The Amazon river basin receives ~2000 mm of precipitation annually and contributes ~17% of global river freshwater input to the oceans; its hydroclimatic variations can exert profound impacts on the marine ecosystem in the Amazon plume region (APR) and have potential far-reaching influences on hydroclimate over the tropical Atlantic. Here, we show that an amplified seasonal cycle of Amazonia precipitation, represented by the annual difference between maximum and minimum values, during the period 1979-2018, leads to enhanced seasonalities in both Amazon river discharge and APR ocean salinity. An atmospheric moisture budget analysis shows that these enhanced seasonal cycles are associated with similar amplifications in the atmospheric vertical and horizontal moisture advections. Hierarchical sensitivity experiments using global climate models quantify the relationships of these enhanced seasonalities. The results suggest that an intensified hydroclimatological cycle may develop in the Amazonia atmosphere-land-ocean coupled system, favouring more extreme terrestrial and marine conditions.
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http://dx.doi.org/10.1038/s41467-020-18187-0 | DOI Listing |
Neotrop Entomol
January 2025
Lab of Environmental Sciences and Biodiversity, Univ Estadual do Maranhão, São Luís, Maranhão, Brazil.
The diverse ecosystems of the Amazon biome play a vital role in the maintenance of biodiversity and delivering essential ecosystem services at both local and global levels. Small-bodied generalist insects, such as those from the order Odonata, contribute significantly to these services and are recognized as sensitive bioindicators of environmental quality. The present study evaluated the diversity and distribution of adult odonates in the Legal Amazonia zone of the Brazilian state of Maranhão, to identify the key environmental drivers shaping local odonate communities.
View Article and Find Full Text PDFBraz J Biol
January 2025
Instituto Nacional de Pesquisas da Amazônia - INPA, Programa de Pós-graduação em Ecologia - PPGEco, Manaus, AM, Brasil.
Pentaclethra macroloba is a hyperdominant species with multiple uses in the Amazon. This species tolerates varying flood amplitudes, however the effect of flood topographic gradient on its ecophysiology remains unclear. We want to know if individuals from the high (10 trees) and low (20 trees) várzea show distinct phenological patterns as a function of the flood gradient, as well as their colonization strategies and their seed predators.
View Article and Find Full Text PDFAm J Primatol
January 2025
Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada.
The Riverine Barrier Hypothesis posits that species distributions are limited by large rivers acting as geographical barriers. Accordingly, large rivers have long been thought to be a major driver of the extensive speciation and high levels of biodiversity among platyrrhine primates in South and Central America. Direct observations of river crossings provide evidence that complements studies of genetic diversity that can together shed new light on this hypothesis.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Centre de Recherche sur la Biodiversité et l'Environnement, Université de Toulouse, Institut de Recherche pour le Développement, Institut National Polytechnique de Toulouse, Université Toulouse 3 - Paul Sabatier, Toulouse F-31062, France.
Unlike most rivers globally, nearly all lowland Amazonian rivers have unregulated flow, supporting seasonally flooded floodplain forests. Floodplain forests harbor a unique tree species assemblage adapted to flooding and specialized fauna, including fruit-eating fish that migrate seasonally into floodplains, favoring expansive floodplain areas. Frugivorous fish are forest-dependent fauna critical to forest regeneration via seed dispersal and support commercial and artisanal fisheries.
View Article and Find Full Text PDFEcohealth
January 2025
Wildlife Conservation Medicine Research Group (WildCoM), Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
Peccaries (collared peccary-CP-and white-lipped peccary-WLP) are an essential source of protein and income for rural communities in the Amazon region. Since 1980s, researchers in the Amazon have reported recurrent local disappearances of WLP populations. Although such disappearances impact the species conservation and the food security of rural societies, no studies have drawn consistent conclusions about the causes of these population collapses.
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