paper 3 Flashcards
what is an ecosystem?
a grouping of biotic and abiotic factors that interact with eachother and the environment
what is a biome?
a large scale global ecosystem defined by the plants + animals that live there
features of a Taiga (boreal) biome?
high latitudes
trees adapted to cold- needles
doesn’t get much sun energy
features of the tropical rainforest biome?
found along the equator
hot
heavy rainfall
equatorial regions where hadley cells meet
features of the temperate biome?
forest
high rainfall
seasonal variation
trees lose leaves
cool winters
high rainfall where polar and ferrel cells meet
features of the tundra biome?
within the artic circle
little sunlight/rainfall
only tough short grasses survive
features of the desert biome?
close to the Tropics of Cancer/Capricorn
hot air sinks here
lots of sunlight
around hadley cell with little rainfall and high temperatures
features of the grasslands?
have seasonal rainfall
too low for tree growth
what local factors affect biome distribution?
altitude- different things grow at different heights
rock + soil type - can affect how fertile soil is
drainage- bogs/swamps only have adapted plants
what is a biotic factor?
a living component of an ecosystem
what is an abiotic factor?
a non-living component of an ecosystem
what is biodiversity?
the variety of biotic components within an ecosystem
abiotic/biotic reasons for Taiga having low biodiversity
abiotic= long cold winters, low precipitation, frozen soil
biotic= small amounts of food, only well adapted plants survive, small number of animals
the 3 stores in the nutrient cycle?
litter store
biomass store
soil store
-trees grow
-shed leaves
-decaying vegetation decomposes
-nutrients enter soil
-roots take up nutrients
why is there higher productivity and biodiversity in tropical rainforest (in relation to nutrient cycle)
larger biomass store- plentiful vegetation and trees quickly absorb nutrients
smaller litter store and larger decay transfer- ideal conditions for bacteria to decompose matter
larger growth transfer-year round plant growth
larger leaching transfer- lots of precipitation leaches nutrients through the soil
reasons for increasing demand for resources
urbanisation
higher food production, water shortages,
affluence- richer people consume more expensive resources (eg. meat, fossil fuels)
population growth (esp rapidly in asia)
industrialisation
what do we get from the rainforest?
medicines- aloe
poppies-> morphine
food
fuel
building materials
how does the biosphere act as a life support system?
regulates the water cycle -> plants slow down rivers and filter water
↳roots bind soil to prevent erosion, trap silt for purer water, plants intercept and transpire water
regulates carbon cycle -> photosynthesis
↳purified atmosphere and reverses global warming
nutrient cycle -> keeps soil healthy (abundant nitrogen and potassium) so more plants can grow
↳ insects and animals dig into soil to allow air to circulate
what is the climate like in the tropical rainforest?
between 25-30°C
-up to 300mm precitation in March
-reasonably high rainfall all year
-humid
-2000mm annual rainfall
-no distinct seasons
what are plant adaptions in the rainforest?
thick/tall roots to support the tree so it can grow high (buttress roots)
waxy, drip tips to prevent mould growing which blocks sunlight
shallow roots to get the nutrients which are on the top of the soil
liana plant vines climb trunks to reach sunlight and nutrients
what are animal adaptations in the rainforest?
primates have long tails for balance and strong claws for grip- can live in canopy where food is plentiful
big cats have camouflaged fur to blend into shade and sunlight on shrub layer
birds have loud calls to hear mates and powerful beaks to break open nuts
what are the layers of the rainforest?
> emergent 40m+
canopy
under canopy
shrub layer
herb layer
what are the adaptions of Taiga plants?
needle shaped leaves/ waxy= reduced water loss
coniferous= dark green leaves which don’t shed to maximise photosynthesis all year
cone shaped= shed heavy snow
grow close together= reduce wind damage
shallow, wide roots- support tree and avoid permafrost
acidic layer of pine needles
what are the adaptations of Taiga animals?
birds often migrate due to lack of food
moose eats pine needles
brown bear hibernates
animal species have thick, oily fur or feathers to keep them warm and are well camouflaged
small ears and tails to avoid frostbite
why does the Taiga have a low biodiversity + productivity?
-plants can only grow for 3-5 months per year
-litter accumulates until the summer
-thin, acidic, low in nutrient soil
-plants grow slowly
large litter store, very small soil store
what are the causes of deforestation (direct threat)?
agriculture- strips soil of nutrition, commercial clears forest for large plantations, abstinence clears forest for land for unskilled farmers to grow food for their families
logging- hardwood for furniture (eg. valuable mahogany), illegal logging
biofuels and fuelwood- cooking or charcoal
mining- mineral resources found underground
HEP dams- 400 dams along Amazon for electricity, takes up space and floods
cattle ranching- for beef, leather etc, cattle damage land and are often relocated
how does climate change threaten the rainforest?
-bring constant wet weather
-drier/hotter rainforests due rising temp and lower rainfall
-plants/animals are adapted to temp spikes
-higher chance of drought
-stressed animals/plants are less resistant to disease
-increased risk of forest fires
what are the direct threats to the Taiga?
logging for softwood, pulp and paper production- half of the worlds softwood comes from Russia’s taiga.
mining for fossil fuels
HEP dam production flooding the area
what are the indirect threats to the Taiga?
acid precipitation- destroys insects (which are prey for birds), weakens plants’ resistance to disease and weather
pests and disease- damage trees
forest fires (global warming, lightning, human activity)- destroy habitats, saplings
how does global warming threaten the Taiga?
animals with heavy coats so can’t cope with warm weather
new disease to spread to the Taiga and threaten low biodiversity
more frequent forest fires
what is CITES?
convention on international trade in endangered species of wild fauna and flora
stops imports/exports of endangered speies
protects 35000 species, huge national influence (181 countries)
an agreement to tightly control trade in wild animals and plants
what is the advantage of CITES?
huge international influence, 181 countries signed up
works well for high profile ‘cuddly’ species
what are the disadvantages on CITES
very difficult to enforce rules in all countries
protects species rather than ecosystems (ie. does not stop deforestation)
what is REDD?
reducing emissions from deforestation and forest degradation
they try to reduce the rate of deforestation
supports the reduction of deforestation, backed by the UN (large funding)
what are the advantages of REDD?
backed by UN so lots of money is available for projects
what are the disadvantages of REDD?
not clear what they mean by ‘forest’ so some palm tree plantations received funding although they destroy the rainforest
what is sustainability?
the ability to keep something going at the same rate/level for many years
what is sustainable biosphere development?
-ensuring ecosystem can recover
-preventing damage
-help local people benefit from environment
-help local people understand how management benefits them
why should you protect the Taiga?
fragile ecosystem
-pollution remains in ecosystem for decades
-few species so a disease in one species impacts the whole ecosystem
-highly specialised plants/animals so cant adapt to climate change
how do national parks prevent exploitation?
conservation=restoring natural habitats
scientific research= find out what threatens the ecosystem
education= informing visitors
what are the problems with parks and reserves?
migration- cant protect all species
money- oil/gas reserves means pressure from the government to develop them
pollution- easily damaged by pollution but if they are far away no one will visit
what are the problems with sustainable forestry?
expensive and a long term commitment
most parts of the Taiga are leased to businesses however they aren’t interested in protection, only want to clear the area during their lease
why is oil consumption increasing?
increasing population-9.5bil by 2050
affluence- richer so buy cars, a.c
technology- people want newest models
what factors impact oil prices?
financial crisis (recession)
environmental disasters (oil spills)
conflict/wars
political tensions (nuclear weapons)
price wars between suppliers (decrease)
what are the benefits of extracting oil/gas from the Artic?
large reserves
close to important markets
melting ice has reduced costs
what are the drawbacks for extracting oil/gas from the Artic?
exploration costs billions
pollution is expensive to clear up
challenging conditions
if prices drop it will be unprofitable
what are the environmental costs of fracking?
contamination of groundwater
subsidence (sinking of land)
destroying habitats