More than a decade has passed since Inouye’s 2000 paper was published, but the data set is now longer. billy barr continues to collect daily weather data and still records the first spring sightings of many migrating birds, hibernating mammals, and spring flowers. His ongoing data collection allows us to ask new questions.
Is the growing season at RMBL lengthening over the past decade? Has the timing of first sightings of migrating birds or hibernating mammals changed since Inouye’s research was published?
Part I: First, reproduce three plots (figures 1, 3, and 4) from the Inouye et al., 2000 paper using billy barr’s updated data (through 2010). Generate a new regression line and equation and calculate the mean, minimum, and maximum for each data set.
To download billy barr’s updated data set, click here. To visualize billy barr’s data, check out the data visualizer.
You may need a Julian day calendar. To learn what billy barr means by “first sighting”; or how he collects his weather observations, check his metadata.
Part II: Describe how the plots you made in Part I differ from the original plots (in Inouye et al, 2000). In your opinion, do the original plots support the original interpretations? Describe your reasoning. Do the updated plots suggest new interpretations? How have abiotic conditions changed over the extended period of record? How do phenological phenomena change with the extended record? What are your predictions for future change? Record any unanswered questions you may have.
Part III: With your understanding of phenology and a few important RMBL datasets, here’s your chance to ask and answer your own questions. Frame a question that you think you can answer using the data visualizer. Generate one or more graphs and perhaps some statistics to test your hypothesis and support your interpretations. Each group will report out to the class.
In your report, be sure to include your question (reframed as a testable statement or hypothesis), your results and how you obtained them (methods), and your interpretation of the data.
- billy barr’s dataset contains nearly 40 years of data. Is this a long-term data set? What constitutes a long-term data set? Why might long-term data set be difficult to come by?
- What is phenology?
- What is the difference between correlation and causation?
- What is the difference between descriptive statistics and statistics that test for significant differences?
- What is an r-squared value? Why do we calculate it?