APES: Chapter 5 vocab

age structure

age structure

percentage of the population (or number of people of each sex) at each age level in a population

annual

plant that grows, sets seeds, and dies in one growing season. Compare perennial

asexual reproduction

Reproduction in which a mother cell divides to produce two identical daughter cells that are clones of the mother cell. This type of reproduction is common in single–celled organisms. Compare sexual reproduction

biotic potential

Maximum rate at which the population of a given species can increase when there are no limits on its rate of growth. See environmental resistance

carrying capacity (K)

Maximum population of a particular species that a given habitat can support over a given period. Compare cultural carrying capacity.

climax community

see mature community

coevolution

Evolution in which two or more species interact and exert selective pressures on each other that can lead each species to undergo adaptations. See evolution, natural selection.

commensalism

An interaction between organisms of different species in which one type of organism benefits and the other type is neither helped nor harmed to any great degree. Compare mutualism.

competition

Two or more individual organisms of a single species (intraspecific competition) or two or more individuals of different species (interspecific competition) attempting to use the same scarce resources in the same ecosystem

dieback

Sharp reduction in the population of a species when its numbers exceed the carrying capacity of its habitat. See carrying capacity.

dissolved oxygen (DO) content)

Amount of oxygen gas (O2) dissolved in a given volume of water at a particular temperature and pressure, often expressed as a concentration in parts of oxygen per million parts of water.

ecological succession

Process in which communities of plant and animal species in a particular area are replaced over time by a series of different and often more complex communities. See primary ecological succession, secondary ecological succession

environmental resistance

All of the limiting factors that act together to limit the growth of a population. See biotic potential, limiting factor.

epiphyte

Plant that uses its roots to attach itself to branches high in trees, especially in tropical forests

host

plant or animal on which a parasite feeds

immature community

Community at an early stage of ecological succession. It usually has a low number of species and ecological niches and cannot capture and use energy and cycle critical nutrients as efficiently as more complex, mature communities. Compare mature community.

interspecific competition

Attempts by members of two or more species to use the same limited resources in an ecosystem. See competition, intraspecific competition

intraspecific competition

Attempts by two or more organisms of a single species to use the same limited resources in an ecosystem. See competition, interspecific competition

intrinsic rate of increase ( r)

Rate at which a population could grow if it had unlimited resources. Compare environmental resistance

limiting factor

Single factor that limits the growth, abundance, or distribution of the population of a species in an ecosystem. See limiting factor principle.

limiting factor principle

Too much or too little of any abiotic factor can limit or prevent growth of a population of a species in an ecosystem, even if all other factors are at or near the optimal range of tolerance for the species

logistic growth

Pattern in which exponential population growth occurs when the population is small, and population growth decreases steadily with time as the population approaches the carrying capacity. See S– shaped curve.

mature community

Fairly stable, self–sustaining community in an advanced stage of ecological succession; usually has a diverse array of species and ecological niches; captures and uses energy and cycles critical chemicals more efficiently than simpler, immature communities. Compare immature community

mutualism

Type of species interaction in which both participating species generally benefit. Compare commensalism.

parasite

Consumer organism that lives on or in, and feeds on, a living plant or animal, known as the host, over an extended period. The parasite draws nourishment from and gradually weakens its host; it may or may not kill the host. See parasitism.

parasitism

interaction between species in which one organism, called the parasite, preys on another organism, called the host, by living on or in the host. See host, parasite

perennial

plant that can live for more than 2 years. Compare annual

pioneer community

First integrated set of plants, animals, and decomposers found in an area undergoing primary ecological succession. See immature community, mature community.

pioneer species

First hardy species—often microbes, mosses, and lichens—that begin colonizing a site as the first stage of ecological succession. See ecological succession, pioneer community.

population

group of individual organisms of the same species living in a particular area.

population crash

Dieback of a population that has used up its supply of resources, exceeding the carrying capacity of its environment. See carrying capacity

population density

number of organisms in a particular population found in a specified area or volume

population dispersion

general pattern in which the members of a population are arranged throughout its habitat.

population distribution

Variation of population density over a particular geographic area or volume. For example, a country has a high population density in its urban areas and a much lower population density in its rural areas.

population dynamics

Major abiotic and biotic factors that tend to increase or decrease the population size and affect the age and sex composition of a species

population size

number of individuals making up a population’s gene pool

predation

Interaction in which an organism of one species (the predator) captures and feeds on some or all parts of an organism of another species (the prey).

predator

Organism that captures and feeds on some or all parts of an organism of another species (the prey).

predator-prey relationship

Relationship that has evolved between two organisms, in which one organism has become the prey for the other, the latter called the predator. See predator, prey.

prey

organism that is killed by an organism of another species (the predator) and serves as its source of food

primary ecological succession

Ecological succession in a area without soil or bottom sediments See ecological succession. Compare secondary ecological succession

principles of sustainability

Principles by which nature has sustained itself for billions of years by relying on solar energy, biodiversity, and nutrient recycling.

range of tolerance

Range of chemical and physical conditions that must be maintained for populations of a particular species to stay alive and grow, develop, and function normally. See law of tolerance

reproduction

production of offspring by one or more parents

reproductive potential

see biotic potential

resource partitioning

Process of dividing up resources in an ecosystem so that species with similar needs (overlapping ecological niches) use the same scarce resources at different times, in different ways, or in different places. See ecological niche

restoration ecology

Research and scientific study devoted to restoring, repairing, and reconstructing damaged ecosystems.

S-shaped curve

Leveling off of an exponential, J–shaped curve when a rapidly growing population reaches or exceeds the carrying capacity of its environment and ceases to grow.s

salinity

amount of various salts dissolved in a given volume of water

secondary ecological succession

Ecological succession in an area in which natural vegetation has been removed or destroyed but the soil or bottom sediment has not been destroyed. See ecological succession. Compare primary ecological succession.

sexual reproduction

Reproduction in organisms that produce offspring by combining sex cells or gametes (such as ovum and sperm) from both parents. It produces offspring that have combinations of traits from their parents. Compare asexual reproduction.

succession

See ecological succession, primary ecological succession, secondary ecological succession.