Big congratulations are in order for Bert Anderson. Bert graduated this summer with his M.S. in Biology. Bert’s master’s thesis is entitled “The Distribution and Biogeochemistry of Subtropical Intertidal Microbial Mats”.
Microbial mats can be several millimeters thick, and form through a diverse assemblage of microorganisms cohering in an extracellular matrix. Photo: Bert Anderson.
Biological and ecological zonation are quintessential to our models of intertidal communities and ecosystems. In the low-wave energy, depositional intertidal environments of the U.S. Southeast, zonation is typically described as bands of various plant foundation species and growth forms, such as a variety of mangroves, gramminoids, and succulents spread across a low, flat landscape. Often overlooked are unvegetated salt pans. Yet these habitats are biologically rich, as well, hosting a taxonomically and metabolically diverse array of microbiota that are interwoven into cohesive mats that are several millimeters thick and sit atop the sandy surface. These life forms have yielded some of Earth’s oldest fossils and sequestered deposits of recalcitrant carbon.
Salt pans can be sinuous landscape elements, covered with dark microbial mat, nested within the intertidal landscape. The perimeter of this salt pan in west-central peninsular Florida, presents a band of generally unmatted sandy soil, exemplifying structure in the distribution microbial mats. Drone photo by Bert Anderson.
Bert investigated geographical factors that explained variation in the distribution of these mats, as well as biogeochemical footprints created by the mats in the carbon and nitrogen pools of the sand they lie on. Bert found that salt pan boundaries mattered a lot! Mats tended to be found disproportionately toward the sides of salt pans that were close to one of the many tidal creeks that cut up through the intertidal landscape, yet mats tended to stop short of actually reaching the salt pan edges—there seems to be a track of largely unmatted sand that defines the salt pan perimeter. These microbial mat distributional properties then affect spatial variation in soil biogeochemical pools, as the sandy substrate beneath mats tended to be warmer, more saline, and richer with deposits of largely recalcitrant carbon when compared with unmatted salt-pan soil. Bert used a nice mix of photo-interpretation, paired-plot sampling, and lab C and N fractionation techniques to shed light on a little-studied ecological zone, thereby enriching our overarching model of the intertidal landscape.
Congratulations are in order for lab alumnus Viviana Penuela, who just got accepted into the master’s degree program in public and non-profit administration at the University of Central Florida. Great job and good luck!! Viviana has worked at the FL Dept of Environmental Protection since finishing her soil biogeochemistry research and M.S. degree in our lab. She’s now on her way to blending the research and administrative sides of both science and policy. A well-rounded professional indeed!
Jessica schooling Dr. Greg Herbert, director of the USF Anthropocene Working Group.
Jessica Balerna, one of our great PhD students, presents at the USF Anthropocene Symposium. Jessica studies how outcomes of aquifer hydrology management alter surface-water and wetland ecology in ways that feed back on human perceptions of environmental change and management. Jessica’s poster is a great example of how to evolve a dissertation—put yourself out there early with a blend of preliminary data and developing ideas. This is a fruitful natural-social sci collaboration with Becky Zarger of USF Anthropology and Shawn Landry of USF Geosciences, and a university-community partnership with Tampa Bay Water and the Southwest Florida Water Management District, who kindly share data.
Inside a Florida cypress swamp. Is this one hydrologically impaired? Note the exposed base of the tree and slumped ground surface. (Photo: Sharon Feit)
The new academic year is starting. We’re happy to have our graduate student Jessica Balerna back from a summer internship in DC. We’ll get the low-down on what she did there! Last year’s post-bacc researcher Andres Santini, after collecting a great dataset here in FL, spent the summer doing a prestigious National Park Service internship in Alaska. He’s still there in the backcountry! Annie Majette, our honors research student, graduated, and we’re happy to have her move into a technician position, and we’re also excited to welcome new PhD student Cassie Campbell, with her already great experience publishing and teaching.
Bert contemplating Juncus needlerush from the safety of a sand flat
Bert Anderson, a PhD student in our lab, presented one of his dissertation chapters at the 2018 USF Graduate Student Research Symposium. His poster presented findings from his studies of a fascinating and unusual biophysical environment. Bert studies microbial mats growing across sand flats in saline intertidal zones. Microbial mats are taxonomically and metabolically diverse assemblages of microorganisms coexisting in cohesive, fabric-like mats, and the sand flats they grow across are extreme habitats that lack any other plant life. In this presentation, Bert examined the biogeochemical impacts of these mats on the carbon and nitrogen budgets of the soils atop which they grow.
Sand flats interspersed among a mosaic of upland forest, mangrove and salt marsh vegetation, and open water, along the west-central coast of peninsular Florida. (Image Google Maps)
Congratulations to Sandy Voors. In posts below, you’ll see her research described: fascinating studies of the association between plant phenotypic and soil biogeochemical variability. All that work now pays dividends, she graduated with her M.S.!! Sandy was co-advised by Dr. Christina Richards, our awesome ecological (epi)genetics colleague.
Well-deserved smiles! Sandy graduating with her M.S., May 2018. Shown here with Christina Richards, the brains of Sandy’s co-advising team. (Photo shamelessly stolen from Christina.)
Annie showing some Bulls pride at the USF Undergraduate Research Symposium
Annie Majette represented the lab, and presented her USF Honor’s research at the Undergraduate Research Symposium. Congrats!! On both the presentation and doing the work.
Annie’s work examines reservoirs of organic matter and nutrients in coastal soils. She is studying variation in OM and nutrients along 1-4 °C temperature gradients. These are permanent gradients, created by nearby industrial activity, so she is getting the signal of longer-term biological adjustment to altered environments, rather than short term physiological responses to warming, which could offer insights into possible climate change impacts on coastal soil properties and functions.
Sandy explaining it, owning it, defending it.
Congrats to lab member Sandy Voors on defending her Master’s degree! Sandy’s M.S. thesis is entitled “Linking Ecosystem Function and Phenotypic Variation in Spartina Alterniflora Salt Marshes”. Sandy did a great study examining the implications of trait variation in a foundation species (S. alterniflora in salt marshes) for the storage and cycling of carbon and nitrogen in marsh soils. She found a complex association among plant traits, soil biogeochemicial properties, and site effects across several marsh ecosystems. This work contributes to an emerging focus on the importance of populations and phenotypes within species as functionally important sources of biodiversity. Sandy was co-advised by Christina Richards, and did this work as part of a collaboration within Randall Hughes’ Marine Biodiversity lab at Northeastern U. Now that the defense is behind her, graduating in May is the next step!
Check out this recent paper outlining a vision for protecting the least-protected, most-imperiled surfaces waters. It was led by Irena Creed from Western Univ in Ontario, with contributions from a large working group, including us.
Valuation of ecosystem services provided by vulnerable headwater streams and wetlands outside of floodplains in the contiguous U.S.
In the U.S., the Clean Water Act protects interstate “Waters of the USA”. Protecting such waters requires stewardship and conservation of small, upland aquatic systems like wetland basins and headwater streams, whose ecological functions (e.g., flood pulse dampening, pollutant retention, biodiversity reservoir) determine the condition of downgradient Waters of the USA. Yet, conserving upland waters is controversial because preserving them can inhibit land development. Into this fray, the U.S. Supreme Court waded with two landmark cases limiting the Act’s application, and the current administration drags their feet administering the Act. This paper describes the scientific basis for how small & vulnerable waterbodies high in watersheds are linked (biologically and geophysically) to the rivers draining those watersheds, and it provides scientifically grounded options for protecting these vulnerable waters as governments struggle to find solutions for stewarding waters that serve as hotspots of ecological function.
Red mangrove propagules growing the field. Kristen reared huge numbers of these in the greenhouse! (photo: newtonsapple.org.uk/truly-amazing-mangroves)
Congratulations to Kristen Langanke on defending her Master’s thesis and graduating with her M.S. Kristen’s thesis was “Response to nitrogen and salinity conditions in Rhizophora mangle seedlings varies by site of origin”. Kristen collected well over 1200 red mangrove (R. mangle) propagules from a variety of mangrove ecosystem sites, and reared them in the greenhouse under varying conditions of salt and nutrient stress. These two forms of stress are likely to intensify with changing sea levels and pervasive coastal nutrient eutrophication. This study was a nice example of examining phenotypic variation in responses to stress. Kristen’s primary advisor was our frequent collaborator Dr. Christina Richards, and she was a member of the Lewis Lab group as well. Great work Kristen!