Ecological terminology - The living environment

Biomass

the total mass of living, or recently living material in an area

Biome

a large geographical region with particular climatic features, in which a characteristic, unique community of species lives, e.g. taiga, coral reefs, temperate grasslands, tundra, tropical rainforest

Community of species

the populations of all the species living in a particular area

Ecological niche

The role that an organism plays in its habitat, including its use of resources and its inter-relationships with other species.

Ecosystem

The community of organisms living in an area, their inter-relationships and interactions with their abiotic environment e.g. tropical rainforest, savannah grassland, coral reef

Habitat

The place where an organism, species or population lives.

Population

All the individuals of a species living in a particular area. Population = starting population + births + immigrants

Species

A group of organisms that resemble each other more than other organisms and naturally interbreed to produce fertile offspring.

Taxon

A grouping of organisms based on their biological similarities e.g. domain, kingdom, phylum, class, order, family, genus, species.

Taxonomy

The study of how organisms are grouped together based on similarities.

Latin binomial

Each species is given a scientific name made up of two Latin words. These often describe a characteristic that can be a unique identifier. The first word of the binomial is the name of the genus, and the second word is the name of the species.

Evolution

The process that changes the gene pool of a species. The environment selects out welladapted individuals with alleles for beneficial characteristics, and when these individuals reproduce the next generation contains more of these beneficial alleles

Biosphere

The regions of planet earth that are inhabited by living organisms, including the land surface, water, soil and atmosphere

Gene pool

The total number of different alleles present in the population of a species. Large gene pools indicate high genetic diversity in healthy populations. Small gene pools may indicate populations that have crashed and might be in danger of extinction.

Mutation

The natural but slow process that creates new alleles of a gene. If these alleles make the individual better adapted to their environment these alleles will become more common in the population.

Interspecific competition

Competition between individuals of different species for resources such as food. Individuals of different species that share exactly the same niche cannot coexist in a habitat sustainably.

Intraspecific competition

Competition between individuals of the same species for resources such as food. This is often the most important biotic factor in determining population size as individuals of the same species share the same niche

Autotroph

Organisms that make their own food (glucose) using energy from light or chemical processes. Their role is as the producers in all food chains and webs

Heterotroph

An organism that cannot make its own food therefore it gains energy and organic compounds by eating molecules contained in other organisms. In food webs they fulfil the role of consumer.

Indigenous

Species that are native to a particular area

Decomposer

Heterotrophic organisms that break down dead or decaying organisms. Includes both detritivores and saprotrophs

Detritivore

A heterotrophic decomposer that ingests and digests dead and decaying organisms. Examples include woodlice and earthworms

Saprotroph

A heterotrophic decomposer that breaks down dead and decaying organisms by extracellular digestion. They are usually classed as microorganisms. Examples include most fungi and some bacteria