Earth's Natural Systems Flashcards
Name two biodiversity hotspots
Mexico Monarch Butterfly Biosphere Reserve and Madagascar
Why is it important to protect biodiversity hotspots?
- allow nature to flourish
- attract tourists
- can be important to Indigenous groups
- more interconnections = stronger ecosystem
- provide clean air and water
How can migratory animals serve as indicators of environmental changes?
- moving based on temperature → signs of global warming
- decline in turtles → urban activity scaring them away from beaches or light pollution confusing them
- humpback whales feed on krill → decline in krill in certain areas if stop going there
- birds hatching earlier (usually just before warmer temps) → global warming gets warmer faster
- bird stop-over locations changing → lack of food in location
- flying over land instead of ocean → can’t fly over ocean due to storms bc of global warming
Describe the arctic tern’s migratory pattern
- from arctic to antarctic circle (greenland to antarctica)
- avoid winter by flying to different hemispheres - summer has best food and is easier to catch
- fly along South America/Africa when travelling down
- flies towards Africa and then towards Mexico in an ‘S’ when travelling up
What can vary people’s connection to nature?
- proximity to nature
- worldview
- Aboriginal people’s connection to country
- the ‘overview’ effect
What has changed people’s connection to nature?
- reduced proximity to nature (urbanisation & town planning)
- changes in types of leisure (indoor & virtual recreation)
- changes in transport & work
What are the global commons?
- natural systems and resources that don’t belong to any one country
- High Seas
- atmosphere
- antarctica
- outer space
What are key characteristics of the global commons?
- fall outside national jurisdictions
- parts of planet
- all nations have access
- don’t belong to anyone
What are main challenges with management of global commons?
- conflicts over resource use
- enforcement of inernational agreements
- addressing interest of all nations while preserving global commons
What is the overview effect?
- seeing Earth from space
- recognising Earth as a unique, fragile resource
What is the tragedy of the commons?
Where each country acts in their own interest instead of for the common good
What are some of the consequences of the tragedy of the commons?
- overconsumption
- underinvestment
- depletion of resources
- worsens global warming, ocean acidification, pollution, and loss of biodiveristy
Why are higher altitudes generally colder?
Hot air starts at the ground and starts to cool down as it rises
What are the order of cells surrounding the Earth from equator to the poles?
- Hadley cell
- Ferrel cell
- polar cell
What is a keystone species?
species that are critical to the survival of other species in an ecosystem
What are examples of keystone species?
- wildebeest in Serengeti - decrease woodland fires by eating dry, flammable grass
- ochre sea star in Pacific coast - keeps populations of mussels and barnacles in check by eating them → allows for healthy populations of seaweed (mussels and barnacles grow algae) & herbivores
- sea otters in coastal waters - feed on sea urchins which eat kelp
How can keystone species be useful as bioindicators?
- wildebeest follow short, green grass in wet season & rainfall in dry season - change in migration = abnormal weather patterns
- ochre sea star populations decrease → rise in ocean acidification as mussels and barnacles can’t grow shells
- increased starved or starvation deaths in sea otters → ocean acidification as sea urchins can’t survive
How does the ocean regulate global climate?
- cold ocean currents from South pole → equator
- warm ocean currents from equator → South pole
- sequesters 30% of carbon emmissions from human activities
What is oceantiy?
How close you are to the ocean
What is contintentality?
How far you are inland
Why do places at higher altitudes have more rainfall?
They are closer to rainclouds
What is an isolated system?
prevent exchange of matter and energy with their surroundings (don’t exist naturally)
What is a closed system?
permit exchange of energy but not matter (e.g. Earth as a planet)
What is an open system?
exchange both energy and matter (e.g. the spheres)
Which layer of the atmosphere contains all weather processes?
troposphere
What is the composition of the atmosphere from highest concentration to lowest concentration?
- Nitrogen
- Oxygen
- argon
- various greenhouse gases
How does latitude affect insolation?
higher latitudes have more curved surfaces and receive less insolation
What is albedo?
the amount of insolation that is reflected back into space as a percentage
Describe some horizontal transfers of heat
- wind and ocean currents
- carry heat from tropics towards poles
Describe some vertical transfers of heat
- terrestrial radiation
- conduction
- convection currents
- latent heat transfers via condensation
Which parts of Earth have low pressure belts?
- equator
- subpolar
Which parts of Earth have high pressure belts?
- poles
- subtropics
What causes low pressure?
heated air rising
What causes high pressure?
cool air descending
What are jet streams?
- bands of extremely fast-moving air
- rapidly transfer energy
- move eastward
What causes surface winds?
air movements from high-pressure to low-pressure areas
What is required for thunderstorms to occur?
- moist air
- unstable atmosphere
- mechanism to initate development (fronts, troughs, regions of low pressure)
What is a trough?
an area of low atmospheric pressure
What does the stratosphere do?
blocks most UV rays from the sun reaching Earth
What is the order of the atmosphere from Earth to space?
Today Sam Made TEa
1. troposphere
2. stratosphere
3. mesosphere
4. thermosphere
5. exosphere
What are trade winds?
easterly winds within Hadley cells
What is the coriolis effect?
- when Earth spins, the poles spin faster than the equator
- causes objects moving from North to South hemisphere to be deflected to the right (from perspective of object), and objects moving from South to North hemisphere to be deflected to the left
How do you name winds?
- from direction they come from
- Westerlies are just called Westerlies (no North or South)
At what rate does altitude affect temperature?
-6℃ every 1000m
What are microclimates?
climactic differences that occur over very small areas
What causes urban heat islands?
- concrete and roads are dark - asborb more heat
- in the night they release heat
- cars and people release heat
- impermeable surfaces increase run-off - cannot be cooled by evaporation
What is the global water budget?
sum of all inputs, outputs, and net changes in hydrosphere over a period
What is a catchment?
system of rivers, lakes, and wetlands that transfer water from areas with more water to areas with less water
What is a watershed?
ridge of land that separates catchments
What are the inputs and outputs of a river?
- inputs - precipiation and run-off
- ouputs - sediments and silts
How does the mid-altantic ridge support the theory of continental drift?
- mountains are striped with magnetic rock on either side
- magnetic charges switch from North pole to South pole
- charges match up on each side - indicating seafloor spreading
What does the asthenosphere do?
acts as a lubricating layer that allows tectonic plates to slide around
What is regarded as the cause of plate motion?
mantle
What are examples of divergent plate boundaries?
ridges
What are examples of convergent plate boundaries?
- volcanoes
- trenches
- island arcs
- fault lines
- mountain ranges
What are faults?
fractures in the rock structure allowing some blocks of rock to rise up
What are fold mountains?
mountains formed by layers of rock being compressed & forced upwards, causing them to “fold” over
What are block mountains?
formed by faults, allowing some “blocks” of rock to rise up
What is land cover?
physical & biological features of Earth’s surface
What is land use?
the ways humans use the land
What is land cover distinguished by?
- types of soil
- types of vegetation
- how often/long the area is submerged underwater
What natural causes can cause land cover change?
- volcanic activity
- weathering & erosion (degradational processes)
- fire
What is plant succession?
the change in types of plant species occupying an area over time
What are the main steps of plant succession?
- Pioneer species (bare rock → lichens → small amount of plants → grasses & perrenials)
- Intermediate species (grasses, shrubs, shade-intolerant trees)
- Climax community (shade-tolerant trees)
What is primary succesion?
ecological succession in an area without soil or where soil is incapable of sustaining life
What is secondary succession?
ecological succession in an area where natural vegetation has been destroyed but the soil has not been destroyed
What are some human causes for land cover change?
- population growth (incr. demand for food & industrial production)
- technology (large dams & aquaducts, topography & forest clearing change)
- anthropogenic climate change (fossil fuels, deforestation)
How has the atmospheric concentration of CO₂ changed over time?
- below 300ppm for over 400 years
- increased to 318ppm in 1960
- 421ppm in 2022
What were causes of the 2019-2020 Australian bushfires?
- record high temperatures
- strong winds
- drought
What were the results of the 2019-2020 Australian bushfires?
- destroyed over 5900 buildings (incl. 2779 homes)
- killed at least 33 people
- killed around 1 billion animals
- some endangered species went extinct
- emitted 400megatonnes of CO₂
What is a primary forest?
dominated by native tree species & there is no visible signs of human activity
What is a secondary forest?
results from secondary ecological succession after disturbance by human activity
What is a plantation?
a commerically managed forest
What are some natural causes of deforestation?
- forest fires
- disease
- parasites
- extreme weather events
How do moisture and temperature affect the types of vegetation present in forests?
- as moisture decr., there is less vegetation
- as tempreature decr., trees change from canopy trees to cone-shaped
What is forest fragmentation?
division of forests into smaller and more isolated fragments
What are the impacts of forest fragmentation?
- Over time, the edges of each segment become degraded
- may become too small and too isolated from other fragments to support forest ecosystems
- results in deforestation
What is afforestation?
the expansion of forests typically on land previously used for agriculture
What are the 4 main causes of deforestation?
- Agricultural expansion (commercial and local subsistence)
- Urban expansion
- Infrastructure
- Mining
What are the main causes of deforestation in Borneo?
- palm oil plantations
- earns poor farmers 4 times more money than rice or rubber
- climate change-induced fires
Why are Borneo’s rainforests important?
- extremely old
- 15,000 species of plants, 420 birds, and 222 mammals
- home to only 50,000 Bornean orangutans - critically endangered
How has forest cover changed in Borneo?
- 1900-2000 covers almost the entire island of Borneo
- 2020 only covers the middle and north of the island - reduced by over half its original size
What is necessary for a protected area to be successful?
they must be large enough to allow ecological processes to be sustained indefinitely without being negatively affected by activities in surrounding areas
Why are biological corridors important?
- allows for an exchange of individuals between populations
- prevent the negative effects of inbreeding and reduced genetic diversity
- re-establishment of populations that have been reduced or eliminated
How can agribusiness slow the rate of deforestation?
- committing to zero deforestation by adopting business models that are environmentally and socially responsible
- joint design of sustainable land use plans on corporate land
How can humans assist natural forest regeneration?
RERP
* Re-establishing trees from seeds adapted to local soil and climate conditions
* Encouraging pollinators, herbivores, and seed-dispersal agents
* Reducing competition from grasses and other vegetation forms that hinder the growth of naturally regenerating trees
* Protecting an area from disturbances
How have governments and private operators in West Africa made a range of commitments to end deforestation in cocoa supply chains?
- safeguard biodiversity and ecosystem services
- avoiding revenue loss and impacts on local livelihoods
- Cocoa & Forests Initiative of Ghana and Côte d’Ivoire and the Green Cocoa Landscape programme in Cameroon
- support the sustainable development and climate resilience of cocoa production
- prevent further deforestation
- restore degraded forests
What are the 6 main causes of forest loss in the Amazon?
- clearing land for cattle grazing
- small-scale farming
- commercial crops
- fire
- selective logging
- tree plantations (including palm oil)
How much of the pre-1970 forest cover has been lost in the Amazon?
almost 20% by 2021
What are some political factors that influenced deforestation in the Amazon?
- Brazilian Pres. Jair Bolsonaro in 2019 resulted in a relaxation of environmental protection measures
- Brazil had more than 70,000 fire outbreaks in 2019
- most slash-and-burn forest clearing is done illegally
- Brazilian environment agency issued fewer penalties
- ministers sided with those responsible for land clearing rather than Amazonian Indigenous groups
What are some strategies that could save the Amazon Basin?
FILE DELI
* Forest rehabilitation
* Increased productivity of previously forested lands
* Land policy reform
* Expansion of protected areas
* Development based on the sustainable use of existing rainforests - Indigenous, agroforestry, and polyculture techniques
* Ending subsidies for large landowners, restricting trade of specific trees, etc.
* Law enforcement
* International attention - pressure on governments
What is desertification?
land degradation in arid and semi-arid areas
Why are plants important for preventing desertification?
with a lack of plants to keep soil in place, the soil is prone to erosion
What are human causes of desertification?
- increasing population (demand for water)
- over-abstraction (planting water-hungry crops)
- overgrazing (farmers stay in the same place)
- salinisation (salty water for irrigation, water moves out of plant via osmosis)
What are some areas at risk of human-induced desertification?
- Coast of Australia
- Central America
- India
- Middle East
- Sahel & Southern Africa
- Brazil
What has caused desertification in the Sahel?
- dam in River Draa to provide water for large town - people downstream couldn’t get water & had to move
- planting watermelon and cotton because they sell for more money
- Taroudant, Morocco took groundwater for citrus fruit, taking over 3metres of groundwater/year - farmers who couldnt dig deep enough had to leave
- precipitation has been below average
What can be done to prevent desertification?
- using traditional irrigation techniques specific to area
- polyculture farming - provides soil with nutrients
- trees provide soil stability
- manure from animals to fertilise crops
- solar powered electricity
- reforestation - planting drought-resistant trees to provide soil stability
What are three types of plate boundaries?
- converging
- diverging
- transform
What are natural causes of climate change?
- glacial/interglacial periods
- tilt of Earth
- solar flares
- volcanic eruption
