sustaining ecosystems

Question 1

What is an ecosystem?

Answer 1

• A unit that includes all the biotic parts and abiotic parts in an area
• Organisms in an ecosystem can be classed as producers, consumers, or decomposers

Question 2

What is a producer?

Answer 2

• An organism that uses sunlight energy to produce food

Question 3

What is a consumer?

Answer 3

• An organism that gets its energy by eating other organisms (producers or other consumers)

Question 4

What is a decomposer?

Answer 4

• Organism that gets its energy by breaking down dead material
  e.g. dead producers and consumers, or fallen leaves
• Bacteria and fungi are decomposers
• Returns nutrients to the soils where they can be used by plants

Question 5

What is interdependence?

Answer 5

• Parts of an ecosystem depend on the others, so if one part changes, it affects all the other parts.

Question 6

Where are coral reefs found?

Answer 6

• Between 30° N/S of the equator
• Few miles off the coast

Question 7

Where are temperate forests found?

Answer 7

• In the mid-latitudes
• Between the tropics and polar regions

Question 8

Where are tropical rainforests found?

Answer 8

• Around the equator
• Between the tropics

Question 9

Where are deserts found?

Answer 9

• Between 15° and 35° N/S of the equator

Question 10

Where are the polar regions found?

Answer 10

• Around the north and south poles

Question 11

Where are grasslands found?

Answer 11

• Tropical savannah are found between the tropics
• Temperate grasslands are found at mid latitudes

Question 12

What is the climate like in coral reefs?

Answer 12

• Coral reefs are most common in warm areas that receive lots of sunlight
• Mean temp of 18°C
• They grow best in shallow clear salty water - no deeper than 30m

Question 13

What plants are found in coral reefs?

Answer 13

• Few plants grow there as it’s underwater
• Tiny algae live inside the tissue of corals
• Algae and coral depend on each other for nutrients
• Sea grasses commonly found in Caribbean Sea

Question 14

What animals are found in coral reefs?

Answer 14

• Coral is an animal, it has a hard outer coating for protection
• Around 25% of all marine species live in coral reefs
  e.g. fish, molluscs, sea snakes, turtles, shrimps
• Many fish have flat bodies so they can easily swim through and hide in small gaps in the coral

Question 15

What is the climate like in temperate forests?

Answer 15

• Have four distinct seasons - spring, summer, autumn and winter
• The summers are warm and the winters are cool
• Average annual temp of 10°C
• Rainfall is very high (up to 1500mm per year) and there’s rain all year round
• Forests that receive the highest amount of rainfall are called temperate rainforests

Question 16

What plants are found in temperate forests?

Answer 16

• Temperate forests have lots of trees, vegetation depends on type of forest
• Deciduous forests have
  broad-leaved trees that drop their leaves in
  autumn, shrubs and undergrowth
  e.g. oak, brambles
• Forest-floor plants often flower in spring before the trees grow leaves and block out the light
  e.g. blue bells
• Coniferous forests have evergreen tree and an understory of grasses and low-growing plants.
  e.g. pine, fir
• Trees can make use of available sunlight all year round.

Question 17

What animals are found in temperate forests?

Answer 17

• Support many species of mammals, birds, and insects
  e.g. foxes and squirrels, woodpeckers and cuckoos, beetles and moths
• Animals migrate to warmer places or hibernate to escape the cold

Question 18

What is the climate like in tropical rainforests?

Answer 18

• Same all year round - no definite seasons
• Temp between 20-28°C - it’s hot
• This is because near the equator the Sun is overhead all year round
• Rainfall is very high (2000mm per year) - rains everyday usually in the afternoon

Question 19

Name and describe the four distinct layers found in tropical rainforests

Answer 19

• Tallest trees known as emergents; can reach as high as 50m
• Have buttress roots to support trunks and only have branches at their crown where most light reaches them
• Canopy below emergent; receives 70% of sunlight and 80% of rainfall; approx 30m
• Large leaves to absorb as much light as possible
• Under canopy; trees of 20m
• Shrub layer; adapted to living in shade

Question 20

What plants are found in tropical rainforests?

Answer 20

• Most trees are evergreen to take advantage of the continual growing season
• Vegetation cover is dense, so very little light reaches forest floor
• Lots of epiphytes (plants that grow on other living plants and take nutrients and moisture from the air)
  e.g. orchids and ferns

Question 21

What animals are found in tropical rainforests?

Answer 21

• Contains more animal species than any other ecosystem
  e.g. gorilla, jaguars, anacondas, tree frogs, sloths
• Many animals are camouflaged (leaf-tailed geckos) to hide from predators
• Animals are nocturnal (sloths) and sleep through the day and feed at night when it’s cooler, saving energy

Question 22

What is the climate like in deserts?

Answer 22

• Very little rainfall (less than 40mm per year)
• Rain varies a lot - might rain once every two or three years
• Temps are extreme: hot in day (45°C) and cold at night (below 0°C)
• During the day, Sun raise temps
• During the night, lack of cloud cover means heat escapes

Question 23

What plants are found in deserts?

Answer 23

• Plant growth is sparse due to lack of rainfall; most plants are xerophytic
• Plant roots are long to reach deep water supplies or spread out wide near the surface to catch as much water as possible when it rains
• Some plants have fleshy stems and thick, waxy skin to cope with the dry climate - reduce transpiration
  e.g. cacti, thornbushes

Question 24

What animals are found in deserts?

Answer 24

• Home to lizards, snakes, insects and scorpions
• Mammals tend to be small (kangaroo rats)
• Animals are nocturnal, so they can stay in burrows or the shade during the day
• Some bigger animals have evolved to lose very little water & tolerate dehydration
  e.g. camels have humps that store fat and water

Question 25

What is the climate like in savannah grasslands?

Answer 25

• Low rainfall (800-900mm per year)
• Distinct short wet and long dry seasons
• Temps are highest before wet season (25°C) and lowest (15°C) after it

Question 26

What plants are found in savannah grasslands?

Answer 26

• Consist mostly of grass scrub and small plants, with a few scattered trees
  e.g. acacia tree
• Plants adapted to cope with low levels of rainfall - long roots to reach deep water or small, waxy leaves to reduce water loss

Question 27

What animals are found in savannah grasslands?

Answer 27

• Home to species of grasshoppers, beetles, and termites
• Larger animals include lions, elephants, giraffes, zebras, and antelope
• grazing animals travel long distances in search of food and water while others dig burrows to escape harsh climate

Question 28

What is the climate like in temperate grasslands?

Answer 28

• Have hot summers (up to 40°C) and cold winters (-40°C)
• Annual rainfall is 250-500mm mostly in the late spring and early summer

Question 29

What plants are found in temperate grasslands?

Answer 29

• Dominated by grasses and small plants, very few tress
• Grasses often have roots that spread out wide to absorb as much water as possible

Question 30

What animals are found in temperate grasslands?

Answer 30

• Home to few animal species than savannah
• mammals include bison, wild horses
• rodents include mole rats
• grazing animals travel long distances in search of food and water while others dig burrows to escape harsh climate

Question 31

What is the climate like in polar regions?

Answer 31

• Temps usually less than 10°C
• Winters normally below -40°C and can reach -90°C
• Rainfall is low (500mm a year mainly in summer)
• Clearly defined seasons - cold summers and even colder winters

Question 32

What plants are found in polar regions?

Answer 32

• Few plants
• Some lichens and mosses are found on rocks
• Few grasses and flowering plants on the coast where it’s warmer
• Some small, short trees and shrubs grow in warmer sheltered areas

Question 33

What animals are found in polar regions?

Answer 33

• Few different species of animals compared with other ecosystems
• Home to polar bears, penguins, whales, seals, walruses

Question 34

Describe the water cycle

Answer 34

• Water evaporates from water bodies and the land
• Water vapour is moved by winds
• Water vapour condenses to form clouds and then falls as rain
• Water flows from one place to another
• surface run off
• stored in small channels, water flows in small channels
• soaks into ground, stored as ground water, flows through soil and rock
• Water eventually ends up back in the river or sea

Question 35

What is evaporation and transpiration?

Answer 35

• when water is heated by the sun and turns into water vapour
• evaporation of water from plants

Question 36

Name the factors that affect the water cycle

Answer 36

• sun is overhead, hot: evaporation rates are high
• high evaporation rates mean lots of water vapour = rainfall
• vegetation is dense so water is intercepted and stored by plants

Question 37

Describe the nutrient cycle

Answer 37

• Dead leaves and other material fall all year round
• Warm, moist climate means that fungi and bacteria decompose the dead organic matter, releasing nutrients
• Rainwater soaks into the soil and the nutrients are dissolved in the water
• Dense vegetation means nutrient-rich water is rapidly taken up by plants’ roots

Question 38

Explain why rainforest soils are low in nutrients

Answer 38

• Hot wet climate means that chemical weathering is rapid - deep layer of soil & bedrock up to 30m below
• Trees drop leaves all year round forming a thick leaf layer
• Broken down to form humus
• Layer of humus because plants quickly absorb nutrients
• Competition: dense vegetation and fast growing
• Nutrients are leached due to heavy rainfall
• Vegetation have roots close to the surface

Question 39

How does logging affect tropical rainforests?

Answer 39

• No trees to hold the soil together, heavy rain washes away the soil - leads to soil erosion which can enter rivers, silting up habitats that fish use for breeding
• Interrupts water cycle - leads to areas becoming dry with increased risk of wildfires, other areas likely to flood
• Logging requires building of new roads - opens up the rainforest to further development
• Clearing tress makes it less appealing to tourists

Question 40

How does agriculture affect tropical rainforests?

Answer 40

• Land is often cleared using slash-and-burn techniques - produces CO₂, greenhouse effect
• Without trees to intercept rainfall, more water reaches the soil - nutrients washed away, soil fertility reduced
• Artificial fertilisers added to improve soil fertility are washed into streams, threatening wildlife

Question 41

How does mineral extraction affect tropical rainforests?

Answer 41

• Mining of precious metals, e.g. gold, often requires heavy machinery and removal of trees
• Toxic chemicals used to extract and purify the metals are washed into streams and rivers - killing wildlife and polluting people’s drinking water
• Conflict with local people over rights to the land

Question 42

How does tourism affect tropical rainforests?

Answer 42

• Tourists may scare wildlife - e.g. causing nesting birds to abandon their young
• They may damage vegetation and litter
• If unregulated, a lack of infrastructure can lead to pollution of water ways - in order to build infrastructure, vegetation must be cleared

Question 43

How do tropical rainforests help us/ the economy?

Answer 43

• High biodiversity means rainforests are a rich source of goods
  e.g. rubber, coffee, chocolate, medicine
• Hardwoods are used for furniture and building - can contribute to a country’s economy
• Provide opportunities for farming and mining - provides jobs and income
• Directly provide services for people
  e.g. tourist visits

Question 44

How do rainforests help locals/ the planet?

Answer 44

• Plants absorb around 0.7 billion tonnes of CO₂ each year - reduce climate change
• Rainfall intercepted by high density of vegetation - reduce the risk of local flooding, movement of water slowed down
• Regulate the global water cycle - stores water & releases it into atmosphere slowly, reduces risk of drought & flooding

Question 45

Describe the climate in the Arctic

Answer 45

• Avg summer temps less than 10°C
• Avg winter temps about -20 to -40°C
• Annual precipitation less than 500mm

Question 46

Describe the features of the land and the sea in the Arctic

Answer 46

• Majority of Arctic is made up of ocean - lots of drifting pack ice and icebergs, sea ice extends further in winter
• On land there are mountainous regions, areas that are permanently covered with snow and ice, and areas of treeless tundra

Question 47

What flora are there in the Arctic?

Answer 47

• Low-growing shrubs, lichen, moss, some flowering plants
  e.g. arctic poppies

Question 48

What fauna are there in the Arctic?

Answer 48

• Most animals are adapted to the specific conditions of the Arctic
  e.g. whales, seals, fish, wolves, polar bears, reindeer, caribou, lots of birds

Question 49

Describe the climate in Antarctica

Answer 49

• Colder than the Arctic
• Summer temps usually -20°C to -5°C
• Winter temps can reach -90°C
• Annual precipitation is lower - 50mm inland, 200mm at the coast

Question 50

Describe the features of the land and sea in Antarctica

Answer 50

• Is a land mass which is 99% covered with an ice sheet
• A few mountains, e.g. the Transantarctic Mountains
• The sea freezes in winter, nearly doubling the size

Question 51

What flora are found in Antarctica?

Answer 51

• Less vegetation
• Mainly moss and lichen
• Sea contains lots of phytoplankton

Question 52

What kind of fauna are found in Antarctica?

Answer 52

• All the animals rely on the sea
  e.g. for food or to provide a habitat for breeding
  e.g. whales, seals, penguins, sea-birds

Question 53

How does tourism affect polar environments?

Answer 53

• Occurs in both
• Increases shipping and air travel - leads to water and air pollution, risk of boats grounding - causing oil spills
• Tourists can disturb breeding colonies of birds and seals - trampling damages fragile vegetation and erodes the landscape, leaving paths
• Litter and waste disposal damages habitats, harms wildlife - decomposition rates in cold environments are slow
• In Antarctica, concern over the introduction of non-native species - alters food webs

Question 54

How does fishing affect polar environments?

Answer 54

• Commercial fishing takes place in both
• Over-fishing threatens many species
  e.g. the Patagonian Toothfish (Antarctica) nearly extinct
• Reduced fish populations have knock on effects on other species in the food chain - e.g. larger fish and birds that eat them
• Other species affected - e.g. albatrosses and petrels get caught in fishing lines and drown

Question 55

How do indigenous people affect polar environments?

Answer 55

• No permanent inhabitants in Antarctica
• Arctic population: 4 million - Inuit of Greenland and Canada
• Traditional rely on reindeer, herding, or fishing and hunting to support themselves - however, only take what they need
• Many now live in modern towns and cities - e.g. Anchorage in Alaska
• impacts environment through waste disposal, air and noise pollution from vehicles, and heat from buildings melt permafrost

Question 56

How does scientific research affect polar environments?

Answer 56

• Use polar for important research - e.g. global climate change - positive impact on global environmental management and management of polar ecosystems
• Previously, some scientists working in Antarctica dumped rubbish in the sea and abandoned broken equipment - polluted land and sea, damaging habitats and posing a risk to wildlife
• Research stations and ships produce chemical and sewage pollution - research organisations trying to limit this

Question 57

How does mineral extraction affect polar environments?

Answer 57

• Arctic has large gas and oil reserves (e.g. Prudhoe Bay, Alaska) and other mineral deposits (e.g. uranium and phosphate mined in Arctic Russia)
• Drilling for gas and oil is risky - oil spills are difficult to clean up, harms habitats and kill wildlife
• Pipelines built to transport oil and gas - melt permafrost and interrupt the migration routes of caribou herds
• Produces lots of pollution - damages ecosystems

Question 58

How does whaling affect polar environments?

Answer 58

• Big industry in both during the last two centuries
• Species of whales hunted to near extinction
  e.g. Blue, Fin, Minke whales
• Whales are slow breeders - long time for population to recover
• Mostly stopped, however, whales still slowly recovering