Populations

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Population Density Noun

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[pop-yuh-ley-shuhn den-si-tee]

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Population Density

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The number of individuals of a population per unit of area or within a specified amount of space.

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Example: This map shows population density across the U.S. Red areas are densely populated (many people per square mile), while green areas are sparsely populated.

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Population Dispersion Noun

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[pop-yuh-ley-shuhn dih-spur-zhuhn]

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Population Dispersion

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The relative distribution or pattern describing how individuals in a population are spread out over an area.

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Example: This diagram shows one pattern of population dispersion, where individuals (circles) are spread out within a defined area, illustrating their spatial relationship to one another.

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Biotic Potential Noun

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[bahy-ot-ik puh-ten-shuhl]

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Biotic Potential

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The fastest rate at which a species' population can grow when living under ideal environmental conditions.

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Example: This graph shows that biotic potential is the maximum, unrestricted growth of a population over time, represented by the steep exponential growth curve.

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Reproductive Potential Noun

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[ree-pruh-duhk-tiv puh-ten-shuhl]

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Reproductive Potential

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The maximum number of offspring that each female member of a population is capable of producing.

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Example: This image shows the development of male and female reproductive systems in a fetus, which is unrelated to the ecological concept of 'Reproductive Potential'.

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Carrying Capacity Noun

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[kar-ee-ing kuh-pas-i-tee]

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Carrying Capacity

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The largest population size that a given environment can sustainably support over a long period of time.

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Example: This fishbowl represents an environment with limited resources, showing the maximum population of fish it can support, which is its carrying capacity.

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Density-Dependent Factor Noun

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[den-si-tee dih-pen-duhnt fak-ter]

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Density-Dependent Factor

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A limiting factor whose effect on a population increases as the population's density increases.

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Example: This image shows many hands reaching for one piece of bread, illustrating competition for a limited resource, which is a key density-dependent factor.

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Density-Independent Factor Noun

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[den-si-tee in-dih-pen-duhnt fak-ter]

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Density-Independent Factor

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A limiting factor that affects a population's size and growth regardless of the population's density.

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Example: This chart shows data on wildfires, which are a density-independent factor because they can reduce a population's size no matter how crowded or sparse it is.

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r-selected species Noun

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[ahr-si-lek-tid spee-sheez]

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r-selected species

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A species characterized by a high population growth rate, producing many small offspring with little parental care.

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Example: This image shows a sea turtle laying a large number of eggs, a key characteristic of r-selected species which prioritize quantity of offspring over parental care.

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K-selected species Noun

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[key-si-lek-tid spee-sheez]

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K-selected species

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A species characterized by a slow population growth rate, producing few large offspring with significant parental care.

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Example: This image shows a mother bear with her cubs, an example of a K-selected species that has few offspring and provides high parental care.

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Competitive Exclusion Noun

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[kuhm-pet-i-tiv ik-skloo-zhuhn]

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Competitive Exclusion

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The ecological principle that two species competing for the same limited resource cannot coexist at constant population values.

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Example: Two species, like lions and hyenas, competing for the same limited food resources cannot coexist; one will eventually outcompete and exclude the other.