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)
