Ecology: The Biotic Environment

Flashcards about Ecology: The Biotic Environment.

Native species

Occur naturally in that ecosystem.

Indigenous species

Evolved and are an integral part of the natural system.

Alien (i.e. introduced) species

Cause disruptions in the ecosystem and may result in displacement of other organisms.

Local alien species

Geranium Bronze Butterfly, (Cacyreus marshalli).

Local indigenous species

Carob tree (Ceratonia siliqua).

Endemic species

Maltese Wall Lizard (Podarcis filfolensis).

Competition

A race for biotic and abiotic resources.

Predation

The most common relationship in nature that helps to keep both predator and prey in check.

Intraspecific competition

Competition between organisms of the same species.

Interspecific competition

Competition occurs between organisms of different species.

Endoparasite

Living inside the body of the host.

Ectoparasite

Living outside the body of the host.

Carrying capacity

The maximum number of individuals of a species that can be supported by the resources available in a given environment.

Biotic components

Living components of an environment.

Abiotic components

Non-living components of an environment.

Predator

Actively hunts, kills and consumes its prey to meet its energy needs.

Alien or exotic species

Living organisms that were brought into (imported into) an area or country from another.

Producers (autotrophs)

Can convert inorganic molecules, such as water and carbon dioxide, into organic compounds such as carbohydrates (glucose) and proteins.

Consumers (heterotrophs)

Rely on other living organisms as food to obtain energy to survive.

Herbivores

Animals that eat plants.

Carnivores

Animals that feed on herbivores.

Omnivores

Animals that eat both plants and animals.

Decomposers (detrivores)

Decompose plants, animals and faeces of animals.

Symbiosis

A close association between two organisms such that one or both benefits.

Mutualism

Beneficial to both organisms.

Commensalism

One species benefits from the interaction, while the other species is neither harmed nor helped.

Parasitism

A parasitic relationship where one species benefits and the other is harmed.

Parasite

An organism that lives inside or on the surface of another living organism, its host.

Endoparasites

Those that parasitise the host internally e.g. tapeworms.

Ectoparasites

Those that parasitize the host externally e.g. leeches and ticks.

Population

A group of organisms of the same species living together in the same habitat and capable of random interbreeding.

The lag / establishment phase

The population grows rather slowly, because the organism is acclimatizing to the new environment.

The exponential / log phase

The population size increases rapidly, since there is little or no limiting factors.

The equilibrium / stationary phase

The population growth slows down, because the increased population density has increased the effect of detrimental factors i.e. environmental resistance increases.

The death phase

Conditions become unsuitable for the population, possibly because of their own activities. The population size therefore drops.