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Under the backdrop of increasingly frequent wetland alternation between dry and wet conditions driven by global climate change, the differential impact mechanisms of microplastics (MPs) on microbial communities under drought and flooding conditions remain insufficiently characterized. This study established a sediment microcosm experimental system for Poyang Lake wetland to systematically analyze the regulatory effects of polyethylene (PE) and polypropylene (PP) microplastics on sediment bacterial community structure, functional genes, and ecological processes over 180 days under simulated drought and flooded conditions. The results demonstrated that microplastics significantly enhanced the richness (Chao1 index +95.9 %) and diversity (Shannon index +61.6 %) of sediment bacterial communities, with a more pronounced promoting effect under flooded conditions (η = 0.36). Furthermore, PE exhibited a more pronounced influence on community structure than PP, particularly under drought conditions. Under flooding microplastics upregulated nitrogen and sulfur cycling functional genes by enriching Nitrospira and Desulfatiglans, but concurrently increased the abundance of potential pathogenic bacteria (p < 0.001). Under drought conditions, Streptomyces emerged as the core genus, driving the expression of carbon metabolism genes (rho >0.56) and enhancing stress resistance. Null model analysis revealed that bacterial community succession was primarily driven by deterministic processes (contribution rate >51.3 %), while MPs restructured ecological niche by significantly reducing ammonium nitrogen (-14.35 %),and nitrate nitrogen (-13.64 %), while regulating pH and organic carbon levels. This study provides insights into the specific risks associated with "plasticosphere" formation under flooded and drought conditions: flooded conditions may exacerbate pathogen dissemination and metabolic dysregulation, whereas drought promotes carbon sequestration. Based on these findings, a hierarchical governance strategy is proposed, offering new insights for wetland ecological restoration.
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http://dx.doi.org/10.1016/j.jenvman.2025.126531 | DOI Listing |
Oecologia
September 2025
School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA, 70803, USA.
Stomatal closure is a pervasive response among trees exposed to flooded soil. We tested whether this response is caused by reduced hydraulic conductance in the soil-to-leaf hydraulic continuum (k), and particularly by reduced root hydraulic conductance (k), which has been widely hypothesized. We tracked stomatal conductance at the leaf level (g) and canopy scale (G) along with physiological conditions in two temperate tree species, Magnolia grandiflora and Quercus virginiana, that were subjected to flood and control conditions in a greenhouse experiment.
View Article and Find Full Text PDFEnviron Sci Process Impacts
September 2025
Nebraska Water Center, Part of the Robert B. Daugherty Water for Food Global Institute 2021 Transformation Drive, University of Nebraska, Lincoln, Nebraska 68588-6204, USA.
Rice is consumed by ∼50% of the global population, grown primarily in flooded paddy fields, and is susceptible to arsenic accumulation. Inorganic arsenic, particularly in reduced form (As(III)), is considered the most toxic and is more likely to accumulate in rice grains under flooded systems. We postulate that increased levels of highly reactive iron minerals, such as ferrihydrite, in paddy soils can regulate the bioavailability of arsenic and reduce its uptake by priming iron plaque formation.
View Article and Find Full Text PDFJ Acoust Soc Am
September 2025
School of Electrical and Computer Engineering, Tel Aviv University, Tel Aviv 69978, Israel.
This paper presents relatively simple formulations of the problem of acoustic scattering by flooded and hollow elastic shells immersed in fluids, which can serve as a basis for efficient numerical models. The full rigorous formulation of the problem, which involves the Helmholtz equations for acoustic pressures in the fluids and the Navier equation for three-dimensional displacements in the elastic material, is reduced to a boundary value problem only for the Helmholtz equations with effective boundary conditions relating the boundary pressures and normal displacements on both sides of the shell. To that end, the thin elastic shell is regarded as a neighborhood of its midsurface, and the boundary values of the elastic quantities (displacements and stresses) are expressed via their expansions about the midsurface, considering the shell thickness as a small parameter.
View Article and Find Full Text PDFFront Plant Sci
August 2025
Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom.
Climate change is leading to increases in extreme weather events, notably increasing both droughts and floods, which undermine food security. Although each stress individually has been well studied, little is known about the response of cereals to successive water stresses, condition that often occurs in real-world scenarios. To address this gap, we have compared physiological responses of wheat and barley cultivars to cycles of drought and flooding.
View Article and Find Full Text PDFJ Environ Manage
September 2025
College of chemistry and chemical Engineering, Ocean University of China, Qingdao, China. Electronic address:
Tidal estuaries serve as critical zones for biogeochemical connectivity between terrestrial and oceanic ecosystems. With climate change magnifying the impact of flood events on riverine system, dissolved organic matter (DOM) cycling, the largest reactive elemental pool in ecosystems, in tidal estuaries tend to be more complex and remain poorly understood. To address this gap, the response of DOM dynamics to flood events in a typical tidal estuary was explored.
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