SLE103 Ecology and the Environment - Ecosystems Flashcards

A set of vocabulary flashcards covering the fundamental concepts of ecology, ecosystem organization, and energy flow based on the SLE103 Module 2 lecture notes.

Ecology (Etymology)

Derived from the Greek words 'oikos' meaning home and 'logos' meaning to study.

Ecology (Knox et al. 2009 definition)

The study of interactions between organisms and their environment.

Organismal ecology

The branch of ecology concerned with the evolutionary adaptations that enable individual organisms to meet the challenges imposed by their environment.

Population

A group of individuals of the same species living in a particular geographic area.

Community

An assemblage of populations of different species; all the organisms that inhabit a particular area.

Ecosystem

The communities of plants and animals together with the abiotic components of their environment.

Biosphere

The global ecosystem; the sum of all Earth's ecosystems, or all of life and where it lives.

Biotic

The living components of the environment, such as reptiles, insects, trees, and fungi.

Abiotic

The non-living components of the environment, such as rocks, air, water, and soil.

Autotrophs

Organisms, such as plants and algae, capable of synthesizing all their required organic molecules from simple inorganic substances and an energy source.

Heterotrophs

Organisms, such as animals, that cannot synthesize complex organic compounds and must feed on organic material formed by other organisms.

1st law of thermodynamics

Energy cannot be created nor destroyed; it is transferred or transformed.

Photosynthesis Equation

$$6 CO_2 + 12 H_2O \rightarrow C_6H_{12}O_6 + 6 O_2 + 6 H_2O$$

Primary productivity

The rate at which solar radiation is converted into chemical energy, expressed as amount of material or energy per unit time, such as $g/m^2/yr$.

Gross primary productivity (GPP)

The total energy fixed in photosynthesis per unit time.

Net primary productivity (NPP)

The energy fixed in photosynthesis minus the energy used in respiration ($NPP = GPP - \text{Respiration}$).

Biomass

The weight of living tissue per unit area, often measured in $kg/ha$ or dry weight.

Primary consumers

Organisms that feed on producers, typically herbivores.

Secondary consumers

Organisms that feed on herbivores, such as carnivores or parasites.

Scavengers

Animals that eat dead organisms.

Detritivores

Animals that eat organic litter or detritus.

Decomposers

Fungi and bacteria that cause chemical decay of organic matter from all trophic levels.

10% Rule (Energy Transfer)

The average efficiency of energy transfer between trophic levels, where approximately $10\%$ of energy from one level is converted into biomass in the next.

Grazing food chain

A pathway of food transfer that is directly dependent on green plants.

Detritus food chain

A pathway of food transfer where the primary food base is dead and decaying organic matter.

Food web

A network of linked food chains showing how an ecosystem is structured by energy flow.