Participants
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Coral reefs are threatened by increasing temperatures in their environments due to climate change. Corals live in an obligate symbiotic relationship with algal partners, and under higher temperatures this relationship can be compromised in a process called coral bleaching. Environmental stressors (i.e., temperature) can interact with genetic variation in coral hosts, as well as their algal symbionts, which can make predictions of bleaching challenging. Cryptic genetic diversity has been uncovered in at least 25 genera of corals, and understanding their varied responses to stressful conditions, such as increasing global temperatures, is critical for predicting ecological and evolutionary trajectories of different coral genera. This study focused on the stress response of three different lineages of Siderastrea siderea that have been characterized in Bocas del Toro, Panamá. Health status of cryptic lineages was compared over a three-year period using photos of tagged S. siderea colonies in four reef sites. We discovered that lineages were distributed across a depth gradient, with one shallow water (0-5m), one deep water (9-12m), and one depth generalist lineage (0-12m). These data demonstrated that after a heatwave in 2023, the deep water lineage showed significantly higher bleaching rates when compared to the other two. This research uncovers physiological consequences of cryptic coral speciation that will be a critical foundation upon which to build successful restoration efforts for threatened coral reef ecosystems in the coming decades.
Tropical reef-building corals live in an obligate symbiosis with diverse algal communities that undergo photosynthesis to provide necessary nutrients for their coral hosts. However, this symbiosis is threatened by rising sea temperatures, which can cause coral bleaching where the coral host expels its symbionts. When bleaching occurs over long time scales, corals are extremely vulnerable to starvation and disease, and death is imminent. Coral reefs support over 25% of all marine life, and the extirpation of these ecosystems will impact oceans globally. However, some types of algal symbionts are more resilient under thermally stressful conditions, and the interactions between different algal genera and coral hosts can lead to different coral bleaching outcomes. The widespread discovery of cryptic coral lineages, which are morphologically similar but genetically distinct groups, coupled with variation in thermal tolerance across algal genera make predicting coral bleaching a challenge. The spatial distributions of cryptic lineages and their associations with algal symbionts across habitat gradients remain largely unknown. We have uncovered three cryptic lineages of Siderastrea siderea in Bocas del Toro, Panamá, and these lineages exhibit unique distributions across depths from 0-12m. However, the composition of the coral holobiont has not been evaluated. In this study, we establish the relationships between S. siderea cryptic lineages and their algal symbionts to inform restoration potential for these independently evolving groups, as failure to do so would lead to inaccurate assessments of individual species’ physiological limits and tolerance to environmental stress.
Studies have shown that unlike model animals like Drosophila melanogaster and Mus musculus, Aedes aegypti have a non-canonical odor system. Interpreted as instead of having one neuron expressing one chemoreceptor bound to one odor, they have one neuron expressing multiple chemoreceptors, allowing them to be bound to multiple odors. This advantage elucidates how-come there has been ineffectiveness at disrupting sensing of humans by mosquitoes. Consequently, more than 700,000 people are passing away from arboviruses such as yellow fever and dengue when bitten by infected mosquitoes annually. Thus, questions have risen to further study how mosquito olfaction works, with the aim to disrupt the ability of mosquitoes to detect humans. To further study this subject, the Q-system was elicited. The Q-system is a binary expression system used to tag various cell performances including gene expression, turning on and off genes. Since olfactory neurons are in the antenna, maxillary palp and antennal lobe, the q-system was incited to create a specific GFP (green fluorescent protein) activated by a 710 nm wavelength NIR light. The Q-system includes two parts: the QF, a transcription factor, and the QUAS sequence, that once been activated by QF, will enable the expression of the GFP. To do this we carefully nurtured two genotypes: BRP-QF2, that includes the QF, and QUAS-GFP, that includes the QUAS sequence, that we crossed to produce a mosquito with GFP. We first hatched the eggs, then sorted the larvae based on fluorescence, located in their eyes, indicating if it has been modified genetically. After that, we sorted the pupae based on sex, then made the cross: BRP-QF2 male crossed with QUAS-GFP female and BRP-QF2 female crossed with QUAS-GFP male. Finally, we blood fed the colonies and collected the final results–GFP mosquito eggs, all in a span of 6 weeks. The result of this cross will then be used by the post-docs in our lab who will use photoactivation to show cell bodies of projection neurons of olfaction, and study how signals are processed and transmitted to the higher brain, intended in the future to help lock mosquito sensing of humans.
With the expansion of urban areas, urban green spaces are now increasingly replacing natural wilderness. Their greenery gives benefits such as mitigating the heat island effect, providing habitats for animals, and absorbing pollution. However, urban green spaces are subject to more urban stressors such as high temperature, low moisture, and polluted air which are known to threaten plant health and growth — partly by diminishing their nutrient uptake. Additionally, the role of urban green spaces in capturing soil carbon is gaining attention. Yet, little is known how urban stressors affect plant and soil C and N status in urban green spaces. We hypothesized that as urban stressors increase, both soil and leaf samples will see an increase of total N, total C, and no difference in C:N ratio. In order to better understand the urban stress impacts, we collected soil samples along urban-rural and edge-interior gradients in forest sites in MA. These gradients represent the proximity to human activities and edge effects — both of which urban green spaces experience. We analyzed total C and N content for these soil samples and conducted a literature review on leaves to predict the C and N content of soil and leaf samples we collected from urban green spaces in Boston, MA, under varying levels of urban stress. We found soil C and N content significantly decreased in the forest edge compared to the forest interior; while the urban forests showed significantly higher C:N ratios than rural forests. Based on our observations in the forest sites and a literature review, we expect soil total C and N content decreases while leaf total C and N content increases with growing urban stress in the green spaces. We predict the reason for a drop in soil C and N content towards edges may come from a higher microbial activity that causes increased respiration rates that decrease total C content while greater inorganic N uptake by plants lead to organic N left to make up a majority of total N content in soil — this is despite the belief that more CO2 and other pollutants in the atmosphere would lead to an increase in soil C and N content. As urban areas expand, their green spaces can become an oasis among a city of concrete and metal; further research will lead us to answers that will help us maintain the longevity of urban green spaces.
Urban green spaces may help mitigate climate change because of their ability to sequester carbon. However, the environmental variables that control carbon dioxide fluxes in urban herbaceous environments are understudied, making predicting current and future carbon sequestration estimates difficult. Previous urban carbon budgets have classified a range of green spaces as lawns, however these spaces contain more than just grasses. We hypothesized that this plant diversity as well as other environmental factors would impact carbon dioxide fluxes. To test this hypothesis, we quantified carbon dioxide flux in urban spaces dominated by differing herbaceous plants. Using portable greenhouse gas sensors, we measured carbon fluxes and relevant variables (e.g. soil moisture, temperature, site area) at nine sites in the Charles River Boston University campus over a period of three weeks during the peak growing season. During this study and across all sites, the median carbon dioxide flux was -1646.4 µmol CO2 m-2 hr-1. Between sites typically classified as lawn areas, we observed large differences between carbon flux values, ranging from uptake of -23251.3 µmol CO2 m-2 hr-1 (at Charles 4) to release of 15205.2 µmol CO2 m-2 hr-1 (at Lot 8). We found that the strongest correlates with carbon dioxide flux were percent cover of non-grass plants (weeds), which had a negative correlation, and dead plant matter, which had a positive correlation, predicting 27% and 17% of the variability, respectively. Prior research has overlooked the influence of weed and dead plant cover when modeling carbon flux in urban lawns, and these data suggest that including these variables would improve carbon flux predictions.
2-Dimensional (2D) materials are crucial in the construction of nanodevices. CuCrP2S6 is a layered van der Waals material that has strong intralayer forces and weak interlayer forces making it possible to create thin film samples with near perfect surfaces. Unlike other common 2D materials, such as graphene, CuCrP2S6 is multiferroic–meaning that it is both ferromagnetic and ferroelectric. Because of its unique properties CuCrP2S6 is a compound that could be revolutionary in the construction of nanotech. In order to investigate the properties of CuCrP2S6 we used Raman spectroscopy to characterize CuCrP2S6 thin film samples. First we mechanically exfoliated the CuCrP2S6 crystals. Once deposited onto a Si/SiO2 substrate, this resulted in ultrathin layers of CuCrP2S6. Raman spectroscopy uses a laser to excite the vibrational modes of the lattice of a material and collect the scattering light. By analyzing the temperature dependent, thickness dependent, and angular dependent Raman spectrums of CuCrP2S6 we were able to identify some of the unique features. The data shows that, below 10 nm, as the sample thickness gets thinner the intensity of the Raman peaks gets lower. The data also supports the hypothesis that the crystal structure changes from antiferroelectric to ferroelectric as the temperature increases, which results in changes in the Raman spectrum and symmetry of the Raman peaks. Further research into multiferroic CuCrP2S6 will help identify more features of the material and help make further advancements in nanotechnology.
Cryptography, the field of mathematically encrypting data, ensures that when data is shared or transferred, no adversary is able to see it. QueryShield is a cryptographic system for multi-party computation (MPC), allowing parties to perform one joint computation on their data without compromising the privacy of individual inputs. Traditionally, this software requires significant background knowledge that may deter the average user from performing an MPC. To address this issue, I used Streamlit to design a user-friendly interface for QueryShield that allows users to register for an analysis by entering a query. Using QueryShield, a data analyst can publish their analysis to a data owner, who may volunteer their data insofar as it remains private. By first specifying their data schema, threat model, cloud provider, and computational task, a data analyst can register their analysis which is saved to QueryShield’s catalog. Once the analysis is created, data owners may browse and join an analysis after agreeing to the security guarantees. They may upload their data as a CSV file or through a dataframe generated by the frontend, which is split into “secret shares” that are distributed among each computing party. Once a sufficient number of data owners have registered, data analysts can start processing the data, deploying QueryShield’s backend, and outputting a result. Ultimately, the need for secure multi-party computation emerges in many scenarios, allowing users to draw global insights from aggregate data that may not be otherwise accessible.
The terahertz range in the electromagnetic spectrum is of great interest due to the interesting interactions that occur and its ability to resonate with certain phonon modes. Recent advances in condensed matter physics regarding nonlinear magnetic phenomena have made the use of strong magnetic fields crucial for research. However it is difficult to generate strong magnetic fields using tabletop setups. Metamaterials are a proposed solution to this issue and could open up the door to a lot more versatile and precise terahertz research and utility. Metamaterials are objects that derive their properties from their shape rather than the material they’re composed of. Due to its geometry, the metamaterials can have properties that aren’t normally found in nature. One application of metamaterials is to amplify the electric and magnetic fields of the incident light, which is especially relevant for tabletop setups. For our project, we looked at two recently proposed metamaterials: the dragonfly and question mark metamaterials, which have been created to enhance the magnetic field component specifically. We created the metamaterials in a CAD software, SOLIDWORKS, and then ran simulations on the COMSOL physics simulator. Then we observed what effects adjusting the design parameters and symmetry of the geometry has. We find that as the length of the dragonfly wings is increased, the magnetic field resonance shifts to a lower frequency linearly while the electric field remains suppressed. We’ve also observed that for magnetic field enhancement, the asymmetry of the geometry seems to be an important factor. There are many different characteristics to alter, but these findings illuminate the role antenna length plays in enhancing electric and magnetic fields.
Drosophila melanogaster flies utilize their innate immune system to resist infection. Our flies are genetically engineered to produce green fluorescent peptides (GFP) when the immune system makes antimicrobial peptides to fight against infections. This allows us to track the speed and strength of immune activation. By creating bioluminescent bacteria, we can track their growth inside the flies. In this study, we use different kinds of bacteria to observe the growth dynamics between the flies and bacteria along with their immune response. We are interested in two innate immune pathways; the Toll pathway is primarily triggered by fungal and Gram-positive bacterial infections, whereas the IMD pathway responds primarily to Gram-negative bacterial infections. Engineering the iLUX plasmid into the bacteria we have been working with is highly challenging. Each strain requires different conditions to transform when exposed to iLUX, and we tested chemical transformation, conjugation, and electroporation. After chemically transforming iLUX plasmid into RHO3 E. Coli we used it to transfer that plasmid into Enterococcus faecalis through conjugation. Through DNA testing, we discovered that our flies were infected with a parasite known as Wolbachia. To combat this, we are treating them with tetracycline. Resolving this issue is critical because our results could be confounded by an infection that we are not investigating. Researching about flies’ immune systems allows us to know more about immune activation. It is possible to identify targets that either amplify immune activation or reduce the response. Since both have an impact on human health, this study may be applied to human research in the future.
Red bee propolis, a waxy, red substance found on the outside of beehives, has been exploited for thousands of years to treat a range of ailments as a treatment for gastrointestinal diseases, to cure burns, wounds and ulcers, as an antibacterial and anti-inflammatory agent, as well as a fungicide, antioxidant, and immunomodulator. Recently, interest in red bee propolis has increased, due to its antiviral activity against SARS-CoV-2. Hundreds of bioactive compounds have been isolated from Brazilian red bee propolis, including the red isoflavan pigment retusapurpurin A. Despite promising biological activities, no syntheses of retusapurpurin A have been reported, hence, synthesis efforts towards this natural product have been initiated. Experimentation in the lab from this summer demonstrates that the initial steps towards retusapurpurin A are scalable by obtaining high yields on gram-scale reactions. Furthermore, a key step in the synthetic route, namely a phenol acylation, was optimized by demonstrating a shorter reaction time and modifying the requisite extraction procedure to obtain product of a higher purity relative to prior experimentation. Using this optimized route, we can synthesize retusapurpurin A and similar isoflavonoids. A long term goal for our lab will be to evaluate their biological activities.
Anemonefish and anemones have a well known mutualistic relationship, providing each other with protection and nutrients. Generally, it’s been proven difficult to separate the effect of heat stress on anemonefish and anemones from the effect of anemonefish and anemones on each other, because the anemones and anemonefish always live together in the wild; however, BU’s Marine Evolutionary Ecology Lab houses anemonefish (Amphiprion Percula) and anemones (Entacmaea Quadricolor), allowing us to disentangle these effects. We investigated daily anemone movement, a behavior variable, in heated environments (up to 330 C) and controlled environments (270 C), both with and without the presence of A. percula, commonly known as clownfish. To compare anemone movement in 4 environments (2 control, 2 heated), we gradually increased the temperature to 330 C in the heated tanks and tracked the anemones’ oral cavity daily using acetate sheets, a lab-developed technique. We concluded that there was a significant difference in anemone distance between the heated anemone replicates and heated anemone with fish replicates. Additionally, there was a significant difference in movement between the anemone control replicates and the anemone control with fish replicates. However, there was no significant difference in anemone distance traveled between heated and unheated anemone replicates. The anemones without fish traveled more, likely because they lack the mutualistic relationship with anemonefish. Since anemone movement is a sign of stress, these results indicate that anemonefish lower stress levels in anemones. This research can be useful to further understanding the conservation of coral reef ecosystems and biodiverse marine environments, which is increasingly important as marine environments change.
The advancement of spray coating technologies is crucial for various industrial applications, including electronics, optics, and materials science. This study, conducted in the lab of Keith A. Brown at Boston University, focuses on the design and construction of an automated thin-film spooling station integral to an Elliptical Imaging Station project. The primary objective is to develop a system that facilitates the precise spooling of Mylar thin films, which are essential for subsequent optical characterization and spray coating processes. Traditional spray coating techniques are predominantly applied to wafers; however, the need for thin films in real-world applications necessitates the development of an automated spooling mechanism. Mylar, chosen for its optical clarity, serves as the substrate for these thin films, enabling enhanced accuracy in characterizing the coating's performance. This automated spooling station is designed to streamline the preparation of thin films for spray coating, improving efficiency and reproducibility in the coating process. A NEMA 17 motor, as well as an Arduino system, is used to power the spooling as a whole. The proposed system addresses key challenges in spray coating, such as uniform application and substrate handling, which are vital for achieving high-quality coatings across various industrial sectors. The impact of this work extends to numerous applications where thin-film coatings are critical, including in the production of advanced optical devices, electronic components, and protective coatings. By automating the spooling process, this project aims to contribute to the broader field of mechanical engineering and materials science, offering a significant advancement in the manufacturing and application of thin-film coatings.
Shadow enhancer systems are groups of two or more enhancers that regulate the same target gene and can suppress transcriptional noise: i.e. fluctuation during transcription. We are investigating the shadow enhancer system that regulates the Kruppel gene, which is vital for fruit fly early embryo development. We used a recombinant plasmid to isolate one of the shadow enhancers in the system that regulates the Kruppel gene and modify it. Bicoid is a transcription factor that regulates the enhancer. We tried to remove two Bicoid binding sites on the shadow enhancer through site-directed mutagenesis. However, we failed to introduce the artificial mutation into the plasmid due to errors in primers, inadequate elongation time, and incompatible bacteria. In the next trial, elongation time will be extended and more compatible bacteria will be used. If we succeed, the following step is to insert the artificially mutated plasmid into the fruit fly genome. We will then analyze the noise of the fly embryos to reveal the differences between the two shadow enhancers in their ability to affect the transcriptional noise. In the future, the study of shadow enhancer systems might be applied to clinical use to suppress stresses, such as increasing the survival rate of children with birth defects.
Autism spectrum disorder (ASD) is a neuropsychiatric developmental disorder associated with challenges in social interaction and can also be related to difficulties in perception and decision making relative to typically developing individuals. Compared to typically-developing (TD) individuals, individuals with ASD especially struggle with rule-based perceptual decision-making, often making slower and less accurate decisions. In simple perceptual orientation-discrimination tasks, individuals with ASD perform with similar accuracy to TD individuals, though they take longer to make decisions. ASD individuals self-report that this delay is due to a more cautious approach in decision-making. However, in increasingly complex rule-based tasks, individuals with ASD exhibit difficulties in task learning, leading to reduced accuracy as task complexity increases compared to TD individuals. The noradrenergic system and regulation of norepinephrine (NE) may be associated with these observable differences between ASD and TD individuals, as this system plays an essential role in decision-making. Studies suggest that individuals with ASD have a dysregulated, overactive noradrenergic system. Therefore, the goal of this project is to examine whether treatment with clonidine, an adrenergic alpha-2 receptor agonist that helps regulate NE levels, will improve perceptual decision-making accuracy and reaction time (RT) observed in autistic SHANK3 mutant mice compared to treatment with saline. We hypothesized that clonidine administration would improve accuracy and increase RT relative to saline administration. To measure perceptual decision-making accuracy and RT, we used a perceptual evidence accumulation (EA) task with a total of ten mice who underwent 5 sessions each of clonidine and saline injections. We found that clonidine increased accuracy and RT in all mice compared to saline, supporting our hypothesis. The results suggest that longer RTs allowed for the mice to make more deliberate decisions. To further study the effects of clonidine on decision making, the mice could be tested with a more difficult version of the EA task, using an 80/20 flash ratio, to help determine whether clonidine can improve accuracy and RTs under more difficult decision-making conditions. Additionally, the results of this preliminary study support the implementation of a larger study to further evaluate the efficacy of clonidine in improving cognitive function, particularly perceptual decision-making, in individuals with ASD.
Autism spectrum disorder (ASD) is a neuropsychiatric developmental disorder that is characterized by difficulties in social communication, behavioral and cognitive flexibility, and perceptual decision-making. Compared to typically developing (TD) individuals, individuals with ASD especially struggle with decision-making in unstable environments where rules can change unpredictably, leading to reliance on repetitive, habitual behaviors. In perceptual decision-making tasks requiring a choice between two stimuli, individuals with ASD are significantly influenced by their prior choices rather than by the stimuli themselves compared to TD individuals, displaying a consistent decision bias. In tasks with high levels of uncertainty, this bias is significantly stronger, impairing decision-making accuracy. The noradrenergic system and regulation of norepinephrine (NE) may be tied to these observable differences between ASD and TD individuals, as this system plays an essential role in decision-making. Many studies suggest that individuals with ASD have a dysregulated, overactive noradrenergic system. Therefore, the goal of this project is to examine whether treatment with clonidine, an adrenergic alpha-2 receptor agonist that helps regulate NE levels, will alleviate the deficits in perceptual decision-making accuracy and decision bias displayed in ASD. This project uses a SHANK3 mutant rodent model for autism, as well as TD siblings, and a perceptual evidence accumulation (EA) task to measure decision-making accuracy and bias. I hypothesize that clonidine administration will improve cognitive function in our SHANK3 mice by decreasing decision-making bias and increasing accuracy in their perceptual EA task compared to saline administration. Each mouse had 5 sessions per drug condition. We compared the mean, accuracy, and bias between each genotype and drug condition. Ultimately we found that clonidine increased accuracy and decreased decision bias compared to saline for both genotypes. Our data can be used to contribute to a deeper understanding of the benefits of clonidine. Our goal is to contribute to the gap in knowledge about how clonidine can affect individuals with ASD. The next step towards achieving this goal is a replication of this experiment at a larger scale, providing more data to support the use of clonidine in individuals with ASD.
2D van der Waals materials have become increasingly relevant and researched due to their applications in optoelectronics and nanodevices. Being held together by weak van der Waals forces, these materials are able to be exfoliated into different layers, allowing them to have different properties. Van der Waals CuCrP2S6 is a multiferroic semiconductor material, meaning that it simultaneously has ferroelectricity and ferromagnetism, and can conduct electricity under specific conditions. These properties were further investigated using photoluminescence (PL) spectroscopy on mechanically exfoliated thin film CuCrP2S6 under changing temperatures and laser power. The mechanical exfoliation method was used to prepare the thin film CuCrP2S6, and the thin film was deposited onto Si/SiO2 substrate chips. An optical microscope was used to find samples of CuCrP2S6, and the PL spectra of these samples were obtained with a spectrometer. Photoluminescence spectroscopy involves using an excitation laser on a sample and measuring the light emitted from the sample following excitation to reveal information about the material’s electronic properties and band structure. In this study, temperature and power dependent IR and visible region PL spectra of CuCrP2S6 were collected, showing how the material is affected by changing temperature and laser power. In the temperature-dependent PL study, PL peaks were only observed at certain temperatures because of structural changes in CuCrP2S6. Those structural changes resulted in changes to band structure and, therefore, changes to PL emissions. As for the laser power-dependent PL study, the intensities of PL peaks were observed to increase as laser power increased. From the data collected, it was seen that the PL spectra and, therefore, the properties of CuCrP2S6, were affected by changing temperature and laser power. By conducting more research on the properties of van der Waals semiconductor materials with different properties like multiferroic CuCrP2S6, their applications to optoelectronics and nanodevices can be further explored.
As a UNESCO World Heritage Site in modern-day Turkey, the archaeological site Gordion has been well documented in its historical occupation. Less well documented is the extent of agropastoral strategies and the management of sheep, goats, cattle, and pigs deposited at the site. This gap of knowledge on this topic is a limitation on a full understanding of husbandry practices from ancient Gordion. Changes in the isotopic composition of carbon (δ13C) and nitrogen (δ15N) in teeth samples of domesticates from Gordion can provide insights into the husbandry strategies for these animals. This study includes tooth samples from animals that date between the Late Bronze Age (ca. 1400-1200 BCE) through the Hellenistic period (ca. 330-100 BCE). The modified Longin Method, allowed an assessment of the collagen yields of sheep, goats, cattle, and pigs to determine how preservation changed temporally. Results indicate that the preservation of collagen does not change temporally, but that the species of animal may play an impact in the preservation of collagen. Next steps include the generation of the δ13C and δ15N which will reconstruct the dietary, ecological, and pastoral patterns of ancient Gordion, Turkey, ultimately gaining crucial insight into agricultural practices as well as the human population that inhabited Gordion.
Many organisms exhibit a canonical “one-to-one” olfactory system, meaning one chemoreceptor is expressed in one neuron. When one chemoreceptor is stimulated, the signal transmits to one glomeruli, and subsequently expresses its following neuron. However, Aedes aegypti exhibits a unique, non-canonical olfactory system, consistent with multiple chemoreceptors expressing one neuron. This unique finding prompts question as to how these variable chemoreceptors aid in the subsequent coexpression of one neuron. In understanding this issue, we investigate the glomeruli activity of the IR25a chemoreceptor in relation to an array of odorants. We found that through utilizing fluorescence microscopy and GCaMP expression, the response of glomeruli to odorants can be discerned by studying glomeruli fluorescence within Aedes aegypti. As Aedes aegypti is exposed to different odors, the IR25a chemoreceptor expresses different neurons allocated throughout the antennae lobes. In understanding the intricacies of how these chemoreceptors coexpress neurons—which help aid in human recognition—our lab strives to find further solutions in diminishing odorant sensitivity within Aedes aegypti. With this information, we could further understand how mosquitoes identify humans and improve the mosquito management methods to decrease mosquito-borne disease cases.
Salt marshes - along with other forms of coastal wetlands - are known to host rich microbial communities that are essential to carbon and nitrogen cycling. It is essential to understand where these microbes are and how abundant they are. There is a gap in salt marsh research leaving much to explore. To address this, we collected sediment samples from two Massachusetts salt marshes (Plum Island and Little Sippewissett) and assessed cell abundance under a fluorescence microscope. We found that this environment hosts highly abundant microbes, regardless of marsh or tide pool. This work will build on future sequencing efforts to identify and characterize salt marsh microbial ecology.
In the next 100 years, climate change is expected to increase soil temperatures during the growing season and decrease the extent of insulating winter snowpack in northern hardwood forests. Due to the loss of an insulating snowpack, which protects soil from freezing, these forests are projected to experience more events of soil freezing and thawing per winter. Previous studies have shown that warmer soils in the growing season can lead to higher productivity while increasing soil freeze-thaw-cycles (FTCs) in winter can reduce growth due to root damage. However, the long-term effects of both soil warming and FTCs on tree productivity are unknown. At the Hubbard Brook Experimental Forest in New Hampshire, six plots were established in 2012 to study year-round climate change conditions: two plots for reference, two with soils warmed 5oC during the growing season using buried heating cables, and two with both soils warmed 5oC during the growing season and FTCs induced in the winter through snow removal. Litterfall samples were collected each fall in all plots over a decade of treatment. Samples were then weighed, sorted by species, homogenized, and analyzed for carbon content to investigate litterfall mass and mass of carbon which is indicative of tree productivity. Results show that overall total litterfall mass increased with growing season warming but was offset by soil FTCs in winter. The total litterfall mass of red maples increased with soil FTCs in winter, which may be due to an increased allocation of resources to litterfall to enhance photosynthesis. Understanding these combined effects is crucial for informing future practices and policies to mitigate the impacts of climate change on forest productivity.