Environmental Bio Test 2

key terms

populous nations

nations that contain the largest population

population density

measures the number of people occupying a certain land area

crude birth/death rate

the number of births/deaths per 1,000 individuals per year

age structure diagrams

Demographers are able to project population growth, or decline, over time by analyzing a population’s size broken down by its age structure and sex ratio; these are called _________.

population momentum

the tendency of a young population to continue to grow even after birth rates drop to replacement fertility (two children per couple)

transitional population

Population rise is bound to slow. There are noticeably more males than females

unstable population

Japan has a population with a fairly even distribution of age classes. This is an example of a _______________ with a possibility of increasing or decreasing

total fertility rate

average number of children a woman has in the course of her lifetime

population growth rate

the change in population size over time that takes into account the number of births and deaths as well as immigration and emigration numbers.

demographic factors

population characteristics such as birth rate that influence changes in population size and composition

pronatalist pressures

factors that increases the desire to have children

childhood mortality rate

the number of children under 5 years of age who die per every 1,000 live births in that year

replacement fertility

the rate at which children must be born to replace the previous generation

age structure

the percentage of the population that is distributed in various age groups

demographic transition

a theoretical model that describes the expected drop in once-high population growth rates as economic conditions improve the quality of life in a population

1. preindustrial
2. industrializing
3. mature industrial
4. postindustrial

the four stages of the demographic transition

preindustrial demographic transition

birth and death rates are high but similar, so population growth is slow or stationary; population size is low

industrializing demographic transition

better conditions lead to lower death rates; however, birth rates remain high, resulting in rapid population growth

mature industrial demographic transition

birth rates begin to fall, though they still outnumber deaths; population is still growing but at a slower rate

postindustrial demographic transition

birth rates are similar to death rates, so population growth stabilizes at a new higher population size

carrying capacity

the maximum population size that a particular environment can support indefinitely; for human populations, it depends on resource availability and the rate of per capita resource use by the population

zero population growth

the absence of population growth; occurs when birth rates equal death rates

desired fertility

the ideal number of children an individual indicates he or she would like to have

total fertility rate

the number of children the average woman has in her lifetime

childhood mortality rate

the number of children under 5 years of age that die per every 1,000 live births in that year

education

It turns out that the __________ of girls and economic opportunities for women correlate with lower population growth in many regions.

overpopulated

When the number of individuals in an area exceeds the carrying capacity of that area, it has become _________.

ecological footprint

the land area needed to provide the resources for and assimilate the waste of a person or population

urban areas

densely populated regions that include cities and the suburbs that surround them

urban

Ever since 2008, and for the first time in human history, more than half the world’s population lives in __________ areas.

urbanization

the migration of people to large cities; sometimes also defined as the growth of urban areas

carbon footprint

the amount of CO2 (and other greenhouse gases that contribute to climate change) released to the atmosphere by a person, company, nation, or activity

environmental justice

the concept that access to a clean, healthy environment is a basic human right

urban flight

the process of people leaving an inner-city area to live in surrounding areas

suburban sprawl

low-population-density developments that are built outside of a city

exurbs

towns beyond the immediate suburbs whose residents commute into the city for work

green spaces

a natural area such as a park or an undeveloped landscape containing grass, trees, or other vegetation in an urban area, usually set aside for recreational use

green city

a city designed to improve environmental quality and social equity while reducing its overall environmental impact

smart growth

strategies that help create walkable communities with lower environmental impacts

infill development

the development of empty lots within a city

green building

construction and operational designs that promote resource and energy efficiency and provide a better environment for occupants

Leadership in Energy and Environmental Design (LEED)

a certification program that awards a rating (standard, silver, gold, or platinum) to buildings that include environmentally sound design features

species

a group of plants or animals that have a high degree of similarity and can generally only interbreed among themselves

biosphere

the sum total of all Earth’s ecosystems

biomes

one of many distinctive types of ecosystems determined by climate and identified by the predominant vegetation and organisms that have adapted to live there

ecosystem

all of the organisms in a given area plus the physical environment in which and with which they interact

biotic

refers to the living (organic) components of an ecosystem, such as the plants and animals and their waste (dead leaves, feces)

abiotic

refers to the nonliving components of an ecosystem, such as rainfall and mineral composition of the soil

population

all the individuals of a species that live in the same geographic area and are able to interact and interbreed

community

all the populations (plants, animals, and other species) living and interacting in an area

matter cycles

movement of life’s essential chemicals or nutrients through an ecosystem

energy flow

the one-way passage of energy through an ecosystem

biomass

Earth is materially closed but energetically open. In other words, the living and nonliving material that make up an ecosystem, called ______, does not enter or leave the system — we get no appreciable amounts of “new” matter from space

sinks

abiotic or biotic components of the environment that serve as storage places for cycling nutrients

residence times

Organisms acquire nutrients from a sink, and those nutrients are then cycled through the food chain, eventually returning to a sink where they linger for various lengths of time, known as ________.

terresterial, marine, and freshwater

the three broad categories of biomes

range of tolerance

the range, within upper and lower limits, of a limiting factor that allows a species to survive and reproduce

photosynthesis

the chemical reaction performed by producers that uses the energy of the Sun to convert carbon dioxide and water into sugar and oxygen

producers

organisms that convert solar energy to chemical energy via photosynthesis

consumer

organisms that obtain energy and nutrients by feeding on another organisms

cellular respiration

the process in which all organisms break down sugar to release its energy, using oxygen and giving off CO2 as a waste product

carbon cycle

movement of carbon through biotic and abiotic parts of an ecosystem via photosynthesis and cellular respiration as well as in and out of other reservoirs such as oceans, soil, rock, and atmosphere

nitrogen cycle

a continuous series of natural processes by which nitrogen passes from the air to the soil to organisms and then returns back to the air or soil

nitrogen fixation

conversion of atmospheric nitrogen into a biologically usable form, carried out by bacteria found in soil or via lightning

nitrification

conversion of ammonia to nitrate (NO3−)

denitrification

conversion of nitrate to molecular nitrogen (N2)

phosphorus cycle

a series of natural processes by which the nutrient phosphorus moves from rock to soil or water to living organisms and back to soil

community ecology

the study of all the populations (plants, animals, and other species) living and interacting in an area

habitat

the physical environment in which individuals of a particular species can be found

niche

the role a species plays in its community, including how it gets its energy and nutrients, what habitat requirements it has, and with which other species and parts of the ecosystem it interacts

niche specialists

a species with very specific habitat or resource requirements that restrict where it can live

niche generalists

a species who occupies a broad niche because it can utilize a wide variety of resources

food chain

a simple, linear path starting with a plant (or other photosynthetic organism) that identifies what each organism in the path eats

food web

a linkage of all the food chains together that shows the many connections in the community

producers

an organism that converts solar energy to chemical energy via photosynthesis

consumers

an organism that obtains energy and nutrients by feeding on another organism

indicator species

a species that is particularly vulnerable to ecosystem perturbations, and that, when we monitor it, can give us advance warning of a problem

trophic levels

feeding levels in a food chain

detritivores

consumers (including worms, insects, and crabs) that eat dead organic material

decomposers

organisms such as bacteria and fungi that break organic matter all the way down to constituent atoms or molecules in a form that plants can take back up

resilience

the ability of an ecosystem to recover when it is damaged or perturbe

species diversity

the variety of species, including how many are present (richness) and their abundance relative to each other (evenness)

species richness

the total number of different species in a community

species evenness

the relative abundance of each species in a community

ecotones

regions of distinctly different physical areas that serve as boundaries between different communities

edge effects

the change in species diversity that occurs due to the different conditions that either attract or repel certain species at an ecotone

keystone species

a species that impacts its community more than its mere abundance would predict, often altering ecosystem structure

predation

species interaction in which one individual (the predator) feeds on another (the prey)

competition

species interaction in which individuals are vying for limited resources

intraspecific competition

competition that which occurs among members of the same species

interspecific competition

competition that which occurs among members of different species

resource partioning

the use of different parts or aspects of a resource by different species rather than direct competition for exactly the same resource

symbiosis

a close biological or ecological relationship between two species

mutualism

a symbiotic relationship between two individuals of two species in which both parties benefit

commensalism

a symbiotic relationship between individuals of two species in which one benefits from the presence of the other but the other is unaffected

parasitism

a symbiotic relationship between individuals of two species in which one benefits and the other is negatively affected

restoration ecology

the science that deals with the repair of damaged or disturbed ecosystems

ecological succession

progressive replacement of plant (and then animal) species in a community over time due to the changing conditions that the plants themselves create (more soil, shade, etc.)

primary succession

ecological succession that occurs in an area where no ecosystem existed before (e.g., on bare rock with no soil)

pioneer species

species that move into an area during early stages of succession