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Unlabelled: Extant climate observations suggest the dry season over large parts of the Amazon Basin has become longer and drier over recent decades. However, such possible intensification of the Amazon dry season and its underlying causes are still a matter of debate. Here we used oxygen isotope ratios in tree rings (δO) from six floodplain trees from the western Amazon to assess changes in past climate. Our analysis shows that δO of these trees is negatively related to inter-annual variability of precipitation during the dry season over large parts of the Amazon Basin, consistent with a Rayleigh rainout model. Furthermore δO increases by approximately 2‰ over the last four decades (~ 1970-2014) providing evidence of an Amazon drying trend independent from satellite and in situ rainfall observations. Using a Rayleigh rainout framework, we estimate basin-wide dry season rainfall to have decreased by up to 30%. The δO record further suggests such drying trend may not be unprecedented over the past 80 years. Analysis of δO with sea surface temperatures indicates a strong role of a warming Tropical North Atlantic Ocean in driving this long-term increase in δO and decrease in dry season rainfall.
Supplementary Information: The online version contains supplementary material available at 10.1007/s00382-021-06046-7.
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http://dx.doi.org/10.1007/s00382-021-06046-7 | DOI Listing |
Mar Environ Res
September 2025
Center for Eco-Environment Restoration of Hainan Province, Hainan University, Haikou, 570228, China; Hainan International Joint Research Center for Reef Ecology, School of Ecology, Hainan University, Haikou, 570228, China. Electronic address:
Per- and polyfluoroalkyl substances (PFASs) have gained attention due to their chemical stability, bioaccumulation potential, and toxicity. The ocean serves as the ultimate sink for these compounds in the global environment. With the rapid development of the Hainan Free Trade Port, environmental pollution on Hainan Island has consequently become more pronounced.
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August 2025
RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic. Electronic address:
Water contamination by micropollutants is a global issue, yet there is limited information from low-income regions. To address this, we evaluated surface water quality in rapidly growing Sub-Saharan area of Malawi lacking wastewater treatment. Integrated assessment of passive sample extracts representing wet and dry seasons combined effect-based approach with in vitro bioassays, target and non-target chemical analyses (NTS).
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Laboratório de Imuno-histoquímica e Biologia Do Desenvolvimento, Instituto de, Ciências Biológicas, Universidade Federal Do Pará, 66075-110, Belém, Pará, Brazil. Electronic address:
High natural concentrations of metals in Amazonian soils, combined with rainfall, increase metal availability in rivers and streams. This study objective was the environmental quality of two microbasins using integrated biomarkers in Leporinus friderici. Water, sediment, and fish samples were collected during the rainy and dry seasons from the Parariquara and Potiritá river microbasins, located near an area of mining in Paragominas, Pará, Brazil.
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Instituto de Ecología, Departamento de Ecología de la Biodiversidad, Universidad Nacional Autónoma de México, Campus Hermosillo, Luis Donaldo Colosio s/n, Los Arcos, Hermosillo, Sonora CP 83250, México.
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Hubei Key Laboratory of Regional Ecology and Environmental Change, School of Geography and Information Engineering, China University of Geosciences, Wuhan, 430078, China. Electronic address:
Diatoms, an important group of primary producers, are valuable indicators of environment changes in aquatic ecosystems. Presently, limited knowledge is available on diatoms living on tree bark and their responses to atmospheric environmental changes. Mosses such as Hypnum callichroum living on the bark of Cinnamomum camphora were collected monthly in a 9-year period to explore temporal changes in composition, biomass and valve length of diatoms in a subtropical evergreen broadleaf forest.
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