Ecological Models & Ecosystems

Flashcards covering key vocabulary related to ecological models, food chains, food webs, biomagnification, bioaccumulation, and global food challenges from the Biology 20 lecture notes.

Ecological Models

Demonstrations of how we believe systems work, used by ecologists to track the flow of matter & energy from the abiotic environment through organisms; simplified versions of the natural world.

Food Chains

The simplest ecological model, illustrating one organism at each trophic level starting with producers, with arrows indicating the flow of matter & energy.

Second Law of Thermodynamics (in food chains)

Limits food chain length because some energy is wasted and 'lost' at every transfer from one trophic level to the next, through chemical bonds in waste products or used by the organism.

Food Webs

Ecological models that include a larger number of organisms than food chains, illustrating more relationships and being more accurate but harder to interpret/work with.

Biomagnification

When environmental toxins become concentrated the higher up you go in a food chain.

Bioaccumulation

The buildup of a contaminant in one individual over time, such as mercury in a fish's body.

Polychlorinated biphenyls (PCBs)

Pollutants that enter the ocean as industrial waste and are absorbed by microscopic phytoplankton, demonstrating biomagnification as they move up the food chain.

Mercury (as a pollutant)

A pollutant that enters waterways and lakes through industrial processes, causing bioaccumulation in fish and shellfish over time.

Energy Efficiency (in diet)

The concept that, due to energy loss at each trophic level, more people could be fed on a plant-based diet compared to a diet including more meat.