Communities Flashcards
Levels of Organization
Species Population Community Ecosystem Biome Biosphere
Community
All the populations of all the species that live in a given area
Define questions about any community
How diverse is the community (biodiversity)?
Which species are dependent on which others?
What are the roles (e.g. prey, predator) of each species?
Keystone species
All communities seem to be characterized by species that may not be numerous, but play an irreplaceable role in that ecosystem
Ecological dominants
What are the three types of biodiversity with respect to to communities?
Species diversity - many different species vs. few species
Geographic diversity - broad distribution of species vs. narrow distribution of species
Genetic diversity - high genetic diversity vs low genetic diversity
Habitat
The physical surroundings in which a species normally is found
Niche
The manner in which an organism uses energy; the total interactions of a species with abiotic and biotic elements
Productivity
Means how much of the sun’s energy is “captured” and turned into biomass
Higher biomass = more productive
Resource partitioning
Species share their habitat and have slightly different niches; they use resources slightly differently.
Understand a trophic cascade
Consumers have a negative effect on the trophic level immediately below them, but a positive effect two trophic levels away by alleviating consumer pressure.
Ecological succession
Series of replacements by community members at a given location until a relatively stable endpoint is reached
Primary succession
Starting state is an area where little or no living things exist
What is the order for ecological succession?
Secondary succession, pioneer species, intermediate species, climax community
