Happy Spring!
I have been pleasantly surprised by the amazing weather these past few weeks, especially with all of the phenology assignments we have as the semester winds down! Luckily for me, this nice weather fell on my Phenology Walk day, which was on April 23rd.
When I went on my phenology walk, I started near the Waterman Green and worked my way towards Athletic campus, which meant that I first observed the Norway Maple. The Norway Maple did have buds breaking on many of the branches that I could see, though it was hard to exactly estimate the extent. There were also flower buds on a few of the branches as well, but there were far fewer of these than there were leaf buds.
The next tree I observed was the Red Maple tree. When I was observing the tree, there were lots of open flowers on almost the entire tree, though I couldn’t really tell how many of the leaf buds had broken, if any had broken at all. I did try shaking a few of the lower branches to check to see if the flowers would clearly release any pollen, but as far as I could tell they didn’t.
The next tree I observed was the White Oak tree right next to Aiken! This tree differed from the other trees, as it didn’t have any visible leaf or flower buds that were breaking, though it did have a few leaves left over from the past fall that were orange-brownish in color. They did however have some acorns (fruit!) on the branches though which was interesting!
The second to last tree I observed was the Sugar Maple tree. This tree was in a similar phenological phase as the Red Maple and Norway Maple trees, with lots of buds breaking and open flowers, but no visible pollen being released from the flowers when I shook the branches lightly nor any fruit present. This tree’s similarities with the other maple species made me wonder if maple trees in general experience these phenological phases of leaves and flowers budding at an earlier time than the oak trees!
I tested my thought when I went to visit the final tree, which was the Red Oak tree. However, this tree had breaking buds, unlike the White Oak tree, as well as lots of fruit in the form of acorns on its branches. Many of these acorns had even dropped from the branches, leaving just the caps of the acorns on the branches, which was interesting too!
With all my observations done, I concluded that my assumption that maple species experience these phenological phases around the same time was probably correct, as I feel like it would just make sense that a general species, even if there are more distinct subspecies or forms of that species in general, would all experience similar phenological trends. When I thought more closely about the oaks however, I wondered what could possibly make the White Oak lag behind the Red Oak when it came to its phenological phases. My first thought was that possibly the locations they were planted in could have impacted these phases and their timing, as the Red Oak was in a sunnier, more open spot that maybe would allow that tree to experience phenological cues like sun exposure or temperatures differently than the White Oak would experience them, as it was located right next to the Aiken building in a spot that would be shady during certain parts of the day due to the building blocking the sun.
After going on my phenology walk and enjoying the nice weather, I started the second part of this phenology assignment and explored the National Phenology Network’s website, specifically some of their publications regarding phenology and the shifts in the phenological phases different species experience. I found two articles that went well together in an interesting way, which were the ones titled, “It’s not just climate warming – artificial light is shifting phenology” and “Light pollution may help some birds catch up to climate shifts.” At first glance, these articles caught my eye because of the clear opposition they pose to one another; that while light pollution harms the phenology of some species, from the title seemingly in a bad way, that these shifts in phenological phases actually benefit other species, including many species of birds. This made me want to dig deeper into these publications.
I started by reading the first article, “It’s not just climate warming – artificial light is shifting phenology.” It introduced this idea that while a shifting climate does pose, most likely, the largest impact on phenology, that things like light pollution are also large issues as well. It explained how the presence of artificial light actually advances breaking leaf buds and delays leaf color change to a noticeable amount — the authors found that trees broke their buds 9 days earlier with artificial light compared to sites under similar temperature conditions without artificial light, and that leaves turned color 6 days later in sites with artificial light as well. The article points out that this study is special because there have been very few studies looking at the impacts of artificial light at night, that it helps to show that light pollution is an important urgent issue in urban ecosystems, and that there needs to be further guidance on how to design and regulate artificial light to protect the environment.
I then shifted to the next article, “Light pollution may help some birds catch up to climate shifts.” This publication pointed out how in a study done to understand how human caused light and noise pollution might pose additional challenges to birds impacted by climate change that actually light pollution caused many birds to nest earlier in various environments, which then allowed them to catch up to the earlier spring onset and availability of food, which resulted in better nesting success.
I found it really interesting when comparing these two publications how one study highlighted a unique occurrence of human activity actually benefitting certain species when it came to their survival in context of a larger climate issue, while in other cases this same human activity had negative impacts as well. It made me wonder what this meant for how we possibly could approach solutions to the negative impacts of climate on phenology and the timing of certain phenological phases; for example, with our current warming climate, could we use artificial light in a way that would help these birds better adapt and survive the warming climate and earlier spring onsets without having the negative impacts on plant species and their phenological cues?
I think this question is a really interesting one, and really made me think more deeply about how complex phenology really is. It was so interesting that different species could react to similar phenological cues in such different ways, and it made me wonder what it meant about the future of our ecosystems with a warming climate, and the different impacts it will have on different species!
Here are the links to the publications I found as well, just in case you want to take a peak at them more closely!
“It’s not just climate warming – artificial light is shifting phenology”
“Light pollution may help some birds catch up to climate shifts”