Ecology Lecture 2: Terms and Phrases

Competition (Intraspecific vs Interspecific)

Relationship between organisms that srive for the same resources in the same place.

Intraspecific competition is when members of the same species compete for limited resources like food, water, or mates.

Interspecific competition is when individuals of different species compete for the same resources, such as two species of plants vying for sunlight.

Disturbance

A change in environmental conditions that causes a pronounced change in an ecosystem—wildfires, floods, and storms.

Predation

A biological interaction in which one organism, the predator, kills and eats another organism, its prey

Trophic Level

Defines an organism's feeding position within a food chain or food web, indicating the flow of energy through an ecosystem.

Consumers (Primary, Secondary, Tertiary)

Organisms that obtain energy by eating other organisms because they cannot produce their own food through photosynthesis or chemosynthesis

Primary consumers (herbivores) eat producers (plants)

Secondary consumers (carnivores or omnivores) eat primary consumers

Tertiary consumers (carnivores or omnivores) eat secondary consumers.

Decomposers

Any organisms that breaks down or eats decaying material for its energy source.

Controlled Experiments

A scientific test designed to determine a cause-and-effect relationship by changing only one factor (the independent variable) at a time, while keeping all other factors (extraneous variables) constant.

Natural “Experiments“

A scientific test designed to determine a cause-and-effect relationship by changing only one factor (the independent variable) at a time, while keeping all other factors (extraneous variables) constant.

Synergy

Describes when the combined effect of multiple interacting entities—like organisms, species, or ecosystem services—is greater than the sum of their individual effects, leading to enhanced outcomes, stability, or complexity.

Statistical Significance

Indicates a result is unlikely to have occurred due to random chance or error and, therefore, suggests a real effect or difference is present.

P Value

The probability of obtaining observed data, or more extreme data, if the null hypothesis (the default assumption of no effect or no difference) is actually true.