Population Ecology Do Not Write Down anything in YELLOW!

Population Dynamics Population: All the individuals of a species that live together in an area Demography: The statistical study of populations, allows predictions to be made about how a population will change Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

Population Dynamics Three Key Features of Populations Size (How Many) Density (How much in an area) Dispersion (Where are they located) Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

Three Key Features of Populations Population Size: number of individuals in an area Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

Three Key Features of Populations Growth Rate: Birth Rate (natality) - Death Rate (mortality) How many individuals are born vs. how many die. Birth rate (b) − death rate (d) = rate of natural increase (r) Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

Three Key Features of Populations Density: measurement of population per unit area or unit volume Pop. Density = # of individuals ÷ unit of space Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

What do you think??? Do you think governments should be allowed to regulate populations of humans around the world? Explain why or why not. How would you feel about someone telling you, you can’t have a 2nd child, and if you do you will be taxed heavily because of it? What would you do? Explain.

How Do We Affect Density? Immigration: movement of individuals into a population. Emigration: movement of individuals out of a population.

How Do We Affect Density? Density-dependent factors: Biotic factors in the environment that have an increasing effect as population size increases (disease, competition, parasites). Density-independent factors: Abiotic factors in the environment that affect populations regardless of their density (temperature, weather).

+ + - - Population IMPORTANT! Immigration Mortality Natality Emigration

Three Key Features of Populations Dispersion: describes the spacing of organisms relative to each other Clumped (groups, pods, families) Uniform (nesting and breeding grounds) Random (usually plants, algae, corals) Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

Population Dispersion