living world Flashcards
what is an ecosystem?
- all the biotic (living) parts and the abiotic parts of an area
- organisms in ecosystems can be classed as producers, consumers or decomposers
what is a producer?
uses sunlight energy to produce food
what is a consumer?
gets its energy by eating other organisms - can eat producers or other consumers
what is a decomposer?
an organism that gets its energy by breaking down dead material and dead consumers - bacteria and fungi are decomposers
what is the nutrient cycle?
shows how nutrients move through an ecosystem
what are the steps of the nutrient cycle?
- when dead material decomposes, nutrients are released into the soil
- the nutrients are then taken up from the soil by plants - the plants may be eaten by consumers
- when the plants or consumers die - the nutrients are returned to the soil
- this transfer of nutrients is called nutrient cycling
what is a food chain?
shows what eats what
what is a food web?
shows lots of food chains and how they overlap
how is every component in an ecosystem important?
- each part of an ecosystem depends on other parts
- if one part changes it affects all the other parts that depend on it
what is an example of a small-scale ecosystem?
- freshwater pond at Mosely bog
- the area is a mixture of woodland and bog - bogs tend to have rich biodiversity
- producers in its freshwater pond include pondweed and algae
- consumers - buzzards, frogs, minnows, waterboatmen and snails
- decomposers include bacteria, water worms and rat-tailed maggots
what is a biome?
large scale global ecosystem
what are the characteristics of biomes: tundra?
- found at high latitudes (above 60° N)
- winters are very cold
- summers very brief
- little rainfall
what are the characteristics of biomes: tropical rainforests?
- located between 23.5° N and 23.5° S of the equator; where hot + wet all year round °
what are the characteristics of biomes: tropical grassland (savannah)?
- distinct dry + wet seasons
- but rainfall relatively low
what are the characteristics of biomes: temperate deciduous forest?
- summers warm
- winters fairly mild
- rainfall all year round
what are the characteristics of biomes: hot deserts?
- found between 15-35° north and south of the equator
- little rainfall
- very hot during day + cold at night
what are the characteristics of biomes: polar?
- located around north pole (arctic) and south pole (Antarctica)
- very cold, icy + dry as cold air sinks at the poles
- temperatures can fall below -50° C
what is the climate like in tropical rainforests?
- the climate is the same all year round - no definite seasons
- hot - temp generally 20-28° C - because sun’s energy more intense near equator
- rainfall high - around 2000mm per year - rains every day
what is soil like in tropical rainforests?
soil isn’t very fertile - heavy rain washes nutrients away
what are plants like in tropical rainforests?
- most trees are evergreen to help them take advantage of the continual growing season
- many trees are really tall and the vegetation cover is dense - very little light reaches the forest floor
- there are lots of epiphytes
what are animals like in tropical rainforests?
- rainforest ecosystems believed to contain more animal species than any other ecosystem
- gorillas, jaguars, anacondas, tree frogs and many more are found here. also many species of insects and bugs
what are people like in tropical rainforests?
- many indigenous people have adapted to life in the rainforests
- they make a living by hunting and fishing, gathering nuts and berries, and growing vegetables in small garden plots
what is biodiversity like in tropical rainforests?
- rainforests have extremely high biodiversity
- rainforests are stable and productive environments because climate is constant - hot + wet all the time - plants and animals don’t have to cope with changing conditions + always plenty to eat
- many organisms have evolved to depend on just a few other species for survival - are specific to a particular habitat + food source
- many species are also only found in a small area
how is biodiversity in rainforests being threatened?
deforestation and uncontrolled development of rainforest likely to lead to the extinction of many species + loss of biodiversity
how are rainforesrs interdependent ecosystems?
- all parts of rainforest dependent on one another - if one changes everything else changes
- warm + wet climate helps fungi and bacteria on forest floor decompose dead plant material rapidly - makes surface soil high in nutrients - meaning plants can grow easily
- plants pass on their nutrients when eaten by animals - dense vegetation provides lots of food - animal populations high - helps nutrient cycle
- many plants + animal species have formed symbiotic relationships
how are humans interfering with interdependent ecosystems?
- changes to one part of rainforest can have knock-on effects on whole ecosystem - ex deforestation
- trees intercept + take up lots of water + release back into atmosphere providing moisture for further rainfall - reducing tree cover may increase risk of drought - affecting plants and animals in rainforest ecosystem
- trees stabilise soil with roots and provide some nutrients when drop leaves - with fewer trees - soil less protection from heavy rainfall - few nutrients present wash away easily + plants struggle to grow
how are plants adapted to physical conditions in tropical rainforestss?
- trees compete for sunlight by growing tall
- many trees - smooth bark - smooth surface helps runoff
- large, stable buttress roots support the tall trees’ trunks
- climbing plants - like lianas - use tree trunks to reach sunlight
- plants have thick, waxy leaves with pointed drip-tips - encourages runoff so weight of water doesn’t damage plant - waxy coating helps to repel rain
how are animals adapted?
- some animals camouflaged
- many animals spend entire lives high up in canopy - have strong limbs so can move around habitat quickly
- some animals adapted to low light levels on forest floor - so can detect predators without seeing them
- many animals nocturnal - feed at night when colder - helps them to save energy
- suction cups help some animals climb
- others have flaps of skin that helps them glide between trees
- many animals can swim - helps them cross river channels
what are the causes of deforestation in malaysia?
- 𝗹𝗼𝗴𝗴𝗶𝗻𝗴 - Malaysia became the worlds largest exporter of tropical wood in 1980s
- 𝗺𝗶𝗻𝗲𝗿𝗮𝗹 𝗲𝘅𝘁𝗿𝗮𝗰𝘁𝗶𝗼𝗻 - deforestation for mines + roads - drilling for oil also started in Borneo
- 𝗽𝗼𝗽𝘂𝗹𝗮𝘁𝗶𝗼𝗻 - government encouraged poor urban people to move to countryside - leadings to felling of 15,000 hectares of rainforest during late 1900s
- 𝗰𝗼𝗺𝗺𝗲𝗿𝗰𝗶𝗮𝗹 𝗳𝗮𝗿𝗺𝗶𝗻𝗴 - Malaysia worlds largest exporter of palm oil - in 1970s large areas of rainforest were cleared for palm oil plantations
- 𝘀𝘂𝗯𝘀𝗶𝘀𝘁𝗲𝗻𝗰𝗲 𝗳𝗮𝗿𝗺𝗶𝗻𝗴 - slash and burn - using fire to clear land for food - fires can grow out of control
what are the impacts of deforestation in malaysia?
- 𝐬𝐨𝐢𝐥 𝐞𝐫𝐨𝐬𝐢𝐨𝐧 - tree roots kept the soil stable - when trees were removed - soil was easily eroded
- 𝐜𝐥𝐢𝐦𝐚𝐭𝐞 𝐜𝐡𝐚𝐧𝐠𝐞 - deforestation means less CO2 absorbed causing warming
- 𝐞𝐜𝐨𝐧𝐨𝐦𝐢𝐜 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭 - can bring short-term economic gains :
- jobs created in mining, farming + energy - tourism boosted with better transport
- companies pay taxes - can be spent on improving public services like education
- economic losses
- water pollution + drier climate may cause water shortages
- plants that could bring important medical benefits and profits could become extinct
why are tropical rainforests valuable to people + the environment?
- if species become extinct - harder to discover new medicines + develop new products
- sustainable development can offer long-term economic benefits eg ecotourism
- protecting rainforests may reduce greenhouse effect
- some impacts of rainforest destruction could affect all countries - not just countries where it is happening
- rainforests also help regulate climate + water cycle - without them risk of drought + flooding in certain areas can increase
how can selective logging help tropical rainforests be sustainably managed?
- only some trees felled
- less damaging to forest than clearing whole area
- canopy remains + soil isn’t exposed - allows forest to regenerate
how can replanting help tropical rainforests be sustainably managed?
- when new trees are planted to replace ones that are cut down
how ecotourism help tropical rainforests be sustainably managed?
- minimises damage to environment - only small number of visitors alowed in area at a time
- benefits local people - provides them a source of income
how can education help tropical rainforests be sustainably managed?
- educating international community about impacts of deforestation can encourage people to buy products from sustainable sources
- local people might damage rainforest without realising long-term effect of actions
- teaching local people alternative ways to make money that dont damage environment - means wont be dependent on unsustainable options to make a living
how can conservation help tropical rainforests be sustainably managed?
- many countries have set up national parks + nature reserves within rainforests - in these areas damaging activities are restricted
- but lack of funds can make difficult to police the restrictions
- as result, some countries have set up funds which overseas govts + businesses can invest in
- money can used to enforce restrictions + promote sustainable use of rainforests
how can reducing debt help tropical rainforests be sustainably managed?
- many tropical rainforests found in lower-income countries - which often borrow money from wealthier countries/ organisations
- money must be paid back with interest - poorer countries log, farm + mine in rainforests to make money + pay back debt
- reducing debt means countries don’t have to do this + rainforests can be conserved
- conservation swap good solution - part of country’s debt paid off in exchange for a guarantee money will be spent on conservation
how can international hardwood agreements help tropical rainforests be sustainably managed?
- hardwood - general term for wood from certain tree species - the wood tends to be dense + hard, so often used to make furniture
- high demand for hardwood from consumers in richer countries - hardwood trees becoming increasingly rare as more cut down
- international agreements in place to try to prevent illegal logging + promote use of hardwood from sustainably managed forests
