Category: Publication

In Print: Jill Olin Co-Authors Article Suggesting Subsequent Studies Spotlighting Sharks

Jill Olin
Jill Olin

Jill Olin was co-author of a paper that recently appeared in the Journal of Fish Biology. The co-authors argue that research about sharks and their populations needs to be expanded in the face of recent spikes in shark-human interactions in the coastal areas of New York. In addition, ECO Magazine recently mentioned the paper in a story about shark attacks along the New York coast.

Dr. Olin is a community ecologist who studies the processes that affect the structure and stability of ecosystems. She studies issues in coastal marine and freshwater ecosystems due to the diversity and economic importance of species inhabiting these environments and the fact that they are threatened by anthropogenic influences. She teaches courses in Ecology and Evolution, Marine Ecology, and Ecogeochemical Tracer Techniques.

About the Biological Sciences Department

Biological scientists at Michigan Technological University help students apply academic concepts to real-world issues: improving healthcare, conserving biodiversity, advancing agriculture, and unlocking the secrets of evolution and genetics. The Biological Sciences Department offers seven undergraduate degrees and three graduate degrees. Supercharge your biology skills to meet the demands of a technology-driven society at a flagship public research university powered by science, technology, engineering, and math. Graduate with the theoretical knowledge and practical experience needed to solve real-world problems and succeed in academia, research, and tomorrow’s high-tech business landscape.

Questions? Contact us at biology@mtu.edu. Follow us on Facebook and Instagram for the latest happenings.

In Print: Erika Hersch-Green and Angela Walczyk

Congratulations to Dr. Angela Walczyk (recent Ph.D. from Biological Sciences) and her advisor Dr. Erika Hersch-Green for their two new publications! You can access the papers here:

Erika Hersch-Green
Erika Hersch-Green

1. Exciting findings that genome size can affect resource requirements and genomic/transcriptomic functional trait trade-offs. 

Abstract

Premise: Increased genome-material costs of N and P atoms inherent to organisms with larger genomes have been proposed to limit growth under nutrient scarcities and to promote growth under nutrient enrichments. Such responsiveness may reflect a nutrient-dependent diploid versus polyploid advantage that could have vast ecological and evolutionary implications, but direct evidence that material costs increase with ploidy level and/or influence cytotype-dependent growth, metabolic, and/or resource-use trade-offs is limited.

Methods: We grew diploid, autotetraploid, and autohexaploid Solidago gigantea plants with one of four ambient or enriched N:P ratios and measured traits related to material costs, primary and secondary metabolism, and resource-use.

Results: Relative to diploids, polyploids invested more N and P into cells, and tetraploids grew more with N enrichments, suggesting that material costs increase with ploidy level. Polyploids also generally exhibited strategies that could minimize material-cost constraints over both long (reduced monoploid genome size) and short (more extreme transcriptome downsizing, reduced photosynthesis rates and terpene concentrations, enhanced N-use efficiencies) evolutionary time periods. Furthermore, polyploids had lower transpiration rates but higher water-use efficiencies than diploids, both of which were more pronounced under nutrient-limiting conditions.

Conclusions: N and P material costs increase with ploidy level, but material-cost constraints might be lessened by resource allocation/investment mechanisms that can also alter ecological dynamics and selection. Our results enhance mechanistic understanding of how global increases in nutrients might provide a release from material-cost constraints in polyploids that could impact ploidy (or genome-size)-specific performances, cytogeographic patterning, and multispecies community structuring.

Angela Walczyk
Angela Walczyk

2. Finding that tetraploid Giant Goldenrods may be pre-adapted to be good invaders but that polyploidy per se does not increase phenotypic plasticity. 

Abstract

Polyploidy commonly occurs in invasive species, and phenotypic plasticity (PP, the ability to alter one’s phenotype in different environments) is predicted to be enhanced in polyploids and to contribute to their invasive success. However, empirical support that increased PP is frequent in polyploids and/or confers invasive success is limited. Here, we investigated if polyploids are more pre-adapted to become invasive than diploids via the scaling of trait values and PP with ploidy level, and if post-introduction selection has led to a divergence in trait values and PP responses between native- and non-native cytotypes. We grew diploid, tetraploid (from both native North American and non-native European ranges), and hexaploid Solidago gigantea in pots outside with low, medium, and high soil nitrogen and phosphorus (NP) amendments, and measured traits related to growth, asexual reproduction, physiology, and insects/pathogen resistance. Overall, we found little evidence to suggest that polyploidy and post-introduction selection shaped mean trait and PP responses. When we compared diploids to tetraploids (as their introduction into Europe was more likely than hexaploids) we found that tetraploids had greater pathogen resistance, photosynthetic capacities, and water-use efficiencies and generally performed better under NP enrichments. Furthermore, tetraploids invested more into roots than shoots in low NP and more into shoots than roots in high NP, and this resource strategy is beneficial under variable NP conditions. Lastly, native tetraploids exhibited greater plasticity in biomass accumulation, clonal-ramet production, and water-use efficiency. Cumulatively, tetraploid S. gigantea possesses traits that might have predisposed and enabled them to become successful invaders. Our findings highlight that trait expression and invasive species dynamics are nuanced, while also providing insight into the invasion success and cyto-geographic patterning of S. gigantea that can be broadly applied to other invasive species with polyploid complexes.

In Print: Trista Vick-Majors

Congratulations to Trista Vick-Majors and colleagues who recently published a paper titled “Constraints on the Timing and Extent of Deglacial Grounding Line Retreat in West Antarctica” in AGU Adventures.

Graph indicating the subglacial core locations along with filling and draining amounts
(a) Southern Ross Sea sector ice streams with previous subglacial core locations (Whillans Subglacial Lake (SLW; Tulaczyk et al., 2014), Whillans Grounding Zone (WGZ; Venturelli et al., 2020), the upstream site at of Whillans Ice Stream (UpB; Engelhardt & Kamb, 1997), and Crary Ice Rise (CIR; Bindschadler et al., 1988) marked with gray circles, Mercer Subglacial Lake (SLM) indicated with a purple circle, and the lake directly upstream Conway Subglacial Lake (SLC) labeled. Ice velocity (Mouginot et al., 2019) is overlain on an imagery mosaic (Scambos et al., 2007), with active subglacial lake areas (blue polygons; Siegfried & Fricker, 2018), hydropotential flow paths (blue lines; Siegfried & Fricker, 2018), and grounding line (black; Depoorter et al., 2013) indicated. (b) Volume changes in Mercer Subglacial Lake inferred from CryoSat-2 radar altimetry (Siegfried et al., 2023) with a yellow star marking the timing of sampling.

Abstract

Projections of Antarctica’s contribution to future sea level rise are associated with significant uncertainty, in part because the observational record is too short to capture long-term processes necessary to estimate ice mass changes over societally relevant timescales. Records of grounding line retreat from the geologic past offer an opportunity to extend our observations of these processes beyond the modern record and to gain a more comprehensive understanding of ice-sheet change. Here, we present constraints on the timing and inland extent of deglacial grounding line retreat in the southern Ross Sea, Antarctica, obtained via direct sampling of a subglacial lake located 150 km inland from the modern grounding line and beneath >1 km of ice. Isotopic measurements of water and sediment from the lake enabled us to evaluate how the subglacial microbial community accessed radiocarbon-bearing organic carbon for energy, as well as where it transferred carbon metabolically. Using radiocarbon as a natural tracer, we found that sedimentary organic carbon was microbially translocated to dissolved carbon pools in the subglacial hydrologic system during the 4.5-year period of water accumulation prior to our sampling. This finding indicates that the grounding line along the Siple Coast of West Antarctica retreated more than 250 km inland during the mid-Holocene (6.3 ± 1.0 ka), prior to re-advancing to its modern position.

In Print: Jill Olin

Congratulations to Jill Olin and her postdoctoral fellow, Jim Junker, who recently published a paper titled “Can biodiversity of preexisting and created salt marshes match across scales? An assessment from microbes to predators” in the Ecosphere Journal. You can learn more about the research on the LSU website.

Jill Olin
Jill Olin
Jim Junker

Abstract: Coastal wetlands are rapidly disappearing worldwide due to a variety of processes, including climate change and flood control. The rate of loss in the Mississippi River Delta is among the highest in the world and billions of dollars have been allocated to build and restore coastal wetlands. A key question guiding assessment is whether created coastal salt marshes have similar biodiversity to preexisting, reference marshes. However, the numerous biodiversity metrics used to make these determinations are typically scale dependent and often conflicting. Here, we applied ecological theory to compare the diversity of different assemblages (surface and below-surface soil microbes, plants, macroinfauna, spiders, and on-marsh and off-marsh nekton) between two created marshes (4–6 years old) and four reference marshes. We also quantified the scale-dependent effects of species abundance distribution, aggregation, and density on richness differences and explored differences in species composition. Total, between-sample, and within-sample diversity (γ, β, and α, respectively) were not consistently lower at created marshes. Richness decomposition varied greatly among assemblages and marshes (e.g., soil microbes showed high equitability and α diversity, but plant diversity was restricted to a few dominant species with high aggregation). However, species abundance distribution, aggregation, and density patterns were not directly associated with differences between created and reference marshes. One exception was considerably lower density for macroinfauna at one of the created marshes, which was drier because of being at a higher elevation and having coarser substrate compared with the other marshes. The community compositions of created marshes were more dissimilar than reference marshes for microbe and macroinfauna assemblages. However, differences were small, particularly for microbes. Together, our results suggest generally similar taxonomic diversity and composition between created and reference marshes. This provides support for the creation of marsh habitat as tools for the maintenance and restoration of coastal biodiversity. However, caution is needed when creating marshes because specific building and restoration plans may lead to different colonization patterns.

Be Brief: Glow

Changes in pH cause the rhodol dyes to glow differently, offering insight into diseases that affect mitophagy.Fluorescent dyes help scientists see the inner workings of disease. In a new paper by Haiying Liu (Chem), Rudy Luck (Chem) and Thomas Werner (Bio Sci)—along with student researchers—they examine the efficacy of a rhodol-based fluorescent dye.

Diseases like Alzheimer’s and certain kinds of cancers affect the powerhouses of cells — mitochondria. To keep these powerhouses working efficiently, cells remove damaged mitochondria. This process, called mitophagy, is like a cell taking out the trash. In diseased cells, the garbage piles up and the cell’s pH changes. The rhodol dye responds to pH changes and glows brighter.

Luck adds that he considers it a privilege to be able to contribute to Liu’s attempts to find commercially viable probes. The team also acknowledges that the High-Performance Computer system Superior, managed under Director Gowtham, has advanced the research considerably.

Read more about the next steps of this research on the campus research blog Unscripted and celebrate National Chemistry Week with other Unscripted reads about surface chemistry, the science of brewing and mass spectrometry.

Library Launches Work by Janice Glime

Photo by Michael Lüth
Photo by Michael Lüth

“Bryophyte Ecology” is the result of more than a decade of research, collaboration and composition by Professor Emerita Janice Glime (Bio Sci) and many contributors and photographers.

The five-volume work is unique not only as the most recent comprehensive reference on bryophyte ecology, but because it is “open” to the world. “Bryophyte Ecology” was initially self-published on the web and is now accessible on Digital Commons @ Michigan Tech.

Moving the work to Digital Commons ensures long-term preservation and easier access. Additionally, the work reaches top slots using any search engine.

Glime’s goal in creating an open work “was to reach a broad audience in an affordable format with lots of illustrations and a readable style.

“Bryophyte Ecology” has been used as a textbook, reference source and field guide. It contains many color photographs, information on physiological ecology, bryological interactions, methods of collection and various uses of bryophytes as well as question sections throughout to facilitate learning.

Discover the world of bryophytes here.

Digital Commons @ Michigan Tech, the university’s digital repository, is a platform for storing, sharing and showcasing research and educational resources. To learn more or to consider adding your own work contact digitalcommons@mtu.edu.

Multiple faculty In Print

From Tech Today:

Amy Marcarelli
Amy Marcarelli

Amy Marcarelli  recently co-authored recently published book chapter: “Stream-lake interaction: understanding a coupled hydro-ecological system.” Pp 321-348 in: Jones JB, Stanley EH (eds) Streams in a Changing Environment. Academic Press.

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Casey Huckins
Casey Huckins

Casey Hucking co-authored “Genetic and phenotypic evidence for splake presence in brook trout and lake trout spawning habitats,”  in the Journal of Great Lakes Research 42(3): 738-742.

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Chandrashekhar Joshi
Chandrashekhar Joshi

Chandrashekhar P. Joshi (Dept. Chair Bio Sci) co-authored “Virus Induced Gene Silencing (VIGS) Mediated Functional Characterization of Two Genes Involved in Lignocellulosic Secondary Cell Wall Formation.” In Plant Cell lReports DOI 10.1007/s00299-016-2039-2.