distribution of organisms Flashcards
what are the two factors that can affect biodiversity?
- biotic factors
- abiotic factors
what are biotic factors?
living factors affecting biodiversity
- predation
- grazing
- disease
- competition
- food availability
what are abiotic factors?
non-living factors affecting biodiversity
- temperature
- light intensity
- pH
- moisture
how can biotic factors be sampled?
- pitfall trap
- quadrats
what are the sources of error and the limitations of the error for pitfall traps?
- using a small sample size: set up several PT to ensure the results are reliable
- trapped organisms may be eaten by predators: camouflage the PT using foliage
- trapped organisms may escape: add ethanol to trap and check contents regularly
what are the sources of error and the limitations of the error for quadrats?
- using a small sample size: set up several quadrats to ensure the results are reliable
- sample site may be specifically chosen: throw quadrat at random to ensure results are not biased
- counting organisms more than once: follow simple counting rules to ensure each organism is only counted once
how can abiotic factors be sampled?
temperature: thermometer
light intensity: light meter
soil moisture: moisture meter
soil pH: pH meter
what is the error and limitation of the error for light meters?
shading the light meter: point the sensor directly at the light source
what is the error and limitation of the error for moisture/pH meters?
cross-contamination between samples: clean prope between readings
what is the error and limitation of the error for thermometers?
inadequate time to read temperature: allow dial to settle before taking a reading
what is an indicator species?
a species that by their presence or absence indicate levels of environmental quality
what can indicator species be used to indicate levels of?
- water pollution
- air pollution
what are paired statement keys?
a series of paired statements used to identify different organisms based on their physical appearance
