On March 31, 2025, I set out for my phenology walk around campus! The goal was simple: observe the phenophases of five different trees.
In all five trees, I noticed there were not many phenological changes underway. Spring is still so young, so I can’t say I was that surprised. Vermonters have been falling for Fools’ Spring, but the trees don’t seem to be buying it. In the five trees, nearly all the buds were still tightly closed and no flower growth was underway.
Norway Maple 3261 and Sugar Maple 618 have both started growing what I believe are leaf stems. I was not 100% sure on this, but it was my most educated guess. They were thin string-like parts growing out of the trees branch with a little ball on the end of each one. There was no leaf on these stems yet, but I assume they will make their way out shortly!
On Red Oak 615, there were a plethora of acorn caps holding onto the tree still. Knowing that the nut grows and then the cap, I assume these left over cupules (acorn caps) were from the fall. Furthermore, acorn nuts typically start to develop in the late summer or early fall, so it wouldn’t make sense for these to be new developments on the trees. Both on this tree and Sugar Maple 618, there are dried leaves that still hanging on! The sugar maple especially demonstrated this trend. I wonder if this has anything to do with marcescence–something that is seen a lot on American Beech trees. This trend is still undergoing research, so why it occurs remains unclear. Scientists theorize if trees keep their leaves to protect buds, collect moisture, protect their buds and branches from predators, or recycle nutrients.
While looking at White Oak 761, I was surprised to see something I had not before. It was a small ball attached to the branch that, at first, I thought was a fruit or nut. However, with the use of iNatrualist, I discovered it was a wasp gall. A gall is made of plant material and holds wasps’ eggs and larvae. I was worried this would be harmful for the tree, but after some googling, I discovered it posed no significant threat for the oak. Once the insects emerge, the gall dries up and falls right off. How fascinating!
Red Maple 280 had a feature that I hadn’t seen on the other four trees–flower buds! There were so many of them, but none had started to develop. They were small, red, and tightly closed. It will be exciting to see how they open and grow as the temperatures warm and spring goes fully underway.
When exploring NPN’s website, I came across an article titled “Are Plant and Animal Species Responding Differently to Climate Change?” Even though it makes me anxious, I think there is so much value in understanding how climate change is affecting our planet. The article shared that researchers have been observing and using previous data to compare phenological changes in over 2,000 species in the past years. They found that in plants, some spring and summer phenological events are occurring earlier than they did 40 years ago. Flowers and fruits are ripening much quicker, but leaf fall is seeing little change. On the other hand, animals are feeling climate change’s effect at a much weaker degree. These differences in responses create a mismatch between plant and animal species, reducing the likelihood of key processes that keep ecosystems functioning, such as pollinating.
These effects may soon be seen in the trees around campus. It will be interesting to see if the flowers develop sooner than in past years and if there is a rift between the animals, insects, and plants. Projects like these are valuable for many researchers as they use observations from the community on platforms like Nature’s Notebook. I am so happy I could add to this expansive database and enjoyed the taste of field data collection!