the major themes of environmental science
human population growth and how that leads to environmental problems
sustainability, the environmental goal
global perspective to solve the many problems arising across the earth and trying to find a global solution
an urbanizing world and what that means for the environment
people and nature (how they are interconnected)
science and values
to preserve the current population while still using sustainable practices we must ….
expand efficient and sustainable farming practices
turn to other energy resources besides oil
reduce the amount of babies being born
sustainability of an ecosystem
an ecosystem is sustainable if we continue its primary functions for a specified time in the future
sustainable economy
economically viable, doesn’t hurt the enviorment and is socially just for all people
careful management and wide use of the planet and its resources in relation to the management of money and goods
attributes of a sustainable economy
social, legal and political system that’s dedicated to sustainability, equity and justice
effective population control, restructuring of energy programs and instituting economic planning
carrying capacity
the maximum number of individuals of a species that can be sustained by an environment without decreasing the capacity of the environment to sustain that same number in the future
Gaia hypothesis
created by James Lovelock and Lynn Margulis
says that over the history of life on earth, life has significantly changed the global environment which improves the chances of continuation of life on earth
economic development leads to urbanization
in developed countries, 75% of the population lives in urban areas
growth of mega cities
2 in 1950 (NYC and London)
22 in 2005
pros of big cities
usually have extensive public transport
people live in smaller homes that are easier to heat and cool
goods travel less distance to get to customers
two paths when it comes to people and nature
assume the environmental problems are a result of human action and the solution is to simply stop
scientific analysis → problem solving, accepts the connection of people and nature and looks for long-lasting solutions
examples of people and nature being intimately integrated
soil is necessary for plants, so therefore its necessary to us
the atmosphere lets us live through oxygen and protects us from UV rays
big idea
a sustainable environment and a sustainable economy might be compatible, that humans and nature are intertwined and success for one needs to include success for the other
humanness = connected to nature (we drink water and breath air)
precautionary principle
1992 the Rio earth summit on sustainable development
says when there is a threat of serious or irreversible environmental damage, we shouldn’t wait for scientific proof to take action
adopted by EU and San Fransisco
being proactive not reactive
utilitarian justification
some aspects of the environment are only valuable because its beneficial economically or is absolutely necessary for survival
ecological justification
the ecosystem is necessary for the species of interest or the system provides some benefit
aesthetic/recreation justification
appreciation of the beauty of nature and the ability to go outside and enjoy it
gaining legal basis (ex: Alaska recognizing its otters are a recreational attraction and protecting their habitat)
moral justification
our environment has the right to exist and we have a moral obligation to help it
cultural justification
different cultures have many of the same but also different values about the environment
ex: Buddhist monks have strong environmental ethics and won’t even disturb earth worms
Easter island example of humanity permanently damaging an environment
loss of forest loss of soil → no new trees
Sea otters have an important role for maintaining the kelp forest ecosystem and their disappearance causes the collapse in the functioning of that ecosystem. Because of this they are known as...
keystone species
A species of bird living in the branches of the Acacia tree protect the tree from herbivores and eat the nutrient rich fruits on the tree.
mutualism
Which of the following is the largest reservoir within the hydrologic cycle?
the ocean
Which organisms have the most available energy in an energy pyramid?
producers
If 10,000 J of energy is in the producer trophic level, how much would pass on to the primary consumers?
1000 J
abiotic factors
nonliving parts of the environment
biotic factors
living parts of the enviorment
Habitat
Place where an organism lives out its life; Where it finds shelter, food, and reproduces, etc
niche
organism’s specific role in a habitat
Reduces competition with other types of organisms
Use of resources/functional role
Affected by organisms tolerance
fundamental niche
Entire set of conditions under which an animal (population, species) can survive and reproduce itself
realized niche
Set of conditions actually used by a given animal (population/species) after interactions with other species (predation and competition) have been taken into account
generalist species
Able to eat a wide variety of foods within a range of habitats
Main problem is competition
Can adapt to changing environments better
specialist species
Narrow range of habitat and diet
Not much competition
Giant panda (main concerns predation and habitat loss)
tend to do well with constant environments; don’t respond well to changes
Niche Overlap/Resource Partitioning
If niches overlap, then species may have to compete for resources like food and living space
Degree that resources are limited determines intensity of competition
If resources are not limited, then species may overlap in many niche dimensions and still exhibit no competition
competition
negative interactions between species(interspecific competition) or within species (intraspecific competition).
predation
organisms that feed on other organisms
Prey species increase in population when predator population is low
As predator populations increase (because of more prey), prey populations decrease
symbiosis
interactions between organisms that may be beneficial or harmful
Interspecific Competition
Competition among members of different species for an important, limiting resource
types of interspecific competition
competitive exclusion and species coexistence
competitive exclusion
Inevitable elimination from a habitat of different species with identical needs for resources
This often happens when Invasive species are introduced to endemic species
species coexistence
Species live in same area
Adjust behaviors to reduce competition
birds that feed on insects from tree trunks vs canopy
intraspecific competition
Competition among members of same species for an important, limiting resource
Primates in general will compete with members of their own species for food, habitat, reproductive mates.
keystone species
Species that have major impacts on community functioning
Not necessarily abundant but has a disproportionate impact on the health of the entire ecosystem
ecosystems engineers
Organisms that create, modify and maintain habitat
Ecosystem engineering can alter distribution and abundance of large numbers of plants and animals, and \n significantly modify biodiversity
Humans are most prolific and dangerous ecosystem engineers
Indicator Species
Indicator species provide info about overall equilibrium and health of an ecosystem
Birds b/c: found everywhere and respond quickly to environmental changes
mutualism
type of symbiosis in which both species benefit
commensalism
type of symbiosis in which one species benefits and other species is neither harmed nor benefited
parasitism
type of symbiosis in which one species benefits and the other species is harmed
Photosynthesis
Ultimate source of energy for biological processes is sun
Basis of living systems is solar energy captured through light-dependent reaction of photosynthesis
Use of energy to make living material is called productivity
Primary Productivity
Rate at which energy is bound by photosynthesis, Measured in kcal/m^2/yr
biomass
Amount of living material present at a given time, Measured in g/m
gross production (GPP)
Amount of production before metabolic costs (respiration) are subtracted
net production (NPP)
The amount of production after metabolic costs (respiration) are subtracted.
Most productive temperate systems are ____
marshes, nutrients are continually brought in andwastes are flushed out as water moves through them
first law of thermodynamics
energy is not created or destroyed, but can be transferred from one form to another
second law of thermodynamics
heat flows from high to low temperature objects until equilibrium is reached
Trophic level
each step in transfer of energy
Food chain
steps in the transfer of energy – how matter and energy move through an ecosystem
food web
A network of connected food chains; more complex than a food chain, more realistic b/c most organisms feed on more than one species for food
Autotrophs
make their own food (plants and some bacteria)
Heterotrophs
Organisms that cannot make their own food and must eat other organisms
Decomposers
an organism, especially a soil bacterium, fungus, or \n invertebrate, that break down dead plants and animals
scavengers
an animal that feeds on carrion, dead plant material, or \n refuse.
10% rule
only 10% of energy from one trophic level is able to move up to the next
Evaporation
liquid water changes into gaseous water; occurs when sunlight warms \n the surface of the water
Condensation
process by which water vapor is changed into liquid water; crucial to \n cloud formation. Occurs due to reduction in the energy of the water particles (cooling temps)
Precipitation
Water that falls from the atmosphere to Earth’s surface; water released \n from clouds in various forms (rain, snow, sleet, etc). Water drops in \n clouds condense into bigger drops; when heavy enough they fall from clouds
Infiltration
physical process of water entering the soil - dependent upon soil conditions such as saturation level of the soil as well as the porosity \n and permeability of the soil.
Percolation
movement of water through the soil; occurs after infiltration water moves into the deeper layers of soil until it reaches the water table and below (and becomes groundwater)
Surface Runoff
flow of water from precipitation (or irrigation) that is pulled by gravity \n across land’s surface some runoff may go into the ground and some may flow into surface waters and to the ocean
Transpiration
the release of water from plant leaves; water is absorbed through the root hairs, transported through the plant, and exits through stomata
Evapotranspiration
evaporation of water from the soil AND from plants over a given area
Aquifers
geologic formations made up of gravel, sand, sandstone, or fractured rocks like limestone. Water can move through these materials because they are permeable - they have large connected spaces. The speed at \n which groundwater flows depends on the size of the spaces in the soil or rock and how well connected they are.
floodplain
Areas nearest a river that are flooded periodically; areas of nutrient rich soil from frequent deposition of river sediments. Agriculture thrives on floodplains and riparian (riverside) habitats
ground water
water found underground in the cracks and spaces in soil, sand, and rock. It is stored for various times (some short term, some long term) and moves slowly through aquifers
challenges when establishing national parks
requirement of new laws
need for international support
native people already live there
the possible solutions to conserve national parks
making conservation of habits an economic benefit
environmental economics
persuading society to act in a way that benefits the environment, doesn’t pollute the environment and keeping our resources sustainable in a democratic framework
intangible factor
something you value but you can’t touch
public-service functions (nature capital)
such as nature cleaning air and soil cleaning itself
colony collapse disorder
where many of a hive’s worker bees disappear (which makes food prices go up)
tragedy of the commons
individuals will use shared resources in their own self-interest rather than in keeping with the common good, thereby depleting the resources (commons: publicly owned land with public access for private uses)
resource sustainability
harvesting or using only the net biological productivity each year
indirect cause
costs that are not directly accountable to a cost object (hidden costs)
carrying capacity
the changes in population are because of the population’s size in relation to a maximum (s-shaped logistic growth)
maximum sustainable yield (MSY)
max growth rate that a population could sustain indefinitely
maximum sustainable yield population
the population size at which the maximum growth occurs
minimum viable population
the smallest population that can maintain its self and its genetic variability indefinitely
optimum sustainable population
population size between a minimum and carry capacity
in a logistic curve
the greatest production occurs when population is 1/2 its carrying capacity
impossible to keep a wild population at a specific number and over calculating = growth decline
in a logistic population
the population is described simply as a total number (all the individuals are the same)
wildlife management approaches
time series + historical range of variation
census taking in certain areas
age structure of useful information
shifts towards younger ages and decline in catches → exploitation to where the animals can’t grow old
harvests as an estimate of numbers
catch per unit effort
catch per unit effort
assumes same effort is excreted by all harvesters and they have the same technology (which can calculate pop)
endangered species
any species that is in danger of extinction (US endangered species act of 1973)
threatened species
any species that can become an endangered species in the foreseeable future
local extinction
a species has disappeared from only part of its range
global extinction
a species can no longer be found anywhere
population risks
variations in population rates of a low abundance species
environmental species
variation in physical/biological environment (meaning difference in predators, prey and food source)
natural catastrophe
sudden change in the environment that is not caused by humans