Ecology Flashcards
(41 cards)
Population Density
Describes how many individuals are in a certain area
Three Main Types of Dispersion Patterns
- Clumped: individuals live in packs that are spaced out from each other
- Uniform: individuals are evenly spaced out across a geographic area.
- Random: species are randomly distributed across a geographic area.
Population
Collection of individuals of the same species living in the same geographic area.
Community
Collection of populations of species in a geographic area.
Ecosystem
Consists of the individuals of the community and the environment in which it exists.
Biotic Components
Living organisms of the ecosystem.
Abiotic Components
Non-living players in an ecosystem, such as weather and nutrients.
Biosphere
Entire life-containing area of a planet-all communities and ecosystems.
Niche of an Organism
Consists of all the biotic and abiotic resources used by the organism.
Biotic Potential
Maximum growth rate of a population given unlimited resources, unlimited space, and lack of competition or predators
Carrying Capacity
Maximum number of individuals that a population can sustain in a given environment
Limiting Factors
Factors that keep population size in check such as: predators, diseases, food supplies, and waste produced by organisms.
Density-Dependent Factors
- Limiting factors that show up as the population approaches or passes the carrying capacity
- Examples: food supplies that run low, waste products that build up, population-crowding-related disease such as plague.
Density-Independent Factors
Limiting factors that have nothing to do with population size like DISASTER.
Exponential Population Growth
- The population grows at a rate that creates a J-shaped curve
- The population grows as if there are no limitations as to how large it can get.
Logistic Population Growth
- The population grows at a rate that create an S-shaped curve
- Limiting factors are responsible for the S shape of the curve, putting a cap on the size to which the population can grow.
K-selected Populations
- Populations of roughly constant size whose members have low reproductive rates
- The offspring produced require extensive postnatal care until they have sufficiently matured
- Humans are a K-selected species.
R-selected Populations
- Populations that experience rapid growth of the J-curve variety
- Offspring produced are numerous, mature quite rapidly, are require little postnatal care.
- Also known as opportunistic populations and tend to show up when space in a region opens up due to environmental change.
Three Types of Survivorship Curves
- Type I: individuals live a long life until an age is reached where the death rate increases rapidly
- Type II: individuals have a death rate that is roughly constant across all ages
- Type III: individuals have a steep downward curve for those of young age that flattens out as they get older.
Commensalism
- Symbiotic relationship between two organisms in which one organism benefits while the other is unaffected.
- Example: cattle egrets feast on insects that are aroused into flight by cattle that are grazing.
Mutualism
-Symbiotic relationship between two organisms in which both organism reap benefits from the interaction
Example: acacia trees and ants
Parasitism
Symbiotic relationship between two organisms in which one organisms in which one organism benefits at the other’s expense
Example: tapeworms in an individual’s GI system.
Aposematic Coloration
Warning coloration adopted by animals that possess a chemical defense mechanism.
Predators have grown cautious of animals with bright color patterns due to past encounters with such animals
Batesian Mimicry
An animal that is harmless copies that appearance of an animal that is dangerous to trick predators
Example: a beetle whose colors resemble those of bees