| Plot | Nutrients added | # of species |
| 1 | 0 | 36 |
| 2 | 0 | 36 |
| 3 | 0 | 32 |
| 4 | 1 | 34 |
| 5 | 2 | 33 |
| 6 | 3 | 30 |
| 7 | 1 | 20 |
| 8 | 3 | 23 |
| 9 | 4 | 21 |
| 10 | 4 | 16 |
What effect do nutrient additions have on plant speciesdiversity? Long-term experiments at the Rothamstead ExperimentalStation in the U.K. sought to investigate the relationship, withsome interesting findings.
The data can be found in the linked Google Sheetsdocument  - you'll want to copy it to Excel and use theData Analysis ToolPak.
1) Produce a scatter plot of the data (click here for a genericyoutube video on creating a scatter plot from excel data - this isfor informational purposes only - it's not your data)
- Which is the explanatory variable? (nutrients OR species)
- Which is the response variable? (nutrients OR species)
- Looking at your scatter plot, do you observe a positive ornegative relationship? Â
2) Add the least-squares regression line to your scatter plot.(click here for a generic youtube video on adding trendlines toscatter plots - this is for informational purposes only - it's notyour data)
- What fraction of the variation in the number of plant speciesis "explained" by the number of nutrients added? Answer to twodecimal places.
3) Test the hypothesis of no treatment effect on the number ofplant species.
- What is your t-value? Â
- Do you accept or reject the null hypothesis?
