As we approach fall, one of the most prominent and widely noticed phenological events is the changing color of leaves. iNaturalist's new leaf phenology annotation capabilities will help us more easily study the timing of autumn color changes.
To test these capabilities I spent some time this week annotating Eastern Cottonwood observations from Indiana to leverage the new leaf annotation options to gather data on when Eastern Cottonwood leaves change color and how this process unfolds throughout the season.
I started with an examination of iNaturalist observations of Eastern Cottonwood (Populus deltoides) made in Indiana during August (any year): Eastern Cottonwood Observations in August. At the time of writing, there are 142 observations. The number you see when you click the link will likely be higher.
I visually inspected observations, one by one, adding annotations for green leaves and colored leaves, aiming to tag all those with colored leaves. Currently, 56 of these observations from Indiana now include some form of leaf phenology annotation, which could indicate colored leaves, green leaves, breaking leaf buds, or no live leaves. You can view them here: Leaf Phenology Annotations. Of these, 37 observations are annotated for colored leaves.
If you’re curious about autumn leaf color in Eastern Cottonwood trees in Indiana, the Colored Leaves Annotationed iNaturalist observations provide a good overview of how the color changes—from green to yellow or brown—starting in July, peaking in September, and continuing through October.
This is a time-consuming process and we are just getting started. By using these new annotation capabilities, we’re gaining a better understanding of the phenological patterns in our local trees, which will ultimately help us make better predictions and enjoy the beauty of fall foliage at its peak.
Learn to add phenology annotations to iNaturalist observations. We’re offering two sessions this fall:
September 18, 2024, 10:00 AM – 11:30 AM: Register Here
October 29, 2024, 6:30 PM – 8:00 PM: Register Here
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