ELLS KQ 2 Flashcards
What is the average precipitation of a tropical rainforest ?
60mm
what is a biome ?
a large scale community of plants and animals that have common characteristics for their environment
how does the water cycle link into the tropical rainforest ?
- heavy rains that wash organic matter from the soil
- high transpiration rates feed into the high levels of humidity
- ## thousands of tributaries
what are three ways the water and carbon cycle depend on each other in the amazon ?
- photosynthesis is completely reliant on the presence of water for al plant growth
- carbon can be directly dissolved into oceans
- when dissolved in water, cos reacts with water molecules and forms carbonic acid . this causes weathering which releases carbon back to the hydrosphere. This requires water
give one example fo feedback in the amazon ?
increased transpiration may result in more precipitation, which in turn increases plant productivity , which amplifies transpiration more
what are human influences in the amazon ?
farming practices
plantations
deforestation and land clearance
dams
modifying the flow of rivers
mining
cattle ranching
permanent agriculture
forest clearance
in Manaus , what is the average temp and total rainfall ?
average temp - 31 degrees
more than 2300 mm annualy
what are some general characteristics to the amazon rainforest ?
home to 1 in 10 species on earth
stretches for 7,000,000 square km
regulates the planets atmosphere
5 billion tonnes of carbon
why is the amazon important ?
trees are bringing in co2 and stroing it as carbon
describe the annual temp of the amazon ?
highest temp is 27 , lowest temp is 26
range of 1
What are the limitations ofa climate graph ?
not always the same evry year
just averages
doesnt reflect diurnal changes
doesnt show spatial variations
why is there no seasons at the equator ?
each day the sun strikes at about the same angle
what has the hadley cell got to do with the climate of the amazon ?
the warm surface conditionsm result in locally low pressure. The warm air rises at the equator producing clouds and causing instability in the atmosphere . This instability causes thunderstorms to develop and release large amounts of latent heat.
how does convectional rainfall occur ?
caused by warm air at the earths surface . It rises ,cools and ocndenses forming cumulonimbus clouds
what are soils called in the trf ?
ferralitic soils
(latosols)
why is the humus layer thinin the trf ?
rapid decomposition and mixing of organic matter by intensive biota activity e.g. ants and termites
why are soils in the trf red ?
heavy rainfall causes the release of iron
why is the nutrient content low in soils in the trf ?
nutrients are taken up by the trees after rapid decomposition , the soil is then deprived of the nutrients
soils in the trf are easily damaged by heavy rain , what does this lead too ?
dthem being gullied and eroded
what does having an dense root mat mean for trf soils ?
intercepts and can take up as much as 99.9 percent of the nutirents released by decomposition of organic matter. Aslo, helps the rapid recycling nutrients in the humus cycle.
why are trf soils deep?
due to the rapid breakdown of parent material by chemical weathering due to the warm and wet conditions.
often up to 20 m deep
what percentage of prepication in the amazon is recycled by evapotranspirtaion ?
50-60%
what does continuous leaf fall cause in the trf ?
a thick litter layer
what does leaching reuslt in ?
the removal of silica
what is the vaerage of water into the atlantic ocean by the amazon ?
approximately 175,000 m cubed per second , or between 1/5 and 1/6th of the total discharge into the oceans of all the worlds rivers
of the rainfall that is evapotranspired back into the atmopshere how much falls as rain again ?
48%
how much carbon is locked up in the amazon ?
100 billion tonnes
how much carbon is released by photosynthesis and released by decomposition ?
2.4 billion tonnes and 1.7 billion tonnes
what is the yearly net primary productivity of the amazon ?
2500 g/msquared/year
why doesnt the leaf litter build up ?
rapid decomposition
whay are decomposition rates so high ?
humid conditions
why s there such rapid uptake of nutrients by trees ?
it is warm all year
what is net primary productivity ?
the rate at which plants accumulate organic matter
rate of photosnythesis - rate of respiration
what is the largest store of carbon in the amazon ?
biomass
what is leaching ?
rainwater dissolves nutrients in the litter and soil and washes them away
how does decomposition affect the carbon cycle in the trf ?
completed by bacteria,fungi and other soil organsims
releases nutrinets to the soil , emits co2
ideal climate for it
how does photosynthesis affect the carbon cycle in the trf ?
what is the difference 10 years after deforestation of the total c absorption ?
before- 30.4
after - 12.3
units - tonnes of c per ha per year for fluxes, tonnes of C per ha for stocks )
what is the difference 10 years after defprestation for amounf of c emitted by respiration ?
before- 24.5
after- 25.1
what is the difference after 10 years of deforestation of c stored in above-ground biomass ?
before - 180
after - 43
why is there low overland flow in the rainforest ?
there is so much evaporation and infiltration
why are there high interception rates in the trf ?
due to continuous canopy
how does temp affect rates of evapotranspiration ?
higher the temp higher the evapotranspiration
how does temp affect precipitation in the trf ?
convection is strong so leads to the development of thunderstorm clouds and intense preciptation
how does temp affect the atmosphere store in the trf ?
water is cycled continuously between the land surface, forest trees and the atmosphere by evaporation, transpiration and precipitaion
what is the relief like in the amazon basin ?
,most of the amazon basin comprises of extensive woodlands. - steep in the wets - andes
how would relief affect overland flow ?
steeper the slope, the more overland flow which will occur
how would relief affect throughflow ?
where there is a gentle relief as water will gtravel horizontally through the soil to streams and rivers.
how would relief affect the groundwater store ?
large store in flat lowlands
widespread inundation across exstensive floodplains occurs annualy , storing water for several months and slowing its movement into rivers.
what is the gelogy like in the amazon basin ?
crystaline shields - impermeable sedimentary basins (e.g. chalk , sst, lst )
how would geology affect infiltration ?
igneous - little infiltratin
porous - loss of infiltration
how would geology affect surface run off ?
rapid runoff where there is impermeable crystalline rocks. Slow run off where permeable and porous
how would geology affect the gorund water store ?
impermaeble and crystalline rocks- minimal storage capacity
permeabele and porous - stores rainwater
whicj facotr affects the inputs the most ?
temperature because it causes high rates of evapotranspiration and convection and that leads to rainfall
which factor affects the outputs the most ?
geology affect river discharge and relief
temp affects evapotranspiration
how much water does a fuklly grown tree in the amazon transpire ?
between 200 and 1000 litres of water a day
what is a flying river ?
huge jets of rapid, humid air that constanty flow above the canopy
how much water do flying rivers carry per day ?
20 billion tonnes a day
which winds drive the flying rivers and on which direction ?
trade winds blow east to west
Why are the andes important for flying rivers ?
act like a giant barrier causing the winds and rivers to redirect southwards
what is the impact of deforestaion on flying rivers ?
causing them to dry up . draught and higher temps
how do flying rivers form above the amazon ?
1) ocean water evaporates and clouds are formed
2)winds blow these clouds to the amazon rainforest and cause rain
3)rain water reaches the forest and evaporates quickly , forming more clouds
4)these clouds move west until they hit the andes mountains
5)clouds follow the contour of the andes mountains and produce rain for the midwest , southeast and south of brazil
what was the average deforestaion rate in amazonia between 1970 and 2015 ?
17500 kmsquared /yearh
ow much rianforets was cleared in bolivia and peru and why ?
30000 km^2 between 2000 and 2012 for subsistence farming and cattle ranching
give 3 impacts fo the floods of the madeira river in april 2014 ?
60 people died
outbreak of disease
68000 homes evacuated
what proportion of rainfall falling on grasland goes directly itno rivers ?
half
when forest is converted to grassland, by what factor is runoff increased ?
27ist
list 3 important roles that trees play in the water cycle ?
interception
roots absorb water
stabalises ground temp
how much might regional decrease by in the future in amazonia ?
20%
what is the prupose of a flux tower ?
measure movement of carbon between stores
why are flux towers so tall ?
measure carbon in the atmopshere above the canopy
how does the trf play a big part in reducing climate change ?
giant carbon sink
they remove C from the atmosphere which means they slow the ghouse effect and global warming
two reasons why photosynthesis is fundamental to the carbon cycle ?
provides every tree and plant in the trf with an energy source to be able to grow
keeps global warming in check
what is the gross primary productivity ?
measure of total amount of carbon fixed by photosynthesis
why does gpp remian high all year in rainforests , but is only high for a few months in the boreal forests of russia and canada ?
boreal forests lose their leaves in winter and so GPP drops for the winter months. However, in the trf it is warm all year round
what is the significance of respiration in plants in term of the carbon cycle ?
releases co2 back into the atmosphere when plants break down carbohydrates to release energy for growth and repair
why is carbon use efficiency an important element of the carbon cycle ?
it tells us overall how much carbon is being fixed compared to how much is being released
why are rainforests such effective carbon sinks ?
because over the whole year there is a positive carbon balance . they fix more carbon that they release
globally, what is the significance of rainforests in the carbon cycle ?
they lock away between 3 and 4,000 tones of carbon per year.
they store more carbon that the rest of the worlds ecosystems put together
what was the total tree cover loss in 2019 ?
extended to 2.4 million hectares
how have drip tips and smooth bark allowed some trees to adapt to climactic conditions in the rainforet ?
if the water is stored on the leaves, they would rot but the drip tips and smooth bark prevent this
how does heavy rainfall reuslt in soils becoming poorer in the primary forest ?
leaching - leaves behind nutrients have been washed down and out - hit the bedrock
explain how plants cope with poor soils in rainforests ?
trees take up the nutrients quickly before they are washed away
why do compunds like iron and aluminium oxides remain and increase in concentration in rainforest soils ?
they are insoluble - this gives the reddish colour
how does deforestation affect the water cycle in the trf ?
less rain is intercepted
falls directly into the forest floor , which washes away nutrients and increases surface run off
increases intensity of rainfal; hitting the ground
how does road and infratructure building affect the water cycle in the trf ?
more exposure of bare soil - increases leaching and surface run off- increases soil erosion meaning more sediment in rivers which might then silt up, become shallower and flood
assess the impacts of palm oil plantations on areas of former primary rainforest
when they replace the primary forest - less interception - gaps between trees of bare soil
more overland flow and channels form
how does deforestation reduce rainfall ?
so less water vapour in the atmosphere to condense and form clouds so less precipiation
how does deforesttaion cause drought ?
there will be a lack of rain for a significant period of time
how does deforestation create a positive feedback loop in the water cycle ?
less rain - trees unable to grow back
less evapotransipration and rain making the climate even drier and killing even more trees
explain the purpose of building a flux tower in the middle of an oil palm plantation ?
for research on the impacts of land use change on co2 flux. To compare plantation with primary forest
what is the impact of logging on GPP ?
decrease - no leaves to photosynthesise
what is the impact of logging on the amounf of co2 ?
increase
detritivores breakdown left behind stumps and trunks and release co2
explain the impact of logging on the balance between the rainforest as a carbon sink versus a carbo source ?
the rate of decomposito n is now greater than the rate of photosynthesis . the rainforest will become a carbon source
explain how the developemtn of an oil palm plantation can result in changes in leaf cover ?
less dense leaf cover because of loss of canopies
how does the developemnt of an oil palm plantation change how much co2 is fixed compared to a primary forest ?
fix less than half of the co2 per hectare pf a primary rainforest
why must oil palms be replaced every 20 - 30 years , and the impact that this has on the carbon cycle ?
to keep them productive which meas that carbon isnt stored in the long term . every time they are replaced, more carbon is released
how does selective logging impact carbon balance ?
reduces C store by 50% . overall becomes a source not a sink
how does selective logging impact density of leaf cover ?
fewer leaves in the canopy
how does selecitve logging impact biomass ?
its reduced in the short term
how does selective logging impact the amount of co2 fixed by photosynthesis ?
less than primary forest (900-2200g)
how does selective logging impact the amount of co2 released ?
increases from litter layer and from dead wood that was left behind as it decomposed by bacteria and fungi
how does clearance for palm oil plantations impact on carbon balance ?
overall is a source of C not a sink
what is a carbon balance ?
carbon source v carbon sink
how does clearance for palm oil plantations impact on density of leaf cover ?
less dense leaf cover because fo loss of canopies
how does clearance for palm oil plantations impact biomass ?
30 tonnes per ha
how does clearance for palm oil plantations impact on the amount of co2 fixed by photosynthesis ?
fix less than half of the co2 per hectare
900g/msquared/ha/yr
how does clearance for palm oil plantations impact on the amount of co2 released ?
100 tonnes of carbon released
how does conservation impact on carbon balance ?
sink not a source ie. photosynthesis >respirationhow
how does conservation impact on densiry of leaf cover ?
no change - high leaf density cover
how does conservation impact on biomass ?
300+ per ha due to layers
how does conseravtion impact amount of co2 released ?
much less released mainly from respiration
what three categories do modern strategies to help amazon fall into ?
protection , projects to reforest , improving agricultural techniques
how can you manage soil fertility ?
can be maintained by rotational cropping and combining livestock and arable operations
how does integrating crops and livestock help ?
allow a fivefold increase in ranching productivity and help slow rates of deforesttaion
what are human engineered soils ?
dark soils made from inputs of charcoal , waste and human maniure could be used to grow more crops instead of relying on the poor infertile soils found in amazon
how much land does the amazon regional protected areas cover ?
20 times the size of beligum
by 2015, what % of brazilian amazon comprised of national parks, wildlife reserves and indigenous reserves where farming is banned ?
44
what did natura do in 2013 ?
purchased 120,000 tonnes of carbon credits from the surui, first carbon credit sale by indigineous people in amazonia
in 2009 what did the surui do ?
first indigineous group in amazon to join UN’S reducing emissions from deforestation and degrardation scheme
the scheme provides payment to the tribe for protecting the rainforest and abandoning logging
what is the parica project ?
in Rondonia, in western amazon
sustianble forestry scheme aims to develop 1000km squared commerical timber plantation on government owend , deforested land
what is the plan for projects to reforest in the amazon ?
20 million fast growing , tropical hardwood seedlings , planted on 4000 smallholdings, to mature over a period of 25 years
what are the advantages of the conservation and education strategy ?
works with communities
people make a living
stops hunting
protects w+c cycles by reducing deforestation large lake/lagoon for water storage
what are the disadvantages of the conservation and education strategy ?
needs monitoring , need to have security patrolling, costs lost of money
so only small places can be protected
what is limoncocha national park ?
4603 hectares
10,000 tourists per year
v high biodiversity
ramsar site
what is a ramsar site ?
treaty in 1971 - protects wetland areas across the world
what is yasuni national park ?
ecuador
taegaeri and taromaname indigineous groups
1 hectare has more diversity than the whole of north america
how many barrels of oil are under yasuni national park ?
846 million
if dug up would emit 407 million tonnes of C
what is the international agreement to do with yasuni ?
ecuador government wanted 1/2 of the value of the oil and they would leave it untouched
deal didnt happen and oil extraction began in 2014
what are some agriuculture, logging and microfinance techniques ?
banana circles to maintain soil fertility
organic waste placed in the centre of circle (slowly decomposes) - provides nutrients to surrounding plants
need to control logging - ;arge scale commerical logging is restricted
now have to harvest timber under new management plan
advantages fo agriculture, logging and microfinance schemes ?
timber can be half of small farmers income
new laws and a gorwth in protected areas
rate of destruction slows
how much land does the tundra cover ?
1/5 of earth
why is the tundra important ?
plays a large role in temp regulation of the planet
winter home for many bird species
what is the location of the tundran ?
southern and northern hemispheres
found in countries such as russia, alaska, canada and greenland
what is the climate like in the tubdra ?
very long, cold winters with the sun hardly above the horizon
what are some key features of tundra soils ?
dark brown/ black peat
active layer
permafrost
limited drainage
acid humus
limited mixing by organisms
slow decomposition (
cold temps)
waterlogging and gleying
freeze thaw weathering of rock
blue grey colour
anaerobic conditions
what are the five main species of tundra vegetation ?
lichens, mosses, garsses, low shrubs and cushion plants
why does tundra vegeation have small leaves ?
to limit transpiration
why does tundra vegetation have short roots ?
avoid the permafrost
why is the tundra waterlogged in summer ?
because fo impermeable permafrost preventing infiltartion
what vegeation is there on gentle relief in the tundra ?
mosses, cotton grass and sedges thrive
why is there low photosynthesis in the tundra ?
lack of sunlight
what is the permafrost ?
majority of soil layer is permanently frozen
why are transpiration rates low in the tundra ?
sparseness fo vegetation cover and the short growing season
why are evaporation rates low in the tundra ?
much of the suns energy in summer is expended . melting snow so that ground temps remain low and inhibit convection
why is the surface water store high in the tundra ?
permafrost - which impeeds infiltartion
why are infiltration rates low in the tundra ?
water cant percolate and permafrost
why is the snow and ice store high in winter and low in summer in the tundra ?
it will be hotter so it will melt
why are precipitation levels low in the tundra ?
(50-350mm ) there is small amounts of water vapour in the atmopshere to cool and condense
most precip = snow
how does rock permability affect the water cycle in the tundra ?
permeabolity is low due to the permafrost and the crystalline rocks which dominate the geology of the tundra in artic and sub artic canada
how does temp affect stores in the tundra ?
cold temps mean water is stored most of the year as ground ice in the permafrost layer. This melts in the most summer and forms shallow lakes
how does temp affect flows in the tundra ?
liquid water flows on the surface
meltwater forms millions of pools and shallow lakes
drainage is poor - water cant infiltrate in soil because of permafrost
in winter - sub zero temps prevent evapotranspiration .
in summer, some evapotranspiration occurs from standing water.
what is the active layer ?
portion of soil above permafrost that thaws and freezes seasonally
what is the npp of the tundra ?
140 g /msquared/yr
how much biomass si there in tundra compared to rainforets ?
1/75th
what is the carbon cycle in the tundra ?
how does climate change cause permafrost melting ?
increasing the temp and leading to widescale melting of it
how does removal of tundra vegetation ready for construction ?
a decrease in the ground protection which exposes the permafrost
how does construction of buildings for workers causes [ermafrost to melt ?
the ground beneath them is heated
how does the construction of roads and other infrastructure cause permafrost melting ?
they are ofte made of dark tarmac which has a lower albedo than oce so localised warming occurs
how does the construction of pipelines cause permafrost melting ?
localised warming as the oil is warm
how does dust deposition at the sides of the roads cause permafrost to melt ?
the albedo of the land, causing warming and melting
how does drilling for oil cause permaforst to melt ?
frictional heat and localised melting of permafrost
what are some causes of permafrost melting ?
climate change
removal of tundra vegetation
construction of buildings
construction of roads
construction of oil pipelines
dust deposition at the side fo raods
drilling for oil
how does melting permafrost impact on the water and carbon cycel in the tundra ?
more liquid water in area
increased surface storage and run off - increased evaporation
how does strip mining affect the water and carbon cycle in the tundra ?
creates artificial lakes
distrupts drainage and exposes permafrost to melting
how does destruction of tundra vegetation affect the water and cycle in the tundra ?
decrease in evaporation and transpiration
less insulation over permafrost so melting increases
how does water abstraction for industrial and commercial use affects the water and carbon cycle in the tundra ?
reduces localised run off
where is north slope alaska located ?
north of alaska
to the north is the beaufort sea and to the west is the berling sea
what happened in 1968 on north slope alaska ?
oil and gas were discovered here at prudhoe bay
what happened in 1970s and 1980s at north slope alaska ?
massive fixed investments in pipelines, roads, oil production plants, gas processing facilities, power lines, power generators and gravel quarries were completed then
what happened in the early 1990s in north slope alaska ?
accounted for nearly a quarter of the usas domestic oil production
what is happening 2014- today in north slope alaska ?
today proportion is 6% though alaska remains an important oil and gas province
decline in recent years reflects two things :high production costs on the north slope and the massive growth of the oil , shale industry in the usa
what are the main issues in north slope alaska ?
melting permafrost
changes to the ecosystem
damage to environemtn , e.g. oil spillages
impacts on the local people
what is insulated ice and gravel pads ?
insulates round the pipe to reduce the amount of heat transferred
what is refigerated supports ?
used to stabilise pipelines that transport oil and gas across alaska
what is drilling laterally beyond drilling platforms ?
extracting oil and gas horizontally
drill at a right angle
allows multiple wells to be dry from a certain site
what os buildings and pipleines elevated on piles ?
prevents heat from reaching the permafrost
what is stratergies to decrease reliance on oil ?
by promoting alternative energy sources, improving energy efficiency by introducing regulations
goal - reverse demand for fossil fuels
how does insulated ice and grvael pafs proetct the carbon cycle ?
decreases the maount of permafrost meltign which dcereases the amount of carbon released , which gets relased as co2 and methane
how does refigerated supports protect the carbon cycle ?
decrease in thawing permafrost
reduces amount of c stored in permafrost
hwo does drilling laterallt beyond drilling platforms protect the carbon cycles ?
?
how does buildings and pipelines elevated on piles protect the carbon cycle ?
prevents thawing of permafrost in winter
reduces carbon stored in permafrost being released into the atmosphere
stops decomposers breaking down
how does strategies to decrease reliance on oil protect the carbon cycle ?
cuts down co2 emissions in atmos
how does insulated ice and gravel pads protect water cycle ?
less permafrost melts prevents excessive run off and erosion
excess surface run off could cayse increase in surface pooling , increases infiltration to gorund
how does refrigerated supports protect the water cycle ?
less melting of permaforst - less run pff
how does drilling laterally beyond drilling platforms protect the water ccyel ?
drilling from more locations - fracking requires large amounts of water - less stress on local water resources
how does buildings and pipelines elevated on piles protect the water cycle ?
reduces permafrost thawing, reduces amount of water stored as ice on surface
increase in melting water , increases surface run off
how does strategies to decrease reliance on oil protect the water cycle ?
reduces water pollution from oil spills
long term effect on local and regional scale
decreases amount fo water used in fossil fuel extraction
why might insulated ice and gravel pads nto protect the cycles ?
effective in reducing thermal impacts - however do not elimintae carbon emissions from drilling operations themselves
why might refrigerated supports not pretct the cycles ?
been around since 1970s
only effective if the surface air temp is colder than the subsurface temp
comapnies now have cooling devices to chill the permaforst
why might drilling laterally beyond drilling platfroms not protect the cycles ?
as your extracting oil and gas its still burning the carbon.
water is still used for cooling down fossil fuels
why might drilling pipelines elevated on piles not protect the cycles ?
focuses on preventing phsyical destruction to permafrost rather than adverting the carbon emissions
only reduces local disturbance
How long has it been since cos levels in the atmosphere have been so high ?
800,000 years
what co2 concentrations was in 1750 ans what are they today ?
1750- 280ppm
today - 400ppm
what is the total mass od anthropohenic co2 emissions since 1750 ?
2000 tonnes
how much do co2 emissions increase by every year ?
1ppm
in which decade did co2 emissions increase the most by ?
2000-2009
how many parts per million of co2 there would be in the atmosphere in the oceans and biosphere had they not been absorbed anthropogenic co2 ?
500ppm
why is coal the biggest contributor to atmopsheric co2 ?
gets burnt the most cos its cheaper to extract
what is ccs ?
carbon capture and storage
what is ccus ?
carbon capture use and storage
what is direct air capture ?
use of chemical or physical processes to extract co2 directly from the amibent air . if extracted co2 is sequestred in safe-long term stoareg , the overall process will achieve co2 removal and will be a negative emissions technology
what are some benefits to CCS ?
lot of investment
40 million tones of co2 have been captured
oil and gas industry already use cc for oil recovery
how much carbon has been captured by ccs ?
40 million tonnes
what does 40 million tonnes of co2 have been captured show ?
if the world is to be on the rigth path for net zero that number would need to rise around 1.7 billion tonnes of cos by 2030
what are some challenges of CCS ?
very expensive
used to help to recover more oil and gas
needs to increase x40 to prevent climate change
removing co2 after burning fossil fuels might prevent investment in renewables
what does buried carbon is not a source of revenue for oil and gas companies mean ?
is a commercial use for this can be found that would make it more economically attractive
what is BECS ?
negative emissions tech
wood pellets which are burned and stored in the ground
what does GIS stand for ?
geographic information system
what does GIS do ?
recreates world spatial data. as digitalised themed data ‘layers’
what are some positives of GIS ?
can use a variety of base maps to enhance understanding
able to compare distances
visualise data at a range of scales
what are the negatives of GIS ?
requires training
expensive software not appropriate for schools
may lack key map features
may leave out locational info
in urban areas why does precipitation flow quickly into rivers ?
artificial surfaces are impermeable so they allow no infiltration
in urban areas why is water storage capacity reduced ?
drainage systmes designed to remove water rapidly, (e.g. gutters, pitched roofs, sewage systems )
give 2 reasons why farming reduces carbon soil storage ?
soil carbon sequestration 0- process in which co2 is removed from the atmopshere and stored in the soil carbon pool
which has a higher NPP ? prairie grasslands or whet crops
prairie grasslands
why are carbon exchanges through photosynthesis lower in a field of crops than in a natural ecosystem ?
due to lack of biodviersity in farmed systems which emans there is often just one species and a lack of structure at different heigths .
growth is compressed into 4-5 months instead of year round
how does crop irrigation affect water ccyels ?
diverst surface water from rivers and groundwater to cultivated land
some of this water is extracted by crops from soil storage and released by transpiration , but most is lost in evaporation
how does growing crops affect interception ?
more plants there are the more interception
how does growing crops affect evaporation /
more water will evaporate of the leaves
how does ploughing and heavy machinery affect flows in the water cycle ?
p- increases evaporation and soil mopisture loss , and furrows ploughed down slope act as drainage channels , accelerating run off and soil erosion
how do conifer plantations affect interception and evaporation ?
needle like structure of conifer leaves, their evergreen habit and high density of panting all contribute to high rates of interceotion
why do plantation firest cause long lag times and reduced water yield for public supply?
low peak flows and low total discharge
reduced run off
high interception and evaporation rates and the absorption of water by roots, drainage basin hydrology is altered
where is most carbon stored in a tree ?
wood or the tree stem
what are typical transpiration rates for Sitka Spruce in the Pennines ?
around 350mm/year of rainfall equivalent
what are the effects on the water cycle of felling and harvesting timber ?
increasing run off , reducing evapotranspiration and increasign stream discharge
give stats to show how forestry increases carbon stores ?
typical plantation in UK - mature forest trees contain 170-200 tonnes C/ha. - ten times higher than grassland and 20 times higher than hearthland
how does froestry affect the soil carbon store ?
increases carbon stores
represents an even larger carbon pool
in england- measurements of forest soil carbon are around 500 tonnes C/ha
explain why forestry plantations have a rotation period of 80-100 years ?
forest trees only become an active sink (ie. absorbing more caebon than they release)
for the first 100 years or so after planting
therefore the amount of carbon captured levels off and is balanced by inputs of litter to the soil, the release of co2 in respiration and activity of an ecosytem
why do co2 concentrations fall during a glacial period ?
changes in ocean currents that bring nutrients and phytoplankton to the surface and therefore increase photosynthesis
phytoplankton die , sink, and take the carbon to the deep oceans
what happens to sea level during a glacial period ?
decreases because net transfer of water from ocean store transferred to storage in ice sheets, glaciers and permafrost
what does the term ‘eustatic ‘ mean ?
global sea level change.
what are the consequences of explanding ice sheets and glaciers ?
destroy extensive tracts of forest and grassland. - plants cant grow in ice
what happens to tropical climates and ecosystems ?
climate becomes drier and deserts and grasslands displace large areas of rainforests.
how are rates o fproccesses affected by a glacial period ?
lower rates of evapotranspiration during glacial phrases reduce exchanges of water between the atmosphere and the oceans, bisophere and soils. This , together with so much freshwater stored as snow and ice, slows the water cycle appreciably
what role might ocean curretns play in redcuing atmospheric co2 during glacial periods ?
changes in ocean currents - bring nutrients and phytoplankton to the surface - increase photosynthesis - phytoplankton die, sink and take the carbon to the ocean
describe other changes in the terrestrial biosphere ?
carbon pool is vegetation shrinks during glacials as ice sheets advance and occupy large areas of the continents
why is there a net flow of carbon from the atmopshere to the biosphere in summer ?
rates of photosynthesis ae much higher than the rates of respiration in the summer when radiation leavels and foliage are high
why do global atmospheric co2 levels fall between april and september ?
there is more foliage in the summer months, which means that more photosyntehsis will take place as there is more sunlight. co2 levels will fall as more is absorbed
why seasonal fluctuations in the carbon cycle greater in the middle and higher latitudes ?
because the areas away from the equatore have greater seasonal extremes of temp whereas the tropics have very little seasonal variation
why are seaosnal fluctuations greater in the northern hemisphere than in the southern hemisphere ?
because the northern hemisphere has larger land masses that have forests of vegetatin on them
what are the effects of rising water and more intense sunglight in the oceans ?
phytoplankton increase their photosynthetic actuarity (take in more co2)
the resulting algae blooms are visible from space
what are some short term changes to the carbon cycel ?
photonytheis , co2 levels
what causes short term chnges to the carbon cycel ?day
daylight hours
sunlight
temperature
what are some short term changes to the water cycel ?
decrease in evaporation and transpiration due to lower temps at nigth
water vapour is a greenhouse gas , more vapour in the atmosphere
