sustaining ecosystems Flashcards
1
Q
What is an ecosystem?
A
- 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
2
Q
What is a producer?
A
- An organism that uses sunlight energy to produce food
3
Q
What is a consumer?
A
- An organism that gets its energy by eating other organisms (producers or other consumers)
4
Q
What is a decomposer?
A
- 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
5
Q
What is interdependence?
A
- Parts of an ecosystem depend on the others, so if one part changes, it affects all the other parts.
6
Q
Where are coral reefs found?
A
- Between 30° N/S of the equator
- Few miles off the coast
7
Q
Where are temperate forests found?
A
- In the mid-latitudes
- Between the tropics and polar regions
8
Q
Where are tropical rainforests found?
A
- Around the equator
- Between the tropics
9
Q
Where are deserts found?
A
- Between 15° and 35° N/S of the equator
10
Q
Where are the polar regions found?
A
- Around the north and south poles
11
Q
Where are grasslands found?
A
- Tropical savannah are found between the tropics
- Temperate grasslands are found at mid latitudes
12
Q
What is the climate like in coral reefs?
A
- 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
13
Q
What plants are found in coral reefs?
A
- 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
14
Q
What animals are found in coral reefs?
A
- 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
15
Q
What is the climate like in temperate forests?
A
- 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
16
Q
What plants are found in temperate forests?
A
- 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.
17
Q
What animals are found in temperate forests?
A
- 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
18
Q
What is the climate like in tropical rainforests?
A
- 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
19
Q
Name and describe the four distinct layers found in tropical rainforests
A
- 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
20
Q
What plants are found in tropical rainforests?
A
- 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
21
Q
What animals are found in tropical rainforests?
A
- 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
22
Q
What is the climate like in deserts?
A
- 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
23
Q
What plants are found in deserts?
A
- 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
24
Q
What animals are found in deserts?
A
- 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
25
Q
What is the climate like in savannah grasslands?
A
- 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
26
Q
What plants are found in savannah grasslands?
A
- 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
27
Q
What animals are found in savannah grasslands?
A
- 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
28
Q
What is the climate like in temperate grasslands?
A
- 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
29
Q
What plants are found in temperate grasslands?
A
- Dominated by grasses and small plants, very few tress
- Grasses often have roots that spread out wide to absorb as much water as possible
30
Q
What animals are found in temperate grasslands?
A
- 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
31
Q
What is the climate like in polar regions?
A
- 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
32
Q
What plants are found in polar regions?
A
- 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
33
Q
What animals are found in polar regions?
A
- Few different species of animals compared with other ecosystems
- Home to polar bears, penguins, whales, seals, walruses
34
Q
Describe the water cycle
A
- 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
35
Q
What is evaporation and transpiration?
A
- when water is heated by the sun and turns into water vapour
- evaporation of water from plants
36
Q
Name the factors that affect the water cycle
A
- 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
37
Q
Describe the nutrient cycle
A
- 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
38
Q
Explain why rainforest soils are low in nutrients
A
- 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
39
Q
How does logging affect tropical rainforests?
A
- 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
40
Q
How does agriculture affect tropical rainforests?
A
- 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
41
Q
How does mineral extraction affect tropical rainforests?
A
- 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
42
Q
How does tourism affect tropical rainforests?
A
- 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
43
Q
How do tropical rainforests help us/ the economy?
A
- 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
44
Q
How do rainforests help locals/ the planet?
A
- 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
45
Q
Describe the climate in the Arctic
A
- Avg summer temps less than 10°C
- Avg winter temps about -20 to -40°C
- Annual precipitation less than 500mm
46
Q
Describe the features of the land and the sea in the Arctic
A
- 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
47
Q
What flora are there in the Arctic?
A
- Low-growing shrubs, lichen, moss, some flowering plants
e.g. arctic poppies
48
Q
What fauna are there in the Arctic?
A
- Most animals are adapted to the specific conditions of the Arctic
e.g. whales, seals, fish, wolves, polar bears, reindeer, caribou, lots of birds
49
Q
Describe the climate in Antarctica
A
- 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
50
Q
Describe the features of the land and sea in Antarctica
A
- 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
51
Q
What flora are found in Antarctica?
A
- Less vegetation
- Mainly moss and lichen
- Sea contains lots of phytoplankton
52
Q
What kind of fauna are found in Antarctica?
A
- 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
53
Q
How does tourism affect polar environments?
A
- 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
54
Q
How does fishing affect polar environments?
A
- 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
55
Q
How do indigenous people affect polar environments?
A
- 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
56
Q
How does scientific research affect polar environments?
A
- 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
57
Q
How does mineral extraction affect polar environments?
A
- 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
58
Q
How does whaling affect polar environments?
A
- 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
