Category: Publication

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.

Coble, Marcarelli research group publication

CobleRecent PhD graduate Ashley Coble published a paper in collaboration with her advisor, Amy Marcarelli, and other Michigan Tech researchers.

“Temporal patterns of dissolved organic matter biodegradability are similar across three rivers of varying size”

Authors Ashley A. Coble, Amy M. Marcarelli, Evan S. Kane, David Toczydlowski, Robert Stottlemyer

Journal of Geophysical Research, Biogeosciences

http://onlinelibrary.wiley.com/doi/10.1002/2015JG003218/full