Phenology Research Projects in Maine

Researcher Caitlin McDonoughCaitlin McDonough is a PhD candidate in the Biology Department at Boston University.  Her current projects include research on changes in species abundance and phenology at Acadia National Park and at the Quackenbush homestead in Oxbow, ME. In this interview, she shares findings from research in Acadia and her passion for phenology.

How did your science training lead you to study phenology at these particular Maine sites?

I did my masters at the University of Vermont and worked in the White Mountain National Forest on the Appalachian Mountain Club’s Mountain Watch citizen science program.  I came into my PhD with this background in citizen science and monitoring phenology.  One of the things that always struck me about working in the White Mountains was that it was always someone’s vacation when they went there to collect data, so we didn’t have a lot of repeat volunteers. Acadia really excited me because it was the same person who has this really committed sense of place.  In Acadia, the historical data from the 1880s and 1890s is all from Edward Rand, who came here when he was in college and spent the next 14 summers returning to the island to study flowers.  Acadia seems to be the kind of place that just draws people in and they can’t really leave.  People who summer or live here hike the same trails and the same carriage roads repeatedly.  I really appreciate that about work here and it makes it more of a community type of research in some ways.  It’s been so cool to take that citizen science background and bring it to a place where there is already a community in place.

What have you found through your research that is significant for Maine?

My lab has done a lot of work in Concord, MA [using historical data from Thoreau] and we’re hoping to do a big comparison between Acadia and Concord because there are over 300 plant species that occur in both locations.  I know how things have changed in abundance in Maine and my lab has studied changes in abundance in Concord.  I hypothesized that, if you have the same species in both locations, they’re going to be changing in the same direction. So, for example, a species that’s becoming more rare in Concord is likely also becoming more rare in Acadia.  I did a preliminary analysis and that turns out not to be true.  There’s a big mix where many species are changing in opposite directions.

Were the results for any particular species or habitat unexpected?

We broke all of the species into coarse habitat categories, like fields, grasslands, forests or wetlands.  I definitely expected that we would find one habitat that lost the most species.  I thought it would be grasslands because a lot of the open field habitats from 1894 are now more forested or wetlands because there are a lot of wetland species that are sensitive to changes in hydrology.  However, it was very interesting when we looked at the broad picture and we didn’t find any difference between wetland species and forest species.

How do you distinguish between species loss due to climate change as opposed to habitat loss?

It’s difficult to say that climate change is directly contributing to any one species that’s lost, but we can start ruling out different things.  My lab found very similar rates of species loss in Concord, but they had to chalk at least some of that up to development pressure.  In Acadia National Park, I could automatically get rid of development pressure as one of the drivers of species loss.  I thought that looking at a broad habitat category would help us to figure out if there are certain habitats that seemed to be more sensitive to species loss over the past hundred years.  We wanted to see if there was any pattern specifically because, as a National Park, no one is mowing fields or maintaining open grasslands.  We thought there would be a loss of grassland and field species and maybe not as many lost from forests, as those former grasslands are now reforested. But, when we did the analysis, we found that there was no significant relationship among wildflower species between habitat category and species loss.  All habitats seem to be losing species at a very similar rate. That has allowed us to take this broad view and say it’s not habitat that seems to be driving this species loss.  It seems to be something bigger than habitat.  It’s affecting all the habitats at once, so perhaps climate change is an indirect driver of this species loss.

Do you have plans to continue monitoring these sites?

I probably only have two more field sessions left.  That will be great for me because I’ll have four years of data for my dissertation, but four years is definitely not enough if we want to look at long term changes.  Acadia is interested in getting visitors to make observations and in looking long term at phenology as a way to track climate change.  I followed existing trails on Cadillac, Sargent, and Pemetic Mountains which makes it easy for this work to be adapted into a volunteer project once I graduate.  It’s very much a work in progress, but I’m hopeful that these transects will end up being something that volunteers can do for years and years into the future.

Is there a particular aspect of your research that you enjoy the most?

I like being outside and I love when I get to hike the same transect over and over again.  Every time I’m hiking, it’s almost like seeing a whole new mountain because I notice flowers that weren’t there the week before or leaves that just came out.  I’ve come to know the trail really well so that I notice things like that.  Even though I’m doing the same trail about 15 times every spring, it’s like doing 15 different hikes.  It’s a nice feeling to have a deep sense of place about the place where I’m doing my research because I feel connected to it on a deeper level than just doing the science.

How did you become involved in analyzing the Quackenbush journals?

It’s a really interesting story. After Quackenbush died, his family understood the value of his journals and donated the journals to Acadia National Park.  The Park contacted College of the Atlantic (COA) and handed them off to a professor.  He had them stored in the attic of Turrets at COA, which is this big, old mansion that was transformed into office and classroom space.  About three years ago, while Turrets was under reconstruction, the attic was emptied and they found the boxes full of the Quackenbush journals.  COA handed them back to Acadia.  This was my second year working in the park and I was there when these huge boxes of paper that had been unbound from journals arrived at the park service.  It was really cool just to see the sheer volume of stuff that Quackenbush had written.  That summer a Masters student from the University of Maine was working as an intern and he scanned the entire set of journals into PDF format.  My advisor heard about them from the park service and thought we should look into them.  I didn’t think anyone from the park service was actively analyzing the data, so they gave the journals to us at Boston University; and I started going through them.

The amazing thing about the journals is that at the end of his life, Quackenbush sat down and indexed the dates by year and by species for the first appearance of flower and bird species and for leaf out of the tree species.  This must have taken him so much time, but it made it really easy for me to do the analysis.  I had beautiful indices of the things that he had pulled out that were most important.

How have you used these journals in your current research?

I was able to pull out his dates for 15 flowering species over 12 years and 10 species that leaf-out over 16 years in the 1940s and 50s.  This isn’t a very long time period, so you couldn’t see trends of what was happening over time and we couldn’t really compare it to today, because we only have a year or two of current data.  What we could do is look at the temperature for each of those springs and see if there was a correlation between spring temperatures and the dates of leaf-out or the dates of flowering.  Using weather records from a local NOAA dataset, I determined mean April temperatures for each of the years that we had flowering or leaf-out data.  In years where there was a warm April, plants would leaf-out and flower earlier and, for cooler years, they would leaf-out and flower later.  There was a strong correlation between temperature and flowering or leaf-out.  We also did this for each individual species and found that individually most of the species have a relationship between temperature and their leaf out date or their flowering date.  Knowing that, we can predict based on our current weather what kinds of shifts in flowering and in leaf out that we would expect today.  For the most part, the observations we have from last year actually fell within those estimations made on the correlation from the 40s and 50s.  There’s a clear trend between temperature and phenology and that makes it easy for us to use them as indicators of climate change.

Did you find that there were species missing when you visited Oxbow, ME?

When we realized how rich this dataset was, we contacted some professors at the University of Maine Presque Isle. We flew up there to see them and to try and track down Quackenbush’s house.  We actually found his old barn; it’s still standing.  We started a collaboration with UMaine Presque Isle and they are continuing the Quackenbush observations both in Presque Isle on campus and out in Oxbow in the area where Quackenbush used to live.  I believe that our collaborators have been able to find all of those species in Presque Isle.  The species that we used for flowering and leafing-out data are pretty common, such as dandelion or lilac.  Quackenbush himself wasn’t a professional botanist, so he was probably looking for the things that were most common and that were easiest to identify.

Were there any nuances to using data from someone without formal scientific training?

Quackenbush was interested in what was going on around him and he had such an amazing attention to detail that it’s incredible how much he was able to capture in his journals.  Just the whole concept of reading someone’s journal for ecological data, I find that fascinating.  For a while, I didn’t really believe him because he kept talking about the leafing-out of red oak trees, but Oxbow’s pretty far north in Maine.  I didn’t think that there would be red oaks up there.  When we went to see his old place, we found that right behind his house there’s a line of three red oak trees that he would have been able to see from his kitchen window.  They’re the only red oaks in the entire town of Oxbow!

Are there other known data sets in Maine?

I wish that there were Quackenbushes everywhere that a National Park had digitized.  I think there probably are a lot of journals like Quackenbush’s, but they just haven’t made it to the public eye yet.  One of the things I’ve been doing in Acadia is trying to get people, especially local people or people who’ve been summering up here for generations, to go up to their own attics and see if they have something like a Quackenbush journal.  So far, I haven’t found any that are as detailed or as long term as Quackenbush’s.  I think they’re out there.  It’s definitely something that people used to pay a lot more attention to.

What would you say to a volunteer about the importance of citizen science?

In general, we wouldn’t be able to do this kind of research, looking at how climate change has affected phenology, without citizen scientists.  All of the baseline data that we use is from citizens, like Thoreau or Quackenbush.  In order to make comparisons today, we need to draw on the expertise of people who were not professional botanists and weren’t professional scientists.  They’re providing the foundation for this kind of research.  Even more than that, there’s only so much that a researcher can do.  I can go to my transect once or twice a week, but having a whole network of citizen scientists, like the Signs of the Seasons Program, to be the eyes and ears of spring phenology makes the data much more robust.  It enhances the dataset by capturing changes as they’re happening.