Distribution Of Organims Flashcards
When does competition occur?
Competition will occur between organisms when they require the same resources but it is in short supple
What may animals compete for?
Food
Water
Shelter
Mates
What may plants compete for?
Light
Water
Soil nutrients
Space to grow (root space)
What is intraspecific competition?
IntrAspecific competition occurs between members of the sAme species
E.g. polar bears competing for food
What is interspecific competition?
IntERspecific competition occurs between member of diffERent species
What competition is more intense?
Intraspecific as it’s competition for all resources required
What are the 2 types of factors that affect biodiversity?
Biotic and Abiotic
What are abiotic factors?
Non living factors
What are some examples of abiotic factors?
Temperature, pH, moisture and light intensity
What are biotic factors?
Factors that are directly related to living organisms
What are some examples of biotic factors?
Competition, disease, food availability, predators and grazing
How does predation affect biodiversity?
How does competition affect biodiversity?
How does disease affect biodiversity?
How does food availability affect biodiversity?
How can soil pH be measured?
Insert the probe of a pH meter into the soil and take reading
How can light intensity be measured?
Direct the solar panel of a light meter towards the light source being measured and take a reading
How can temperature be measured?
Insert a thermometer into the soil and take reading
How can moisture level be measured?
Insert the probe of a moisture meter into the soil and take reading
What may a source or error be when using a pH meter?
Reading may be contaminated from a previous measurement
How can you minimise the room for error when using a pH meter?
Wipe the probe clean between each use
What may a source or error be when using a light meter?
Sensor blocked
How can you minimise the room for error when using a light meter?
Stand to the side of the meter when taking a reading
What may a source or error be when using a moisture meter?
Reading may be contaminated from a previous measurement
How can you minimise the room for error when using a moisture meter?
Wipe probe clean and dry between each use
What may a source or error be when using a thermometer?
Reading may be inaccurate
How can you minimise the room for error when using a thermometer?
-Leave for a time to adjust before reading
-Insert probe to same depth each time
What is a pitfall trap?
A pitfall trap is used to measure small invertebrates that live on the ground
It’s a pot with small holes in the bottom and is placed in the ground with the top flush to ground level. It is covered and collected regularly.
What may a source or error be when using a pitfall trap?
-Trap not level with soil : organisms don’t fall in
-Trap left to long or not checked regularly : organisms eat each other
-Not camouflaged : predation occurs e.g. birds eating the contents of the trap
-No drainage holes : trap floods and organisms lost
How can you minimise the room for error when using a pitfall trap?
-Check traps regularly and record
What is a quadrat?
A quadrat is used to sample plants and animals that don’t move. It is a metal/plastic square of varying different sizes
What may a source or error be when using a quadrat?
-Non random sampling
-Sample size to small
How can you minimise the room for error when using a quadrat?
-Throw the quadrat at random
-Throw many quadrats
-Use a transect line
What is a transect line?
A transect is a line across or part of a habitat. It can be as simple as a string or rope placed in a line on the ground
It allows that number of organisms of each species to be observed and recorded at regular intervals along the transect
What effects can biotic and abiotic factors have on biodiversity and the distribution of organisms?
Both biotic and abiotic factors can increase or decrease biodiversity in an area and affect the distribution of organisms
What is an indicator species?
An indicator species by their presence or absence with give an indication of the quality/ levels of pollution in the area
