A couple weeks ago, I went on a field trip for my Wetlands Ecology class to learn about different types of wetland ecosystems. We followed the Patuxent River along a salinity gradient from freshwater (less than 0.5 parts per thousand (ppt) salinity) near the head of the river to salt water towards the mouth of the river, which drains into the Chesapeake Bay. The first stop was at Patuxent Wetland Park, a freshwater wetland. We saw firsthand the ways that wetland plants adapt to the stresses of a low oxygen environment. Soil is a mixture of particles separated by spaces called pores. In many ecosystems, these pores are filled with a mixture of water and air. In wetlands, these pores are frequently or permanently filled with water and plant roots cannot acquire oxygen through them. Therefore, they have special adaptations to fill their oxygen needs. For example, the water lily uses aerenchyma, or spongy tissue with air channels to pipe oxygen from above the water table down to its roots. Our second stop was at the Clyde Watson Boating area where the salinity ranged from about 5 to 7.5 ppt. We noticed salt buildup on the leaves of many of the plant species here. These plants adapt to saline conditions by extruding salt through specialized glands. It was a hot day and everyone decided to cool off in the river in their full chest-wader getups. The third stop was a salt marsh at Island Creek Marina where the salinity ranged from about 10 to 12.5 ppt. Here I spoke to the class a bit about my work in these ecosystems. We passed around a soil sample for everyone to smell the hydrogen sulfide produced by the specialized microbes that colonize salt marsh soil. I knew the rotten egg smell well from this past summer’s research and I felt right at home as I excitedly nerded-out to the class about redox conditions. At each of these sites, we split into groups and took a vegetation survey using a PVC quadrat. This allowed us to determine the dominant plant species present in each wetland type. We noticed how dramatically the plant species composition shifted with these salinity changes. Specifically, plant biodiversity dropped sharply as salinity increased from site to site. As an impromptu final stop, the group decided to check out Battle Creek Cypress Swamp, which contains one of the northernmost stands of Cypress trees in the United States. We noticed the stubby cypress “knees,” or part of the roots that sit above the water line. Though their function is not entirely confirmed, researchers think that the knees help to bring air down to the lower parts of the plant roots. We took a walk across the swamp on a beautiful newly build boardwalk. I also got to collect some edible fruits from the native Pawpaw tree as we strolled along. Despite being completely covered in mud at the end of the day, I was so happy to spend my Saturday outside learning about these very unique ecosystems!
- By Dani Weissman
In early August, Bri and I attended and presented our research at the national Ecological Society of America conference. This was a great opportunity for us to present our research to ecologists throughout the country. From Monday through Friday of the conference, there were talks scheduled throughout the entire conference center. I was amazed by the wide array of topics; there was everything from biogeochemistry to conservation management to population and community dynamics. We used the very handy ESA program app to sort through the talks and find the ones that best fit our interests. Consequently, we also found ourselves running laps through the convention center to try to see everything! I also jumped outside of my familiar realm of soil science and nutrient cycling to attend a symposium on trophic cascades as they relate to the reintroduction of wolves in Yellowstone. It was very fun to explore a different facet of ecology. There were also some very interesting exhibitors at the conference as well. We stopped by the Union of Concerned Scientists table and learned about how science can be better promoted and used to drive policy.
On Tuesday, August 8, I spoke on my work on saltwater intrusion and nutrient cycling in coastal agricultural areas. Later that week, Bri presented her work on cover crops and nitrogen leaching in agricultural systems. On Friday of that week, I moderated a session organized by Kate on sea level rise and ecosystems services. The session was comprised of five very short (<5 minute) talks from different researchers followed by a lengthy discussion period. The speakers gave a lighthearted bend to a very serious topic by dotting their talks with silly limericks and jokes. I think we all may have been a little worn out by the end of the week!
As we were bustling about the convention center, everyone couldn’t help but notice the layer of smog that hung over the city of Portland for the entire week and obscured our view of the beautiful mountains. This was due to smoke traveling south from forest fires raging in nearby British Columbia. I made the immediate connection between the environment outside and the work presented at the conference. Ecological research has such a pressing importance in our daily lives. Climate change and human activities will most certainly alter the range, frequency, and intensity of these fires, as well as many other earth processes. I left the conference with a sense of encouragement—it was wonderful to see so many dedicated researchers working towards an overarching goal.
- By Dani Weissman
As we set out on our last porewater sampling trip of the 2017 summer, I get a bittersweet feeling. I’m happy about all the progress we’ve made on Dani’s saltwater intrusion project, and proud of all I have contributed to the study, but I know I’ll miss spending every other week on Maryland’s beautiful Eastern Shore. Over the summer I have met some awesome people, and I’m grateful that half the time “another day at the office” meant knee-high boots and a machete, but I think I’ll miss the marsh wildlife the most.
Growing up I was always outside looking for snakes, frogs, and bugs, and when I had to be inside I was watching animal planet or reading National Geographic. I left no stone unturned…literally. Instead of growing out of this fascination with life, I only became more interested as I got older, and now I own field guides for just about any critter in North America. The marsh and forests on the shore are rich with animals, and participating in this study was a perfect opportunity to pursue my love for environmental science, and to get up close and personal with the fauna. I must say the mosquitos, deer flies, and chiggers got a little too up-close and personal at times, but it was all worth it. After four water sampling trips and a soil sampling “campaign,” I think we all were starting to feel like marsh wildlife ourselves.
Working with the AgroEcoLab has been an amazing experience, and I look forward to continuing our work into the fall semester, but I will miss the wildlife of the Eastern Shore. In all we’ve rescued four turtles in the middle of the road, hopefully that’s enough good karma to last us until we can get back down there.
- by John Dietrich
I have been working in the Agroecology Lab for almost a year now researching the movement of nitrogen through the soil profile and into cover crops. In this time, I have installed instrumentation in the field, processed data using a combination of R and excel, and collected over a thousand soil and plant samples.
Our instrumentation includes lysimeters and Time-Domain Reflectometers (TDR). Lysimeters are used to collect porewater samples, which we use to quantify nitrate and ammonia concentrations 60 cm down the soil profile. This will give us an idea of how much nitrate-N is leaching out of the system. Our TDR’s are used to measure soil temperature, volumetric water content, bulk relative permittivity, electrical conductivity, and soil pore water electrical conductivity at 0-10 cm, 20-30 cm, and 50-60 cm down the soil profile. The TDR’s were installed for approximately 4 months and collecting data every 10 minutes yielding 252, 870 data points. This forced me to quit using excel all together and familiarize myself with R Studio. Data processing in R Studio has been a wonderful, rewarding experience.
Over 900 soil samples sounds quite intimidating. However, we processed all of our soils shortly after the collection date, so it was quite manageable. Unfortunately, some sources of contamination are entirely unexpected and are left undiscovered until the data processing stage. Four of our sampling dates had unusually high levels of ammonia. Contamination is part of working in a lab and is something we are all very careful about. After a while we discovered the potential source of contamination: our filter papers. I rummaged through my archived soils and began the process all over again. Luckily, with the help of our amazing lab crew: Cullen, John, Gabe, and Tony we were able to complete all 900+ extraction in seven days!
- By Josh Gaimaro
Last week the lab ventured into the wilderness that is Somerset County for a soil sampling expedition. In total, we came in with six people and two augers and after an intense three days we returned with a ~hundred bags of soil, more than fifty chigger bites collectively (although Kate got the worst of it), and a deep appreciation for air conditioning. A lot of planning, coordination, and hard work went into collecting these data points, but still Reviewer 3 is hard to please when it comes to sample size. Up until this trip I had not really put much thought into how the soil I have been running extractions on was collected. But now working with a sample from initial collection to data processing and graphing really adds a new depth (horizon?) of understanding.
Some highlights from the trip:
Overall, great experience but just another day in the office for the AgroEcoLab!
-By Tony Pham (visiting intern from Boston University)
Last week, I received the wonderful news that Maryland Sea Grant will fund a part of my project on saltwater intrusion and nutrient cycling in coastal ecosystems! I have recently decided to continue into the PhD program at University of Maryland, and this award will go a long way towards helping me expand my research project. Maryland Sea Grant is a partnership between the University of Maryland and the National Oceanic and Atmospheric Administration (NOAA). The program funds coastal science research, education, and outreach throughout Maryland. To best serve the coastal community in the state, Maryland Sea Grant has developed a strategic plan with four main focus areas: Healthy Coastal Ecosystems, Sustainable Fisheries and Aquaculture, Resilient Communities and Economies, and Effective Environmental Science Education. My project will address the first focus area by uncovering key biogeochemical processes that occur as sea level rise causes tidal salt marshes to encroach on farm fields. This Fellowship includes a strong public outreach component to allow me to share my findings outside of the scientific and academic community. To reach more people through my research, I have partnered with staff at The Nature Conservancy, a national non-profit environmental conservation group that shares some common goals with Maryland Sea Grant. The Nature Conservancy and Maryland Department of Natural Resources have completed a statewide Coastal Resiliency Assessment to help guide preservation and restoration decisions. As I delve into the basic scientific research behind my project, I am constantly challenged with creating ways to effectively connect the public with my findings. The big-picture goal of my project is to better guide environmental land management decisions in changing ecosystems. I am thrilled that I will now have the resources to work closely with people who incorporate scientific and environmental outreach into their jobs every day!
- By Dani Weissman
In March, 2017, Kate and her colleague, Dr. Jarrod Miller, a UMD extension agent in Somerset Co. proposed a project to UMD's College of Agriculture and Natural Resources with the overall goal of integrating both extension (UME) and research (MAES) in the development of best management practices for adapting and mitigating coastal farms in eastern Maryland to intruding saltwater via rising sea-levels. Since little research has investigated the effects of sea-level rise on coastal farmlands and farmers in this region are actively seeking strategies to mitigate the effects of saltwater intrusion, Kate and Jarrod's proposal was accepted and funding was granted to support the collection of preliminary data for a more robust USDA proposal they are currently writing.
Last week, they met at their field site near Princess Anne, MD to set up plots and begin experimental treatments using various crops and management strategies. Overall, the field crew made light work of the tasks at hand but no one managed to leave without a few aching muscles or tick bites. By the second week of July, experimental sampling will begin and we expect to learn much about the survival and productivity of various crops, the quality of pore water in terms of nutrients and hydrology, and soil nutrients in order to elucidate this issue for the public. Stay tuned for more information in the coming months!
- By Cullen McAskill
Kate's research on soil health and pathogen survival in organic systems was covered in AmericanFarm.com
Check out the recent article in AmericanFarm.com, which highlights work conducted by Dr. Cassandra Swett, Dr. Kate Tully, and Emmi Koivunen on methods to suppress pathogen survival while improving soil health in organic berry systems.
link to article
This spring was full of excitement and pride (on my part) as members of the AgroEcoLab were recognized far and wide for their accomplishments.
Edem Yevoo won first place in the Undergraduate Research Day for his poster on saltwater intrusion! Jesse Wyner and Natalie Agee were members of the UMD Soil Judging Team, which took home first place in the National Championships! Dani Weissman won Outstanding Graduate Student both in the Department of Plant Science and in the College of Agriculture and Natural Resources!
I was also fortunate to be awarded a National Socio-Environmental Synthesis Center (SESYNC) Workshop Grant to bring together the leading experts in saltwater intrusion across the North American Coastal Plain for a three-day workshop in Annapolis, MD in April. Along with my collaborator, Keryn Gedan (George Washington University), we built the framework for collaborative research and coordination on future proposals.
Now, it is full-steam ahead, as we set out for a summer filled with fieldwork. We also welcome five interns to the summer crew: John Dietrich, Phil Evich, Tony Pham, Cullen McAskill, and Gabe Moses. Be sure to stay tuned as they will be blogging about their summer adventures in the months to come!
- By Kate Tully
Dr. Kate Tully
Kate is an Assistant Professor of Agroecology at the University of Maryland.
Briana is a MS student in AgroEcoLab and studies how cover crop management affects weed suppression and nutrient cycling.
Dani is a PhD student in the AgroEcoLab and studies the effects of sea level rise on coastal farming communities and estuarine biogeochemistry.
Resham is a PhD student in the AgroEcoLab and studies how to improve water and nutrient use efficiency in cover crop systems.