| plotcode | Croptype | AraInd | AraSpec | CaraInd | CaraSpec | IsoMyrInd | IsoMyrSpec |
|---|---|---|---|---|---|---|---|
| 1 | WW | 111 | 17 | 191 | 15 | 6 | 2 |
| 4 | SM | 102 | 20 | 149 | 14 | 52 | 2 |
| 5 | WW | 154 | 19 | 96 | 11 | 16 | 4 |
| 10 | SM | 13 | 8 | 80 | 12 | 10 | 1 |
| 12 | ZR | 125 | 14 | 108 | 18 | 14 | 4 |
| 13 | WW | 107 | 15 | 178 | 18 | 23 | 3 |
| 16 | WW | 81 | 19 | 97 | 12 | 23 | 3 |
| 20 | WR | 132 | 20 | 327 | 12 | 8 | 3 |
| 24 | KE | 66 | 12 | 141 | 13 | 9 | 2 |
| 26 | WW | 100 | 17 | 136 | 17 | 4 | 2 |
Ex06: Crop vs. Species
Many studies in landscape ecology deal with species data. Usually, these studies follow a plot based design to compare different environments and ecosystems in terms of abundances or species diversity. To practice everything we’ve learned so far we want to have a look at another real world dataset. The species data below was collected by Michael Meyer. To find out more about the original goal of why this data was collected you can have a look at Meyer et al. (2019). While the statistical analysis of this paper is more advanced and not suited for this beginner course, the structure of the data is very easy and also allows the practice of more simple methods.
The column names and crop types appear very cryptic at first sight. Here are some explanations:
GP = Grain Pea
SB = Sugar Beet
SM = Silage Maize
WR = Winter oilseed Rape
WW = Winter Wheat
Ara = Araneae
Cara = Carabidae
IsoMyr = Isopoda and Myriapoda
Ind = Number of individual animals
Spec = Number of species
Tasks
- How many different crop types where analysed in the study?
- How many plots are there for each crop type?
- Which plot had the most individual animals? (regardless of species)
- Which plot had the most species?
- What is the average number of Carabidaes on all the plots containing winter wheat?
- What is the average number of individuals and species per crop type? (Hint:
dplyr::group_by,dplyr::summarise)
- Visualize the number of Carabidaes per crop type.
- Compare the number of species of Araneae, Carabidae and IsopodaMyriapoda with a boxplot. (Hint:
tidyr::pivot_longer)
- Plot the number of Araneae species in relation to the number of individual Araneae.
- If there are more individual Araneae on a plot, are there also more Araneae species? (Hint:
lm)
References
Meyer, Michael, David Ott, Philipp Götze, Heinz-Josef Koch, and Christoph Scherber. 2019. “Crop Identity and Memory Effects on Aboveground Arthropods in a Long-Term Crop Rotation Experiment.” Ecology and Evolution 9 (12): 7307–23. https://doi.org/10.1002/ece3.5302.