modules 3 and 4 Flashcards
From an energy standpoint, why is it important to eat low on the food chain?
Because about 90% of energy is lost at each level so it is less energy costly to eat lower on the food chain.
Explain the difference between density-dependent and density-independent forms of environmental resistance. give an example
environmental resistance is the ways in which the environment limits growth
density-dependent factors: growth is limited by density of population
- supply of nuts is based on squirrel population and vice versa
density-independent factors: growth is limited by factors that have nothing to w/ size of population
- polar vortex leads to cold temps and inability for the squirrels to survive the cold which will decrease the squirrel population
carrying capacity
number of organisms that a region can support without environmental degradation
mutualism
both organisms benefit
example: bees and flowers (pollination)
commensalism
1 organism benefits, other 1 is neutral
example: fish hiding in coral
competition
1 benefits, 1 suffers/gets consumed
example: cheetah hunting a zebra
Describe an example of how the removal of a predator species can have effects throughout the entire food chain.
With fewer total predators, the regulation of the animals directly below in the food chain will decrease. They will then thrive and as their population increase they will eat more of the lower levels. This can lead to a depletion of the lower levels; therefore, the available food for the species that initially thrived will be gone and eventually this can lead to the end of an ecosystem.
What are 2 variables that distinguish biomes from each other besides the typical vegetation cover?
precipitation
temperature
soil type
ecosystem services
provisioning
regulating
cultural
supporting
provisioning
provides services
food, raw materials, water, medicine
regulating
regulates:
air quality
climate
water
waste
erosion
disease
extreme events
pollution
cultural
mental/physical health
recreation
aesthetics
spiritual/religious values
supporting
nutrient cycling
soil formation
photosynthesis
Explain how one could try to assess the value of ecosystem services provided by a particular species. Why would it be helpful to assess this?
bats:
1 bat species on a cotton farm consumes insects so because of this they’re valued. they save about 15% of the cotton from being eaten by insects so they’re valued at 15% of the farm’s total sales. Without some measure of ecosystem services, the services may be undervalued, and it may be difficult to assess needed funding for sustainable management of these resources/to track the condition of nature or its economic role and value.
Describe two reasons why there tends to be higher species abundance nearer the equator.
the climate is warmer and more consistent
no ice sheets
Explain why we should care about biodiversity hot spots.
they have endemic species and have less than a third of original vegetation
endemic species
any species whose range is restricted to a limited geographical area
What different metrics do the Living Planet Index and IUCN Red List track?
number of population of different species
threatened species and level of threat
There are two components to the Multidimensional Biodiversity Index. explain the difference between the two and which one focuses on instrumental values.
2 components: biodiversity for nature and biodiversity for people
Biodiversity for nature measures diversity, abundance, and function. Biodiversity for people measures regulation, materials and assistance, and non-materials; this focuses on instrumental value and measuring how nature is useful for humans.
What are the largest two global land uses?
pasture
cropland
Name some ecosystem services of forests and wetlands, and classify them.
forests: stabilize soil (r), prevent erosion (r), purify water (r,p), release oxygen (r), moderate climate (r), play role in nutrient cycling (s), wood (p)
wetlands: remove pollutants (r), attract people for recreation (c), store carbon (r), absorb and store water (r)
Consider a palm oil plantation. Which of the forest ecosystem services are still provided by it, and which were lost when the natural forest was converted to a monoculture?
keep: carbon storage and runoff reduction (regulation and provisioning)
lose: biodiversity (affects regulation and nutrient cycling in soil-supporting)
What are the particular factors that lead to the different patterns of deforestation? (fishbone, radial, dendritic, rectangular)
roads, small-scale farming, large farming (slash and burn), paths to transport goods
How do current rates of change in forest cover differ between temperate and tropical forests?
temperate forests are recovering and have a net gain of forest
tropical forests are still in a net loss
Explain why people living in the U.S. bear some responsibility for deforestation in the Amazon
We buy products that contain the crops such as palm oil that resulting in the deforestation of the Amazon
What is an ecosystem service that motivated the Ramsar Convention?
motivated by migratory birds
wetlands were being drained for housing so losing carbon uptake
Describe multiple ways in which roads can impact a forest ecosystem.
give access to previously undisturbed land
provide a transportation route for harvested materials
barrier to species movement
Explain the difference between deforestation and degradation.
deforestation changes land in a way that permanently gets rid of forest
degradation temporarily thins a forest without change in use of land
What is causing forest degradation even in the absence of direct impacts from human activity?
climate change leads to wildfires
Which drivers of biodiversity change primarily impact individual species vs. ecosystems?
individual species: fishing, hunting, island invasions
ecosystems: pollution, climate change, fire, agriculture/forest clearing
Rank the drivers of biodiversity change, from largest to smallest level of impact.
land use change, direct exploitation, climate change, pollution, invasive species
Describe different pathways by which an invasive species may be introduced to an ecosystem, both accidental and intentional.
horticulture, aquaculture, pet, live food trades (commerce in living organisms)
shipping ballast discharge, canals, planes, land vehicles (transportation)
Describe the different stages of invasion, and how the spatial scale and solution varies at each stage.
introduction: prevent arrival/release/escape
establishment: early detection/eradication
spread: slow the spread
long-term: control and adapt
the spatial scale impacts the solution because it’s harder to get rid of something over a larger area
How were zebra mussels introduced to the US, how do they spread, and what ecological and human impacts do they have?
carried in ballast water from Eastern Europe
they attach to anything solid
clog pipes and filter plankton out of water so sunlight can penetrate deeper so weeds can now grow
Give examples of two other invasive species and how they were introduced to the U.S.
stink bugs were introduced through shipment of trade goods
asian carp were intentionally imported because they eat a lot
Describe one strategy to prevent, one strategy to contain, and one strategy to control an invasive species. What are two reasons why control is usually more expensive than prevention?
prevent: fumigate wood packaging/treat ballast water before release
contain: physical barriers
control: remove manually/toxic chemicals
continual cost and on a much larger scale so costs more money
Describe ecological restoration strategies that were implemented in two different biomes around the world.
reintroduction of native plants
anti-poaching programs
building fences
changing infrastructure to reduce impacts
education
invasive species removal
Imagine you have just discovered that there is an endangered species on the land where you want to build a shopping mall. Under the Endangered Species Act, what actions are now prohibited? How can you avoid those restrictions and still develop your property?
can’t kill or harm it, can’t destroy its habitat, can’t trade it
can still build if a Habitat Conservation Plan is developed
Using the example of Health in Harmony’s work, describe how a focus on planetary health can lead to improvements in the environment, human health, and economics. (Bonus for tying these into the SDGs.)
radical listening
focuses social/economic needs of a community as well as environmental
Health care clinic (w/lower prices
for non loggers), “Chainsaw Buyback” business
program, Reforestation efforts, Education
Describe two ways in which advances in genetics have helped advance conservation efforts.
cloning which may help prevent extinction of species
genetic testing has helped identify location of origin of poaching so people can be held accountable/charged
plants are more resilient
What does CITES stand for? How is it similar and how is it different from the Endangered Species Act in what it regulates?
CITES: Convention on International Trade in Endangered Species
ESA is US specific whereas CITES is international
ESA protects their habitat too and prevents the killing of threatened species
Both identify threatened species and restrict trade
Compare and contrast the goals and challenges of polyculture and monoculture.
polyculture:
pros: reduce fertilizer use, increase pest resistance, increase soil stability, reduce water demand, “insurance” if one crop fails
cons: labor intensive which is expensive
monoculture:
pros: efficiency which saves time and money
cons: depleted soil nutrients, erosion after harvest, vulnerability to pests/diseases
Define “yield” and give possible units for measuring food production.
yield: output per area
units: kg/ha
Describe three examples of changes made to plants to increase yield.
shorter and stronger to support heavier heads of grain
mature more quickly
grow any time of year
resistance to pests
thrive under intensive farming
Which input to food production is associated with the problem of eutrophication?
fertilizer
What are three different sources of greenhouse gases from food production systems?
methane from livestock
fossil fuels from equipment
fertilizer/chemicals used on plants
Which negative impacts of meat production are reduced and which are worsened in a confined animal feeding operation?
land use is reduced
risk of disease is worsened
ethical questions
concentrated outputs
Explain why switching from our current global diet to a vegan diet would require less land.
land use for pastures would drastically decrease
land use for food would decrease
What were two foods for which one was more harmful in some impacts and the other was worse in others? How did they differ?
eggs had a larger carbon footprint than chickpeas
chickpeas had a larger land use footprint than eggs
Explain which stages of the food life cycle are most important if you are worried about energy use vs. if you are worried about GHG emissions.
energy: agricultural production and origin of resource
GHG emissions: processing, packaging, distribution, production, consumption, end of life disposal
Describe or draw the reinforcing loop associated with land cover and soil. How can the nature of this loop be used in a positive way for the environment?
vegetation cover–> roots held in place–> erosion –> extent of soil to support vegetation growth
Explain how irrigation can lead to a decline in soil fertility.
can result in salt buildup in the soil
Choose three different stages of the food life cycle and identify a way in which food waste occurs in each of them.
food processing: bad-looking ones get tossed
consumption: people take too much food and can’t finish it
agricultural production: crops go bad because they over-ripened/wasn’t enough water for them
Draw/explain the food waste hierarchy. Name at least 4 levels in the hierarchy.
prioritizes actions organizations can take to prevent and divert wasted food
source reduction, food rescue, home composting, small-scale composting, large-scale composting, mixed waste treatment, landfill
Consider two categories of GM crops, herbicide-tolerant and pesticide-resistant. Which one will lead to more chemical spraying? Explain why.
herbicide-tolerant will lead to more chemical spraying because the plant won’t be damaged by these chemicals used to kill weeds
Describe three concerns with wild fishing
destruction of natural habitat
overfishing
illegal fishing
bycatch
What are two different methods for catching wild fish that have distinctly different negative impacts on the environment? Briefly describe each impact.
purse seine which is like a big drawstring bag. may take too many fish causing pressure on fish populations
bottom trawl ruined ground habitats and lots of bycatch
Explain how aquaculture can have negative impacts on wild fisheries and the local communities that depend on them.
decrease of fish supply in local waters because they are used are food for fish in aquaculture
increase in water pollution from processing facilities
decrease in tourism due to dead fish/blood in water
Describe three benefits of aquaculture.
reduces pressure on wild stock
reduces bycatch
employment especially for women
easier to track supply chain practices
lower environmental impacts than most animal agriculture
cheaper
What does the FIFO ratio measure, and how can you use it to decide what kind of farmed fish are best to consume?
fish in to fish out so how many kgs of fish it takes to produce 1 kg of fish
Describe three benefits of seaweed production.
nutritious
carbon uptake
promotes biodiversity
fertilizer
industrial use (cosmetics/pharmaceuticals)
biofuel
socioeconomic benefits
