biological project，due within 6 hours

Dealing with the forest field study data
 Finding the data for your focal species

1. Go on Canvas, Lab 10 folder, and download the spreadsheet with the data for your field study time period (e.g. if you are in a B section, you will download the spreadsheet

Forest data - B sections - Monday 2pm).

2. The data for your focal species (in this example, R. ursinus) are in one of the columns with the yellow label. E.g., R. ursinus (let’s assume that this is your group’s focal species) is in column C. Data on abundance in the deciduous forest is in rows 11 - 71.

BIOL140 2019 - LABS 10+11 �1

If you scroll down, you’ll find data for the coniferous forest (here, rows 76 - 136).

Preparing the graphs for the presentation (with appropriately sized labels)

3. You will need to first get Excel to calculate the mean abundance for your focal species (and it’s a good idea to also get the standard deviation) for the 60 quadrats sampled. To do so, below quadrat #60 add a row for the mean and one for the SD. In the appropriate cells (in your focal species column) have Excel calculate the mean and the SD.

4. Do the same for the coniferous forest data (your mean and SD will be just below the data in the last quadrat).

5. Find a clear space on the spreadsheet and set up a little ‘table’, similar to the one shown in the figure below, where you’ll record the mean abundance for each of the two sites and where you’ll have Excel calculate the standard deviation

BIOL140 2019- LABS 10+11 �2

6. To make your graph, proceed as you did for your Lab experiment results, but this time we will use a ‘bar graph’ (known in Excel as ‘Column’ ‘Clustered column’. The error bars should be the standard deviation. A few things to remember (that many groups missed in their oral presentation:

❖ no title for the graphs (Excel will likely include a ‘Chart Title’; remove it) ❖ no ‘Excel legend’ (this is different from a figure legend…check the Conventions) ❖ yes proper axes labels! (If you have selected a graph style that does not give you

labels, you can add them in when you copy-paste your graph into your presentation ❖ A figure legend is optional.

BIOL140 2019 - LABS 10+11 �3

7. To format your graph such that it is suitable for the presentation, copy and paste it into PowerPoint, ‘stretch it’ (to make it as large as possible), and don’t forget to make the font size larger too! (It does not automatically get bigger as you ‘stretch’ the graph).

8. To change the font size you need to work in PowerPoint and: ❖ click on an axis label ❖ go to font>size and change the size to what you want it to be (recommended is 24, if

this looks really to big go with 20 — smaller fonts are very difficult to see from the back of the room with the lighting available in the labs!)

❖ repeat with each axis label and with each axis. It is also suggested that you change the colour of the bar graph to something very

visible that however does not mask the error bars (e.g. dark grey, etc.). Note that the example below is a work in progress.

BIOL140 2019- LABS 10+11 �4

Performing the t-test and reporting t- and p-values

1. Go to: http://www.physics.csbsju.edu/stats/t-test.html and click on Click here to perform Student's t-test via copy and paste.

2. From the Excel spreadsheet, copy the deciduous forest data for your focal species (in this example, cells C11 to C71) into the ‘Data for Group A’ box, and the coniferous forest data (in this example, cells C76 to C136) into the ‘Data for Group B’ box.

3. Click on the Calculate now button. The program should return a page similar to the image below.

4. Identify the t-value and the p-value for your statistical test and report them on the slide where you have your graph with the means and 95% CI.

Alternatively, you can use the t-test tool on GraphPad, as for your lab experiment.

BIOL140 2019 - LABS 10+11 �5

This is the p-value!

p<0.0001t-value =8.22