Flashcards in Chapter 54: Community Ecology II Deck (20)
- Defined by species diversity and trophic structure
- Feeding relationships among organisms in a community
Food chain/web (def.)
Link trophic levels from producers to carnivores and track transfer of food energy
Why most chains are limited to five or fewer steps?
- Energetic hypothesis
- Length of food chains are limited because energy use is inefficient (about 10% of energy is transferred)
Community structure and composition are affected by what?
- Species may have impact on structure
- Interactions within community (trophic interactions)
Dominant species (por qué son dominante?)
- Species that are most abundant or that collectively have highest biomass
- Superior competitors(best at surviving under certain conditions)
- Most successful at avoiding predation
Keystone species (def.)
- Species that exert strong control on community by altering the physical environment
Organisms that have strong influence on community by altering the physical environment
Organism that has some control over genetic selection
- Indirect interactions between species
- Removing predator = more prey, less of the species upon which typical prey prey
- Utilization of indirect interactions to restore ecosystems
- Affects community structure
- Event that changes community composition by removing organisms or altering resource ability
Disturbance regime characterization criteria?
- How large
- How often
- How severe
- Extremely disturbed: high frequency and high intensity
Importance of disturbance
- Allow species to populate again, restarts nutrient cycle I suppose?
Intermediate disturbance hypothesis
- Moderate levels of disturbance can create conditions that foster greater species diversity than low or high levels of disturbance
Ecological succession use?
- Transitions in species composition of community after a disturbance
- Disturbed area is colonized by variety of species
- Occurs when environment in which substrate devoid of vegetation and other organisms usually lacking in soil is deposited