I'm back home now, but I'm so glad I had the opportunity to work in the Fulweiler lab this summer! I learned so much about lab work, salt marshes, biogeochemistry, and made some great friends along the way. It was such a great experience, and it confirmed that environmental science is what I want to pursue in college and as a career. Everyone was so welcoming, and I never felt like I was treated differently because I was the only high school student in the lab. I got valuable first-hand advice about college life and the application process, in addition to learning about how higher education works in the sciences. I got to work on a fascinating project, and found that an invasive marsh plant species, Phragmites australis, was a better greenhouse gas sink than the native species Spartina alterniflora. My poster turned out great after many revisions, and I am looking forward to writing my project into a paper with Hollie and Professor Fulweiler's assistance. I really appreciated that the whole lab came out to see my poster and hear about my project on Friday, and good luck to everyone in the lab on their future endeavors! It was great to meet you all.
On Friday I helped out in the lab acid washing dirty lab equipment we used in the field this week, and finished separating out the live roots and rhizomes from dead peat material in a soil core Morgan started. We separate out the below-ground plant biomass to better understand how the plants work, and to see how plant structure could affect greenhouse gas emissions from the plants. We also went through the above-ground plant material we collected on Wednesday and recorded the plant species, plant heights, and the number of leaves for each plant found at each study site. Usually this process is done in the field, but we forgot to bring a meter stick with us when we went on Wednesday.
When recording the species composition of the plots, we found Salicornia europaea (glasswort), Distichlis spicata, and Spartina patens in addition to In addition to the Phragmites australis and Spartina alterniflora marsh plants. It was really neat to see all the different plant types together in the same plot.
We encountered some difficulties when measuring the plant heights because the huge Phragmites plants are similar in structure to bamboo, and we had to break the stalks to fit them in bags to take back to the lab. Some of the dead Phragmites stalks snapped when they were stored, and it was pretty difficult to put the fragments back together to measure the height, especially when there was more than one dead plant in a plot. Lesson learned: be prepared when going into the field.
Today Hollie and I went back to the marsh to collect porewater, soil samples, and biomass from all the sites to take back to the lab. We cut off the plants from the vegetated sites at ground level for the above-ground biomass, and then we took a soil core from the middle of the plot to extract the below-ground biomass in the lab. Taking the soil core was hard work because you had to hammer a PVC pipe deep into the ground with a rubber mallet, then pull it up and get the soil out of the pipe which was very difficult if the soil was dry. There was no porewater at most of the sites, so Hollie decided to take extra soil samples to centrifuge back at the lab. Hopefully we will be able to extract some in order to determine the pH and salinity of the soil water at each site.
We also took soil samples to find out the density, porosity, and composition of the soil, which could all potentially affect greenhouse gas emissions. It started raining when we were almost half way done, and when lightning touched down across the marsh, we went into the woods for safety. Unfortunately there were many more mosquitoes in the woods than on the marsh, and I got bitten a lot. The storm stopped pretty quickly, and we were able to finish collecting samples and drive back to the lab. There was a huge storm on our way back, and we had to unload the car in the pouring rain. It was another long day (almost 11 hours), and taking the soil samples was a lot of work, bu t I definitely learned a lot.
I'm excited for my first trip to the field tomorrow! We're leaving for the Massachusetts Audubon Society’s Rough Meadows Sanctuary in Rowley, Massachusetts at 8 in the morning. It's going to be very hot (high 90's), so I'll be bringing a hat, sunglasses, and plenty of sunscreen. I got a 3 quart container of water at CVS because Hollie recommended that everyone bring a minimum of 2 liters of water to stay hydrated. We're going to be gone all day measuring greenhouse gas fluxes from different species of marsh plants, in addition to other environmental parameters such as temperature, atmospheric pressure, and light.
To prepare for our trip I flushed exetainers (glass vials used to collect gas samples) with helium gas to avoid contamination. Helium is used because it is a noble gas and is very stable, so it won't react with the gas in samples and skew data. After flushing the exetainers with helium, I evacuated them with a needle and syringe to remove the air inside in preparation for sample collection tomorrow. We will be collecting samples for greenhouse gases – CO2, N2O, and CH4.
I had an exciting time in the field this week! On Tuesday I went to the marsh with Hollie, Devon, Marc, and Sarabeth to collect gas flux data for the project I am working on with Hollie. We measured the greenhouse gas emissions from different marsh plants and un-vegetated areas. Devon and I worked together to collect data from the sites with Spartina plants, while the others collected data from the Phragmites plants. At each site there were two red rings in the ground, one with plants and one without. We put clear plastic chambers over the rings (gas tight) and then used syringes to extract two gas samples from each chamber every six minutes. One of us would take the gas sample while the other person kept track of the time and transferred the gas sample from the syringe into an exetainer for storage. We also recorded the amount of light, soil temperature, chamber temperature, and the final humidity in the chamber. We went through this procedure for three more sites across the marsh.
It was really hot, especially because we had to wear long sleeves and long pants to keep the bugs off. They were everywhere. Even with bug spray, I was still bitten a few times. No one fell into the tidal creeks, but Hollie did get sunburned. After we finished doing all the gas fluxes and lugging the equipment back across the marsh to the car, we stopped to get ice cream! It was a really long day because I was with the lab or in the field for almost twelve hours!
Today I helped Mary-Kate prepare her Acetylene reduction Assay to measure N-fixation from her sediment samples.
I also spent some time acid-washing lab equipment that was used in the field this week. We have to acid wash things because the nutrients measured in samples are also present in the air, in tap water, and on our skin, so we need to decontaminate everything to be sure what measure is real and not from us.
After a few rounds of acid washing, I read some scientific papers to learn more background information for my project. I read about the invasive marsh grass species Phragmites australis that out-competes native species because it can grow up to 6 meters tall and shade out smaller native plants. Human activities such as building roads through marshes contribute to the spread of this invasive species by blocking or impeding tides from the ocean. This lowers the salinity and sulfide content of the restricted marsh area -- conditions very favorable to Phragmites australis growth.
Hi all! This summer I'm interning in Professor Fulweiler's lab at Boston University for six weeks through the Boston University Research Internship in Science and Engineering (RISE) Program. I will be studying the nitrogen cycle and greenhouse gases in salt marshes. I'll be updating this page frequently with what I've been doing in the lab, so check back often! And follow us on Twitter @Fulweilerlab - I'll be posting there too.
My big project today was helping Taylor label 1,000 new exetainers (glass vials) with numbers and then taping over the labels. We got up to number 536 today! The vials will hold the greenhouse gas (CO2, CH4, & N2O) samples I will collect with Hollie on Monday from a salt marsh just north of Boston. I also learned about filtering water for dissolved inorganic nutrients and I made about 50 filter tips to be used out in the field tomorrow!