101 Flashcards
open system
flows of e and matter in and out
closed system
flows of e in and out
all systems on earth are
open
the earth is what typw of system
closed
e sources for earth systems
sun moon extraterrestrial material grav radioactivity chem sources
system flow of co2-temp
inc co2 inc temp less snow n ice dec albedo inc temp (pos feedback, vicious)
pos feedback
reinforcement
vicious/virtous
neg feedback
self regulating
dampening down of origional signal
by 2100 how much temp inc range
0.3 to 4.8
by 2100 how much sea level rise range
26 to 82 cm
1st law of thermo
e not created or destroyed, only transferred
2nd law of thermo
transformations only occur when degredation occurs
ie) pe to ke
autotrophs
primary producers, form biomass from simple inorganic sources
heterotrophs
rely on other organsims for e
consumers
loss of e on small food chains can be
20-90%
aver solar e at top of atmos
2.63x10^6 kcal/m^2/y
planetry albedo %
36
clouds, atmos, dust n surface
% of insolation absorbed n re radiated
64
visible light wavelength
400-700nm
diurnal variation of insolation
midday and dawn
m: max vert intensity
d: low angle, spread
how do seasons vary insolation
orbital tilt cause change in pos of sun n local incidence
eccentricity of orbit (how much deviates from circular)
eccentricity of earth
0.0167
variation in insolation due to seasons
+- 3.5%
when did biosphere 2 project begin
sept 91, 8 sealed in
aim of b2
create balanced and slef sustaining replica of earths ecosystems
initial decline of o2 in b2 thought to be bc
system stabilisation
after how long was o2 pumed into b2
18/24, non self sustaining
reason for o2 depletion in b2
microbes in soil metabolise at abnormally large rate
why didnt plants uptake large co2 in b2
reacted w calcium hydro in concrete
how much more calcium carb found inside than out in b2
10x
what thrived in b2
crazy ants, cockroaches, morning glory
how many small vertibrate species died in b2
19/25
how many insects died in b2 and effect on plants
almost all inc pollenating so no plant prop
other issues w b2
water too nutrient rich (leeching)- had to run over algae mats
level of dinitrate ox dangerously high (b12)
albedo of: trop rain for farmland woodland grass
13%
16-18%
15-26%
25%
3 photosynthetic pathways
c3
c4
cam
what happens to plants during daytime
stomata open- co2 in, water out
percentage of c3 plants
85
purpose of photosynthesis
synthesise carbs from co2 n soil moisture
why os c3 inefficient
low co2 in chloro
c3 plants are adpated to
high co2
low temp
low moisture stress
when did c4 plants first evolve
7m years ago miocene
why did c4 plants become
low co2 and high aridity
what is moisture stress
water levels in plants lower than optimum/ norm
fixed co2 in c3 can be released by
photoresp
how c4 photo work
Co2 in
Fixed in mesophyll cells to 4C
Transported to chloro in centre of leaf within vascular bundles
Completed by rubisco
what secondary process doesnt occur in c4
photoresp
what is a biogeochemical cycle
how resources are utilised w/in geochemical cycle by living organisms
90% of biomass is composed of
c/h/o
earths reservoirs
biosphere
atmosphere
geosphere
geochemical cycles
the flow of elements through the Earth’s reservoirs (biotic and abiotic)
natural carbon source
volcanic and mid oceanic ridge subduction
co2 inc from 1750-2014
280-over 400 ppm
co2 levels currently are highest since
800,000 years afo
in 50 yrs @ mauno loa how much has co2 inc
310-390ppm
how often does mauna loa erupt
33 time since 1843
main sources of co2 (anthrop)
land cover change
fossil fuel combustion
cement manufacture
what percentage of anthrop co2 enters atmo
around 50
3 main carbon sinks
atmosphere
biosphere
oceans
if rate of photo is higher than resp
biomass inc
how do oceans store c
carbonic acid
phyloplankton form calcareous ooze on sea floor
corals/ mosuscs bicarbonate from water (>21oC)
anerobic carbon cycle
methanogenic bact produce methane
methanotrophs convert to co2 aerobically
methane levels highest since
800,000 years ago
more effective greenhouse gas? co2 or methane
methane
methane levelshave increase by how much since 1750
150%
methane is created in a process called
fermentation
anthrop methane sources
rice paddies domest cattle biomass burning coal mining gas flaring gas leakage rubbish dumps
nitrogen cycle involves what processes
ammonification
nitrification
denitrificztion
nitrogen cycle ‘equation’
nitrogen-ammonia-ammonium-nitrite-nitrate
ammonification
convert n to ammonia/ammonium in upper soil layers
what organisms cause ammonification
bacteria
actinomyceres
fungi
nitrification
ammonium absorbed to clay particles
denitrification
the loss or removal of nitrogen or nitrogen compounds
denitrif occurs…
anaerobically (waterlogged soils) up to 15% lost
in denitrif what reduces nitrites
heterotrophic bacteria
nitrites can be lost thru
leeching
leeching leads to
eutrophication
what is the process of industrial production of ammonia
haber bosch process
when was haber bosch process discovered
20th century
how does hb process work
convert nitrogen to ammonia when reacgted w/ hydrogen (catalyst at high temp n pressure)
what is a nitrate vulnerable zone
land w/ drains into nitrate polluted water/ water that could become polluted by nitrates
eu mandate on nitrates
max 50 mg per litre in drinking water
reduce fertiliser
no fertilisers at winter
change times animal waste is applied
why did the eu mandate prevent fertiliser use in winter
run off greatest
plant uptake lowest
large amounts of leeching as result
the sulphur cycle has many fluxes between
abiotic and biotic components
abiotic sulphur mainly in
rocks
some in atmos from fossil fuels
why is sulphur important
required for chlorophyll creation
the sulphate anion
released in weathering/ oxidation of rocks
present in soil and soil water
absorbed by plants roots for proteins and vita
passed along food chains
main ways sulphur goes from land to atmos
volcanic activity
soil dust
insudtrial
bacterial
main ways sulphur goes from oceans to atmos
HTVs
biogenic gases
sea spray
main ways sulphur enters the ocean
decompostion
river water
sulphur can be deposited to in two forms
wet and dry
who ‘discovered’ acid rain and when
robert angus smith
when did acid rain become major international concern
70s
effect of acid rain on trees
rarely kills but stunts growth by soil degradation
soil degradation leads to
nutrient depreivation
effect of acid rain on natural weathering
accelerated
acid rain falling on soil…
lowers ph as inc uptake of hydrogen ions and toxic aluminium oins
sphagnum moss thrives after acid rain bc
tolerant of low ph and high aluminium conc
how many swedish lakes are severly acidified
around 17,000
lake accidification effect on eco systems
highly degraded
what is liming
short term solution to neutralise water ph
long term solution to lake acidification
control pollution
where is the homer city generatng station?
pennsylvania
what is homer city generating station
bituminous coal fired power station
the legal battle of homer city
releases most amount of sulphur dioxide of all us power stations, in 2012 installed a desulphurising unit at cost of 750m dollars
phosphorus role in plants
moves e from atp to other molecules (drives enzyme reaction and cellular transport)
used to form nucleic acids and phospholipids (cell membrane/ bilayer)
limits net primary production
where is phosphorus naturally found
crystalline rock, released by wweathering
phosp avaliability depends mostly on…
soil ph
if soil is acidic phosphorus is
relatively insoluable
if soil is alkaline phosphurus is
insoluable
if soil is neutral phosphorus is
absorbed by clay
phosphorus in neutral soil is composed as
orthophospjate anion
mineralisation
microbial action which converts org phos to inorg phos (insoluable to soluable)
why is soil phos usuallu what limits plants
low avaliability
opposite of mineralisation
immobilisation (soluable to insoluable)
phos anthropogenic influences
p fertiliser (particularly asia)
agricultural intensification (soil erosion)
used in detergents
sewage treatment eliminates pathogens not nutrients
phosphorus in lakes leads to
eutrophication
how was role of phosphorus in eutrophication discovered
whole lake fertilisation experiments
example of whole lake fert exper
NW Ontario, CAN divided by vinyl curtain lower- p/n/c upper- n/c lower basin became eutrophic (phytoplankton/ algae)
by 2050 how much will demand for phos inc
50-100%
phosphorus is what type of resource?
non renewable
by when will phos reserves be depleted at current rates
50-100 years
issues of phos reserves
potentially more costly and contaminated
main phos reserves
morocco, china n usa
biogeography
study of past n present geographic distribution of life on earth
related disciplines of biogeography (b.c.e.eb.g.p.p.ss)
botany climatology ecology evolutionary biology geology palaeontology physiology soil science
island biogeography
study of distribution n dynamics of species in island env
islands act as __________ ffor biogeography
natural labs
3 types of islands
seperated by sea level rise (biota similar to mainland eg britain)
volcanic arc/ mountain chain
hot spots- hawaii
how do organisms get to islands
floating islands of veg
hurricanes
example of floating island
1969 vegetation travelled 150km from east cuba
example of hurricane transporting organisms to island
1995 logs n uprooted trees transported to anguilla from guadeloupe (250km)- iguanas?
plaants better adapted to travel long distances
island biodiversity depends on
rate of colonisation
distance
richness of source
