Edexcel IAL Biology: Ecology Study Notes

Vocabulary flashcards covering fundamental ecological terms, succession, fieldwork techniques, productivity, the carbon cycle, and climate change concepts from Edexcel International A Level Biology.

Ecology

The study of interactions between organisms and their environment.

Species

A group of organisms that can interbreed to produce fertile offspring; this biological definition has limitations for asexual organisms.

Population

All the organisms of one species living in a particular area at a particular time.

Community

All the populations of different species living and interacting in an area.

Habitat

The place where an organism lives.

Ecosystem

A community, its abiotic environment, and the interactions between them.

Niche

The role of a species in an ecosystem, including the resources it uses, conditions it tolerates, and interactions with other organisms.

Abundance

The number of individuals of a species in an area.

Distribution

Where organisms of a species occur within an area.

Succession

A directional change in the species composition of a community over time.

Primary succession

Succession starting on a newly exposed surface, such as bare rock, that initially has no developed soil and retains little water.

Pioneer species

The first species to establish on a newly exposed or disturbed habitat (such as lichens on bare rock).

Climax community

A relatively stable community that develops under prevailing conditions, influenced by climate and other environmental factors.

Secondary succession

Succession that begins in a previously occupied area after disturbance where soil remains, such as abandoned farmland.

Line transect

A systematic sampling technique that records organisms touching a line placed along an environmental gradient.

Belt transect

A sampling technique that uses quadrats placed along a line, either continuously or at fixed intervals, across an environmental gradient.

Percentage cover

An estimate of the fraction of quadrat area covered by a species, useful when separate individuals are difficult to count.

Abiotic factors

Non-living physical and chemical conditions in an environment that affect the survival, reproduction, abundance, and distribution of organisms.

Biotic factors

Factors arising from living organisms and their interactions that affect the survival, reproduction, abundance, and distribution of species.

Intraspecific competition

Competition for resources in limited supply between individuals of the same species.

Interspecific competition

Competition for resources in limited supply between individuals of different species.

Gross primary productivity (GPP)

The total rate at which producers fix energy in organic molecules by photosynthesis.

Net primary productivity (NPP)

The rate at which energy remains stored as new producer biomass after respiratory losses ($\text{NPP} = \text{GPP} - R$).

Biomass

The mass of living material; dry mass is used to avoid variation due to water content.

Carbon capture and storage

A management method aiming to capture carbon dioxide and store it rather than release it into the atmosphere.

Enhanced greenhouse effect

The alteration of Earth's energy balance caused by human activities increasing greenhouse gas concentrations, resulting in more outgoing infrared radiation being absorbed and re-emitted towards the surface.

Global warming

The long-term increase in global mean surface temperature.

Climate change

Long-term changes in climate, including temperature, rainfall, and patterns of extremes.

Anthropogenic

Caused by human activity.

Phenology

The seasonal timing of biological events, such as flowering, insect emergence, migration, and breeding.

Ecology

The study of interactions between organisms and their environment.

Species

A group of organisms that can interbreed to produce fertile offspring; this biological definition has limitations for asexual organisms.

Population

All the organisms of one species living in a particular area at a particular time.

Community

All the populations of different species living and interacting in an area.

Habitat

The place where an organism lives.

Ecosystem

A community, its abiotic environment, and the interactions between them.

Niche

The role of a species in an ecosystem, including the resources it uses, conditions it tolerates and interactions with other organisms.

Abundance

The number of individuals of a species in an area.

Distribution

Where organisms of a species occur within an area.

Succession

A directional change in the species composition of a community over time.

Primary succession

Ecological succession beginning on a newly exposed surface, such as bare rock, that initially has no developed soil and retains little water.

Pioneer species

The initial species to establish on a newly exposed surface that help weather rock and contribute organic matter to soil formation.

Climax community

A relatively stable ecological community that may develop over time, influenced by climate and other environmental conditions.

Secondary succession

Ecological succession that begins in a previously occupied area after disturbance where soil remains, such as abandoned farmland.

Line transect

A systematic sampling method that records organisms touching a line placed across an environmental gradient.

Belt transect

A systematic sampling method that uses quadrats placed along a line, either continuously or at fixed intervals.

Percentage cover

An estimate of the fraction of quadrat area covered by a species, useful when separate individuals are difficult to count.

Abiotic factors

Non-living physical and chemical conditions in the environment.

Biotic factors

Ecological factors arising from living organisms and their interactions.

Intraspecific competition

Competition for resources in limited supply among individuals within the same species.

Interspecific competition

Competition for resources in limited supply between individuals of different species.

Gross primary productivity (GPP)

The total rate at which producers fix energy in organic molecules by photosynthesis.

Net primary productivity (NPP)

The rate at which energy remains stored as new producer biomass after respiratory losses ($NPP = GPP - R$).

Biomass

The mass of living material; dry mass is used to avoid variation caused by water content.

Carbon capture and storage

A technique that aims to capture carbon dioxide and store it rather than releasing it into the atmosphere.

Natural greenhouse effect

The process in which incoming short-wave solar radiation warms Earth's surface, which emits long-wave infrared radiation that is absorbed and re-emitted by greenhouse gases to warm the surface and lower atmosphere.

Enhanced greenhouse effect

The amplification of greenhouse warming caused by human activities increasing greenhouse gas concentrations, leading to more absorption and re-emission of outgoing infrared radiation.

Global warming

The long-term increase in global mean surface temperature.

Climate change

Long-term changes in climate, including temperature, rainfall and patterns of extremes.

Anthropogenic

Caused by human activity.

Phenology

The study of seasonal timing of biological events, such as flowering, insect emergence, migration and breeding.