Environmental Science Final Exam
gross primary productivity
The total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time
net primary productivity
GPP-respiration; measured as plant growth: biomass produced per unit per area of time
biome
a large naturally occurring community of flora and fauna occupying a major habitat
theory
a well-tested and supported idea; widely accepted explanation, validated by a high volume of previous research
trophic level
an organism's feeding status in a food web; plants = producers and animals = consumers; primary consumers = herbivores, secondary and tertiary consumers = omnivores, carnivores; organisms that recycle dead bodies and remove waste are scavengers/detritivores and decomposers; the abundance of organisms in a given trophic level is proportional to the amount of energy transfer available
predator
any organism that feeds directly on another organism, whether or not this kills the prey
global nitrogen reservoirs
atmosphere (largest), ocean (inorganic), soil (ammonia)
tolerance limits
each environmental factor has both minimum and maximum levels, or tolerance limits, beyond which a particular species cannot survive or is unable to reproduce. the factor closest to the limits is the critical factor that determines where an organism can live
environmental protection stage 1: pragmatic resource conservation
(1780s-late 1800s) george perkins marsh - man and nature published in 1864; influenced theodore roosevelt and his conservation advisor, gifford pinchot; pinchot developed pragmatic utilitarian conservation, which advocated using natural resources but exploiting them wisely "for the greatest good for the greatest number for the longest time" and is reflected today in the multiple use policies of USFS
environmental protection stage 3: modern environmental movement
(1960s to 1990s) goal is anti-pollution protection; rachel carson awakened the public to the environmental threat posed by pesticides in her book silent spring (1962); david browser introduced the use of litigation, regulatory intervention, and the use of mass media to environmental activists; barry commoner was an activist scientist who spoke out about environmental hazards emphasized the link between science, technology and society; wangari maathai founded the green belt movement in 1997 to organize poor rural African women to restore the local environment by planting trees, also promoting justice and equality
environmental protection stage 4: global environmentalism
(1990s/2000s to present) modern information technology now allows for increased international communications. local and regional environmental leaders increasingly have a worldwide impact; goal is global environmental citizenship, focus on sustainability and endurance of systems processes
environmental protection stage 2: ethical and aesthetic nature preservation
(late 1800s) John Muir - president/founder Sierra Club; introduced inherent value: nature deserves to exist for its own sake—regardless of degree of usefulness to humans and opposed Pinchot's view; Aldo Leopoldo was Pinchot's student and authored "The Land Ethic"—humans are a part of nature and should strive to maintain "the integrity, stability, and beauty of the biotic community.
ecosystem
a biological community of interacting organisms and their physical environment
paradigm
a dominant view—may shift if new result show old results or assumptions to be incorrect
chemosynthesis
a few very ancient organisms called archaea are able to get their energy from inorganic compounds that bubble up from vents in the sea floor or from hot springs
parasitism
a form of predation, is also sometimes considered a symbiosis because of the dependency of the parasite on its host
renewal
ability to repair damage after a disturbance
biological community
all of the populations living and interacting in a particular area
species
all organisms of the same kind that are genetically similar enough to breed in nature and produce live, fertile offspring
population
all the members of a species living in a given area at the same time
hypothesis
an educated prediction or an idea that can be tested
mutualism
both organisms benefit from their association
mutations
changes in DNA coding sequence that occur by chance (random mistakes in DNA replication, exposure to radiation, toxins...)
environment
circumstances or conditions that surround an organism or group of organisms; complex of social or cultural conditions that affect an individual or community
environmental justice
combines civil rights with environmental protection to demand a safe and healthy environment for everyone
intraspecific competition
competition among members of the same species which can be reduced if young disperse, one exhibits strong territoriality, or resource partitioning between generations
interspecific competition
competition between members of different species
ecological niche
descrbes either the role played by a species in a biological community or the total set of environmental factors that determine a species distribution; generalist = broad, specialist = narrow
first law of thermodynamics
energy is neither created or destroyed, it is conserved
selective pressure
environmental factors or influence that may lessen reproduction in a population and therefore contributes to evolutionary change (or extinction) through natural selection
matter
everything that has mass and takes up space
critical limits
for some species, the interaction of several factors, rather than a single limiting factor, determines biogeographical distribution; tolerance limits may affect the distribution of young differently than adults
sustainable development
meet the needs of the present without compromising future generations' ability to meet needs and raise the living standard for the world's poorest people while protecting the functions of natural systems
cells
minute compartments in a living organism which carry out processes of life
ecosystem engineers
modulate the availability of resources to other species, modify physical habitats
species coexistence
neither species fully excludes the other from resources, so both survive
pool/reservoir
location where element is stored
secondary productivity
manufacture of biomass by organisms that eat plants
organic compounds
material making up bio molecules, which in turn make up living things; all contain carbon; lipids, carbohydrates, proteins, and nucleic acids
flux/exchange
mechanism by which element moves between reservoirs
consensus
general agreement among informed scholars; stems from a community of scientists who collaborate in a cumulative, self-correcting process
batesian mimicry
harmless species mimic the warning coloration of harmful species to gain protection
keystone species
have especially great impact on community, relative to its population, often top predators, if removed community changes greatly—may produce a trophic cascade
environmental racism
inequitable distribution of environmental hazards based on race
food web
interconnected food chains as most consumers have multiple food sources
constancy
lack of fluctuation in composition or function
watershed
land surface that drains into one river
competitive exclusion
no two species can occupy the same ecological niche at the same time. the one that is more efficient at using resources will exclude the other
diversity
number of different species, ecological niches, or genetic variation; measured using species richness or diversity indices such as the Shannon-Wiener index
chemistry
the scientific study of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances
allopatric speciation
occurs due to geographic isolation whereby a subpopulation becomes separated from the main population and can no longer share genes with it
photosynthesis
occurs in chloroplasts within plant and algal cells, water and carbon dioxide in the presence of sunlight and chlorophyll yield glucose and oxygen
commensalism
one species benefits while the other neither benefits nor is harmed
predator-mediated competition
one species may be the best competitior in a given location, but predators may reduce its abundance and allow the weaker competitor to increase its numbers
sympatric speciation
organisms continue to live in the same place but become isolated by some other means
coevolution
over time predator and prey evolve in response to one another
phosphorous cycle
path of phosphorous through environment; phosphorous compounds are leached from rocks and minerals and usually transported in aqueous form; taken in an incorporated by producers, passed on to consumers, returned to environment by decomposition; cycle takes a long time as deep ocean sediments are significant sinks
hydrologic cycle
path of water through the environment; solar energy continually evaporates water stored in the oceans and land, and distributes water vapor around the globe; condenses over land surfaces, supporting all terrestrial systems; responsible for cellular metabolism, nutrient flow in ecosystems, and global distribution of heat and energy
ecological structure
patterns of spatial distribution of individuals and populations within a community; random, uniform, or clustered distribution
environmental factors that determine where an organism can live
physiological stress due to inapporporiate levels of moisture, temperature, pH, light, nutrients, competition with other species, predation, parasitism, disease, luck
directional selection
the shift toward one extreme of a trait
critical factor
the single factor in shortest suply relative to demand
nitrogen cycle
plants take up inorganic nitrogen from the environment and build protein molecules which are later eaten by consumers. nitrogen-fizing bacteria change nitrogen to a more useful form by combining it with hydrogen to make ammonia. other bacteria convert ammonia to nitrites and nitrates, which can be taken up by plants to make proteins. nitrogen reenters the environment through the death of organisms and excrement and urinary waste when denitrifying bacteria break down nitrates into N2 and nitrous oxide gases; humans have altered the nitrogen cycle through use of synthetic fertilizers, nitrogen-fixing crops, and fossil fuels
foundation species
play strong role in providing structure of community; often primary producers, low trophic levels (trees in forests)
toxic colonialism
practice of targeting poor communities or communities of color as waste disposal areas
stabilizing selection
range of a trait is narrowed
primary productivity
rate at which organic matter is created by producers in an ecosystem
source
reservoir decreasing in size/capacity
sink
reservoir increasing in size/capacity
inertia
resistance to perturbation
resource partitioning
species co-exist in a habitat by utilizing different parts of a single resource
indicator species
species whose specific set up tolerance limits are useful indicators for environmental quality
cellular respiration
splits carbon and hydrogen atoms from sugar and recombined them with oxygen to produce carbon dioxide and water; how heterotrophs access energy for life
environmental science
the systematic study of our environment and our proper place in it; draws on many disciplines, skills, and interests; integrates natural sciences, social sciences, and humanities
elements
substances that cannot be broken down into simpler forms by ordinary chemical reactions
adaptation
the acquisition of traits that allow a species to survive in its environment
productivity
the amount of biomass produced in a given area during a given period of time
evolution
the change in heritable characteristic of biological populations over successive generations; there must be variation in genetic traits (genotype), a trait must be heritable in order to be passed to offspring, individuals with certain traits are better able to survive or produce more offspring (selection), over time selection results in changes in species
speciation
the development of a new species
natural selection
the differential survival and reproduction of individuals due to difference in phenotype (traits)
complexity
the number of trophic levels and number of species at each trophic level in a community; diverse community may not be complex if all species are clustered in a few trophic levels; highly interconnected community may have many trophic levels, some of which can be compartmentalized
carbon cycle
the path of carbon through the environment: begins with intake of CO2 during photosynthesis. carbon atoms are incorporated into sugar which is eventually released by cellular respiration either in the plant or in organisms that consumed it. sometimes the carbon is not recycled for a long time; coal and oil are the remains of organisms that lived millions of years ago - the carbon in these is released when we burn them. some carbon is also locked in calcium carbonate
habitat
the place or set of environmental conditions in which a particular organism lives
realized niche
the portion of the fundamental niche that is actually filled due to competition or other species interactions
biosphere
the regions of the surface, atmosphere, and hydrosphere of the earth (or analogous parts of other planets) occupied by living organisms.
ecology
the scientific study of the relationship between organisms and their environment; how matter and energy are exchanged between organisms and their surroundings
water table
the upper limit of groundwater in an aquifer
abundance
total number of organisms in a community
disruptive selection
traits diverge toward the two extremes
mullerian mimicry
two harmful species evolve to look alike
symbiosis
two or more species live intimately together with their fates linked
implicit bias
unconscious attitudes and stereotypes that often arise as a result of trying to navigate the overwhelming stimuli in a very complicated world
condensation and precipitation
water condenses and falls from the atmosphere
evapotranspiration
water enters the atmosphere by evaporation from surfaces and transpiration from leaves
infiltration
water infiltrates into aquifers (underground reservoirs), becoming groundwater
runoff
water runs off the land surface into streams, rivers, lakes, and eventually the ocean
eutrophication
when a body of water becomes overly enriched with nutrients which induces excessive algal growth
fundamental niche
when a species fulfills its entire role by using all the available resources
10% rule
when energy is passed in an ecosystem from one trophic level to the next, only ten percent of the energy will be passed on
second law of thermodynamics
with each successive energy transfer, less usable energy is available to perform work
