Week 6: Communities Flashcards
Lecture, Labs, Readings (terms)
Metapopulation
A group of spatially separated populations of the same species which interact at some level.
Patch
An area of habitat differing from its surroundings, often the smallest ecologically distinct landscape feature in a landscape mapping and classification system.
Disturbance
A temporary change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements.
Gap
The species or ecosystem occurs in the protected area system, occurrence is either of inadequate ecological condition, or the protected area(s) fail to address species’’ movements or specific ecological conditions needed for long-term survival or ecosystem functioning.
Founder-controlled community
Species are approximately equivalent in their ability to invade gaps and can hold the gaps against all comers
during their lifetime.
Dominance-controlled community
Some species are competitively superior to others, and an initial colonizer of a patch cannot necessarily maintain its presence there.
Community Succession
Disturbances that open up gaps lead to reasonably predictable sequences of species, because different species have different strategies for exploiting resources.
Climax stage
When the most efficient competitors oust their neighbours.
Primary Succession
If an opened-up gap has not previously been influenced by a community,
Secondary Succession
Where the species of an area has been partially or completely removed but seeds and spores remain,
Chronosequence
A set of ecological sites that share similar attributes but represent different ages.
Food web
Consists of all the food chains in a single ecosystem. Each living thing in an ecosystem is part of multiple food chains. Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem.
Trophic level
The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain.
Direct effect
Deal with the direct impact of one individual on another when not mediated or transmitted through a third individual.
Indirect effect
The impact of one organism or species on another, mediated or transmitted by a third
