Ecology Notes

Ecosystem

A community of living organisms and their interactions with the abiotic components of their environment.

Biome

A large geographic biotic unit consisting of similar ecological communities keyed to a particular climate.

Trophic Levels

The hierarchical levels in an ecosystem, comprising producers at the bottom and various levels of consumers above them.

Autotroph

An organism that produces its own food, typically through photosynthesis or chemosynthesis.

Heterotroph

An organism that cannot produce its own food and consumes other organisms for energy.

Decomposers

Organisms that break down dead organic material, returning nutrients to the ecosystem.

Food Web

A complex network of feeding relationships among various organisms in an ecosystem.

Carrying Capacity

The maximum population size that an environment can sustain indefinitely.

Limiting Nutrient

A nutrient that is in short supply and limits the growth of organisms in an ecosystem.

Symbiosis

A close interactions between two species, which may benefit, harm, or have no effect on one another.

Mutualism

A type of symbiotic relationship in which both species benefit from the interaction.

Commensalism

A type of symbiotic relationship where one species benefits and the other is neither helped nor harmed.

Parasitism

A symbiotic relationship in which one organism benefits at the expense of the other.

Biodiversity

The variety and variability of life on Earth, including the variety of species, ecosystems, and genetic difference.

Biogeochemical Cycle

The circulation of substances through living organisms from or to the environment.

Exponential Growth

A growth pattern in which the population size increases at a constant rate per time period.

Logistic Growth

A growth pattern that starts exponentially but slows as the population reaches carrying capacity.

Interspecific Competition

Competition for resources between individuals of different species.

Competitive Exclusion Principle

The principle that two species competing for the same resources cannot coexist at constant population values.

Predation

An interaction where one organism (the predator) feeds on another organism (the prey).

Keystone Predator

A species that has a disproportionately large effect on its environment relative to its abundance.

Eutrophication

The process by which a body of water becomes enriched in nutrients, often leading to excessive growth of algae.

Greenhouse Effect

The warming of Earth’s surface due to the trapping of heat by greenhouse gases in the atmosphere.

Renewable Energy

Energy from sources that are naturally replenished, such as solar or wind energy.

Tragedy of the Commons

A situation in which individuals acting in their own self-interest deplete shared resources.

Population Density

The number of individuals per unit area or volume.

Boom and Bust Cycles

Fluctuations in population size that can lead to periods of rapid growth followed by significant decline.

Dead Zones

Hypoxic areas in water bodies that cannot support marine life due to low oxygen levels.

Carbon Footprint

The total amount of greenhouse gases emitted directly or indirectly by an individual or organization.

Müllerian Mimicry

A form of mimicry where two unpalatable species evolve to resemble each other, reinforcing their avoidance by predators.

Batesian Mimicry

A form of mimicry in which a harmless species imitates the warning signals of a harmful species.

Primary Productivity

The rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances.

Density Dependent Factors

Factors that affect population growth in relation to the population density, such as availability of resources.

Density Independent Factors

Factors that affect population size regardless of the population’s density, such as natural disasters.

Human Impact on the Environment

Human activities that alter the natural environment, including pollution, habitat destruction, and overexploitation.

Niche

The role or function of an organism or species within an ecosystem, including its habitat, resource use, and relationships.

Abiotic Factors

Non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems.

Biomagnification

The process by which the concentration of toxic substances increases in organisms at each trophic level.

Ecological Footprint

A measure of human demand on the Earth's ecosystems, representing the amount of natural capital used.

Human Population Growth

The increase in the number of individuals in a human population, influenced by birth and death rates.

Climate

The long-term average of weather patterns in a particular area.

Resource Partitioning

The division of resources among species to reduce competition.