Critical Thinking 3 Flashcards
Community
The association of interacting populations is defined by the nature of their interactions or the place where they live.
Interdependent Communities
Communities in which species depend on each other to exist.
Ecotone
A boundary created by sharp changes in environmental conditions over a relatively short distance, accompanied by a major change in the composition of species.
Species richness
The number of species in a community (area).
Relative abundance (evenness)
The proportion of individuals in a community is represented by each species.
Log-normal distribution
A normal, or bell-shaped, distribution that uses a logarithmic scale on the x-axis.
Species diversity
Number of species in an area and their relative abundance (evenness).
Alpha (local) diversity
Average diversity (number & evenness) of species in a habitat or local area
Beta (turnover) diversity
Differences in species among habitat
Gamma (regional) diversity
Number of species in all of the habitats that comprise a large geographic area.
Keystone species
A species that substantially affects the structure of communities, although it might not be particularly numerous.
Food chain
A linear representation of how different species in a community feed on each other
Food web
A complex and realistic representation of how species feed on each other in a community
Bottom-Up control
When the abundances of tropic groups are determined by the amount of energy available from producers.
Top-Down control
The abundance of tropic groups is determined by the existence of predators at the top of the food web.
Energy residence time
The length of time that energy spends in a given trophy level; the longer the residence time, the greater the accumulation of energy in that trophic level.
Biomass residence time
The length of time that biomass spends in a given trophic level
Consumption efficiency
The percentage of energy or biomass in a trophic level that is consumed by the next higher trophic level.
Assimilation efficiency
The percentage of consumed energy that is assimilated into flesh.
Primary productivity
Determines: 1) Number of tropic levels. 2) Herbivore and Predator abundance.
In terrestrial systems
Pyramids of biomass and energy look similar.
High plant longevity and defenses
Low consumption
In aquatic systems
Pyramids of biomass and energy look inverted.
Low plant longevity and defenses
High consumption
