Biology: Ecosystems and Ecological Successions

This flashcard set covers the fundamental concepts of ecosystems, including biotic and abiotic factors, animal and plant adaptations, population dynamics, interspecific and intraspecific relationships, trophic levels, and the stages of ecological succession.

Ecosystem

A system formed by a set of organisms, the physical environment in which they live, and the relationships established between them.

Biotope

The non-living (abiotic) part of an ecosystem, comprising the physical space and environmental factors.

Biocenosis (Community)

The living (biotic) part of an ecosystem, encompassing the set of living beings and the relationships established between them.

Adaptations

Changes in the anatomy, physiology, and behavior of living beings modified by environmental factors.

Temperature Range

The range between $0\,^{\circ}\text{C}$ and $50\,^{\circ}\text{C}$ in which most living beings exist.

Homeotherms

Animals capable of regulating their body temperature, often covered in feathers or hair; some may hibernate.

Poikilotherms

Animals whose body temperature depends on the surrounding environment; they may migrate, hide, or hibernate.

Humidity

The relative amount of water vapor in the air, influenced by precipitation, distance from the coast, and temperature.

Salinity

The relative amount of mineral salts dissolved in water; oceans have nearly ten times higher levels than rivers and lakes.

Stenohaline

Animals that can only survive within a narrow range of water salinity.

Euryhaline

Animals capable of surviving in waters with different salt concentrations, such as salmon.

Species

A group of individuals with similar anatomical and functional characteristics capable of reproducing with each other.

Population

A group of individuals of the same species that occupy a geographical region during the same period of time and exchange genetic information.

Gregarious Relationship

A temporary intraspecific relationship for defense, reproduction, or migration, such as herds of zebras or flocks of birds.

Colonial Relationship

A relationship between descendants of the same parent that reproduces asexually, such as corals.

State Relationship

A permanent intraspecific relationship showing a distribution of tasks and a hierarchy, such as in ants and bees.

Mutualism

An interspecific interaction ($+$, $+$) where two or more species benefit temporarily; the bond can be broken without affecting survival.

Symbiosis

A permanent relationship between two species where both benefit and their survival depends on each other, such as lichens.

Parasitism

A relationship where a parasite benefits ($+$, $-$) from a host that is harmed but not killed.

Commensalism

A relationship where one species benefits ($+$, $0$) while the other is neither harmed nor benefited, such as epiphytic plants.

Producers

Autotrophic organisms like plants, algae, and cyanobacteria that manufacture their own food from inorganic matter using solar energy.

Primary Consumers

Herbivorous heterotrophs that feed on plants and algae.

Secondary Consumers

Carnivorous predators that feed on primary consumers.

Tertiary Consumers

Superpredators that feed on both primary and secondary consumers.

Decomposers

Heterotrophic organisms like bacteria and fungi that feed on remains of living beings and convert them back into inorganic matter.

Trophic Chain

A linear graphic representation showing the sequential feeding interrelationships between specific organisms in an ecosystem.

Trophic Web

A complex graphic representation composed of various interconnected trophic chains.

Pyramid of Energy

A trophic pyramid showing energy per unit of surface and time, measured in $kJ/m^2 \cdot \text{year}$, which cannot be inverted.

Primary Succession

The slow, gradual process of colonization starting on bare, uninhabited terrain, beginning with pioneer species.

Secondary Succession

A rapid recovery process that occurs after a disturbance (natural or anthropic) destroys a large part of an existing ecosystem.

Climax

The stage when an ecosystem acquires a maximum level of organization, stability, and diversity in perfect equilibrium with the environment.

Ecological Regression

An alteration that causes a retreat in the degree of maturity of an ecosystem, making it more unstable and fragile.

Pioneer Species

Undemanding organisms like lichens that are the first to colonize a bare environment during primary succession.