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