Biology subjects

Cary, S. C.

Publications and source records attributed to Cary, S. C..

5 recordsLinked to original sources

bioRxiv2025

Gaps and Advances in Long-Term Monitoring of Antarctic Near-Shore and Terrestrial Ecosystems

Environmental change due to greenhouse gas emissions is affecting ecosystems globally; in the polar regions in particular there is already significant evidence of change. The Antarctic Near-Shore and Terrestrial Observation System (ANTOS) aims to establish a cross-continent, cross-national observing network to assess environmental variability and change in the southern polar region. To understand how near-shore and terrestrial Antarctic ecosystems have and will continue to be impacted by anthropogenic environmental changes, a comprehensive review of current long-term monitoring efforts, and two surveys targeting Antarctic researchers, were carried out to evaluate existing monitoring efforts, environmental changes recorded, and to identify areas currently lacking sufficient observations. Results indicate that most data collection is manual and intra-annual, with significant long-term monitoring concentrated in regions with already established infrastructure. The surveys highlight the urgent need for comprehensive coverage of the Antarctics rapidly changing ecosystems using standardized monitoring protocols and increased collaboration. We recommend prioritizing areas experiencing rapid climatic changes and leveraging existing infrastructure to minimize environmental impact of monitoring activities and enhance data comparability across sites.

ecology↗

bioRxiv2024

Antarctic geothermal soils exhibit an absence of regional habitat generalist microorganisms

Active geothermal systems are relatively rare in Antarctica and represent metaphorical islands ideal to study microbial dispersal. In this study, we tested the macroecological concept that high dispersal rates result in communities being dominated by either habitat generalists or specialists by investigating the microbial communities on four geographically separated geothermal sites on three Antarctic volcanoes (Mts. Erebus, Melbourne and Rittman). We found that the microbial communities at higher temperature (max 65{square}) sites (Tramway Ridge on Erebus and Rittmann) were unique from each other and were dominated by a variety of novel Archaea from class Nitrososphaeria, while lower temperature (max 50{square}) sites (Western Crater on Erebus and Melbourne) had characteristically mesophilic communities (Planctomycetes, Acidobacteriota, etc) that were highly similar. We found that 97% of the detected microbial taxa were regional habitat specialists, with no generalists, with community assembly driven by high dispersal rates and drift (25 and 30% of community assembly, respectively), not environmental selection. Our results indicate that for microbial communities experiencing high dispersal rates between isolated communities, habitat specialists may tend to out-compete habitat generalists.

microbiology↗

bioRxiv2024

Geothermal ecosystems on Mt. Erebus, Antarctica, support diverse and taxonomically novel biota

Mt. Erebus, Antarctica, is the southernmost active volcano in the world and harbors a diverse and geochemically unique array of geothermal ecosystems including Subglacial and Exposed features, surrounded by a vast desert of ice and snow. Previous studies, although limited in scope, have highlighted the unique and potentially endemic biota present on Mt. Erebus. In this study, we provide a systematic biodiversity study across all domains of life and all types of geothermal features present on Mt. Erebus. We present physicochemical and biological data from 39 Exposed samples and 9 Subglacial samples from Mt. Erebus. The taxonomic novelty of prokaryotes and fungi found supports past hypotheses of high endemism among the biota of Mt. Erebus; in particular, the large number of taxonomically divergent fungal sequences was surprising. We found that different site types had unique physicochemistry and biota; in particular, Exposed sites were significantly warmer than Subglacial sites (median: 40 vs 10 for Exposed and Subglacial, respectively) and tended to have greater abundances of photosynthetic organisms (Cyanobacteria and Chlorophyta). Subglacial sites were characterized by a greater abundance of prokaryotes from the phylum Actinobacteriota, correlated with the greater concentrations of Ca, Mg, and Sr present. Additionally, we found that Tramway Ridge differed from other Exposed sites as well as all Subglacial sites in physicochemistry (significantly greater conductivity, water content, total carbon, and total nitrogen levels) and biota (greater relative abundances of order Nitrososphaeria and phylum Bacteroidota). In this study, we provide a blueprint for future work aimed at better understanding the novel biota of Mt. Erebus.

microbiology↗

bioRxiv2021

How do symbiotic associations in lecideoid lichens respond to different environmental conditions along the Transantarctic Mountains, Ross Sea region, Antarctica?

Lecideoid lichens as dominant vegetation-forming organisms in the climatically harsh areas of the southern part of continental Antarctica show clear preferences in relation to environmental conditions (i.e. macroclimate). 306 lichen samples were included in the study, collected along the Ross Sea coast (78{degrees}S-85.5{degrees}S) at six climatically different sites. The species compositions as well as the associations of their two dominant symbiotic partners (myco- and photobiont) were set in context with environmental conditions along the latitudinal gradient. Diversity values were nonlinear with respect to latitude, with the highest alpha diversity in the milder areas of the McMurdo Dry Valleys (78{degrees}S) and the most southern areas (Durham Point, 85.5{degrees}S; Garden Spur, 84.5{degrees}S), and lowest in the especially arid and cold Darwin Area (~79.8{degrees}S). Furthermore, the specificity of mycobiont species towards their photobionts decreased under more severe climate conditions. The generalist lichen species Lecanora fuscobrunnea and Lecidea cancriformis were present in almost all habitats, but were dominant in climatically extreme areas. Carbonea vorticosa, Lecidella greenii and Rhizoplaca macleanii were confined to milder areas. In summary, the macroclimate is considered to be the main driver of species distribution, making certain species useful as bioindicators of climate conditions and, consequently, for detecting climate change.

ecology↗

bioRxiv2018

Microbial biogeography of 1,000 geothermal springs in New Zealand

Geothermal springs are model ecosystems to systematically investigate microbial biogeography as they i) represent discrete, homogenous habitats; ii) are abundantly distributed across multiple geographical scales; iii) span broad geochemical gradients; and iv) have simple community structures with reduced metazoan interactions. Taking advantage of these traits, we undertook the largest known consolidated study of geothermal ecosystems (http://1000springs.org.nz) to determine factors that influence biogeographical patterns. Rigorously standardised methodologies were used to measure microbial communities, 46 physicochemical parameters, and metadata from 1,019 hotspring samples across New Zealand. pH was found to be the primary influence on diversity in springs < 70 {degrees}C with community similarity decreasing with geographic distance. Surprisingly, community composition was dominated by two genera (Venenivibrio and Acidithiobacillus) in both average relative abundance (11.2 and 11.1 %) and prevalence (74.2 and 62.9 % respectively) across physicochemical spectrums of 13.9 - 100.6 {degrees}C and pH < 1 - 9.7. This study provides an unprecedented insight into the ecological conditions that drive community assembly in geothermal springs, and can be used as a foundation to improve the characterisation of global microbial biogeographical processes.

microbiology↗