Unformatted text preview: AP REVIEW ECOLOGY bPOPULATION - a group of organisms of same species living in the same place at the
same time. E |' E l l' :
1. Growth patterns: exponential (J) growth; logistic (3) growth
carrying capacity - number of individuals an environment can support
2 Mortality patterns: 3 different survivorship curves—Survivallthousand vs. %
of life span—Humans type I... .most individuals approach life span
3. Age structure: proportions of individuals of different ages (cohorts) in pop.
4 Density - number of individual per unit area or volume
5 Dispersion: pattern of distribution — random, clumped, regular Beguiaﬂnrmipopulatiom = limiting factors 1. Range of tolerance for factors such as light, temp. available water,
salinity, nesting space, and shortages of nutrients 2. Density-dependent factors cause changes in birth or death rate as density changes; ex. infectious disease, competition 3. Density-independent factors cause changes that are unaffected by size or
density of population; ex. environmental factors-drought, storms, volcanoes A Eiﬁ I “.E ll'l E II 1. Prodigal (opportunistic; r-selected) organisms exploit an environment and
then move on, but have remarkable powers of recuperation-dandelions 2. Prudent (equilibrium; K—selected) organisms are long-lived slow-to-mature
are very slow to recover when their size is reduced-elephants IMPORTANT APPLICATION: effects of human population growth COMMUNITY - all the populations of organisms inhabiting a common environment and
interacting with one another. These interactions are major forces of natural selection.
Inﬂuence the number of individuals in a population and number and kinds of species in
the community. II'II I' . B .l 1. Competition: intraspeciﬁc and interspeciﬁc
a. effects overall ﬁtness and reproductive success
b. greatest among organisms that have similar requirements and life style
2. Principle of Competitive Exclusion: The species less efficient at utilizing
or controlling a resource will eventually be eliminated. . . No two organisms
can occupy exactly the same niche when resources are limiting.
3. Ecological Niche- "way and organism makes a living." Includes physical
factors, biological factors, and aspects of behavior. ...
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