Phenology Report at the Flat Iron Lake Preserve
Dorthea Leisman and Professor Dave Warners
Introduction
This past summer, I worked with Professor Dave Warners on a long-term phenology
project at Calvin College’s Flat Iron Lake Preserve in Greenville, Michigan. The phenology
project is studying how the natural cycles of the local wildflowers are being affected throughout
a series of summers by various weather patterns and more broadly over time by climate change.
Monitoring the opening and closing of blooms creates data points that when analyzed, will be
helpful in understanding the relative influence of weather and climate change on different
species.
The Flat Iron Lake Preserve was donated to Calvin College by Carol and Fritz Rottman
in a series of smaller parcels over the course of several years. The final parcel was deeded in
2009, thus completing the donation. Broken down into roughly five different habitat areas, the
preserve itself supports high biodiversity. The largest area consists of a restored prairie that hosts
the largest variety of flowering plant species. In addition to the prairie, there is also a sizable
forest, two swamps, and an east lot of successional old field along the lakeshore. This wide range
of habitats is quite opportune to study as provides home to more than one hundred unique
wildflowers.
Research Methods
Over the course of ten weeks, I maintained weekly rounds inspecting each area of the
preserve and documenting changes in the vegetation. On these rounds I would search for any
plants that were in bloom and when found would document the plant’s location, describe its
morphology and important features, and sketch a picture in my notebook. I would also make sure
to photo document each new species I located. All of this helped me later identify the plant and
verify it with the Michigan Flora Project’s database, the University of Michigan’s herbarium and
county records (http://michiganflora.net/). From identification on, the ever-increasing list of
plants were copied into my notebook and then taken on my rounds as a check list to monitor
when the plants faded and finally closed. In addition to gathering data for the phenology study, I
also collected seeds from these local genotypes to later be grown in our plant nurseries at Calvin,
and pressed close to a hundred plant specimens. The pressed plants can later be sent to Michigan
Flora, be included in the Calvin herbarium, or simply be used for further identification.
Results
The methods for collecting, recording, and analyzing data for the Flat Iron Lake
phenology project have varied widely. Last year Neil Gilbert, my predecessor, began using more
consistent methods after standardizing data from previous years. Using Neil’s data, along with
some condensed data from other years, I created graphs comparing those prior years to the 2013
data. Keeping in mind the changing weather patterns (last year we experienced record high
temperatures and very little rainfall whereas this year it was an unusually cold and late blooming
spring), it was clear that the vast majority of the plants began to flower earlier in 2012 than 2013.
Looking back and charting data from 2010, it was also noticeable that some of the compared
plants, such as Solomon’s Seal, seemed to be more resilient than others and less influenced by
weather fluctuations, while others, such as the White Avens, seemed to fluctuate quite a bit from
year to year. However, whether they fluctuated a lot or not, all of the plants appeared to be
affected to some degree by the changing weather patterns. From this study and others like it in
the future, it will be interesting to see how the changing climate will affect the plants of Flat Iron
Lake Preserve. Will they begin to bloom earlier and earlier such as in 2012? If so will their
ecosystems also adapt with pollinators life cycles shifting earlier as well? These long term
questions cannot yet be answered at this point, but we are beginning to piece together some
initial interpretations. Hopefully in the decades to come though, with continued study, we will be
able to identify more conclusive trends.
Personal Benefits
Having the opportunity to continue the research for this long-term phenology study at
Flat Iron Lake has been such a privilege. Not only have I learned to identify over a hundred new
local species by sight, but I have also had the opportunity to experience field biology research
firsthand, which is what I hope to do eventually with my degree in biology. I was also so blessed
to get to know Carol Rottman this summer and gain from her a deeper appreciation for the
beautiful land she donated for this project. Overall it was a wonderful experience and I am
thankful to have had the opportunity to be part of this project.