exam2- chaps 3, 7, 9 Flashcards
biosphere
the region of our planet where life resides, the combination of all ecosystems on Earth
transpiration
the release of water from leaves during photosynthesis
runoff
water that moves across the land surface and into streams and rivers
limiting nutrient
a nutrient required for the growth of an organism but available in a lower quantity than other nutrients
nitrogen fixation
a process by which some organisms can convert nitrogen gas molecules directly into ammonia
disturbance
an event, caused by physical, chemical, or biological agents, resulting in changes in population size or community composition
resilience
the rate at which an ecosystem returns to its original state after a disturbance
watershed
all of the land in a given landscape that drains into a particular stream, river, lake, or wetland
tragedy of the commons
the tendency of a shared, limited resource to become depleted because people act from self-interest for short-term gain
clear-cutting
a method of harvesting trees that involves removing all or almost all of the trees within an area
environment impact statement (EIS)
a document outlining the scope and purpose of a development project, describing the environmental context, suggesting alternative approaches to the project, and analyzing the environmental impact of each alternative
urban sprawl
creation of urbanized areas that spread into rural areas and remove clear boundaries between the two
malnourished
having a diet that lacks the correct balance of proteins, carbohydrates, vitamins, and minerals
food insecurity
a condition in which people do not have adequate access to food
famine
the condition in which food insecurity is so extreme that large numbers of deaths occur in a given area over a relatively short period
industrial agriculture (agribusiness)
agriculture that applies the techniques of mechanization and standardization; also known as industrial agriculture
salinization
when the small amounts of salt in irrigation water becomes highly concentrated on the soil surface through evaporation
organic fertilizers
composed of organic matter from plants and animals
synthetic (inorganic)
produced commercially
monocropping
the prominent agricultural practice in the US where wheat and cotton are typically grown in monocrops of 405 hectares
pesticides
substances that kill or control organisms that we consider pests
insecticides
targets species of insects and other invertebrates that consume crops
herbicides
target plant species that compete with crops
broad-spectrum
ability to kill many different types of pests
selective
pesticides that focus on a narrower range of an organism
persistant
pesticides that remain in the environment for a long time
bioaccumulation
the process where pesticides such as DDT accumulate in the fatty tissue of predators
resistant
when organisms survive a pesticide or have a few individuals not susceptible
genetically modified organisms (GMO)
manipulation of genes so production can be rapidly produced with desirable traits that may be impossible to develop using traditional breeding techniques
conventional agriculture
agriculture that applies the techniques of mechanization and standardization; also known as industrial agriculture
desertification
the process in which soil becomes very poor in nutrients, and no longer is able to be used for sufficient farming
sustainable agriculture
fulfills the need of food and fiber while enhancing the quality of the soil, minimize use of nonrenewable resources, and enhances economic viability for farmer
fishery
a commercially harvestable population of fish within a particular ecological region
bycatch
the unintentional catch of nontarget species while fishing
aquaculture
farming aquatic organisms such as fish, shellfish, and seaweeds
aquifers
a permeable layer of rock and sediment that contains groundwater
water table
the uppermost level at which the water in a given area fully saturates rock or soil
groundwater recharge
a process by which water percolates through the soil and works its way into an aquifer
saltwater intrusion
an infiltration of salt water in an area where groundwater pressure has been reduced from extensive drilling of wells
floodplain
the land adjacent to a river
oligotrophic
low dissolved nutrient concentration
mesotrophic
moderate of dissolved nutrient concentration
eutrophic
high dissolved nutrient concentration
impermeable surfaces
pavement or buildings that do not allow water penetration
levee
an enlarged bank built up on each side of a river to prevent flooding
dikes
a body of rock, either sedimentary or igneous, that cuts across the layers of its surroundings
reseviour
a body of water created by blocking the natural flow of a waterway
dam
a barrier that runs across a river or stream to control the flow of water
aqueducts
a canal or ditch used to carry water from one location to another
desalination (desalinization)
the process of removing the salt from salt water
point sources
a distinct location from which pollution is directly produced
nonpoint sources
a diffuse area that produces pollution
wastewater
water produced by human activities including human sewage from toilets and gray water from bathing and washing of clothes and dishes
dead zones
in a body of water, an area with extremely low oxygen concentration and very little life
eutrophication
a phenomenon in which a body of water becomes rich in nutrients
septic system
a relatively small and simple sewage treatment system, made up of a septic tank and a leach field, often used for homes in rural areas
septic tank
a large container that receives wastewater from a house as part of a septic system
leach field
a component of a septic system, made up of underground pipes laid out below the surface of the ground
manure lagoons
human-made ponds lined with rubber, built to handle large quantities of manure produced by livestock
acid deposition
acids deposited on Earth as rain and snow, or as gases and particles that attach to the surfaces of plants, soil, and water
thermal pollution
nonchemical water pollution that occurs when human activities cause a substantial change in the temperature of water
maximum contaminant levels (MCL)
the standard for safe drinking water established by the EPA under the Safe Drinking Water Act
gray water
wastewater from baths, showers, bathrooms, and washing machines
what elements do all living things have within themselves
C, H, N, O, P
(carbon, hydrogen, nitrogen, oxygen, phosphorus)
what is corn sweat
the process by which corn plants release moisture into the air to stay cool; it brings the midwest a surge in humidity every summer
ocean acidification
increased carbon in the water affects the pH of the water (and therefore marine life)
denitrification
removal of the nitrates or nitrites from soil, air, or water by chemical reduction (like certain bacteria)
why might a farmer plant soy with no intent to harvest
to add nitrogen to the soil
what are somethings that are leading to dead zones in water
organic v. nonorganic crops wastewater treatment; sceptic systems
green revolution (aka the 3rd agriculture revolution) resulted in what developments + spanned what time period
mechanization, irrigation, fertilizers, monocropping; 1940s-60s
cons of the green revolution
- deforestation, timber was not as profitable as using the area as farm land
- mechanization increased the burning od fossil fuels
- irrigation caused water logging that killed off bacteria, some of which helped with denitrification
- over fertilization resulted in runoff that disrupted the nutrient cycle and lead to dead zones
- monocropping lead to a loss in biodiversity, pesticides too
benefits of GMOs
- greater yields of a crop due to salt resistance, drought resistance, pest resistance
- higher quality products: more nutritious, larger, fewer pesticides
what are some methods of sustainable agriculture
(not industrial agriculture)
intercropping; crop rotation; agroforestry; contour plowing; no-till agriculture; organic agriculture
organic agriculture
bans GMOs but not pesticides, fertilizers, antibiotics (does it require a limitation?)
how much of population gets their main source of protein from fish
30%
urban blight (aka urban decay)
the sociological process by which a previously functioning city, or part of a city, falls into disrepair and decrepitude; usually caused by ageing, neglect, and lack of financial support for maintenance
how much of the u.s. is monocultured grass lawns
50,000,000 acres (50 million) out of 1.9 billion acres
CSA (farming)
community sustainable agriculture
what percent of fisheries globally had collapsed as of 2006
30%
four federal land management agencies and their top focuses
national park service- recreation and conservation
fish and wildlife services- wildlife conservation, hunting
u.s. forest service- timber harvesting, cattle grazing
bureau of land management- cattle grazing, mining, timber harvesting
what are the two leading water quality laws in the u.s.
clean water act (1972)
safe drinking water act (1974, 1986, 1996)
what is nutrient cycling
movement and conversion of matter in the biosphere (closed system)
what percent of carrying capacity level can an organism be harvested down to and still keep the maximum sustainable yield
50%
what is the difference between ecosystem resistance and resilience
resilience refers to how quickly an ecosystem can bounce back from disturbance
resistance means there is no effect to energy and matter
what is the definition of a fishery collapse
population decline of 90%
define the difference between confined and unconfined aquifers
confined aquifers are stuck underground with a recharge area, unconfined has an opening on surface
what are the two leading water quality laws in the usa
clean water act, safe drinking water act
what does CAFO stand for
concentrated animal feeding operation
list three benefits of CAFOs
improve feeding efficiency, takes up less space, increase % of food energy converted to biomass
what does the idealized exponential growth model look like
population size on y-axis and time on x-axis: the right half of a ‘U’
what does the idealized logistic growth model look like
population size on y-axis and time on the x-axis: goes up like the right half of a ‘U’ and then forever goes to a point along the y-axis
