The Living World Flashcards
define an ecosystem
a natural system of plants, animals and the environment.
it includes the biotic and abiotic parts of an area
define biotic components
the living features of an ecosystem ie plants and fish
define abiotic components
non living factors ie climate (temp and rainfall), soil rainfall & light
define producers
- convert energy from the sunlight into food (glucose)
- ie plants that convert the suns energy by photosynthesis ie pond weed
give examples of small scale ecosystems
pond
hedgerow
give examples of large scale ecosystems
tropical forests
deciduous woodland
define consumers
consumers get energy from the sugars produced by the producers as they eat plants
- ie in a pond it would be heron or pike
define decomposers
break down the plant/ animal material and return the nutrients back to the soil
in a pond it would be rotting leaves
define food chain
this shows the direct links btwn producers & consumers in the form of a single line
define food web
this shows all the connections btwn producers & consumers in a more complex way
define nutrient cycling
when nutrients are transferrered throughout the ecosystem
- dead material decomposes -> puts nutrients into soil
- plants take nutrients in from soil -> consumer eats plants
- consumer dies & nutrients return to the soil
in a food web which way does the line go
from the food source to the consumer
shows the transfer of energy (from the thing that is being eaten)
ie acorn —> squirrel
what’s the climate like in tundras. give an example of one
- extremely cold climate (may drop to -20*) as its v. far north
- low rainfall (high pressure belt meaning sinking air stops clouds from forming)
- northern Canada/ northern Europe
how are tundra ecosystems distributed around the world
from arctic circle to 60-70* north of the equator
- very few in the southern hemisphere as there’s hardly any land
how are tropical rain-forests distributed around the world
close to the equator
give an example of a natural change to an ecosystem and how it can impact on the ecosystem
volcanic eruptions mean that lava damages forests & ash clouds block sunlight so temp lowers & plants cant survive
give an example of a natural change to an ecosystem and how it can impact on the ecosystem
- volcanic eruptions mean that lava damages forests & ash clouds block sunlight so temp lowers & plants cant survive
- extreme weather (heatwave so pond dries up & animals die)
give an example of a human change to an ecosystem and how it can impact on the ecosystem
farming (eutrophication - fertilisers have nitrates in them. when it rains they get washed into lakes. river algae grows trapping sunlight & taking up all of the oxygen)
what is the location of tropical rainforests (latitude)
0* - 25* north and south of the equator
found on the equator, the tropic of capricorn and tropic of cancer
what is the climate like in tropical rainforests (temp & rainfall)
- av. temp is 27*C (high temp all year round. little variation bc at the equator sun is overhead all year round)
- heavy rainfall. av is 2000mm. rains every day
- climate same all year round. no definite seasons
what is the soil like in tropical rainforests
- infertile & poor quality
- very shallow
- nutrients mainly close to surface bc rotting leaves rot at top
- heavy rainfall washes away nutrients (called leaching)
what are the plants like in tropical rainforests
- most trees are evergreen (dont shed leaves seasonally) taking advantage of the continual growing season
- many trees very tall as v. little light reaches forest floor
- drip tip, waxy leaves so water drains off
- thick butress roots to hold tall trees steady
- wide root netwrok to get nutrients from soil
- climbing plants (lianas) use trees trunks to get to light
what are the animals like in tropical rainforests
- prehensile (gripping) tails to live in the canopy ie howler monkey
- camouflage to hide in the shrub layer ie gecko
- suction pads on feet to grip in trees ie tree frog
- nocturnal to avoid heat of the day ie sloth
- strong bills on birds to crack nuts
how do plants adapt to the TRF
- lianas are woody vines that use tree trunks to grow up trees to reach sunlight and absorb as much light as possible for photosynthesis
- plants have thick waxy leaves with pointed tips (drip tips which channel the water so it runs off. & there’s no standing water for fungi to grow in)
how do animals adapt to the TRF
- many animals are nocturnal ie sloths. sleep in the day & feed at night when its cooler helping them to save energy
- some animals are adapted to low light levels on rain-forest floor ie anteaters have a sharp sense of smell & hearing so can detect predators without seeing them as its dark
give facts about the importance of the biodiversity in the TRF
- contain 50% of all plants/ animals in the world
- ‘green lungs of the world’ 28% of worlds oxygen comes from TRF
- absorb and store co2, regulating the climate
- 25% of all medicines come from rain-forest plant/animal species
- 20 % of worlds freshwater comes from the amazon river basin
give examples of what would happen if biodiversity in the TRF was reduced
- without tree canopies to intercept & tree roots absorbing rain, more water reaches soil reducing fertility as nutrients are washed away from plants#
- livelihood of some ppl who depend on animals/ plant to earn money is disrupted as they’re lost to deforestation & cant support families
- with no trees hokding soil together, heavy rain erodes/ washes away soil causing landslides/flooding
what are the different types of deforestation
everything except urbanisation ppl just want the space
- 40% cattle farming (deforest for fields for cows. supply meat to other countries increasing amount of meat needed globally)
- 20% commercial farming (clearing forests to grow crops ie cocoa beans/ palm oil)
- 17% subsistence farming (indigenous ppl who farm to live. “slash & burn” makes soil nutritious to farm when burned. small scale.)
- 11% urbanisation (houses/roads/mines/building dams. ppl want access to roads for a long time & wont replant trees)
what are the impacts of deforestation
- damages the food chain (many organisms have evolved to depend on a few species for survival, specific to a small area. if this is cut down the species may go extinct )
- brazil’s endangered species rose from 218 in 1989 to 628 in 2008
- as trees absorb CO2 burning trees gives out co2 contributing to the greenhouse effect deforestation responsible for 15% of global co2 emmissions
- logging & farming create jobs
- long term, can destroy resoucrces countries depend on ie timber & reduce attractiveness of area to tourists
why should we protect the trees & reduce deforestation
- ## vital undiscovered cures could not be found if the rainforest was destroyed
how can we protect trees & reduce deforestation through selective logging
selective logging & replanting
- is managed carefully so is more sustainable & planned to do selective logging than clear felling as they replant the trees after
- introduced in Malaysia 1977. 100 small areas picked & chose which trees to chop down then replanted in another area & constantly monitors the area
what is selective logging & replanting. what is clear felling
- clear felling (all trees chopped down in the area being cleared, completely destroying the ecosystem)
- selective logging (only certain trees chopped down then replanted)
what is conservation
- when rainforests are preserved in conservation areas ie national parks/ nature reserves which can be used for education/ scientific research & tourism
how can we protect trees & reduce deforestation through ecotourism
- costa rica have promoted their forests for ecotourism aiming to introduce ppl to natural world.
- through income from generated by ecotourism locals & the government benefit by retaining & protecting
the environment for the future - more sustainable than cutting them for short term profit
how can we protect trees & reduce deforestation through conservation & education
- rain-forest can be protected & used for education/ scientific research
- large international companies support conservation projects in exchange for carrying out scientific research /provision of raw materials
- givaudan (swiss perfume co.) works w conservation international to protect 148000ha of Venezuelan rain-forest. locals encourage to harvest & sell tonka beans. beans can be stored & dried in a warehouse built 2012, improving the bean quality & increasing their value
what are the 2 main sources of nutrients
- rainwater washes chemicals out of the atmosphere
- weather rock releases nutrients into the soil
give one human and one natural example of how a change in the balance of an ecosystem can affect the other parts of the ecosystem
NATURAL
- climate change = warmer temp meaning ponds dry up so plant/ animal species die
HUMAN
- fertilisers wash into rivers causing algae to grow, taking up too much oxygen so the fish die
where are the biomes distributed. why do the vegetation & climate vary?
- broad belts from east to west, parallel to the lines of latitude
- vary due to atmospheric circulation (rainfall) and how close to the equator they are (temp)
what’s the climate like in a hot desert (climate and rainfall). give an example of one.
- low rainfall (less than 250mm per year) bc its on a high pressure belt (sinking air stops clouds forming)
- high daytime temp, low nighttime temp (close to the equator)
- Sahara desert/ Egypt
where are hot deserts distributed?
30* north and south of the equator
what’re the physical characteristics of a tropical rainforest
- warm temperatures
- heavy rainfall
- infertile soil
- dense vegetation (evergreen trees, thick shrub layer w/ v. little light)
- indigenous ppl who’ve adapted to life there & survive by hunting, fishing, growing crops
what are the causes of deforestation (%)
- 70% commercial cattle farming
- 20% small scale subsistence farming
- 5% commercial farming ie soy beans
- 3% logging
- 2% other activities ie mining of iron ore/urbanisation (clearing space)/ HEP (dams & reservoirs)
economic impacts of deforestation
- creates jobs for local ppl (mine in peru employs 3100)
- economic growth from selling goods ($7 bill in 2008 from cattle in brazil)
- taxes being paid to improve public services ie health/education
- HEP is cheap & renewbale
- destroys indigenous ppl’s livelihoods
environemtnal impacts of deforestation
- loss of biodiversity
- increase in CO2 in atmosphere = climate change
- soil erosion leads to flooding & landslides
- soil fertility decreases (no canopy to protect the soil & nutrients wash away)
locate a case study for deforestation. and give a fact about the scale of deforestation there
- amazon rainforest in south america
- 750,000 km2 has been deforested
name some strategies to manage the tropical rainforest
- selestive logging & replanting
- conservation & education
- ecotourism & international agreements
- debt reduction
what’re the physical characteristics of Tundra biomes
- 10 to -20*C
- low rainfall
- layer of permafrost
- no or thin soil
- not very fertile soil
- few plants which grow slowly & are short
- few species of animals
how are plants adapted to living in tundra/polar biomes
- become dormant (stop growing) in cold winters
- low growing and cushion-like to insulate and protect
- hairy stems to retain heat due to cold conditions
- thin & waxy leaves to retain moisture due to the low rainfall
- shallow roots & grow under a layer of snow to photosynthesise in v cold conditions
- short growing season
how are animals adapted to living in tundra/polar biomes
- well insulated w/ thick fur/ blubber ie seals
- hibernate to conserve energy in winter/migrate to warmer areas ie arctic terns
- white fur for camouflage from predators/prey ie arctic hares
- adapted to survive on limited food
why should cold environments be protected
- wilderness areas provide us w/ scientific knowledge
- vital for biodiversity
- indigenous ppl who rely on ecosystem for survival (polar NOT tundra)
describe the location for the case study for cold environements
- alaska, usa
- northern hemisphere
- bordered by canada
development opportunities in alaska
- fishing (78,000 jobs BUT its seasonal)
- mineral extraction = mining (gold,silver,zinc creates jobs BUT envirinmental damage to ecosystem due to chemicals)
- tourism (1-2 mill visitors per year BUT seasonal & poorly paid. also most come on cruises which dump fuel in sea)
- energy (mainly oil but also HEP & geothermal. 90% taxes come from oil, 400 ppl employed in the industry BUT environmental damage from oil spills & 80% jobs taken by migrants instead of loals)
methods of protecting cold environments
- use of technology to improve construction of buildings & communication
- role of governments ie USA protection of the arctic & its natural resources
- international agreements ie antarctic treaty which protects the area
- conservation groups ie WWF & greenpeace encouraging protection of areas
challenges in alaska
- extreme temp (dangerous/difficult working outside - special clothing needed)
- inaccessibility (sparsely populated & poor road network makes it hard to travel around)
- buildings & infrastructure (provision is difficult & expensive. some buildings collapsing due to melting permafrost)
outline one positive economic impact of deforestation
creates jobs meaning residents pay taxes and the country develops
outline two environmental impacts of deforestation
- contributes to the greenhouse effect as CO2 which is taken in from trees will be released/ less trees are taking in CO2
- reduces biodiversity as many habitats are destroyed so animals have less space to live/ die
explain how soil and plants in tropical rainforests are depentant on each other
- plants depend on the soil to provide nutrients to help them grow
- soil relies on plants to return nutrients back to the soil when they decompose after death
outline two characteristics of vegetation in tropical ranforests
most are evergreen to take advantage of the continual growing season
most are tall to reach the sunlight as there isnt a lot of sunlight
