Princeton Review AP Environmental Science Chapter 5

biotic

living components of Earth

abiotic

nonliving components of Earth

3 abiotic components of Earth

atmosphere, hydrosphere, and lithosphere

biogeochemical cycle

process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another

reservoir

a place where a large quantity of a resource sits for a long period of time

exchange pool

a site where a nutrient sits for only a short period of time; the opposite of a reservoir

residency time

the amount of time a nutrient spends in a reservoir or an exchange pool

Law of Conservation of Matter

states that matter can neither be created nor destroyed; despite this, nutrients can be rendered unavailable for cycling through certain processes

precipitation

when atmospheric water condenses from the gaseous state to form a liquid or solid, thus becoming dense enough to fall to the Earth because of the pull of gravity

groundwater

water that fills the cracks and spaces in underground soil and rock layers

runoff

water that flows over the ground surface rather than soaking into the ground

evaporation

process by which water is returned to the atmosphere from both Earth's surface and from living organisms

transpiration

the evaporation of water from the leaves of a plant

respiration

plants and animals "inhale" oxygen and "exhale" carbon dioxide (CO2)

photosynthesis

plants take in carbon dioxide (CO2), water, and energy from the sun to produce carbohydrates; living things can act as exchange pools

combusted

when fossil fuels are burned

nitrogen fixation

the process of converting nitrogen gas (N2; atmospheric nitrogen) into usable forms, like ammonia (NH3) or nitrates (NO3^1); most often the result of bacteria that allow nitrogen to be made biologically available (STEP 1 OF NITROGEN CYCLE)

rhizobium

important bacteria that participates in nitrogen fixation

nitrification

the process by which soil bacteria converts ammonia (NH3) or ammonium (NH4^+) into nitrates (NO2) and to one of the forms of nitrogen that can be used by plants- nitrate (NO3^-) (STEP 2 OF NITROGEN CYCLE)

assimilation

the process of plants absorbing ammonium (NH4^+) and nitration (NO3^-) through their roots, thus enabling heterotrophs to obtain nitrogen when they consume plants' proteins and nucleic acids (STEP 3 OF NITROGEN CYCLE)

ammonification

decomposing bacteria convert dead organisms and other waste into ammonia (NH3) or ammonium ions (NH4^+), which can be reused by plants or volatilized (STEP 4 OF NITROGEN CYCLE)

volatilized

released into the atmosphere as a gas

denitrification

specialized bacteria convert ammonia back into nitrites and nitrates, and then into nitrogen gas (N2) and nitrous oxide gas (N2), which then rise to the atmosphere (STEP 5 OF NITROGEN CYCLE)

phosphorus cycle

the cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment

where phosphate is mostly found

soil, rock, and sediments

mycorrhizae

symbiotic relationships that form between fungi and plants; mycorrhizal fungi colonize host plant's root system, which increases the water and nutrient absorption capabilities of the plant, while the plant provides the fungi with carbohydrates formed from photosynthesis

limiting factor

any factor that controls a population's growth (ex. food, space, water, etc.)

terrestrial cycle

part of any (specifically phosphorus) cycle that occurs on land

eutrophication

occurs when a body of water receives excess nutrients; can cause an overgrowth of algae and deplete the water of oxygen

sulfur cycle

the chemical and physical reactions by which sulfur moves into or out of storage and through the environment

natural ways that sulfur enters the atmosphere

volcanic eruptions, certain bacterial functions, decomposition in estuaries, and the decay of once-living organisms

biomes

ecosystems that are based on land

aquatic life zones

ecosystems based in aqueous environments; mostly categorized by salinity

ecotones

the transitional area where two ecosystems meet

ecozones (ecoregions)

smaller regions within ecosystems that share similar physical features

deciduous forest biome

a biome characterized by its leaf-shedding trees and its seasons; this biome experiences all four seasons - winter, spring, summer, and fall (ex. North America, Europe, Australia, and Eastern Asia)

tropical rainforest biome

located near the equator, warm all year long, more species than any other biome and gets large amounts of rain (ex. South America, West Africa, and Southeast Asia)

grasslands biome

interior flatlands with lots of grass and other low plant life; tropical or temperate climate (ex. North American plains, prairie, and savanna; Russian steppes; South American velds; Argentinian pampas)

coniferous forest (Taiga) biome

a biome with mountainside forests and tall, narrow trees that grow close together, which have thick bark and pine needles (ex. northern North America and northern Eurasia)

tundra biome

very short cold summers and very long and extremely cold winters with strong winds and little precipitation; contains permafrost; contains many lichens (ex. the northern latitudes of North America, Europe, and Russia)

chaparral biome

areas that have hot and dry summers with mild winters; located on most continents with flat plains, rocky hills and mountain slopes (ex. western North America and the Mediterranean region)

desert biome

a biome that has little or no plant life, long periods without rain, and extreme temperatures; usually have either extremely hot or extremely cold climates (ex. 30 degrees north or south of the equator)

Law of Tolerance

describes the degree to which living organisms are capable of tolerating changes in their environment

Law of the Minimum

states that living organisms will continue to live, consuming available materials until the supply of these materials is exhausted

biodiversity

describes the number and variety of organisms found within a specified geographic region (ecosystem)

autotrophs

organisms that can produce their own organic compounds from inorganic chemicals

heterotrophs

obtain food energy by consuming other organisms or products created by other organisms

producers

organisms that are capable of converting radiant energy (chemical energy) into carbohydrates (ex. plants and alga)

anaerobic

without oxygen

chemosynthesis

process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates

chemotrophs

organisms that obtain energy from chemicals

Net Primary Productivity (NPP)

the amount of energy that plants pass on to the community of herbivores in an ecosystem

Gross Primary Productivity (GPP)

the amount of sugar that the plants produce in photosynthesis (measured in kcal/m^2/y)

NPP formula

NPP = GPP - amount of energy the plants need for growth, maintenance, repair, and reproduction

consumers

organisms that must obtain food energy from secondary sources (ex. eating plant or animal matter)

primary consumers

animals that feed on producers (ex. herbivores) (ex. mouse)

secondary consumers

organisms that consume primary consumers (ex. snake)

tertiary consumers

organisms that consume secondary consumers (ex. wolf)

detritivores

organisms that derive energy from consuming nonliving organic matter such as dead animals or fallen leaves

decomposers

organisms that consume dead plant and animal material (ex. mushroom); the process of decomposition returns nutrients to the environment

saprotrophs

decomposers that use enzymes to break down dead organisms and absorb the nutrients (ex. bacteria and fungi)

trophic level

step in a food chain or food web

food chains

energy links between different organisms in an ecosystem based on feeding habits; shows the transfer of energy through the trophic levels

10% Rule

only 10% of the total energy produced at each trophic level is available to the next level; the amount of energy passed up to the levels of the food pyramid reduces as you go up (therefore, producers have the most energy in an ecosystem)

energy pyramid

the amount of energy (in kcal) available at each trophic level organized from GREATEST TO LEAST

bioaccumulation

describes the accumulation of a substance, such as a toxic chemical, in the tissues of a living organism, such as a producer or a primary consumer

biomagnification

describes the increasing concentration of toxin molecules at successively higher trophic levels in a food chain

food web

network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

evolution

the change in a population's genetic composition over time

phylogenetic tree

a family tree that shows the evolutionary relationships thought to exist among groups of organisms; can be very broad or very specific

speciation

formation of new species

species

a group of organisms that are capable of breeding with one another- and incapable of breeding with other species

evolutionary fitness

a measurement of the degree to which an organism can successfully adapt to its environment and can reproduce fertile offspring; coined by Charles Darwin

natural selection

a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits; beneficial characteristics that can be inherited are passed down to the next generation, and unfavorable characteristics that can be inherited become less common in the population

gene pool

the total genetic makeup of the population

genetic drift

the accumulation of changes in the frequency of alleles (variations of a gene) over time due to sampling errors (changes that occur as a result of random chance); small populations are more sensitive to this than large populations

microevolution

a population displays small-scale changes over a relatively short period of time

macroevolution

large-scale patterns of evolution within biological organisms over a long period of time

extinction

occurs when a species cannot adapt quickly enough to environmental change and all members of the species die

biological extinction

the true extermination of a species (no individuals of that species left on the planet) (ex. dodo bird; passenger pigeon)

ecological extinction

there are so few individuals of a species that this species can no longer perform its ecological function (ex. alligators in Everglades- 1960s; wolves in Yellowstone before reintroduction in 2010s)

commercial (economic) extinction

a few individuals exist but the effort needed to locate and harvest them is not worth the expense (ex. groundfish in Grand Banks, Maritimes of Canada)

population

a group of organisms of the same species in a given area

community

when populations of different species occupy the same geographic area

niche

the total sum of a species' use of the biotic and abiotic resources in its environment

habitat

the area or environment where an organism or ecological community normally lives or occurs

competition

the struggle between organisms to survive in a habitat with limited resources; arises when two individuals of the same or of different species are competing for resources in the environment

intraspecific competition

when the two individuals that are competing are of the same species

interspecific competition

when the two individuals that are competing are of different species

competitive exclusion

when two different species in a region compete and the better adapted species wins

Gause's principle

states that no two species can occupy the same niche at the same time and that the species that is less fit to live in the environment will relocate, die out, or occupy a smaller niche

predation

occurs when one species feeds on another, and it drives changes in population size

predator

an animal that hunts other animals for food

prey

an organism that is killed and eaten by another organism

symbiotic relationships

close, prolonged associations between two or more different organisms of different species that may, but do not necessarily, benefit each member (the three types are mutualism, commensalism, and parasitism)

mutualism

a relationship between two species in which both species benefit (ex. clown fish and sea anemones)

commensalism

a relationship between two organisms in which one organism benefits and the other is unaffected (ex. trees and epiphytes)

parasitism

a relationship between two organisms of different species where one benefits and the other is harmed (ex. fleas and dogs)

keystone species

a species whose very presence contributes to an ecosystem's diversity and whose extinction would consequently lead to the extinction of other forms of life (ex. fig trees)

indicator species

species that are used as a standard to evaluate the health of an ecosystem; they are more sensitive to biological changes within their ecosystems than are other species- therefore, they can be used as an early warning system to detect dangerous changes to a community (ex. trout)