanisation,
| everywhere
114
Every group of animals is shifting north except..
herptiles
115
... ... ... simulate future climates. A classic study of this is between two UK limestone grasslands (most species rich plant communities in europe) - ..., Derbyshire and ..., Oxfordshire.
Field manipulation experiments,
Buxton - ancient pasture w/ low fertility,
Wytham - More fertile + early successional
116
When talking about plants, resistance =
ability of the plant community to maintain composition and biomass
resilience = rate of recovery
117
Buxton has had ... ..., whereas wytham has had ... ... of communities
little change, large divergence
118
Wytham is in an early successional state so the community is...
more dynamic and prone to change
- past climate is drier at Wytham but this did not predispose it to be resistant to change
- early successional, fertile communities of fast-growing, short-lived species will respond rapidly to climate change
119
Buxton is much more...
resistant to change
| - more mature, less fertile communities will respond more slowly
120
Land use change is replacing unproductive systems with more fertile systems, therefore..
we are making plant communities more responsive to climate change
121
Why is Buxton resistant to change?
- infertile system - slow-growing, long-lived perennials with persistent shoot and root systems
- opportunities for establishment of new individuals rare and low influx of propagules from outside
- grassland plants well-adapted to grazing (so grazing doesn't mask impacts of climate change)
- local variation in soil moisture and nutrients means system accomadates species that would otherwise be lost from more homogenous environments
122
The more "in succession" the ecosystem...
the more responsive to global change
| - ancient stable ecosystems are more resistant to global change
123
"... ..." is now recognised as a major barrier to change in systems of long-lived plants, e.g.....
space occupancy,
Heathlands and upland grasslands
- disturbance may trigger sudden shift
