Article
Geochemistry & Geophysics
Megan C. Corcoran, Aaron F. Diefendorf, Thomas V. Lowell, Brenda L. Hall, Meghan M. Spoth, Anna Schartman, Paul Brickle
Summary: The hydrogen isotope composition of terrestrial plant waxes (delta H-2(wax)) is widely used to reconstruct past hydroclimate. By analyzing 11 common plant species on the Falkland Islands, it was found that the most commonly observed plants, Empetrum rubrum and Cortaderia pilosa, contribute the most to the waxes in sediment archives. The fractionation between n-C29 alkane delta H-2(wax) and delta H-2(precip) values was calculated to be similar to the global average, indicating that delta H-2(wax) values can be interpreted as mean annual delta H-2(precip) values in plant wax-based paleoreconstructions.
ORGANIC GEOCHEMISTRY
(2022)
Editorial Material
Environmental Sciences
William C. Daniels
Summary: Paleoclimatologists use lake sediments to reconstruct past changes in precipitation and evaporation. Recent research in Arctic lakes shows that aquatic plants contribute significantly to the wax signals, providing a method for identifying the sources of plant waxes in these lakes.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2022)
Article
Geography, Physical
Meghan Spoth, Brenda Hall, Thomas Lowell, Aaron F. Diefendorf, Megan C. Corcoran, Paul Brickle
Summary: The Southern Hemisphere Westerlies (SHW) have the potential to drive abrupt climate change, and their past temporal and spatial changes have been studied using lake sediment proxies. The result shows that the position of the SHW during the last glacial maximum was north of the Falkland Islands, but gradually migrated southwards during the early Holocene and then northwards during the remainder of the Holocene.
QUATERNARY SCIENCE REVIEWS
(2023)
Article
Environmental Sciences
Kayla Hollister, Elizabeth K. Thomas, Martha K. Raynolds, Helga Bultmann, Jonathan H. Raberg, Gifford H. Miller, Julio Sepulveda
Summary: Sedimentary plant wax delta H-2 values are commonly used as proxies for hydrology in the poorly understood Arctic region. This study investigates the sources of mid- and long-chain plant waxes in Arctic lake sediments and concludes that mid-chain waxes primarily come from aquatic plants, while long-chain waxes are a mix of terrestrial and aquatic plants. These findings highlight the importance of considering the contribution of different plant types when interpreting climate data from sedimentary plant waxes.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2022)
Article
Geochemistry & Geophysics
Jochem Baan, Meisha Holloway-Phillips, Daniel B. Nelson, Ansgar Kahmen
Summary: Variation in plant organic compound 82H and 818O values among species is common, but the extent to which this is driven by leaf water or biochemical isotope effects is unclear. Comparing leaf water and organic compound isotope values across 192 species, we found that variation in leaf water values may not strongly drive the variation in organic compound values.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geography, Physical
Robert D. Bourque, Peter M. J. Douglas, Hans C. E. Larsson
Summary: This study used fossilized plant wax n-alkanes in fluvial sediments to reconstruct changes in plant ecology and carbon and water cycling across the Cretaceous-Paleogene boundary. The results show an increase in the relative abundance of terrestrial plants immediately after the boundary, possibly facilitated by the extinction of large herbivores. Additionally, the study found short-lived carbon and water cycle changes associated with the K-Pg impact in Western Canada, while longer-lasting ecological shifts in plant communities were observed.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geochemistry & Geophysics
Anic Imfeld, Alexandre Ouellet, Peter M. J. Douglas, Gregor Kos, Yves Gelinas
Summary: Sediments contain a variety of inorganic and organic components, with the composition of organics not fully characterized. Research focused on n-alkanes in coastal sediments shows variations in abundance and sources along the terrestrial-marine continuum. Isotopic analysis of odd and even n-alkanes can be used to determine their sources.
ORGANIC GEOCHEMISTRY
(2022)
Article
Geochemistry & Geophysics
Daolai Zhang, Emily J. Beverly, Naomi E. Levin, Efrain Vidal, Yannick Matia, Sarah J. Feakins
Summary: The study demonstrates that comparing the carbon isotope δ13C values can determine the distribution of C-4 grasslands in different types of carbon-bearing materials. Soil samples from the Serengeti ecosystem show that plant wax and organic material δ13C values are most accurate in recording vegetation cover, and they have broad applicability in various environments.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Soil Science
C. Wiltshire, T. W. Waine, R. C. Grabowski, J. Meersmans, B. Thornton, S. Addy, M. Glendell
Summary: This study explores the use of multiple soil biomarkers, including biomarkers from plant, fungal, and bacterial sources, to distinguish sediment sources from different land uses. The results suggest that the inclusion of short chain neutral lipid fatty acids (SC-NLFA) improves the discrimination between land uses. By using a Bayesian un-mixing model, the performance of combined n-alkanes and SC-NLFA biomarkers in distinguishing sediment sources was assessed. The study finds that combining n-alkanes and SC-NLFA or using SC-NLFA and their compound specific stable isotope signatures alone can more accurately differentiate land use sources.
Article
Environmental Sciences
Jinzhao Liu
Summary: The study showed that δ H-2(wax) values can be reliably used as a proxy for reconstructing paleoelevation in arid conditions. However, it will be necessary to identify other proxies to supplement δ H-2(wax) values under a dual-isotope approach in future research.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Biochemistry & Molecular Biology
Rory Connolly, Margarita Jambrina-Enriquez, Antonio Herrera-Herrera, Carolina Mallol
Summary: This study conducted heating experiments on lipid biomarkers extracted from different tissues of Celtis australis plants, revealing isotopic variations during short-term low-temperature combustion. It emphasizes the cautious interpretation of δH-2(wax) values in archaeological or highly anthropogenic environments, and highlights the potential for palaeoclimate information analysis.
Article
Geosciences, Multidisciplinary
Mark D. Peaple, Tripti Bhattacharya, Tim K. Lowenstein, David McGee, Kristian J. Olson, Justin S. Stroup, Jessica E. Tierney, Sarah J. Feakins
Summary: The climate of southwestern North America has undergone significant changes between wet and dry phases over the past 200,000 years. A multi-proxy biomarker study conducted on sediment cores from Searles Lake, California reveals the timing, magnitude, and paleoenvironmental impacts of these hydroclimate changes. Precipitation isotopes show a connection with glacial to interglacial changes, but do not align with evidence of wet-dry vegetation and lake conditions, suggesting a partial disconnect between atmospheric circulation and landscape moisture availability. Limnological conditions during Termination II indicate a fresh, productive, and well-mixed lake, while temperature estimates during Heinrich stadial 11 suggest wetter conditions compared to the last glacial maximum and Heinrich 1.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2022)
Article
Environmental Sciences
Yan Chen, Yanhua Wang, Kangkang Yu, Zihan Zhao, Xiulu Lang
Summary: This study investigated the occurrence and temporal variations in the fluxes and compositions of n-alkanes and polycyclic aromatic hydrocarbon (PAHs) in sediment cores from a small catchment in western Dianchi lake, China. The results showed the ongoing organic contamination from inputs to outputs, highlighting the influence of agricultural and industrial economy on the catchment outlets.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Jinzhao Liu, Jiaju Zhao, Ding He, Xianyu Huang, Chong Jiang, Hong Yan, Guanghui Lin, Zhisheng An
Summary: Terrestrial leaf wax n-alkane biomarkers play a significant role in paleoenvironmental reconstruction, but the effects of plant types on their accuracy are important. This review examines the impact of plant types on leaf wax n-alkane biomarkers, including their distribution, hydrogen isotope composition, and carbon isotope composition, and provides examples of cross-calibration in paleo-applications.
EARTH-SCIENCE REVIEWS
(2022)
Article
Environmental Sciences
Ricardo N. N. Santos, Enno Schefuss, Livia Gebara M. S. Cordeiro, Dulce Oliveira, Armand Hernandez, Alexandre M. M. Ramos, Teresa Rodrigues
Summary: This study characterizes the leaf waxes of dominant plants in a high-mountain glacial lake area in Portugal and examines their potential for reconstructing climate and environmental changes. The results show that the vegetation is dominated by C-3 grasses/herbs and shrubs, with different molecular and compound-specific signatures.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Engineering, Environmental
Linnea K. Honeker, Gina A. Hildebrand, Jane D. Fudyma, L. Erik Daber, David Hoyt, Sarah E. Flowers, Juliana Gil-Loaiza, Angelika Kuebert, Ines Bamberger, Christopher R. Anderton, John Cliff, Sarah Leichty, Roya AminiTabrizi, Juergen Kreuzwieser, Lingling Shi, Xuejuan Bai, Dusan Velickovic, Michaela A. Dippold, S. Nemiah Ladd, Christiane Werner, Laura K. Meredith, Malak M. Tfaily
Summary: This study examined the effects of drought on root metabolic profiles and carbon allocation pathways of three tropical rainforest species. The results showed that drought had species-specific impacts on metabolic profiles and spatial distribution in different plants. The presence of microbial also influenced root metabolic pathways.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Geochemistry & Geophysics
Ding He, S. Nemiah Ladd, Jiwoon Park, Julian P. Sachs, Bernd R. T. Simoneit, Joseph M. Smoak, Rudolf Jaffe
Summary: This study investigates the potential and applicability of taraxerol as a proxy for hydroclimate reconstruction in mangrove ecosystems. The isotopic composition and spatial trends of taraxerol in mangrove leaves and sediments are examined, providing insights into past climate changes in mangrove swamps. However, caution should be taken when interpreting the delta C-13 values of taraxerol due to species-specific correlation with salinity and potential diagenetic enrichment.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Ecology
Cameron M. Hudson, S. Nemiah Ladd, Miguel C. Leal, Carsten J. Schubert, Ole Seehausen, Blake Matthews
Summary: The study compared the differences in fatty acid composition between different stickleback lineages and ecotypes. Wild fish and lab-reared fish exhibited different levels of fatty acids, while females had lower omega-6:omega-3 ratio than males.
Article
Microbiology
Kathrin B. L. Baumann, Raoul Thoma, Cameron M. Callbeck, Robert Niederdorfer, Carsten J. Schubert, Beat Mueller, Mark A. Lever, Helmut Buergmann
Summary: The nitrogen cycle is crucial for global ecosystems, and excessive use of nitrogen fertilizers can harm aquatic ecosystems. However, the microbial communities involved in nitrogen removal in freshwater lake sediments are poorly understood. This study investigates the abundance of microbial nitrogen transformation genes in two lakes with contrasting trophic states and demonstrates the importance of understanding the genomic potential for nitrogen transformation in interpreting nitrogen process rates.
Article
Geosciences, Multidisciplinary
Jasmine S. Berg, Mathilde Lepine, Emile Laymand, Xingguo Han, Hendrik Vogel, Marina A. Morlock, Niroshan Gajendra, Adrian Gilli, Stefano M. Bernasconi, Carsten J. Schubert, Guangyi Su, Mark A. Lever
Summary: This study comprehensively investigates the deep lacustrine biosphere in Lake Cadagno and its impact on sediment geochemistry and vice versa. The findings reveal distinct redox gradients, microbial activities, and organic carbon remineralization processes in the deep sediment layers compared to the water column.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Plant Sciences
Meisha Holloway-Phillips, Jochem Baan, Daniel B. Nelson, Marco M. Lehmann, Guillaume Tcherkez, Ansgar Kahmen
Summary: This study analyzed the δH-2 and δO-18 of leaf sucrose, leaf cellulose, and leaf and xylem water in multiple species for the first time. The results showed that the δH-2 of sucrose can explain 66% of the variation in cellulose δH-2, which is influenced by the H-2 enrichment of sucrose relative to leaf water. The study also found that hydrogen isotopic exchange in sugars is related to dark respiration and carbohydrate turnover time.
PLANT CELL AND ENVIRONMENT
(2022)
Correction
Geosciences, Multidisciplinary
Jasmine S. Berg, Mathilde Lepine, Emile Laymand, Xingguo Han, Hendrik Vogel, Marina A. Morlock, Niroshan Gajendra, Adrian Gilli, Stefano M. Bernasconi, Carsten J. Schubert, Guangyi Su, Mark A. Lever
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Multidisciplinary Sciences
Joseph Byron, Juergen Kreuzwieser, Gemma Purser, Joost van Haren, S. Nemiah Ladd, Laura K. Meredith, Christiane Werner, Jonathan Williams
Summary: Monoterpenes, emitted by vegetation, have different enantiomers with distinct emission patterns and ecological functions. This study reveals the emission differences of monoterpene enantiomers in response to drought and rewetting, and their impact on cloud formation, contributing to a better understanding of the atmospheric feedbacks to climate change.
Article
Plant Sciences
Angelika Kuebert, Maren Dubbert, Ines Bamberger, Kathrin Kuehnhammer, Matthias Beyer, Joost van Haren, Kinzie Bailey, Jia Hu, Laura K. Meredith, S. Nemiah Ladd, Christiane Werner
Summary: The isotopic composition of xylem water (delta(X)) can be estimated using the isotopic composition of transpired water (delta(T)). In a rainforest experiment, the transpiration-derived isotopic values were found to be closely related to the source water values. This suggests that the in-situ transpiration method is a useful tool for studying rapid dynamics in plant water uptake and use.
PLANT CELL AND ENVIRONMENT
(2023)
Article
Ecology
Gregoire Saboret, Dominique Stalder, Blake Matthews, Jakob Brodersen, Carsten Johnny Schubert
Summary: Based on a study of seven perialpine lakes, it was found that the main source of organic carbon in lake food webs is from algae, rather than terrestrial plants. However, a significant portion of organic carbon in fish comes from bacteria. The sources of nitrogen vary among lakes, but the sources of organic carbon are relatively consistent and not strongly influenced by trophic status. This study provides new methods for estimating the source of organic carbon in lake ecosystems.
FRESHWATER BIOLOGY
(2023)
Article
Environmental Sciences
Giuliana Panieri, Jochen Knies, Sunil Vadakkepuliyambatta, Amicia L. L. Lee, Carsten J. J. Schubert
Summary: During the Pleistocene, there were significant changes in Earth's climate, leading to increased ice volume and methane leakage. Borehole data from the Arctic-Atlantic gateway region reveals three main seafloor leakage episodes prior to and during the mid-Pleistocene transition. Combining this data with hydrate stability modeling, it is proposed that tectonic stress changes associated with ice volume changes controlled episodic methane leakages.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Plant Sciences
Meisha Holloway-Phillips, Lucas A. Cernusak, Daniel B. Nelson, Marco M. Lehmann, Guillaume Tcherkez, Ansgar Kahmen
Summary: Oxygen and hydrogen isotopes of cellulose in plant biology can be used to understand environmental conditions, but their covariation is not well understood. This study compared plant water, leaf cellulose, and branch cellulose across an aridity gradient in Northern Australia. The researchers found a decline in covariation from xylem to leaf water, and from leaf to branch wood cellulose. The results suggest that postphotosynthetic isotope exchange with water is more apparent for oxygen isotopes, while variable kinetic and nonequilibrium isotope effects complicate the interpretation of metabolic-induced d(2)H patterns.
Article
Geochemistry & Geophysics
Mariliis Eensalu, Daniel B. Nelson, Anna Buczynska, Oliver Rach, Eric S. Klein, Justin P. Dodd, Anneli Poska, Nathan D. Stansell
Summary: Studies of plants in modern catchment systems can improve the understanding of sedimentary plant wax hydrogen isotope data. This study compared two lake catchments in Estonia and investigated the link between local climate conditions, plant source water, leaf water, and plant lipids. The results provide insights into how hydro-climatic signals from precipitation are modified by environmental conditions and plant physiology.
ORGANIC GEOCHEMISTRY
(2023)
Article
Environmental Sciences
Kathrin Kuehnhammer, Joost van Haren, Angelika Kuebert, Kinzie Bailey, Maren Dubbert, Jia Hu, S. Nemiah Ladd, Laura K. Meredith, Christiane Werner, Matthias Beyer
Summary: Deep rooting is a crucial drought-mitigation trait that plays a significant role in the water cycling of ecosystems. However, there is limited knowledge regarding the quantitative water use of deep roots and the dynamic shifts of water uptake depths with changing ambient conditions, especially for tropical trees. In this study, researchers conducted a drought, deep soil water labeling, and re-wetting experiment in the Biosphere 2 Tropical Rainforest. They found that deep soil serves as an essential water source for tropical trees, mitigating the negative impacts of drought caused by climate change. The water uptake largely depends on precipitation input.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Geochemistry & Geophysics
Xinze Lu, Geoffrey J. Gilleaudeau, Brian Kendall
Summary: The Late Ordovician mass extinction is the first major extinction event in the Phanerozoic, but the reasons for the decline in global biodiversity before the extinction are not well understood.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)
Article
Geochemistry & Geophysics
Junyao Kang, Daniel D. Gregory, Benjamin Gill, Shiqiang Huang, Changxin Lai, Zhaoshan Chang, Huan Cui, Ivan Belousov, Shuhai Xiao
Summary: Sedimentary pyrite is an important geological archive, but it can be altered by diagenetic and hydrothermal processes. This study successfully trained machine learning algorithms to distinguish pyrite origins using trace element data. The approach was validated and applied to identify the origins of pyrite in two sedimentary successions in South China.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)