DISTRUBUTION OF ORGANISMS Flashcards
what are biotic factors?
living factors in an ecosystem (such as animals and plants)
examples of biotic factors?
- disease
- competition for resources
- predation
- grazing
- food availability
What are abiotic factors?
Non-living elements of an ecosystem
Examples of abiotic factors?
climate, temperature, water, and soil type.
What is an indicator species?
The presence, abundance or absence of these organisms provides information such as the level of pollution in the environment.
What is a pitfall trap?
A sampling technique used to trap small invertebrate animals living on the soil surface or in leaf litter.
What is a quadrat?
A square frame of known area used for sampling the abundance and distribution of slow or non-moving organisms.
Pitfall traps can be used to sample
invertebrate animals that move around surfaces
Quadrats and pitfall traps can be used
quantitatively or qualitatively to estimate populations of organisms.
Sampling techniques such as those involving quadrats or pitfall traps are limited in what they can measure and can potentially create
sources of error
Quadrats can be used to sample organisms that are
fixed, or partly fixed, to a surface or those that spend a significant time motionless.
Abiotic factors can be measured using
instruments designed to give numerical values
A sample can be taken to represent a
population of an organism in a habitat or an ecosystem
