Essential Ecological Terms Defined

Core Concepts in Ecology

Ecology

The study of interactions between organisms and their environment.

Population

All individuals of the same species living in a specific area.

Community

A group of different populations of species interacting with each other within the same habitat or medium.

Abiotic Factors

Non-living physical and chemical conditions that influence living organisms.

Limiting Factor

An environmental factor that is closest to the minimum or maximum tolerance level for an organism, thereby restricting its growth, distribution, or population size.

Adaptation

An evolutionary process where organisms develop traits that enhance their survival and reproduction in specific environmental conditions.

Euryoic Organisms

Organisms that can tolerate a wide range of changes in an environmental factor, exhibiting a broad tolerance margin.

Stenoic Organisms

Organisms that can only tolerate a narrow range of changes in an environmental factor, being highly adapted to stable environments with a very limited tolerance margin.

Tolerance Range

The interval of values for an ecological factor within which an organism can survive.

Homeotherms

Organisms that maintain a constant internal body temperature, regardless of external temperature fluctuations.

Poikilotherms

Organisms whose internal body temperature varies with the ambient environmental temperature.

Osmosis

The net movement of water molecules across a selectively permeable membrane from a region of higher water concentration to a region of lower water concentration.

Environmental Resistance

Environmental factors that limit the growth, reproduction, or survival of a population, slowing its increase.

Carrying Capacity

The maximum population size of a biological species that can be sustained indefinitely by a given environment, considering available resources.

Biome

A large ecological area on Earth with a distinct climate and dominant plant and animal life, characterized by specific environmental conditions.

R-Strategists

Species that prioritize rapid reproduction and high growth rates, effectively exploiting available resources to quickly form large populations. They typically have short lifespans and produce many offspring.

K-Strategists

Species that are highly adapted to their environment, characterized by stable population growth, longer lifespans, and fewer, larger offspring, with significant parental care.

Biodiversity

The variety of life in a particular habitat or ecosystem, encompassing the diversity of species, genes, and ecosystems.

Ecological Succession

The process of change in the species structure of an ecological community over time.

Primary Succession

The ecological succession that occurs in an area where no soil or life previously existed, such as newly formed volcanic islands or bare rock. Pioneer organisms colonize the area, gradually enriching the soil and increasing biodiversity, leading to a climax community.

Secondary Succession

The ecological succession that occurs in an area where a community has been removed or disturbed, but the soil or substrate remains intact, allowing for faster recolonization and development of a new community.

Ecological Regression

A process where a community loses a vital part of its populations or complexity, often due to disturbance or environmental degradation.

Parasitism

A symbiotic relationship where one organism (the parasite) lives on or in another organism (the host), obtaining nutrients at the host's expense, often causing harm and potentially leading to the host's death.

Ecosystem

A biological community of interacting organisms and their physical environment, including all living components, physical factors, and their interrelationships.

Biotope

The physical environment or habitat where a biological community (biocenosis) lives.

Biocenosis

The living component of an ecosystem, comprising all the populations of different species interacting within a biotope.

Habitat

The natural environment or place where an organism or species typically lives.

Ecological Niche

The role and position a species has in its environment, including how it meets its needs for food and shelter, how it survives, and how it reproduces.

Producers

Organisms, primarily autotrophs, that produce their own organic compounds from inorganic substances, typically through photosynthesis or chemosynthesis, forming the base of the food web.

Biomass

The total mass of organisms in a given trophic level, population, or ecosystem at a particular time, typically expressed as dry weight per unit area or volume.