Glaciated environments have been highlighted as important sources of bioavailable nutrients, with inputs of glacial meltwater potentially influencing productivity in downstream ecosystems. However, it is currently unclear how riverine nutrient concentrations vary across a spectrum of glacial cover, making it challenging to accurately predict how terrestrial fluxes will change with continued glacial retreat. Using 40 rivers in Chilean Patagonia as a unique natural laboratory, we investigate how glacial cover affects riverine Si and Fe concentrations, and infer how exports of these bioessential nutrients may change in the future. Dissolved Si (as silicic acid) and soluble Fe (<0.02 μm) concentrations were relatively low in glacier-fed rivers, whereas concentrations of colloidal-nanoparticulate (0.02-0.45 μm) Si and Fe increased significantly as a function of glacial cover. These colloidal-nanoparticulate phases were predominately composed of aluminosilicates and Fe-oxyhydroxides, highlighting the need for size-fractionated analyses and further research to quantify the lability of colloidal-nanoparticulate species. We also demonstrate the importance of reactive particulate (>0.45 μm) phases of both Si and Fe, which are not typically accounted for in terrestrial nutrient budgets but can dominate riverine exports. Dissolved Si and soluble Fe yield estimates showed no trend with glacial cover, suggesting no significant change in total exports with continued glacial retreat. However, yields of colloidal-nanoparticulate and reactive sediment-bound Si and Fe were an order of magnitude greater in highly glaciated catchments and showed significant positive correlations with glacial cover. As such, regional-scale exports of these phases are likely to decrease as glacial cover disappears across Chilean Patagonia, with potential implications for downstream ecosystems.
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http://dx.doi.org/10.1029/2020GB006611 | DOI Listing |
Zool Stud
July 2024
Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an 710069, China. E-mail: (Li); (R. Pan); (H. Zhang); (H. Wang); (Zou); Zhang); (H. Pan); (J. Wang); (G. Guo); (Hou); (Huang); (S. Guo); (He); (P. Zhang).
Understanding how climate, ecological and environmental changes, and anthropogenic activities have driven animals' development and predicting their prospective distribution profiles are essential to making a tangible conservation strategy. Macaques () distributed in China provide an ideal research model for such an effort. We reconstruct their geographic distribution profiles from the last inter-glaciation (LIG, 120,000-140,000 years BP), the Last Glacial Maximum (LGM, 22,000 years BP), and the present (1970-2000), based on which we deduce their distribution perspective in the 2050s.
View Article and Find Full Text PDFAnn Bot
December 2024
Institute of Plant Science and Microbiology, University of Hamburg, Germany.
Background And Aims: Oophytum (Aizoaceae) is a locally endemic genus of the extremely fast evolving subfamily Ruschioideae and consists of only two formally accepted species (O. nanum and O. oviforme).
View Article and Find Full Text PDFMol Ecol
December 2024
Department of Herpetology, American Museum of Natural History, New York, New York, USA.
Glacial cycles during the Pleistocene had profound impacts on local environments and climatic conditions. In North America, some regions that currently support diverse biomes were entirely covered by ice sheets, while other regions were environmentally unsuitable for the organisms that live there now. Organisms that occupy these regions in the present day must have expanded or dispersed into these regions since the last glacial maximum, leading to the possibility that species with similar geographic distributions may show temporally concordant population size changes associated with these warming trends.
View Article and Find Full Text PDFSci Total Environ
December 2024
Guangdong Key Lab of Geodynamics and Geohazards, School of Earth Sciences and Engineering, Sun Yat-sen University, Zhuhai 519082, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China. Electronic address:
Previous studies have advanced our understanding of paleoclimate features and dynamics in East Asia, particularly within the East Asian monsoon domain (EAMD) since the last glacial period. However, a lack of quantitative reconstructions in the boundary area between tropical and subtropical zones has largely hindered our spatial comprehension of the relationship between precipitation and temperature throughout the EAMD. In this study, we present a continuous pollen record from the Pearl River delta over the past 13.
View Article and Find Full Text PDFAn Acad Bras Cienc
December 2024
Universidade Federal do Rio Grande do Sul, Instituto de Geociências, Centro Polar e Climático, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brazil.
Glaciers are sensitive to environmental climatic conditions and show their variability over time. This study investigates the environmental characteristics and variation in glacial cover of the Greenwich, Livingston, Robert and Snow islands, Antarctica, between 1956 and 2023. The glacier extension mapping was based on visual interpretation of the Landsat 4, 7 and 8 optical images and normalised difference indexes combination.
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