Grass sprouts out of the black muck underneath a huge blue sky. The land is flat, very flat, so that your field of vision is filled with blue and green and blue – blue sky, green grass, blue water. The water is salty, the air is a little salty, and every creature that lives here is a bit salty.
This is a salt marsh. A coastal land feature, made of sediment held in place by grass roots, submerged twice daily by the salty ocean tides. Maybe you’ve never heard of this ecosystem or ever seen one, but they have a global distribution (see map). More than 75% of fisheries species (including shrimp and crab) need salt marshes during their life cycle. And just by existing, salt marshes reduce the risk of flooding in coastal cities. (Learn more)
It seems simple when you stand at a distance. But as salt marsh ecologists studying arthropod food webs, we spend much of our time out here looking down and up close. Between the sediment and the grass stalks, we easily find dozens of fiddler crabs (Uca pugnax) darting out of burrows, hundreds of coffee bean snails (Melampus bidentatus) lurking in the mud, and millions of plant hoppers (Prokelesia spp.) bouncing stem to stem. Thousands of species, from microbes to insects to fish to birds, have been identified at our research site, the Great Bay Boulevard Wildlife Management Area in Ocean County, New Jersey.
We study this Great Bay NJ salt marsh because its nearly 6000 acres are in natural, healthy conditions. The Great Bay is considered one of the cleanest and most pristine estuary ecosystems on the east coast of the U.S. (Learn more). Most salt marshes in the highly populated Boston to Washington DC coastal region have been disturbed: fragmented by human development, polluted with agricultural and urban runoff, dredged, or over-exploited for fish. How can we discover which disturbance caused which change in salt marsh function? In the healthy salt marsh, we can experimentally manipulate a disturbance and record the ecological response. If we did this research in a disturbed salt marsh, we wouldn’t be able to tell whether the ecosystem was responding to our experiment or the other factors out of our control.
The salt marsh is the center stage for my PhD research. During the summer, about once a week, we drive from Georgetown University to the salt marsh and conduct our experiments. Some of my labmates are experimenting with the snails to understand grass decomposition and carbon storage. My first research question is about the grass (Spartina alterniflora). Is it mostly clonal colonies, or is it mostly growing from seeds? S. alterniflora grass is thought to be very clonal, asexually spreading through rhizomes. But once a year, the grass flowers and seeds, so some new grass must be coming from seeds. What percent of grass stands are clonal, and are there any spatial patterns to clonality? I’m interested in this because clonal colonies are genetically identical, which may make them more susceptible to disturbances – but that’s a question for another summer.
When we’re not in the salt marsh, we are in the lab looking at arthropods under microscopes, extracting DNA from grass snips for genotyping, feeding snails different types of dried grass, or reading about experiments in other salt marshes or other ecosystems. We’re busy, all for the sake of understanding the complex ecological interactions we see when we look down and up close at the salt marsh.
In future posts, I can go into the many practical applications of our salt marsh research, but for now I’d like to wrap up with a note about basic research. Our home is planet Earth, complex and full of life. I believe we should discover everything we can about the other organisms we share Earth with.
Till next time~
My top priority during my first academic year of my PhD was a project called the “qualifying exam.” This term is misleading, though.
What did I do to prepare for this? I did not study for months in preparation to sit down, pull out my pencil, and take an hours long written test, as the word “exam” implies. Instead, I independently developed a proposal for a research project about a topic distinct from my PhD advisor’s ongoing research. This culminated in a ~10 page research proposal that was reviewed by three Biology professors, and a ~2 hour proposal defense (53 slides!) that I presented to those same professors. After my defense, the three professors decide to “pass” or “fail” me. I passed, hooray!
Many familiar with how graduate school works find that the Georgetown Biology department’s “qualifying exam” is an unusual, surprising process. My qualifying exam is separate and in addition to the more familiar, more standard “comprehensive exam” process. I will have my comprehensive exam during my third year, tentatively December 2019. I believe that Georgetown Biology is fairly unique in its first year qualifying exam process- if you have any insight on qualifying exams in the first year PhD, I’d love to hear from you.
Regardless the oddities of my “qualifying exam” process, I have completed the challenge. Intellectually, this is the hardest that I have pushed myself so far, and my final proposal is the most scholarly work that I have produced in my career so far. In hindsight, I am amazed how I managed to write so thoroughly about a topic that I knew essentially nothing about one year ago, and create a step-by step plan to research that topic. My proposal was quite academic and theoretical, which was a step out of my comfort zone of applied ecology. These past several months, I’ve felt like I was literally stretching my brain as if it’s a rubber band around this bulky abstract concept.
So what is this topic that I’ve spent all these months reading and writing about? Plant diversity! If you’re interested in some ecology nerdery, here I briefly summarize important scientific publications on which I based my qualifying exam research project.
Research that inspires my own research on plant diversity:
A framework for community and ecosystem genetics: from genes to ecosystems (link to publication)
These scientists ask “Can heritable traits in a single species affect an entire ecosystem?” and answer “Yes, but more species should be studied.” The poster-child example is the cottonwood tree, Populus spp., an extremely common tree in North America. Cottonwood trees might look all the same to our human eyes, but a population of cottonwood trees can have huge variation in tannin levels. The tannin levels in the trees can affect the activities of beavers, insects, and birds as well as nutrients and carbon in the streamside forests. Through their tannin levels (heritable trait), cottonwoods (a single species) can affect the entire forest (ecosystem).
A global meta-analysis of the relative extent of intraspecific trait variation in plant communities (link to publication)
These scientists collected the same type of data about different plant species in different ecosystems all over the world, then compared the how intraspecific trait variation (variation within species) compared to interspecific trait variation (variation between species).
Example of one study: in old fields in the eastern United States, the plant species composition was recorded. Dominant plants were goldenrods and grasses, but in total 227 plant species were recorded. For the dominant plants, the scientists recorded vegetative height, leaf area, specific leaf area, and leaf dry matter content. From this data, the scientists could analyze how goldenrods varied in height from 60cm to 120cm (intraspecific trait variation), but all of the plants varied in height from 20cm to 120cm (interspecific trait variation).
The global meta-analysis paper synthesizes that kind of data from over six hundred plots and thirty traits and dozens of ecosystems. It involves a lot of math, but examines the status quo that the difference within plant species is negligible compared to between plant species. That’s to say, it challenges the assumption that the difference of one goldenrod and another goldenrod is so small it can be ignored when compared to the difference between the goldenrod and the grass. The results provide insight on which plant traits are more or less variable and other broad patterns on plant diversity.
Finally, I recommend an excellent blog post written by the first author of one research paper that inspires my project:
How variation within species links ecology and evolution (link to blog)
Here the author says: “We hope to draw attention to the conservational importance of preserving variation within species in order to maintain the structure and function of threatened ecosystems.”
Thanks for reading! Have you been through something like a qualifying exam? Did you learn something new about plant diversity? I’d love to hear from you!
The first weekend of February, the Georgetown Biology department hosted an interview/recruitment event for prospective PhD students. I interviewed last year (Feb 2017), so this was the first time that I was on the other side of the admission process. Last year, I was learning about the department, but this year I was telling prospective students about my experience in the Bio department.
My flipped perspective led me to reflect on how different people approach the decision to go into a full-time science PhD program. As it’s a recurring discussion topic, several websites and blogs feature advice both on choosing where to apply and choosing where to accept. When I was the applicant, I liked Inside Higher Ed‘s articles on Financing a Graduate School Education and On the Art of Selecting a Graduate Program, and Next Scientist‘s article How to Choose the Right Graduate School Program.
I relied quite a bit on online resources for advice about the process. Though I have supportive family, friends and great mentors, I had only a couple peers in a science PhD program in my support network at the time I applied. Also, at the time, I was the only person that I knew who was applying to PhD programs.
Ultimately, for me, choosing grad school distilled down to three considerations:
These points sum up how I approached choosing grad school. If this is something you’ve never thought about, I hope I gave you a way to picture how research scientists take their first step. If you’re someone currently applying or interviewing, I hope this helped you! This is something I’m always happy to talk about, so don’t hesitate to comment here, message me, tweet me. How does my experience compare to your job search or school search?
Some people might be curious what an interview/recruitment event is like, so here I describe it.
Georgetown Biology Department applications are due December 1st. The first week of January, just over a dozen applicants are invited to the interview/recruitment event on the first weekend of February. About a dozen prospective students attend the event.
The Georgetown University Biology Department Interview/Recruitment Weekend
Friday morning. Prospective students meet with a few professors in their subdiscipline. This is sort of an interview process, but remarkably informal.
Friday afternoon. Everyone in the department has a social hour for mingling with the prospective students.
Friday evening. A select few PhD students take all of the prospective students to dinner on M Street in Georgetown.
Saturday morning. 2nd, 3rd, and 4th year PhD students give 12min presentations on their research. It’s like a research symposium, with free coffee and snacks provided by the department. All the professors, PhD students, and prospective students attend.
Saturday afternoon. PhD students hang out with prospective students on the National Mall and downtown DC.
Saturday evening. Everyone attends a dinner party at a professor’s house for more mingling with the prospective students.
Hi. I’m Jewel, and I got this idea that I’d start a blog for a couple of reasons…
Reason 1: Science should be a service for improving society. Right now, I’m in the middle of my first year as a Biology PhD student at Georgetown University in Washington, DC. I’m in the awesome Dr. Gina Wimp’s lab studying salt marsh ecology. Outside of the science departments, however, I realize that the majority of people don’t really get what it means to earn a PhD, work as a scientist, study ecology, or why it matters for society. By sharing my story, I hope to make the unique experience of studying science and its relevance a little more accessible and understandable to everyone.
Reason 2: I’d like to learn from other ecologists about science communication and the latest issues in the field. If you know of scientist blogs or run a scientist blog, please leave comments about blogs I should follow. Also, if you have any tips for the new scientist blogger, I welcome those too.
From my blogging endeavor, you can expect monthly-ish posts about the PhD student experience, field work in the salt marsh, diversity in sciences, Georgetown University, or living in Washington, DC. Additionally, you can let me know if there’s something you’re wondering about being a graduate student or ecology, and I’ll make sure to write about it.
Thanks for reading!
Till next time~ Jewel