Distribution of Organisms
This section perfectly leads on from the previous, as we will now talk about the ways that we measure factors that influence life on Earth.
Continue to imagine the calming voice of David Attenborough enthusiastically amazing you with the wonders of life.
Measuring Abiotic Factors
Abiotic factors, as discussed under “Ecosystems,” are the non-biological conditions that organisms need to survive. These include temperature, soil pH, soil moisture and light intensity.
Temperature can be measured using a thermometer. In soil, temperature can be measured using a thermometer probe.
Light intensity can be measured using light meters, by popping the light meter on the soil and pointing it towards the point with highest light intensity.
Soil moisture can be measured using a soil moisture meter, which is a probe that you just put into the soil and it tells you the moisture levels.
Soil pH meters are used to measure soil pH, which are also probes that can be placed into the soil which then tell you the pH.
Remember, errors can occur when taking these measurements, so take multiple readings when collecting results.
Measuring Biotic Factors
Biotic factors are the interactions that organisms have with other living organisms.
These include disease, competition, for availability and predation.
Plants and animals can be sampled so that we can measure the number of organisms in a habitat, and measure their interactions with one-another.
Sampling techniques for plants include quadrats, which can be placed in a random location so that a representative sample can be taken. Many quadrats can be placed to collect multiple representative samples to increase reliability of the data collected. Small, slow moving animals like slugs can also be recorded using quadrats.
Pitfall traps can be used to sample small animals, like ants and other bugs. You simple create a pit where small organisms can fall into and you place a lid over to stop them getting out. You can then check the pitfall trap and sample the number and species of organism(s) within the trap.
When recording data, paired-statement keys can be used to identify organisms.
Indicator Species
Biotic and abiotic factors can heavily influence the biodiversity within an ecosystem.
Indicator species are a species of organism that, by their presence or absence within an ecosystem, can tell us about the environmental quality of the habitat as well as the levels of pollution.
For example, Tubifex worms within water can indicate how clean the water is. So if these worms are present within water, they indicate that it is not clean.
Another example is Lichen on trees indicating air pollution.
Key Points!
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Abiotic Factors
Temperature can be measured using a thermometer. In soil, temperature can be measured using a thermometer probe.
Light intensity can be measured using light meters, by popping the light meter on the soil and pointing it towards the point with highest light intensity.
Soil moisture can be measured using a soil moisture meter, which is a probe that you just put into the soil and it tells you the moisture levels.
Soil pH meters are used to measure soil pH, which are also probes that can be placed into the soil which then tell you the pH.
Remember, errors can occur when taking these measurements, so take multiple readings when collecting results.
-
Measuring Biotic Factors
Sampling techniques for plants include quadrats, which can be placed in a random location so that a representative sample can be taken. Many quadrats can be placed to collect multiple representative samples to increase reliability of the data collected. Small, slow moving animals like slugs can also be recorded using quadrats.
Pitfall traps can be used to sample small animals, like ants and other bugs. You simple create a pit where small organisms can fall into and you place a lid over to stop them getting out. You can then check the pitfall trap and sample the number and species of organism(s) within the trap.
When recording data, paired-statement keys can be used to identify organisms.
-
Indicator Species
Biotic and abiotic factors can heavily influence the biodiversity within an ecosystem.
Indicator species are a species of organism that, by their presence or absence within an ecosystem, can tell us about the environmental quality of the habitat as well as the levels of pollution.