ecosystems Flashcards
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 these plants and animals die the nutrients are released back into the soil
example of a uk small scale ecosystem
slapton lay reed beds
give examples of what lives in the slapton lay reed beds
- common reed is one of the main producers
- eels and other fish use the reed as shelter
- birds like bitterns and herons nest in the reed bed and feed on fish
- consumers such as moth larvae feed on the reeds
- reed roots bind soil together, preventing erosion
how can changing one part of the ecosystem affect the rest of it or other parts of it
it is an interdependant ecosysytem meaning they all rely on each other
drought dries up pools leading to insect larvae die, fish and frogs that feed on these die, bittern numbers fall as they feed on the fish
name all the different biomes
tundra
grassland
temp deciduous forest
polar
tropical rainforest
hot desert
taiga
tundra
found at high latitudes above 60 degrees. winters are very cold. there is little rainfall. little vegetation. permafrost
grassland
savannah grasslands have dry and wet seasons. most of the vegetation is grasses. temperate are found at higher latitudes and have more variation in temp, no trees
temp deciduous forest
mid lat. 4 distinct seasons. summers are warm winters are mild. rainfall all year round. deciduous trees lose their leaves to cope with winter.
polar
north and south poles. very cold, little rain. remain dark for several months each year so growing season is short.
tropical rainforest
around equator. lot of rain, very warm all year round. dense canopies of vegetation
hot desert
little rainfall. very hot during the dday and very cold at night. shrubs and cacti are sparsely distributed in the sandy soil
taiga
wniters are cold and dry, summers are mild and moist. trees are coniferous - evergreen and have needles
tropical rainforests features
soil isnt very fertile due to heavy rain that washes the nutrients away
rianforests are beleived to have the most amount of species of any ecosystem
people - indigenous people live here, they make a living by hunting, growing crops and collecting berries
plants - most trees are evergreen to help them take advantage of the continual growing season
example of symbiotic relationships in trop rainforests
cecropia trees produce an energy rich foodstuff at the base of their leaves, this makes it an ideal home for Azteca ants, who rely on the trees for food and shelter
why is cutting down trees bad
trees stabalise soil and provide some nutrients when they drop their leaves, with fewer trees the soil would have less protection from heavy rainfall, nutrients would be more easily washed away and plants would struggle to grow
plant adaptations
leaves have a waxy surface and have drip tips, the waxy surface repels water and the drip tips allow for run off of water meaning the weight of water doesnt damage the plant
trees grow to compete for sunlight
animal adaptations
many animals live high up in canopies so have strong limbs to move around quickly e.g. howler monkeys
some animals are camouflaged meaning they can hide from predators e.g. leaf tailed geckos (look like leaves)
four layers of the rainforest
emergent trees - only have branches at the crown where most light is available
main canopy
under canopy - large leaves to absorb more sunlight
shrub layer
how is the global rate of deforestation changing
it is very high currently from 07 to17 an average of 22 million hectares of forest were lost each year - it is generally increasing
it varies between countries
what efforts have been made to reduce deforestation
increased global awareness has reduced the demand for products from deorested areas
costa rica made unautharised deforestation illegal
how are trop rainforests valuable to people
many products including rubber, coffee, chocolate and medicines are sourced from the rainforest
ecotourism
without rainforests flooding could increase as rainforests regualte climate and water cycle
how can rainforests be sustainably managed part 1
selective logging - only some trees are felled (e.g. old ones) - this is less damaging than clearing a whole area, this allows the forest to regenerate as the canopies remain and the structure is kept
replanting - new trees replace ones that have been cut down, it is important that the same type of tree is replanted - some laws are in place to make logging companies replant trees
ecotourism - minimises damage to environment and benefits locals
only a small number of visitors are allowed in an area at once and strict rules apply such as picking up waste
provides a source of income for locals - this means they do not have to log or farm to make money, reducing impact on environment
how can rainforests be sustainably managed part 2
education - educating people about the impacts can encourage them to buy products from sustainable sources
conservation - many countries have set up national parks and nature reserves within rainforests, logging is restricted in these areas although a lack of funds can make it hard to police the restrictions
reducing debt - many rainforests are found in LIC’s meaning they get funds from wealthier countries or orgs. this money must be paid back with interest meaning logging and farming takes place to repay this. reducing debts means countries don’t have to do this and rainforests can be conserved. however there is no guarantee that the repayment money will be spent on conservation - instead a conversation swap can be used where a guarantee that the money will be spent on conservation.
international hardwood agreements
it is word from certain trees e.g. mahogany, used to make furniture
high demand for these hardwoods means that tropical hardwoods are becoming increasingly rare
there are international agreements to prevent illegal logging and to promote use of hardwood from sustainably managed forests
cold environments - polar and tundra
climate - polar - very cold, usually below freezing, winters tend to drop below -40 can reach -90, precipitation is low tundra - warm months 10, cold minus 50
soil - ice sheets over polar areas so no soil is exposed, tundra soil is thin, acidic and not very fertile, permafrost holds trapped greenhouse gasses
plants - polar areas have few plants - lichens and mosses grow on rocks and grasses on the coast - tundra - hardy shrubs e.g. bearberry, grasses, mosses and lichens are all common
animals - few species
polar bears, penguins and seals are found in polar areas and lemmings, wolves and reindeer live in tundra areas
people - mostly unhibited, but the arctic has some indigenous residents. tundra areas are home to many indegenous people as well as oil and gas workers in larger towns
fragile interdependent species
the biotic and abiotic factors of the ecosystem depend on each other closely
cold climate causes plants to grow slowly and to decompose slowly so plant cover is low, meaning the soil is low in nutrients, further limiting plant cover
in the summer when the tundra has greater plant cover the surface plants absorb heat from the sun, preventing permafrost from thawing, this permafrost provides water for plants
what happens if humans trample lots of the plant in cold environments
soil is exposed to sunlight and warms up, thawing permafrost, saturating soil and preventing plant growth, with fewer plants to eat animals will struggle for food
melting permafrost also releases greenhouse gases
plant adaptations of cold environments
most plants become dormant to survive the cold, dark winters
plants are low growing and round shaped to protect from wind
shallow roots cuz of permafrost underneath soil
animal adaptations of cold environments
thick fur like polar bears and blubber for seals to provide insulation, reducing amount of energy used to keep warm
some animals hibernate to conserve energy and survive the winter
many birds migrate to warmer areas e.g. arctic terns live in the arctic in the southern hemisphere summer and the Antarctic for southern hemisphere summer
low biodiversity
means when the pop of one species changes it can affect dependant species e.g. if the pop of lemmings changed this would affect their predator, arctic foxes
