2485 midterm

what is environmental science

interdisciplinary field of research that studies the natural world and how humans interact with their surroundings

environment

sum of all our surroundings, including all the living (biotic) and non-living (abiotic) things with which we interact

5 main causes of environmental problems

1. rapid population growth
2. unsustainable resource use
3. poverty
4. market prices not reflecting environmental costs
5. inadequate understanding of the environment

what is a resource?

something we need or want which is obtained from the environment

anthropocentric view

value is defined relative to human interests, wants, and needs

eco-centric/bio-centric view

values aspects of the environment simply because they exist

renewable resource

resource that is virtually unlimited, or replenished over short periods, so that it is replenished faster than it is withdrawn

non-renewable resource

a resource that is in limited supply, or replenished much more slowly than it is used

Explain why resources exist on a renewable - non-renewable continuum.

some resources can be renewable if they are used or managed properly - that is, so that they replenish faster than we use them

sustainable yield

rate of use < rate of replenishment

environmental degradation

rate of use > rate of replenishment

ecological footprint

cumulative amount of land and water required to provide the raw materials a person or population consumes, and to dispose of or recycle the waste that is produced

Explain what goes into calculating Ecological Footprint.

measures the average environmental impact of individuals in different countries and areas in global hectares (gha)

resources compared to raw materials

biocapacity

ability of a terrestrial of aquatic system to be biologically productive and absorb waste (measured in global hectares)

Compare humanity’s ecological footprint to Earth’s biocapacity.

how many people can be supported in relation to land

sustainability

the principle that requires us to live in a way that maintains earth’s systems and natural resources for the foreseeable future

sustainable development

development (typically economic) that satisfies our current needs without compromising the future availability of natural resources, or future quality of life

Describe how humanity’s Ecological Footprint has changed over time, and what that means for our sustainability.

we are now using more than in the past, we are over the bio capacity and overusing resources, not sustainable

ecosystem service

essential service an ecosystem provides (via its natural resources) that supports life and makes economic activity possible

how are ecosystems degraded

depleting natural resources, destroying habitat, generating pollution

Identify classes of ecosystem services.

* existence value
* scientific value
* use value
* spiritual value
* option value (things not using now but can in the future)
* aesthetic value
* cultural value
* educational value

classical economic model

* transactions in our economy lead to development
* between households and agriculture, industry, business
* closed loop system

classical economic model assumptions

1. resources are infinite and substitutable
2. long-term effects should be discounted (idea that $100 now is worth more than $100 later)
3. costs and benefits are internal (included in the price)
4. growth is good

classical economic model assumptions unmet

1. resources are unlikely to be infinite
2. if we run out of a resource, then there is not the option of having the $100 later
3. there are many externalities
4. planners may value some things like green space and clean air more highly than growth (some things that increase the size of the economy are indefensibly bad like war)

externalities

cost or benefit of a transaction that affects people other than the buy or seller (such as ecosystem services or pollution)

Identify ways of dealing with externalities.

1. develop a new model with new ways of measuring value
2. keep the structure of the economic model with specific modifications to internalize relevant costs and benefits

environmental economists’ model

* features external to the conventional model
* ecosystem services, natural resources, waste acceptance, natural recycling
* externalities might also be positive
* recycling

gross domestic product (GDP)

meausure of the value of all goods and services produced

genuine progress indicator (GPI)

* includes conventional economic activity and adds positive contributions to the economy and subtracts negative impacts such as crime or pollution


* includes economy’s effect on the wellbeing of its people

measuring value

anytime a purchase is made, GDP goes up

Identify what factors lead to population growth.

* births
* immigration
* deaths
* emigration

Describe the differences between exponential growth and logistic growth.

* exponential means the population size keeps growing
* logistic growth pattern means the population plateaus at the carrying capacity

Identify factors that lead to a carrying capacity for a population.

* competition for resources (water, food, space)
* predators
* disease

what happens when the population size exceeds the carrying capacity

populations crash, oscillating pattern of population growth often seen in nature

when overshoot capacity, population will crash to a size below the capacity

what increases human carrying capacity

technology

Explain if the human population has reached or is likely to reach a carrying capacity.

wide range estimate depends on how we use our resources

Explain what is shown in an age pyramid.

* way of looking at how many individuals are in a given population and dividing population size by age
* shows the pre-productive age, reproductive age, post-reproductive age population
* increasing population has a greater population under 30
* decreasing population has smaller children population compared to elderly

Explain the relationship between wealth and population growth.

richer countries have lower population growth than poorer countries

Describe how birth rate, death rate, and population growth rate are affected by industry phases (pre-, transitional, industrial, post-)

* economic improvement lowers death rate, decreases incentive for large families, use of birth control becomes more widespread
* pre: birth and death rate high
* transitional: death rate decreases, high birth rate
* industrial stage: birth rate decreases
* post: birth and death rate are low

Describe the IPATS model.

explains the impact on the environment of several factors, helps policy makers understand the effects that humans can have on the environment

what does IPATS stand for

* Impact on the environment
* population size, for the environment being examined
* affluence - more wealthy populations consume more resources
* technology - new tech can increase or decrease impact on the environment
* sensitivity - some environments are more sensitive to human disturbance

what does the IPATS model predict

* predicts a crash in food, population and output and increase in pollution by 2050
* hit the carrying capacity
* if the population was capped at 8 billion, it is maintained

Describe some environmental effects caused by urban sprawl.

* loss of land, fragmentation of wildlife habitat, increased soil erosion
* contaminated drinking water, noise pollution, traffic congestion
* water contamination, increased flooding
* higher taxes, higher unemployment
* increased energy use, waste, air pollution, greenhouse gas emissions

urban heat island effect

increased temperatures (2-6C) in core urban areas relative to surrounding areas

effects of noise pollution from urban sprawl on wildlife

* high intensity sound induces fear
* singing / calling at higher frequencies
* trouble finding prey
* decreased reproduction

effects of light pollution from urban sprawl

* stargazing
* astronomical resource
* changing animal migration
* aquatic ecosystems, algae and water quality

ecosystem

all organisms that occur and interact with each other and with an abiotic environment at a particular place and time

ecoregion

a large area of land or water containing a geographically distinct assemblage of natural communities that share a large proportion of their species and ecological dynamics

biome

a major regional complex of similar plant communities (defined by its dominant plant type and vegetation structure)

Describe the movement of energy and matter through ecosystems.

* the sun powers everything in the ecosystem and greatly impacts the producers
* consumers eat producers
* consumers and producers produce detritus (non living organic matter)
* detritivores and decomposers exchange with detritus

ecosystems accounts for

water, geological formations, atmosphere, human made structures, plants, animals

climatographs axis

y = temperature and precipitation

x = time of year

what leads to different communities of organisms and vegetation

differences in annual temperatures and precipitation

what is considered a desert

low precipitation

tundra (vegetation, major threat, climate graph)

vegetation: shallow roots, short plants

major threat: climate change (characterized by low temperature so climate change would melt the permafrost and boreal forest takes over areas of tundra)

climate graph: low temperature, short growing season in july, precipitation higher than temperature and peak at the same time

boreal forest (vegetation, major threat, climate graph)

vegetation: conifers (evergreen), nutrient poor soil

major threat: logging (species is uniform and takes long time to replenish)

climate graph: longer growing season in july, temperature and precipitation peak higher than tundras

temperature deciduous forest (vegetation, major threat, climate graph)

vegetation: trees with leaves changing colour

major threat: urbanization (destroys habitat)

climate graph: longer growing season in july and constant high precipitation

temperate grassland (vegetation, major threat, climate graph)

vegetation: grass

major threat: urbanization and cereal cropland

climate graph: moist conditions where temperature is below precipitation and short dry conditions where temperature is above precipitation

temperate rain forest (vegetation, major threat, climate graph)

vegetation: large trees and fertile soil

major threat: overlogging (can cause landslides)

climate graph: large amount of precipitation, temp and precipitation peak in july

tropical rain forest (vegetation, major threat, climate graph)

vegetation: high biodiversity, nutrient poor soil because nutrients are tied to vegetation

major threat: logging for agriculture (the acidic soil of the forest must be treated before crops can be planted - nonrenewable)

climate graph: constant high temp and high rainfall

tropical dry forest (vegetation, major threat, climate graph)

vegetation: plants adapted two separate seasons, flowers for reproduction during rainy season

major threat: clearing for agriculture

climate graph: half the season is dry (temp>precip), growing season in january (precip>temp)

savannah (vegetation, major threat, climate graph)

vegetation: grass and clusters of trees

major threat: drought, overgrazing by wildlife

climate graph: cooler than tropical dry forest, water stress for large portion of the year

desert (vegetation, major threat, climate graph)

vegetation: bare vegetation, short shrubby

major threat: having more desert (adjacent biomes become desert)

climate graph: sparse rainfall, high temperatures

desert dust made of

long dead diatoms (algae organisms that make up glass sand)

chaparral (mediterranean) (vegetation, major threat, climate graph)

vegetation: noncontinuous, influenced by ocean, dry

major threat: fires (dry vegetation)

climate graph: water stress in july, half growing season

Explain the connections between biomes, and why some of these connections are particularly important to the long-term health of the biome.

* connect biotically (migration) and abiotically (wind, water)
* one organism can have an impact on multiple biomes
* wind can move dust and therefore nutrients across biomes

Explain why climate alone is insufficient to predict the plants or animals found in an area.

some species rely on the presence of other species to survive

they are absent from areas even though they we expect them to be present based on climate

keystone species

species that has a large impact on an ecosystem relative to its abundance

Identify if humans are a keystone species and justify your answer.

no, we have a large impact on the ecosystem but we are in large abundance, our impact is likely relative to our large population

biodiversity

variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part

including diversity within species, between species, and of ecosystems

genetic diversity

variations in the genes among individuals of the same species

species diversity

variety of species present in an area; includes the number of different species that are present as well as their relative abundance

ecological diversity

variety of habitats, niches, trophic levels, and community interactions

Describe how the number of species on Earth can be estimated and identify how many species there are on Earth (within a range).

collecting and counting what we can find and extrapolating this data using equations

(finding amount in one area then multiplying it globally)

Describe the rate of extinction today compared to historical levels.

extinctions occur over 100s and 1000s of years, there are many species on the brink of extinction, we may be experiencing one right now

species on the brink of extinction

* fewer than 1000 individuals in the population
* 1.7% of vertebrates on the brink

Explain how the Living Planet Index is calculated, and identify what the Index tells you, and what it cannot tell you.

* evaluates the health of the world’s biodiversity
* tracks the population size
* set to 100% for 1970 and any values below = loss of population size
* losses mean there are more species to be threatened or the threats are threatening a wide variety of species

Rank the threats to biodiversity, both across all habitats, and across just terrestrial biomes

1. habitat degradation, change, loss
2. exploitation
3. climate change
4. invasive species
5. pollution
6. disease

habitat destruction

natural habitat is no longer able to support the species present. organisms that previously used the site are displaced or destroyed

habitat degradation

there is a decline in habitat quality that leads to reduced survival or reproductive success in a population

habitat fragmentation

habitat loss results in the division of large, continuous habitats into smaller, more isolated remnants

invasive species

a non-native species that spreads widely and rapidly, and becomes dominant in a community, interfering with the native community’s normal functions

Explain some of the negative effect of invasive species.

* destroy trees
* economic impacts

Suggest how to control the damage done by invasive species.

* chemical control
* biological control
* physical (mechanical) control

biochemical cycles

source to reservoir to sink

source

a reservoir that releases more nutrients (or other material of interest) than it accepts

reservoir

a location where nutrients (or other materials) in a cycle remain for a period of time

aka pool

sink

a reservoir that takes in more nutrients (or other materials) than it releases

residence time

average time the material remains in the reservoir

steady state

sources = sinks

flux

mass or volume of material flowing per unit of time

turnover time

the time it takes for all atoms of a material to be moved through a reservoir

Identify the largest reservoirs and fluxes of the hydrologic cycle.

largest reservoirs: oceans; ground water; soil water; atmosphere; ice caps, glaciers, and snowfields

largest fluxes: precipitation, evaporation

Describe the relative abundance of fresh water vs. salt water.

97\.5% ocean and 2.5% freshwater (79% ice caps and glaciers)

freshwater

average salinity

marine

average salinity 3%

major differences based on depth and distance from rivers

Identify where the highest productivity marine environments are found and explain why (note the importance of upwellings in your answer).

* shallow water, more photosynthesis able to occur, more benthic species
* more productive near rivers since nutrients are moved
* upwellings bring nutrients to coastlines
* when wind blows across the coast, coriolis effect causes surface water to move away from the coast and there is an upwelling of cold nutrient rich water that replaces the surface water

intertidal zone

water level changes, sometimes above and sometimes below water

continental zone

shallow waters for more diverse ecosystems to occur, sunlight can penetrate to the bottom of the ocean floor

aphotic zone

twilight and no light zones

not full sunlight penetrating through the water