Scientific

Shrub Volume 3

This is a follow-up to Shrub Volume 2.

Dr. Granger is interested in studying the factors controlling the size and carbon storage of shrubs. This research is part of a larger area of research trying to understand carbon storage by plants. She has conducted a small preliminary experiment looking at the effect of three different treatments on shrub volume at four different locations. She has placed two data files on the web for you to download:

• shrub dimensions data
• experiments data

Download these into your data folder and get familiar with the data by importing the shrub dimensions data using read.csv() and then:

1. Check the column names in the data using the function names().
2. Use str() to show the structure of the data frame and its individual columns.

3. Print out the first few rows of the data using the function head().

   Use dplyr to complete the remaining tasks.

4. Select the data from the length column and print it out.
5. Select the data from the site and experiment columns and print it out.
6. Filter the data for all of the plants with heights greater than 5 and print out the result.

7. This code calculates the average height of a plant at each site:

   by_site <- group_by(shrub_dims, site)
   avg_height <- summarize(by_site, avg_height = mean(height))
   

   Modify the code to calculate and print the average height of a plant in each experiment.

8. Use max() to determine the maximum height of a plant at each site.
9. Create a new data frame called shrub_data_w_vols that includes all of the original data and a new column containing the volumes, and display it.
10. Import the experiments data and then use inner_join to combine it with the shrub dimensions data to automatically add a manipulation column to the shrub data.

[click here for output]