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2.5 Ecology - Coggle Diagram
2.5 Ecology
Allows us to understand the connection between plants + animals and their environment. Understand more about the ecosystem and predict human impact.
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Sampling
Random sampling = Select a co-ordinate randomly, go to the co-ordinate and analyse the species in the quadrant
- Least biased, involves no subjectivity = equal chance for each part of the field to be selected
- Quick + repeats
- Large areas may be missed if co-ordinates are not drawn
Systematic sampling = Sample chosen in a regular way = Every meter along a transect line. Lay down a transect line and note down the type of plant that touches the line at each meter mark.
- Easier as no need for a grid (distributing the field eg area A,B)
- Covers the entire area
- Patterns may be missed
Stratified sampling = used when the population contains subsets. Have to know the size of the subsets so that your sample reflects the same proportions eg 30% of population are 21 years and younger. Can be RANDOM or STRATIFIED sampling eg every 5th individual
- Representative of the population if proportions of the whole population are known.
- Flexible with different samples, good for comparing subsets
- HAVE to know the size of the subset
Larger samples are likely to be more representative of the whole population. However too large and there is no longer an advantage to sampling. REPEATS NEEDED
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Identify the organism with a dichotomous key, museum specimen, DNA profiling
Transect
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Continuous = entire transect samples. Interupted = every 0.5 meters or so. Sampling = recording all species the transect touches