ESS: Topic 2.1 Ecosystems & Ecology

Ecology

Ecology

The study of interactions among and between organisms in their abiotic environment.

Abiotic Factors

The non-living, physical factors that influence the organisms and ecosystem — such as temperature, sunlight, pH, salinity, and precipitation.

Biotic Factors

The interactions between the organisms—such as predation, herbivory, parasitism, mutualism, disease, and competition.

Species

A group of organisms that share common characteristics and that interbreed to produce fertile offspring

Habitat

A habitat is the environment in which a species normally lives

Niche

A niche describes the particular set of abiotic and biotic conditions and resources to which an organism or population responds

Fundamental niche

Describes the full range of conditions and resources in which a species could survive and reproduce

Realized niche

Describes the actual conditions and resources in which a species exists due to biotic interactions

Resource Partitioning

The fundamental niches of two species overlap and through competition develop a narrower realized niche

Mutualism

Symbiotic relationship in which both partners benefit

Commensalism

A symbiotic relationship in which one organism benefits and the other one is neither harmed nor helped

Parasitism

Symbiotic relationship in which one species is benefited and the other is adversely affected

Predation

The consumption of one species (the prey) by another (the predator).​

Herbivory

The consumption of a plant species by an animal

Competition

This is the interaction between organisms that are trying to attain the same resources. This might be food but it could also be for mates, territory, nesting sites, etc.

Decomposer

Feeds on dead and decaying material, thus recycling the nutrients.

J-Shaped Curve

A population growth curve showing exponential growth with no carrying capacity reached.

S-Shaped Curve

A population growth curve showing exponential growth followed by slowed growth until carrying capacity is reached.

Carrying Capacity

The maximum population size that a given area can support sustainably.

Limiting Factors

Biotic or abiotic factors which lead to a limit in the population growth.

Density-dependent Limiting Factors

Limiting factors related to how densely packed a population is, e.g. competition

Density-independent Limiting Factors

Limiting factors unrelated to population density such as natural disasters and weather change.

Symbiosis

individuals living on or in individuals of another species where one or both species use the others resources. Includes mutualism, commensalism and parasitism.