Phenology of Oaks: A recap
A huge shout out to our volunteers for quick work on our first NFN Ideas project, which focused on oak phenology. We completed the expedition a week after launching it, with 1944 transcripts of 644 subjects. 53 awesome transcribers took part. A lot of discussion on talk focused on some of the challenges with denoting flowers and fruits — it is harder than it first looks! So folks were interested in whether there was consistency among transcribers, and if the results would be consistent with an expert assessment. We have some initial answers to those questions and more! And a note that ALL of these data – the label data and phenological scoring – were ALL done by Notes from Nature volunteers.
So to get right to it! Transcriber consistency on this expedition was absolutely remarkable. Well above 99%. Yeah. We were surprised, too. There were three cases where we didn’t get consistent results. Just 3! Out of 664 subjects. So apparently there was very strong agreement.
We took a closer look at the three that seemed to prove difficult.
- subject_id: 4308678 –http://www.sernecportal.org/portal/collections/individual/index.php?occid=11108535
- subject_id: 4308659 –http://www.sernecportal.org/portal/collections/individual/index.php?occid=11108069
- subject_id: 4308844 —http://www.sernecportal.org/portal/collections/individual/index.php?occid=11130030
The consensus scoring for those from transcribers were:
- subject_id: 4308678: Flowers: No, Fruits: No
- subject_id: 4308659: Flowers: No, Fruits: Yes
- subject_id: Flowers: Yes, Fruits: No
I then asked NFN’s own Michael Denslow, who is also a darn fine botanist, for his assessment (without reporting anything about transcriber’s scoring), and he was 100% consistent with the three above. He noted for 4308678, “Funky one for sure” and for 4308659, “The terminal buds might be confusing people on these. Based on the collection date (and presence of terminal buds) fruits could be from pervious fall.”
And finally, we wanted to see if we could use these data to look at phenology patterns, so our data scientist Julie Allen did some quick visualizations of the data using the statistical package, R, which has some great plotting functions. You can see our plot above, for two species, Quercus falcata (top) and Quercus marilandica (bottom), two common oaks where we had enough data to examine patterns. The plot shows time on x-axis measured from March through November, and the y-axis is just a yes-no response. For yesses, we show a little emoji, and for no’s you can see those no reports over time for fruits and flowers in different colors. Yup, we decided to go with a tropical flower and fruit motif here, despite oaks definitively not producing pineapples!
The really neat thing is that we do pick up the short, and early flowering period for oaks during Spring, and in Q. falcata, a seemingly quick transition to acorns, and a slower cadence for Q. marilandica (note the longer period between flowering and appearance of acorns). There are still some great questions to examine here — these records were not all from the same year, and maybe some variation we are seeing is due to climate variation year to year. There were a couple “no flower” records during a typical flowering period and these might be either limited information from the sample, or perhaps something about that particular year. We are more than happy to share the raw data from this expedition with anyone who wants a closer look!