C7 Human Dependence + Impact on Ecosystems Flashcards
ecosystem services
benefits supplied to humans by ecosystems, whether they be natural or man-made
ecosystem services
- what?
- categories (4) and examples
benefits supplied to humans by ecosystems, whether they be natural or man-made
- Provisioning: products/resources obtained (wood, metals, wool, medicinal products)
- Regulating: benefits supplied by ecosystem regulation (pollination, erosion/flood control, climate regulation)
- Cultural services: non-material benefits (bushwalking, boating, religious activities, enjoyment)
- SUPPORTING SERVICES: overarching, necessary for entire ecosystem function (nutrient cycles, water cycle, Phs)
Explain the problem with ecosystem services in today’s society.
- there is a clash between short term individual benefits, and long term ecosystem/societal benefits due to: undervaluing of ecosystem services, overvaluing of material products
- there is rapid, unsustainable human growth due to an increasing pop size and a larger per person consumption rate
- a lack of awareness leads to: decrease in biodiversity, alteration of ecosystems
- often human-caused disruptions are hard to reverse
renewable vs non-renewable resources
RENEWABLE
- naturally replenish over time and can keep up with the rate of human consumption
- wood, wind, solar energy, water
NON-RENEWABLE
- do not renew themselves rapidly enough to keep up with the rate of human consumption
- coal, oil, gas, nuclear energy
ecological footprint
- is a measure of the total ecological area that is required to sustain a person/population
- how much productive land/water something requires in order to produce all the resources it consumes, and absorb all the waste it generates
- measured in GHA (global hectares)
biocapacity
- the capacity of an ecosystem to regenerate everything we use/demand from that area
- a measure of how much an area can sustainably provide to society
- 6 demand categories: cropland, fishing grounds, carbon, grazing land, forest products, built-up land (cities)
ecological deficit/reserve
deficit/reserve are the difference between biocapacity and ecological footprint. (take one away from the other)
DEFICIT
- a regions ecological footprint is higher than its biocapacity
- the region is using more than is sustainably available to them
RESERVE
- a regions biocapacity is higher than its ecological footprint
- the region is using less than what is sustainably available to them
State the factors affecting the ecological footprint.
- resource intensity in production of goods/services (how much is needed to produce something)
- consumption of goods/services per person
- population size
Describe the relationship between a region’s GDP and ecological footprint.
- countries with higher GDP have larger ecological footprint per person
- they can afford more, and therefore consume more per person (buy more food/goods, live in larger houses, use more energy, use more water)
pollution vs contamination
POLLUTION
- always human caused
- a substance introduced into an environment causes harm
CONTAMINATION
- not always human caused
- there are higher lvls of a substance than usual
- doesn’t have to cause harm
- there can be contamination w/o pollution, but for pollution to occur, contamination has also occurred.
pollution
- sources (2)
- forms (5)
- impacts (3)
SOURCES
- human (deliberate or accidental)
- natural (volcanic ash, faeces)
FORMS
- organic (e.g. animal waste)
- inorganic (e.g heavy metals)
- organisms (invasive)
- nutrients (e.g. fertiliser)
- energy (light, heat, sound)
IMPACTS
- death to organisms
- decreased health (humans, organisms, ecosystems)
- reduced quality: soil, air, water
categories of pollutants (3)
POINT VS NON-POINT
- Point: one single location that pollution is coming from, easier to identify and control (e.g. pipe)
- Non-point: multiple, dispersed source of pollution, harder to identify and manage (e.g. city air pollution)
PRIMARY VS SECONDARY
- Primary: active/harmful on emission (plastic, CO2, fertilisers)
- Secondary: not necessarily harmful on emission, must react to cause harm (formation of acid rain and photochemical smog)
PERSISTENT VS DEGRADABLE
- Persistent: cannot be decomposed, leads to build-up of pollutant, is passed along food chains, majorly affects high trophic lvls (heavy metals, DDT)
- Degradable: can be decomposed by enzymes or bacteria, does not lead to build up/passed along food chains (modern pesticides, bioplastics)
eutrophication
- what?
- describe process
when water becomes enriched with nutrients due to runoff of artificial fertilisers used in farming (nitrates/phosphates)
PROCESS/CAUSES
- excess nutrients causes algal blooms
- algae block out the sunlight for plants underneath: without Phs, they die
- death of plants + the algae creates thick layer of dead biomass on bottom of waterway
- biomass must be decomposed by large amounts of bacteria, which through CR, use up all the dissolved O2 in the water
- without access to plants or oxygen,
bioaccumulation vs biomagnification
BIOACCUMULATION
- the buildup of persistent chemicals within an organism, due to ingestion/absorption of a toxin
- most affects organisms with a longer lifespan, which have a longer time to accumulate the toxin (higher trophic lvls)
- poisoning occurs once toxin lvl gets too high
BIOMAGNIFICATION
- the buildup of persistent chemicals within a food chain, leading to higher concentrations within higher trophic lvls
Most affects high trophic levels:
- as the organism size increases, it must eat larger quantities of food to survive (due to trophic energy loss)
- leads to magnification of the pollutant due to a higher pollutant conc
- tuna, swordfish, shark etc
State the abiotic factors that the impact of pollution can be measured through.
- pH
- nitrates/ammonia
- dissolved O2
- conductivity (ability to pass electric currents could indicate heavy metals)
- turbidity (how clear)
- faecal coliform tests (bacteria from animal guts)
Describe how dissolved O2/BOD can be used to measure the impact of pollution.
- gets into water via: diffusion from atmosphere, movement of water, Phs by autotrophs
- it is often reduced in the presence of pollutants due to many decomposing bacteria (eutrophication)
Can be measured indirectly through BOD
- biochemical oxygen demand
- the amount of O2 consumed by bacteria + other organisms when breaking down organic matter
- when pollution occurs, more bacteria are required to break down the dead matter, increasing respiration, increasing the demand for O2
INCREASE IN POLLUTANTS = INCREASE IN BOD = DECREASE IN DISSOLVED O2
Describe how biotic factors can be used to measure the impact of pollution.
INDICATOR SPECIES/BIOTIC INDEX
- species that are very sensitive to environmental conditions
- absence/presence/abundance of these will suggest the level of an ecosystem’s health
- the absence of several indicators of similar tolerance lvls may equal pollution
wild harvest fishing
- global production of fish/seafood has quadrupled in the last 50 years in order to feed the growing population
- wild harvest is fish that are taken from the sea (pots, nets, trawling, dredging, traps, longline)
WILD HARVEST FISHING
- describe the impacts of overfishing on aquatic ecosystems.
- when fish are being caught faster than the population can naturally replenish itself: too many adult fish are being caught to repopulate
- this significantly depletes populations = extinction (most threatens sharks/rays)
- population growth will continue to increase the amount of fish caught
- without change, overfishing will destroy ecosystems, biodiversity and ocean health beyond repair
WILD HARVEST FISHING
- describe the impacts of habitat destruction on aquatic ecosystems.
Many methods of fishing destroy habitat.
DREDGING
- metal scoop to harvest clams etc is dragged along the sea floor
- churns up sediment
crushes coral/habitat
- digs up burrowing animals
- decreases water quality
SEAFLOOR TRAWLING
- nets pulled across to collect bottom-dwelling fish
- destroys coral/oysters/sponges (habitat)
- destroys filter feeders (vital for preventing eutroph by eating nutrients)
- depletes benthic fish pop.s (vital for nutrient cycles)
BLAST FISHING
- dynamite thrown into water, causes fish to float to surface for easy capture
- massively destroying species/habitat
WILD HARVEST FISHING
- describe the impacts of derelict fishing gear on aquatic ecosystems.
Ghost fishing gear = gear that has been lost/abandones in the ocean
PLASTIC
- majority of ropes/nets are made of plastic
- lasts for centuries
- releases microplastics, eaten by organisms (cause internal harm + release chemicals)
ENTANGLEMENT
- captures targeted species: fishers have to compete with lost gear (e.g. pots/nets)
- captures non-targeted species (bycatch)
- injures organisms, or prevents from moving or coming up for air
CORAL REEF DESTRUCTION
- broken corals from ghost gear makes them vulnerable to disease
- nets block out light, preventing Phs
WILD HARVEST FISHING
- describe the impacts of bycatch on aquatic ecosystems.
- are non-targeted species
- cannot always be released back, or may be injured
- removes species from sea that are vital to biodiversity/ecosystem
- has negative flow-on effects due to relationships between species
LONGLINE FISHING
- birds attracted to bait
- turtles get bait lodged in mouth and drown
- mammals become trapped in line
TRAWLING
- collects unwanted animals in nets
Describe some solutions to combat the issues with wild fishing.
- better hooks/lines that target species and reduce bycatch
- ‘pingers’ on ships deter marine animals from the area
- bycatch reduction devices on pots
- different methods of collection (e.g. individual oyster harvesting instead of dredging)
- possibly aquaculture (fish farms)
Describe the pros and cons of aquaculture (fish farms).
PROS
- large fish yield: feeds a growing population
- theoretical decrease in wild fishing: allowing pop.s to replenish
- recycles waste from fishmeal/livestock to feed fish
CONS
- mainly, large carnivorous fish are being farmed: means more fish must be caught in wild harvest to feed fish in farms
- habitat destruction: to make room for farms
- escape of non-native species: cross-breeding with local fish causes genetic modification, brings pathogens into ecosystems
- waste produced: uneaten fish food and faeces causes eutroph + smothers seafloor, hormones/chemicals used on fish cause bioaccumulation + bacteria resistance, pathogens/parasites are released from overstocking pens
industrial vs sustainable farming
INDUSTRIAL FARMING
- goal is to produce as much food as possible
- use of: large scale machinery, fertilisers, pesticides
- beneficial to farmers + consumers (low cost due to high yield)
- ensures world food security with a steady supply of food
SUSTAINABLE FARMING
- goal is to protects enviro and human health
- considers: soil health, animal welfare, conservation, energy efficiency, pest management, water usage
- uses more money, time and space (habitat destruction)
- however overall farm sustainability will likely increase farmer’s profits
IMPACTS OF AGRICULTURE: nutrient cycles
- describe
- N, P, + others often limit growth in ecosystems
- when harvesting crops, nutrients are taken out of the soil
- adding fertilisers adds N/P back to soil
- if enters water bodies: eutroph occurs
IMPACTS OF AGRICULTURE: chemical use
- pros
- cons
PROS
- for max land efficiency, chemicals are added
- Pesticides: deal with fungi, insects, plants
- Fertilisers: contain materials used for plant growth
- result in a massive increase in production
CONS
- eutrophication
- human health problems (eating produce, drinking contaminated water)
- effects to beneficial non-targeted species (e.g. pollinators)
- resistance may be developed against chemicals (making pest control more difficult)
IMPACTS OF AGRICULTURE: water use
- describe
- environmental flows
- virtual water
USE
- watering crops (for human/livestock food)
- cleaning of products/areas
- drinking water for livestock
- transport of produce
- demand for water is increasing: growing pop, limited water on Earth
ENVIRONMENTAL FLOW
- water that is released from a dam to maintain river health (native species, water quality, reduce algae)
VIRTUAL WATER
- the ‘hidden’ water in goods/products/services used in the production of the product
- the more steps in the production process, the more virtual water (e.g. meat vs plants)
IMPACTS OF AGRICULTURE: salinity
- describe
- dryland salinity
- wetland salinity
- solutions (general, wetland specific)
- ancient salts in soil are brought to the surface via groundwater
- causes: decrease in soil/water quality, native vegetation and crop death, reduction in biodiversity
DRYLAND SALINITY
- non-irrigated areas
- removal of native trees reduces evapotranspiration
- more precipitation goes into the soil than out
- groundwater lvl rises, bringing salts to surface
- shallow-rooted crops don’t use enough water to counteract this
- results in death of plants due to high salt conc
WETLAND SALINITY
- irrigated areas
- land is irrigated, adding extra water, bringing up groundwater lvl
- clearing of land also causes dryland salinity
SOLUTIONS
- leave vegetation as it is, no land clearing
- replant native vegetation
- reduce flow of water into groundwater (via interception)
- pump out groundwater
- change to more salt-tolerant crops will make land useful once more
- plant multi-year, deeper rooted crops which will use more water
Wetland
- reduce water supply to crops (less excess)
- improve irrigation techniques (reduce flood/boom irrigation released large water amounts, use drip line irrigation instead)
Describe some solutions to combat the sustainability issues in agriculture.
CROP ROTATION
- prevents monoculture, where soil is accustomed to a single crop
- rotation naturally replenishes nutrients (esp legumes due to N fixing bacteria)
- reduces pest/pathogen build-up
WINDBREAKS
- plants absorb less water, reducing water usage
MULCHING
- adds organic material back into the soil, replenishing nutrients
RIPARIAN ZONES
- forest either side of a river absorbs excess nutrients, preventing eutroph
Outline the process of the natural greenhouse effect.
- incoming solar radiation (visible light, UV, infrared) from sun hits Earth’s atmosphere
- half of this is reflected/absorbed/scattered by atmosphere or clouds
- remainder reaches Earth’s surface: sea ice reflects some, heat (IR) is absorbed by land/sea
- IR is reflected back off warm surfaces on Earth: is absorbed by GHGs in atmosphere layer (CO2, methane, H2O vapour), then reemitted back again to Earth’s surface
- GHG are essential: trapping of this heat keeps Earth inhabitable, w/o it, Earth would be far too cold
Explain why GHGs are essential to life on Earth.
- the natural greenhouse effect
- trapping of this heat keeps Earth inhabitable
- w/o it, Earth would be far too cold to sustain life
Outline the process of the enhanced greenhouse effect.
- reduction in carbon sinks (e.g. forests) and increase in carbon emissions (e.g. FF burning)
- results in increased conc of GHG in atmosphere layer (CO2, methane, nitrous oxides, tropospheric O3)
- atmosphere is a better insulator of heat: more IR absorbed + redirected back to Earth
- denser layer prevents heat loss = warming of Earth temps
weather vs climate
- weather: short term atmospheric changes
- climate: average weather conditions over a long period of time
PHOTOCHEMICAL SMOG
- formed how?
- type of pollutant
- human sources
- common time of year
- impacts (human + enviro)
- nitrous oxides produced by internal combustion engines react with UV to form O3, combines with other pollutants + fog to form smog
- secondary pollutant
- Human sources: car exhaust, FF burning
- Common time of yr: summer (hot sun)
Impacts
- Human: irritate eyes/throat, increase severity of resp. conditions, increase risk of resp. infections
- Enviro: reduce Phs, reducing or stopping growth of plants + productivity
INDUSTRIAL SMOG
- formed how?
- type of pollutant
- human sources
- common time of year
- impacts (human + enviro)
- Formed from: sulfur dioxide + smoke particles
- primary pollutant
- Human sources: burning FFs
- Common time of yr: winter (more FF burning for warmth)
Impacts
-Human: irritate eyes/throat, increase severity of resp. conditions, increase risk of resp. infections, KILL if bad enough
- Enviro: reduce Phs, reducing or stopping growth of plants
Outline some solutions to combat the formation of smog (both types).
- decrease use of FFs! *
- limit transportation requiring petrol/diesel
- limit excessive manufacturing
- use renewable energy
- use more energy efficient appliances/buildings
Why does smog affect some cities and not others? (for each type)
- cities in basins/surrounded by mountains allows fog to settle
- Industrial: high humidity traps sulfur dioxide + smoke, forming smog faster
- Photochemical: increased sun exposure, dry, with calm winds, forms smog faster
ACID RAIN
- formed how?
- Impacts (human, soil, forest, water)
- burning of FFs releases sulfur + nitrogen into the atmosphere
- they react w water in the air, forming sulfuric acid + nitric acid, which falls as rain (or sometimes dry particles)
Impacts
- Human: breaks down limestone/marble, causes lung damage/resp problems
- Soil: becomes acidic, decreases plant ability to uptake nutrients, harms nitrifying bacteria, increases solubility to toxic heavy metals
- Forest: mass dying of plants, decreased productivity, increased vulnerability to enviro conditions
- Water: death of sensitive species, decreased reproduction, leached heavy metals = poisoning, some water bodies too acidic to sustain life
Describe how ozone is chemically formed.
- O3 is a gas formed naturally in the stratosphere
- UV (sunlight) breaks apart O2 molecules
- free O molecules then bond with O2 to create O3
‘good’ ozone vs ‘bad’ ozone
Good ozone
- located in: stratosphere (2nd layer)
- forms the natural ozone layer
- essential to life: absorbs majority of UV from sun, decreasing risks associated w sun damage (cancer/eye damage)
Bad ozone
- located in: troposphere (1st layer)
- naturally low in quantity
- burning of FF + sunlight + heat creates ground lvl O3
- common in larger cities/warmer weather/sunnier
- secondary pollutant
Describe how humans affect the formation of good AND bad ozone.
- burning FFs: contributes GHGs which react to cause ozone, creating tropospheric bad ozone
- ODS (ozone depleting substances): destroy stratospheric good ozone, regulated by the Montreal Protocol
Describe some of the impacts of bad (tropospheric) ozone on humans + enviro.
- Human: harmful when inhaled, causes smog, cardiovascular disease, worsens/causes resp. problems
- Enviro: increases enhanced greenhouse effect, affects weather, decreases plant health (decreased: yield, lifespan, seedling growth, ecosystem function)
Describe some other key effects of human induced climate change:
1. Sea level rise
2. Extreme weather events
3. Coastal erosion/flooding
4. Ice melt
5. Changing sea currents
6. Change of species distribution/behaviours
7. Decreased agricultural reliability
SEA LEVELS:
- sea levels are rising and are predicted to continue to rise, this is due to:
- as the oceans warm, the sea water expands taking up more space, causing water lvls to rise (thermal expansion)
= ice/snow on the land (glaciers ) is melting, adding to the amount of water in the ocean
EXTREME WEATHER EFFECTS
- increased frequency and intensity of extreme weather
- enhanced greenhouse effect results in higher global temperatures, increasing rates of evaporation and the air’s ability to hold moisture
- this increases the frequency and intensity of: storms, precipitation, floods, droughts, wildfires, natural disasters (hurricanes, cyclones etc)
- affects humans: resource supply (food/water/materials), safety and health, risk to housing and infrastructure, etc
- affects enviro: species decline/extinction, habitat/resource destruction
COASTAL EROSION/FLOODING
- on and around coastline area experiences erosion and flooding more often
- due to rising sea levels and increasing flooding/precipitation
- damages ecosystems (habitats, soil health, organisms, resources)
- damages human infrastructure, agriculture and aquaculture, etc
ICE MELT
- more ice caps/glaciers/sheets are melting worldwide
- due to enhanced greenhouse effect increases global temperatures, causing more ice to melt
- runs into rivers and streams, contributing to sea level rise
- reduction in habitat for arctic/antarctic organisms
CHANGING SEA CURRENTS
- Earth’s major currents are driven by the sinking of dense salty, cold water
- as sea temperatures warm, and ice sheets melt (adding fresh water back to the ocean), the density of the water is reduced, as it is warmer and less salty
- this decreases its ability to sink and drive the global ocean currents, and slows/alters them
CHANGE OF SPECIES DISTRIBUTION/BEHAVIOURS
- the enhanced greenhouse effect due to burning of FFs causes changes in climate (warmer temperature in air/ocean, more frequent precipitation, different weather patterns, etc)
- species distribution, behaviour, migration, and abundance are being affected, if they prefer/thrive in a specific environment
- this further influences ecosystems (food webs)
DECREASED AGRICULTURAL RELIABILITY
- enhanced greenhouse effect results in more frequent, intense weather events (floods, storms, droughts, wildfires)
- this damages agricultural land (decreased soil health, lack/excess of water, kills crops), livestock die
- decreases global food security
- decrease reliability on farming for economic gain
Describe how human-induced climate change is causing ocean acidification.
- humans are increasing CO2 atmosphere levels, almost half of this is absorbed into the oceans
- it reacts with water to form carbonic acid
- this causes an increase in acidity (lower pH) due to a higher conc of H+ ions
- H+ ions react with carbonate ions, decreasing the number of available carbonate ions
- calcium carbonate is essential for marine organisms that need to build/maintain a shell or exoskeleton (crabs, coral, clams), therefore:
= weaker shells/skeletons
= dissolution of shells/skeletons
Describe how human-induced climate change is causing coral bleaching.
- corals are comprised of a mutualistic relationship: coral animal, + symbiotic algae: which are the coral’s food source and provide them their colour
- increase in atmospheric CO2 has increased the greenhouse effect, causing Earth’s ocean temp to rise
- corals become stressed (heat), the algae produce harmful chemicals and the corals must expel it
- corals lose their source of food
- higher intensity and frequency of rising ocean temps leads to more frequent bleaching
= less time for corals to recover, more corals die
