ecosystems

Question 1

what is an ecosystem?

Answer 1

unit that includes all the abiotic and biotic factors in an area

Question 2

types of organisms in a ecosystem?

Answer 2

producer, decomposers and consumers

Question 3

what is a producer?

Answer 3

an organism that uses sunlight to produce food (plants)

Question 4

what is a consumer?

Answer 4

an organism that gets energy from eating other organisms - either producers or consumers

Question 5

what is a food chain?

Answer 5

shows the direct links between what eats what

Question 6

what is a food web?

Answer 6

shows all of the interconnections of food chains and how they overlap

Question 7

what is a decomposer?

Answer 7

organism that gets its energy by breaking down dead material (bacteria and fungi)

Question 8

what is nutrient cycling?

Answer 8

the transfer of nutrients - when dead material is decomposed, the nutrients are released into the soil, which are taken by the plants. the plants may be eaten by consumers. when they die, the nutrients are released back to the soil

Question 9

types of global ecosystems [6]

Answer 9

• tundra
• grassland
• tropical rainforest
• polar
• hot desert
• temperate deciduous forest

Question 10

characteristics of tundra [3]

Answer 10

• winter is very cold, summers are brief and little rainfall
• found at high latitudes (above 60 N)
• layer of permanently frozen ground called permafrost

Question 11

characteristics of savannah grassland [3]

Answer 11

• found between the tropics
• distinct dry and wet seasons, rainfall is still low
• vegetation is grasses and few trees

Question 12

characteristics of temperate grassland [3]

Answer 12

• found in higher latitudes
• more variation in temp and less rainfall
• no trees only grass

Question 13

characteristics of temperate deciduous forest [3]

Answer 13

• found in mid latitudes
• 4 distinct seasons: warm summers and mild winters and all year rainfall
• deciduous trees lose their leaves during winter

Question 14

characteristics of polar [3]

Answer 14

• found in north and south poles
• very cold, icy and dry
• remain in the dark most of the year

Question 15

characteristics of hot deserts [3]

Answer 15

• found between 15 and 35, N and S of equator
• little rainfall, very hot during day and very cold at night (no clouds to trap in heat)
• shrubs and cacti are sparsely distributed

Question 16

describe the climate of tropical rainforests

Answer 16

• same all year round (no definite seasons)
• near the equator so temperature is hot: around 20-28C
• rainfall is very high, 2000m per year approx

Question 17

describe the soil of tropical rainforests

Answer 17

• not very fertile as the heavy rain washes nutrients away
• there are nutrients on the surface due to leaves decaying, but this is very thin as decay is fast

Question 18

describe the plants in tropical rainforests

Answer 18

• most trees are evergreen and tall
• vegetation cover is very dense so little light reaches forest floor
• there are lots of epiphytes (plants that grow on other living plants and take nutrients and moisture from air)

Question 19

describe the animals in tropical rainforests

Answer 19

-very diverse
- lots of insects and birds
- loud and brightly coloured animals

Question 20

describe the people in tropical rainforests

Answer 20

• make a living by hunting and fishing
• adapted to life over generations

Question 21

how are rainforests interdependent ecosystems?

Answer 21

all parts of the ecosystem are dependant on each other - if one of them changes, so will the others eg: if deforestation happens, the risk of flood increases as the trees cannot intercept and take in water. this affects animals, plants and the people in the ecosystem

Question 22

how have plants adapted to the rainforest conditions?

Answer 22

• buttress roots help support their trunks and compete for sunlights as they are tall trees
• thick and waxy leaves with pointy tips that allow water to run off easily and not weigh down the leaf
• smooth, thin bark as there is no need to protect the trunk from colder weather. smooth bark allows water to run off easily

Question 23

describe the layers of rainforest

Answer 23

forest floor: receive least amount of light, prone to floods
under canopy: shadier and cooler, seedlings lie dormant until bigger plants/trees die
canopy: 20-40 m tall, habitat for most wildlife like insects, birds and animals
emergent: tall around 60 m tall, help trap sunlight to help them grow

Question 24

how have animals adapted to the rainforest conditions?

Answer 24

• most of the animals spend their entire lives in the canopy. they have strong limbs that help them climb and leap
• some animals have flaps of skin that help them glide between trees. others have suction cups to help climb
• some animals can camouflage and hide from predators

Question 25

why are tropical rainforests chopped down? [6]

Answer 25

• population pressure: area for new houses
• mineral extraction: gold and iron are mined to make money
• energy development: building dams to generate hydroelectric power
• commercial logging: cutting down trees to make money
• commercial farming: forest is cleared to make space for cattle grazing, or huge plantations
• subsistence farming: forest is cleared so farmers can grow food for themselves and their families

Question 26

economic impacts of deforestation

Answer 26

• logging, farming and mining creates jobs
• money is made from selling timber, mining, and commercial farming
• deforestation reduces the attractiveness of the area to tourists
• local people’s livelihoods are destroyed

Question 27

environmental impacts of deforestation

Answer 27

• heavy rain washes soil away and can lead to flooding and landslides
• trees remove CO2 from atmosphere
• burning vegetation to clear forests produces CO2, ultimately adding CO2 to the atmosphere, adding to the greenhouse effect

Question 28

how can tropical rainforests be sustainably managed?

Answer 28

• selective logging
• ecotourism
• replanting
• international hardwood agreements
• education
• reducing debts
• conservation

Question 29

how does selective logging work?

Answer 29

• only certain trees are felled (chopped down)
• less damaging to the forest as it can regenerate and be used in the future
• its even better to do drag felled trees with a helicopter instead of large trucks

Question 30

how does replanting work?

Answer 30

• new trees are planted to replace the ones that are cut down
• same type of tree that is cut down should be planted so there will be variety in the trees in the future

Question 31

how does ecotourism work?

Answer 31

• minimises damage to the environment and benefits local people
• only a small number of visitors are allowed in an area at a time
• provides jobs for local people (guides, transport etc) so they won’t have to log or farm to make money
• fewer trees cut down

Question 32

how does international hardwood agreements work?

Answer 32

• hardwood is a general term for specific wood eg: mahogany and teak. usually used for furniture
• high demand for hardwood means some tropical hardwood trees are becoming rarer
• international agreements set to try and reduce illegal logging and promote hardwood from sustainably managed forests