Embedded Files
Outcomes:
Practice simple sampling techniques
Produce an explanation of how and why a practical ecology technique is used.
INTRODUCTION TO SAMPLING
Ecology is often referred to as the "study of distribution and abundance". This being true, we would often like to know how many of a certain organism are in a certain place, or at a certain time. Information on the abundance of an organism, or group of organisms is fundamental to most questions in ecology. However, we can rarely do a complete census of the organisms in the area of interest because of limitations to time or research funds. Therefore, we usually have to estimate the abundance of organisms by sampling them, or counting a subset of the population of interest.
For example, suppose you wanted to know how many ants there were in the park. It would take a lifetime to count them all, but you could estimate their abundance by counting all the ants in carefully chosen smaller areas throughout the park.
Sampling to collect data about a type of ecosystem
The main technique used when sampling is to use a quadrat to find out the percentage cover of plant species.
Quadrats are normally used to sample along a belt transect or an interrupt belt transect.
Data about abiotic factors can be collected using data logging equipment.
The information gathered can be organised by producing kite diagrams and by calculating the Simpson's Index of Diversity.
Lesson #1
Activity:
Your teacher will explain how a belt transect and a quadrat can be used to collect information about the populations of plants that can be found in a habitat. You will have to listen closely and take notes on how to carry out these techniques to collect data. Your teacher will then explain how data can be interpreted to produce a kite diagram, (A form of data visualisation) that can help you to analyse the data to draw conclusions. Again you will have to take your own notes. After taking notes, you will have time to confer with a partner before trying these techniques yourself to collect and analyse data.
Research: BBC Bitesize Biology has some useful introductions to help you if you completely stuck.
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Lesson #2
Activity:
Use the example in the presentation to calculate the Simpson's Index of Diversity for the 3 locations on the Google Doc Simpson's Index of Diversity - Calculations.
Calculate the Simpson's Index of Diversity for the two belt transects you recorded data for in the previous lesson.
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Lesson #3
Activity:
Use the flower and plant print outs to fill your quadrat with data to be collected. When you have decided how many of each flower type to use, take your quadrat into the corridor and set it out in a belt transect with the other groups in the class (each one should be 1 m apart).
When they are all ready you should collect data for each one so you can produce kite diagrams and Simpson's Index of Diversity data.
It is up to you to decide if you think you could collect the data as percentage cover or total numbers, but remember your teacher is there to answer any questions you may have!
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Lesson #4
Activity:
With the data collected we will look at how it can be used to address assessment criteria C.
When we have finished you can start to interpret the data you collected last lesson.
You may want to explore using spreadsheets to help you manipulate data.
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