Testate amoebae are a widely-used tool for palaeohydrological reconstruction from peatlands. However, it has been observed that weak idiosomic siliceous tests (WISTs) are common in uppermost peats, but very rarely found as subfossils deeper in the peat profile. This taphonomic problem has been noted widely and it has been established that WISTs disaggregate and/or dissolve in the low pH condition of ombrotrophic peatlands. Here we investigate the effect of this taphonomic problem on water-table reconstructions from thirty European peatlands through the comparison of reconstructions based on all taxa and those with WISTs removed. In almost all cases the decomposition of WISTs does not introduce discernible bias to peatland water-table reconstructions. However, some discrepancy is apparent when large abundances of Corythion-Trinema type are present (9-12 cm deviation with 50-60% abundance of this particular taxon). We recommend that WISTs should be removed before carrying out water-table reconstructions, and that the minimum count of testate amoebae per sample should exclude WISTs to ensure the development of robust reconstructions.
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http://dx.doi.org/10.1016/j.ejop.2020.125693 | DOI Listing |
Sci Total Environ
January 2025
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China. Electronic address:
Wetlands, one of the largest source of methane (CH) on Earth, are undergoing extensive disturbance globally, resulting in profound impacts on global changes. This study conducted a comprehensive global meta-analysis of field studies to assess the effects of wetland disturbance on CH emissions and the key factors influencing these changes. Our analysis indicates that while CH emissions generally decrease following wetland disturbance, the global warming potential does not necessarily diminish compared to that of natural wetlands.
View Article and Find Full Text PDFAnn N Y Acad Sci
December 2024
Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, Texas, USA.
Tropical cyclones (TCs) are one of the major natural hazards to island and coastal communities and ecosystems. However, isotopic compositions of TC-derived precipitation (P) in surface water (SW) and groundwater (GW) reservoirs are still lacking. We tested the three main assumptions of the isotope storm "spike" hypothesis (sudden spikes in isotopic ratios).
View Article and Find Full Text PDFEnviron Microbiome
December 2024
Innovative Genomics Institute, University of California, Berkeley, CA, 94720, USA.
Background: Underground research laboratories (URLs) provide a window on the deep biosphere and enable investigation of potential microbial impacts on nuclear waste, CO and H stored in the subsurface. We carried out the first multi-year study of groundwater microbiomes sampled from defined intervals between 140 and 400 m below the surface of the Horonobe and Mizunami URLs, Japan.
Results: We reconstructed draft genomes for > 90% of all organisms detected over a four year period.
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Key Laboratory of Water and Sediment Sciences, Ministry of Education, 100871, Beijing, P. R. China.
J Chromatogr A
January 2025
Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 00 Prague, Czech Republic. Electronic address:
Phosphatidylglycerol (1,2-diacyl-sn-glycero-3-phospho-glycerol) (PG) is one of the most abundant lipids in biological membranes. However, the chirality of the carbon atom in glycerol phosphate differs among the three kingdoms: bacteria, archaea, and eukaryotes. It is commonly assumed that archaea, as well as bacteria and eukaryotes, produce only one isomer of PG.
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