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Bioactivity of Ascophyllum nodosum in Mitigating Water Stress Induced by PEG-6000 in Maize Seeds

Janyne Soares Braga Pires

,

Francine Bonomo Crispim Silva

,

Maria Eduarda da Silva Barbosa

,

Geovana Ribeiro Cavilha

,

Mateus Moura Coelho

,

Samile Mardegan Otilia

,

Fernando Gomes Hoste

,

Ana Júlia Câmara Jeveaux-Machado

,

Lúcio de Oliveira Arantes

,

Vinicius de Souza Oliveira

+2 authors

Abstract: Water deficit is one of the main limiting factors for crop establishment and productivity, particularly affecting seed germination and early seedling growth. This study aimed to evaluate the biostimulant effect of Ascophyllum nodosum extract on maize (Zea mays L.) seeds subjected to osmotic stress induced by PEG-6000.Three independent bioassays were conducted under controlled conditions. First, osmotic potentials ranging from 0 to −0.8 MPa were tested to determine stress levels. In the second assay, seeds were treated with increasing doses (0 to 2 mL kg⁻¹) of a commercial seaweed extract and its isolated mineral fraction. In the third assay, selected doses were evaluated under no stress, moderate stress, and severe stress conditions. Germination percentage, normal and abnormal seedlings, radicle and epicotyl length, and vigor index were assessed. Osmotic stress significantly reduced germination and seedling growth, particularly at −0.6 and −0.8 MPa. Seed treatment with A. nodosum did not affect final germination but improved seedling growth and vigor, showing a dose-dependent response. Maximum efficiency was observed at intermediate doses (~0.45–0.66 mL kg⁻¹), which increased the percentage of normal seedlings and promoted root and shoot development. Under water stress conditions, the complete extract outperformed the mineral fraction, indicating that the beneficial effects are mainly associated with bioactive organic compounds. These findings demonstrate that A. nodosum extract is a promising strategy to mitigate water stress effects during maize seed germination, provided that optimal doses are used.

Posted: 04 May 2026

https://doi.org/10.20944/preprints202605.0137.v1

Article
Environmental and Earth Sciences
Space and Planetary Science
LIR-ACheM: Modelling of the D-Region Response to Solar Flares

Pauline Teysseyre

,

Carine Briand

Abstract: A significant fraction of the HF waves is absorbed by the lowest ionospheric layer, the D-region. This region is perturbed by solar flares, which notably cause fast increases in the Sun’s X-ray flux. We present here a new chemistry model, the Lower Ionosphere Region — Absorption and Chemistry Modelling (LIR-ACheM), to study the D-region behaviour. It is based on the Mitra-Rowe [] scheme, and takes into account four distinct sources (EUV, Lyman-α, X-rays and cosmic rays) and seven species (electrons, NO+, O2+, O4+, positive cluster ions, O2− and other negative ions). It thus offers a compromise between accuracy and computing time. The D-region sluggishness and its recovery time after a flare are analysed, highlighting the importance of detachment at low altitudes and soft X-ray fluxes above 80 km.

Posted: 04 May 2026

https://doi.org/10.20944/preprints202605.0134.v1

Article
Environmental and Earth Sciences
Other
Phytase Overdose in Diets with Reduced Calcium and Phosphorus Levels for Pigs from Weaning to Slaughter: Effects on Performance, Carcass and Meat

Cristina Satie Hideshima Marques

,

Marco Aurélio Callegari

,

Cleandro Pazinato Dias

,

Kelly Lais de Souza

,

Claudia Cassimira da Silva Martins

,

Vitor Barbosa Fascina

,

Alexandre Oba

,

Rafael Humberto de Carvalho

,

Caio Abércio da Silva

Abstract: This study aimed to evaluate the extra-phosphoric effect of increasing doses of bacte-rial phytase (RONOZYME HiPhos) in corn and soybean meal-based diets on perfor-mance, carcass yield, and meat quality in pigs during the nursery, growing, and fin-ishing phases (GT). Two hundred and fifty pigs, castrated males and females, with an initial weight of 6.08 ± 0.748 kg and 21 days of age, were subjected to 5 treatments: PC: positive control diets, supplemented with inorganic phosphorus (P) and calcium (Ca), meeting their full nutritional requirements; NC: negative control diets, with re-duced available phosphorus (-0.18%) and calcium (-0.16%); 1000FYT: NC + 1,000 FYT/kg of feed; 2000FYT: NC + 2,000 FYT/kg of feed; 3000 FYT: NC + 3000 FYT/kg of feed. Average daily gain (ADG) in the nursery phase did not differ between the groups supplemented with 1,000; 2,000 and 3,000 FYT/kg (0.430 kg, 0.441 kg and 0.428 kg respectively) and PC (0.481 kg), but was higher (P< 0.05) than NC (0.398 kg). Feed conversion ratio (FCR) in the same phase was similar between PC (1.546) and the groups supplemented with phytase (1.516; 1.535; 1.519), all being better (P< 0.05) than NC (1.676). The quadratic effect for phytase was verified for FCR in the phase, with the best inclusion of 2,320 FYT/kg of feed. In the GF phases and in the overall experi-mental period (21 to 156 days), the results for daily feed intake (DFI), ADG and FCR favored PC and the groups supplemented with phytase compared to the NC (P< 0.05). A quadratic effect was observed for FCR considering the entire GF phase, with the best inclusion of 1,923 FYT/kg of feed. Groups supplemented with phytase and PC obtained better carcass results compared to NC (P< 0.05). Linear effects were observed to percentage and quantity of lean meat in the carcass. There was no difference be-tween treatments for meat quality. Supplementation with phytase in corn and soy-bean meal-based diets with severely reduced inorganic P and Ca improved pig per-formance at all stages, with optimized inclusion values of approximately 2,200 FYT/kg of feed, and dose-dependent benefits on carcass characteristics.

Posted: 04 May 2026

https://doi.org/10.20944/preprints202605.0110.v1

Review
Environmental and Earth Sciences
Sustainable Science and Technology
The Symbiotic Mandate: On the Urgency of a Mutually Uplifting Synergy Between Artificial Intelligence and Sustainability

Ernest Fokoué

Abstract: The current trajectory of Artificial Intelligence (AI) development represents a critical phase transition from a tenable academic pursuit to an untenable industrial behemoth, and ultimately toward an unsustainable environmental burden. In this review, we redefine waste management in sensu lato, encompassing digital redundancy, cognitive underutilization, and the physical e-waste generated by rapid hardware obsolescence. We argue that the current AI paradigm suffers from a ‘Curse of Dimensionality’ not only in its feature space but in its ecological footprint, necessitating a return to Algorithmic Parsimony—rooted in the Minimum Description Length principle [1] and William of Ockham’s razor—as a fundamental pillar of international sustainability standards. By analyzing the interplay between the outcry over blatantly unsustainable data centers [2–5] and emerging green AI frameworks [6,7], this paper provides a roadmap for a mutually uplifting synergy. We further introduce The Symbiotic Policy Covenant—a concrete policy intervention framework comprising f ive pillars: Algorithmic Parsimony Standards, Expanded Waste Taxonomy, AI Equity Safeguards, Paradigm Transition Investment, and International Regulatory Alignment. We conclude that true sustainability in the age of AI requires a holistic adherence to global standards [8,9] that transcend mere climate concerns, fostering a safer, more equitable, and durable integration of machine intelligence with ecological stewardship.

Posted: 04 May 2026

https://doi.org/10.20944/preprints202605.0077.v1

Data Descriptor
Environmental and Earth Sciences
Geochemistry and Petrology
Whole-Rock Geochemical Dataset of Late Variscan Intrusive Rocks from the Serre Batholith (Calabria, Southern Italy)

Annamaria Fornelli

,

Francesca Micheletti

,

Fabrizio Tursi

,

Vincenzo Festa

Abstract: We present a new whole-rock geochemical dataset for intrusive rocks of the late Variscan Serre batholith (Calabria, southern Italy), a well-exposed section of tilted con-tinental crust emplaced between ~305 and 292 Ma. The dataset includes major, trace and rare earth element (REE) analyses for 74 samples collected from the main plutonic units, ranging from tonalites and quartz-diorites at deeper structural levels to peraluminous granites at shallower levels, as well as leucosomes from associated migmatitic metase-diments. Analytical data were obtained using X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). The dataset integrates new and previously published geochemical data into a con-sistent and reusable format, including sample locations (WGS84), lithological classification and stratigraphic attribution. Sampling sites are also provided as a downloadable geo-spatial (.kmz) file for visualization in GIS platforms. The dataset is made available as a supplementary Excel file. These data are intended to support a wide range of applications, including petro-genetic studies of granitoid magmatism and investigations of water–rock interaction processes in crystalline aquifers. The dataset represents a valuable resource for both fundamental and applied geoscientific research.

Posted: 02 May 2026

https://doi.org/10.20944/preprints202604.2200.v1

Article
Environmental and Earth Sciences
Environmental Science
Ecological Determinants and Spatial Distribution of Schistosoma Intermediate Host Snails in Kimpese Region, in the Democratic Republic of the Congo

Germain Kapour

,

Théo Emboni

,

Danoff Engbu

,

Dalton Bakadila

,

Tine Huyse

,

Joule Madinga

,

Patrick Mitashi

Abstract: Schistosomiasis intermediate host snails’ data in the Democratic Republic of the Congo are limited and geographically dispersed. The objective of this study was to characterize snail habitats and identify environmental determinants of their presence. Monthly malacological surveys were conducted at 72 water contact sites. The morphological identification of the snails was complemented by the sequencing of the mitochondrial cox1 gene in order to guarantee confirmation of the species. The physicochemical parameters of the water, as well as human activities on the site, were recorded. The associations between environmental characteristics and snail presence were evaluated using generalized estimating equation models to account for repeated measurements. A total of 172,491 snails were collected, including 4,899 Schistosoma intermediate hosts (Bulinus spp., n = 3,812; Biomphalaria spp., n = 1,087). Biomphalaria pfeifferi, Biomphalaria sudanica, Bulinus truncatus, and Bulinus forskalii were identified. Biomphalaria species were detected in stagnant or slow-flowing waters; however, they occupied distinct habitats. The presence of snails was found to be independently associated with stagnant water and inversely associated with cassava retting, dishwashing/laundry, and river crossing. These findings provide baseline evidence on the distribution and ecological determinants of the Schistosoma intermediate host in Kimpese, supporting targeted malacological surveillance and integrated control strategies.

Posted: 02 May 2026

https://doi.org/10.20944/preprints202605.0039.v1

Article
Environmental and Earth Sciences
Environmental Science
Quantifying Capacity-Commitment Gap: Household Willingness to Pay and Blended Finance for Climate Adaptation in Bangladesh’s Char Regions

Md. Yahia Bapari

,

Mir Khaled Iqbal Chowdhury

,

Abir Hasan Mehedi

Abstract: Background: The char regions of Bangladesh — temporary riverine islands — experience compound climate vulnerability intensified by chronic structural poverty, yet sustainable financing models for community-based adaptation remain underdeveloped. Aim: This study diagnoses the capacity–commitment gap between households’ expressed willingness to support climate adaptation and their actual financial capacity, and proposes an evidence-based blended finance instrument. Methods: Using the Contingent Valuation Method (CVM) with a payment-card format and an open-ended follow-up, we surveyed 400 households across two char sites (Bahadurpur and Vasarpara). Probit models estimate the binary decision to contribute; Tobit models estimate the determinants of the contribution amount conditional on willingness. Results: Willingness to pay is high (65% of households), but capacity is sharply constrained: 90% of willing households pledge ≤ 400 BDT/month (mean = 244.5 BDT, median = 220 BDT). Probit and Tobit estimates show that education (β = 1.46, p < 0.001; β = 101.39, p < 0.001) and direct disaster experience (β = 1.49, p < 0.001; β = 153.85, p < 0.001) are three-to-eight times more influential than income (β = 0.49, p < 0.001; β = 19.33, p = 0.034). An institutional-trust paradox emerges: lower trust in government effectiveness is weakly associated with higher stated contributions (Tobit β = −17.88, p = 0.066), consistent with compensatory self-reliance. Near-universal clustering of WTP in the lowest payment class across seven adaptation strategies (89.7–100%) indicates a binding affordability ceiling rather than strategy-specific variation in valuation. Conclusions: These findings invalidate user-pays models for char populations and reframe household WTP as a signal of prioritised demand under a structural affordability ceiling. We translate this diagnostic into the Char Resilience Bond — a blended-finance instrument that securitises formalised in-kind community co-investments (labour, local knowledge, materials) to credit-enhance and leverage external capital, offering a replicable template for financing adaptation public goods in subsistence economies.

Posted: 02 May 2026

https://doi.org/10.20944/preprints202601.0413.v2

Review
Environmental and Earth Sciences
Remote Sensing
Bibliometric Analysis of Remote Sensing-Based Crop Climate Vulnerability: Trends and Perspectives

Walter Manuel Hoyos-Alayo

,

Jorge Luis Leiva-Piedra

,

Emilio Ramirez-Juidias

,

José Lázaro Amaro-Mellado

Abstract: Climate change is intensifying droughts, heatwaves, and hydrological extremes, increasing crop vulnerability and threatening global food security. This study analyzes the scientific evolution of research on remote sensing-based crop climate vulnerability, with emphasis on temporal, geographical, and thematic patterns. A quantitative, exploratory, descriptive, longitudinal, and retrospective bibliometric approach was applied to 2,343 documents indexed in Scopus between 1985 and 2026. The dataset was processed using Bibliometrix 5.1.1 and VOSviewer 1.6.20 to evaluate productivity, impact, collaboration, and intellectual structure, including Reference Publication Year Spectroscopy (RPYS). Results show a sustained annual growth rate of 4%, with 627 sources, 10,408 authors, an average of 5.17 co-authors per document, 35.3% international collaboration, and 19.93 citations per document. China, the United States, and India lead scientific production, while key journals concentrate dissemination. Thematic analysis highlights the dominance of drought-related studies and the increasing importance of machine learning and cloud-based platforms such as Google Earth Engine. The findings indicate that the field has reached a stage of scientific and technological maturity, transitioning from descriptive monitoring toward predictive and operational geospatial intelligence. However, challenges remain in methodological integration, geographical representation, and the translation of scientific outputs into decision-oriented tools for agricultural adaptation.

Posted: 01 May 2026

https://doi.org/10.20944/preprints202605.0027.v1

Article
Environmental and Earth Sciences
Sustainable Science and Technology
Towards Inclusive Economic Growth in Africa: Recognition of Customary Commons as the Main Asset of the Rural Poor

Liz Alden Wily

Abstract: This paper reviews how far national laws in Africa acknowledge the communal lands of communities as their property, as compared to family house and farm plots. This is examined in context of the role which commons ownership by communities could and should play in lessening rural poverty. These include rangelands, forest/bushlands, marshlands and other off-farm resource lands, often with lucrative extractive and non-extractive potentials. These are generally developed without community partnership. Findings suggest resistance to acknowledgement of communal lands as lawfully owned in over half of all 55 states. In effect, governments sustain their colonial designation as unowned wastelands, albeit lawfully used. Yet the one quarter of African states which do now acknowledge community ownership of resource commons also suggest the tide may be turning. There is need to promote this lawful possession is entrenched as a sustained stake in new takings and exploitation of these lands, not merely for fairer compensation for losses incurred, but towards adoption of economic growth path which are more directly inclusive of the rural poor. Inter alia, it is timely for post-2030 sustainable development goals to promote this.

Posted: 01 May 2026

https://doi.org/10.20944/preprints202605.0025.v1

Article
Environmental and Earth Sciences
Sustainable Science and Technology
Improvement in Beetroot’s (Beta vulgaris) Growth and Yield Parameters in Soils Fertilized with Maize (Zea mays) Biochar Under Drip Irrigation with Treated Wastewater

Baghali Guys Mathapa

,

Tanyala Gaba

,

Khumoetsile Mmolawa

Abstract: Global water scarcity due to climate change coupled with environmental pollution from artificial fertilizers threatens sustainable agricultural productivity. To address these challenges, innovative circular and sustainable agricultural practices are being sought after globally. Two promising sustainable approaches are the utilization of biochar coupled treated wastewater (TWW). In our experiment, maize biochar (MB) was locally produced by pyrolysis of maize stover waste in a Top-Lit-Up-Draft (TLUD) biochar kiln and characterized using FTIR, SEM, AAS, UV-vis and adsorption isotherms. Then, the performance of beetroots (Beta vulgaris) in terms of the germination rate, growth rate and yield in the cultivation soils fertilized with MB under drip irrigation with TWW was investigated. Post-hoc analysis (Bonferroni correction, α = 0.01667) revealed that cultivation soils fertilized with MB produced beetroots with significantly longer leaves and larger-heavier bulbs than the control. However, doubling MB fertilization dosage from 10 g to 20 g in the cultivation soils did not yield statistically significant improvement in the average leave height, mass and circumference of beetroot bulbs. Therefore, the findings demonstrated that combining MB with TWW enhanced beetroot growth and yield, highlighting a sustainable and circular agricultural system.

Posted: 01 May 2026

https://doi.org/10.20944/preprints202605.0034.v1

Article
Environmental and Earth Sciences
Geography
Morphometric and Multivariate Analysis of Geomorphological and Multi-Hazard Dynamics in the La Sabana River Basin, Acapulco – Mexico

Jesús Alfonso Carreto Gutiérrez

,

Oscar Frausto-Martínez

,

Benjamín Castillo Elías

,

Herlinda Gervacio Jiménez

,

Julio César Morales Hernández

,

José Angel Vences Martínez

Abstract: Coastal basins are highly dynamic systems susceptible to flooding and erosion, processes intensified by extreme cyclonic events. This study aims to develop a physical-geographic framework for analyzing the multi-hazard geomorphological dynamics of the La Sabana River basin in southern Mexico. The methodology integrates the analysis of the basin's natural and anthropogenic components with morphometric evaluation and multivariate analysis (PCA) at the sub-basin level. The results show a highly efficient drainage network (3.8-5.4 km/km²) and short concentration times (0.98–2.75), which favor a rapid hydrological response and high susceptibility to flooding and erosion. PCA explained 65.8% of the total variance, identifying basin size, drainage organization, and system shape as dominant controls. Critical sub-basins with rapid hydrological response (Tc ≤ 1.5 h) were identified, coinciding with areas of high anthropogenic exposure. It is concluded that integrating morphometric indices through multivariate approaches provides a robust, replicable basis for risk governance and territorial planning in coastal basins.

Posted: 01 May 2026

https://doi.org/10.20944/preprints202604.2169.v1

Article
Environmental and Earth Sciences
Geophysics and Geology
Aeromagnetic Anomaly Characteristics and Prospecting Direction in the Jiaduoling Area, Northern Segment of the Southwest Sanjiang Metallogenic Belt

Jianchun Xu

,

Yanxu Liu

,

Baodi Wang

,

Xuanjie Zhang

,

Yanan Zhang

,

Xin Wang

Abstract: The Jiaduoling area is located in the northern segment of the Southwest Sanjiang Metallogenic Belt, a region characterized by complex geological structures and abundant mineral resources. This study systematically identifies the spatial correlation between subsurface magnetic bodies and tectonic structures by utilizing 1:50,000 high-precision aeromagnetic data. Advanced processing techniques—including upward continuation, vertical derivatives, total gradient modulus, and Euler deconvolution—were integrated to refine the structural framework and clarify the mechanisms of fault-controlled mineralization.The results indicate that the aeromagnetic anomaly pattern is predominantly governed by NW-trending faults. Specifically, the deep-seated major fault F1 (with a calculated depth exceeding 3 km) served as the primary migration channel for ore-forming fluids, while secondary faults created localized ore-hosting spaces. Physical property analysis reveals a significant magnetic contrast, where Mesozoic intermediate-acid magmatic rocks act as the essential source for mineralization, providing both material and thermal energy for the formation of porphyrite-type iron deposits.Based on these findings, a three-dimensional "aeromagnetic anomaly-structural framework-mineralization" correlation model was established. Finally, two high-potential metallogenic prospective zones (P1 and P2) were delineated, providing precise geophysical evidence and strategic guidance for regional mineral exploration and the targeting of concealed ore bodies.

Posted: 01 May 2026

https://doi.org/10.20944/preprints202604.2188.v1

Review
Environmental and Earth Sciences
Ecology
The Hidden Costs of Selective Logging: Are We Too Confident?

Maria Fabíola Barros

,

Leonardo S. Miranda

,

João Vitor Cohen

,

Ana Luisa Mangabeira Albernaz

,

Marcelo Tabarelli

Abstract: Tropical forests are facing escalating deforestation, while forest degradation, driven by a complex interplay of human-induced factors, emerges as an additional and compounding threat. In this context, regulated selective logging persists as an alternative to conciliate forest protection and economic development. This study synthesizes current knowledge on the impacts of logging, focusing on research trends, geographic distribution, ecological topics, and key variables like logging intensity, time since logging, and number of logging cycles. Since the 1970s, 641 papers listed on the Scopus platform have demonstrated a sharp increase in publication activity over the past five years, followed by a tendency toward stabilization. Papers were concentrated in Brazil and Malaysia, with few papers coming from other countries, particularly from Africa. Notably, 47% of the studies did not report logging intensity, and one-third focused almost exclusively on its impacts on forest physical structure, damage, or biomass—leaving a wide range of other topics largely unexplored until 2022. We refer to 13 topics with less than 20 studies in total, such as nutrient cycling, non-timber forest products, biological invasion, and key biological taxa. Herbs, epiphytes, fish and amphibians were among the least investigated taxa across the regions. Furthermore, when controlling variables like region and logging intensity, most ecological topics had fewer than five dedicated studies. Research remains largely restricted to similar scenarios: first-cycle logging in old-growth forests, leaving substantial knowledge gaps. As logging operations are expected to increase, we argue for a (1) mandatory long-term monitoring in logging regulations; (2) public access to monitoring data, reports and information related to regulated logging; (3) a global platform to exchange experience as long-term monitoring, better practices, silvicultural approaches and sustainability assessment; (4) alignment among regulatory and certification agencies on sustainability standards; (5) capacity building initiatives; and (6) long-term experiments devoted to logging sustainability and better practices.

Posted: 30 April 2026

https://doi.org/10.20944/preprints202604.2230.v1

Article
Environmental and Earth Sciences
Sustainable Science and Technology
An AI-Enabled WEFE Nexus Tool for Assessing Circular Bioeconomy Options and Sustainability Transitions in Mediterranean Agro-Environmental Systems

Brent Villanueva Escobedo

,

Olga Lucia Sánchez Santander

,

Joan García Subirana

,

Jose Luis Pérez

,

Alejandra Calleros-Islas

,

Robert Savé

,

Pau Fonseca i Casas

,

Jordi Morató

Abstract: Transitioning to a circular bioeconomy in agro-environmental systems requires decision-support approaches able to address interdependencies across water, energy, food, and ecosystems (WEFE), especially in Mediterranean regions affected by climate variability, water scarcity, land degradation, and fragmented governance. However, the practical operationalization of the WEFE Nexus remains limited by methodological constraints and insufficient integration of dynamic analysis. This study presents an AI-enabled decision-support tool designed to support the implementation of circular bioeconomy solutions within the WEFE Nexus. The framework integrates participatory multi-criteria assessment, compensation mechanisms, and artificial intelligence-based scenario analysis within the NECADA digital twin environment, enabling the assessment of elements under uncertainty. Developed and applied within the “Ensuring fair NEXUS transition for climate change adaptation and sustainable development implementation based on coupled nature-based systems and bioeconomy (SureNexus)” project, the tool was used to assess two circular bioeconomy solutions, biochar and agroforestry, across Mediterranean agro-environmental contexts. Results show complementary performance profiles: biochar provides targeted benefits for soil restoration, water regulation, and climate mitigation, whereas agroforestry generates broader system-level effects that enhance ecosystem services, resilience, and long-term sustainability. These findings highlight the value of context-specific solution portfolios and show that AI-enabled WEFE tools can support evidence-based policy and planning for sustainability transitions.

Posted: 30 April 2026

https://doi.org/10.20944/preprints202604.2180.v1

Article
Environmental and Earth Sciences
Water Science and Technology
Sodium Alginate/Chitosan/Activated Carbon Composite Hydrogel for Cyanobacterial Inhibition: RSM Optimization and Sustained Release Performance

Dongmei Jiang

,

Yingjun Wang

Abstract: This study presents a sodium alginate/chitosan/activated carbon (SA/CS/AC) gel microspheres loaded with citrus peel allelochemicals for continuous inhibition of Microcystis aeruginosa by controlled release. Preparation parameters were optimized via response surface methodology (RSM) for improved algal inhibition, yielding an optimal formulation: 1.97% SA, 0.76% CS, 0.31% AC. The optimized gel microspheres showed a 7-day inhibition rate of 85.17 ± 2.49%, consistent with the predicted 85.29%. Characterization revealed that AC enriched the gel’s porous structure and surface functionality, increasing allelochemical adsorption sites, enhancing loading efficiency, and sustaining long-term release with a 25-day cumulative release of 70%. Algal inhibition declined slightly from day 7 to 30 due to allelochemical depletion but remained 76.27%, versus 30.58% for the blank SA/CS/AC carrier and 52.81% for the allelochemical-loaded SA/CS gel microspheres. AC thus synergistically strengthens algal inhibition by elevating allelochemical loading and prolonging activity, providing a feasible strategy for sustainable cyanobacterial bloom control.

Posted: 30 April 2026

https://doi.org/10.20944/preprints202604.2211.v1

Review
Environmental and Earth Sciences
Geophysics and Geology
Dynamic Evaluation Model for Stability State of Slope Unstable Rock Masses and Its Engineering Application

Guang Lu

,

Mowen Xie

,

Yan Du

Abstract: Rockfall from slope unstable rock masses, a typical geological hazard induced by brittle failure, is characterized by abrupt occurrence, negligible macroscopic deformation prior to failure, and extremely short lead time for early warning, posing a severe threat to the safety of mountainous transportation systems, water conservancy and hydro-power projects, and urban settlements. Conventional static analysis methods have sig-nificant limitations in real-time acquisition of damage evolution of structural planes and dynamic assessment of stability changes, which can hardly meet the practical re-quirements of early warning for unstable rock masses. The dynamic evaluation method for the stability state of unstable rock masses, based on the principles of structural dy-namics, establishes a correlation model between dynamic parameters (natural fre-quency, damping ratio, mode shape, etc.) and the damage degree of structural planes, providing a new paradigm for dynamic identification and quantitative evaluation of the stability of unstable rock masses. This paper systematically reviews the dynamic behavior mechanism and theoretical evaluation framework of slope unstable rock masses, and elaborates on the damage evolution of structural planes, the disturbance effect of environmental dynamic loads, and the key dynamic parameter system. The single-degree-of-freedom dynamic models and their theoretical derivation for three typical types of unstable rock masses (sliding-type, toppling-type, and falling-type) are thoroughly analyzed, and the cutting-edge advances such as multi-block chain collapse model and data-physics dual-driven surrogate model are reviewed. Meanwhile, the contact and non-contact monitoring methods based on Micro-Electro-Mechanical System (MEMS) and Laser Doppler Vibrometer (LDV) techniques, as well as the de-velopment status of cloud-edge collaborative intelligent early warning architecture, are systematically summarized. On this basis, the core challenges are pointed out, includ-ing the long-term evolution under multi-field coupling, high-fidelity inversion calcu-lation for large-scale rock masses, and the scientific correlation between early warning thresholds and failure probability. The full-life-cycle dynamic simulation based on digital twin is also prospected. The research results provide a systematic reference for the improvement of the theoretical system of dynamic evaluation of slope unstable rock masses and the engineering practice of disaster prevention and mitigation.

Posted: 30 April 2026

https://doi.org/10.20944/preprints202604.2164.v1

Technical Note
Environmental and Earth Sciences
Environmental Science
Insufficient Data: The Need for Standardized Monitoring Networks for Reliable Climate AI

Raúl Rivas

Abstract: This technical note discusses the structural limitations of current climate-related Artificial Intelligence (AI) applications due to the lack of standardized and geographically representative in situ monitoring networks. Drawing on the experience of the Salado River Basin monitoring system in Buenos Aires Province, Argentina, the document highlights the risks of training AI models with non-representative data and the urgent need for multilateral investment in physical infrastructure for satellite validation and environmental monitoring. The note argues that AI will only be as reliable as the measurements that support it, emphasizing the importance of certified, continuous, and well-maintained networks to ensure climate resilience and evidence-based water management.

Posted: 30 April 2026

https://doi.org/10.20944/preprints202604.2076.v1

Article
Environmental and Earth Sciences
Geophysics and Geology
Exceedance Probabilities for Large Earthquakes From DIY Local Earthquake Ensemble Nowcasting and Forecasting: Magnitude, Natural Time, and Calendar Time

John B Rundle

,

Ian Baughman

,

Andrea Donnellan

,

Lisa Grant Ludwig

,

Geoffrey Charles Fox

,

Kazuyoshi Nanjo

Abstract: This paper focuses on the problem of anticipating the local occurrence of future large earthquakes. "Local" is defined as the probability of a large earthquake occurring with a defined circle of arbitrary radius surrounding a point of interest. The main (and for that matter, the only) assumption for all these works is that the Gutenberg-Richter (GR) magnitude-frequency relation holds. Here we describe a method for computing calendar time forecasts in a local area for large earthquakes of a target magnitude MT using a count small earthquakes MS < MT in the area. Using the idea that the GR relation is valid throughout the surrounding region, we define an ensemble of earthquakes in larger surrounding regions to be used in computing the forecast. What follows is simple data mining. The method has significant skill, as defined by the Receiver Operating Characteristic (ROC) test, which improves as time since the last major earthquake increases. The probability is conditioned on the number of small earthquakes n(t) that have occurred since the last large earthquake. The probability is computed directly as the Positive Predictive Value (PPV) associated with the ROC curve. The method is validated by comparison to the UCERF3 forecasts for the UCERF3-defined geographic boxes centered on Los Angeles and San Francisco. The method is then applied to a 125-KM radius circular area around Los Angeles, California, following the January 17, 1994 magnitude M6.7 Northridge earthquake, and short term forecasts (1 year and 5 year ) are computed.

Posted: 30 April 2026

https://doi.org/10.20944/preprints202604.2117.v1

Article
Environmental and Earth Sciences
Environmental Science
Scenario Analysis of Japan’s Food and Feed Systems: Integrating Nutrient Flows with Sustainable Agricultural Policy

Kimiko Ushiyama

,

Masao Takano

Abstract: Recently, the Japanese government has introduced ambitious policies for agricultural sustainability, specifically the MIDORI Strategy, aimed at reducing chemical fertilizer use, expanding organic farmland, and increasing calorie-based food self-sufficiency. To evaluate the feasibility of these goals, this study quantified nitrogen and phosphorus flows within the 2021 food and feed system using a normalized “Nutrient Index.” A scenario analysis was conducted using policy targets as parameters, where currently non-circulated waste streams were modeled as potential sources for domestic nutrient recovery. The results indicate that Scenario A (a 30% reduction of chemical fertilizers) is the most feasible, achieving significant improvements in circulation ratios through recovery of nutrients from sewage and livestock waste. While Scenario B (increasing organic farmland) shows similar trends, its success depends on technological advancements to mitigate the yield gap between organic and conventional systems. Scenario C (increasing calorie-based food self-sufficiency) presents the greatest challenge: maintaining current dietary patterns requires a 20% expansion of farmland and total nutrient recovery from waste. However, shifting dietary habits toward higher domestic rice consumption (Scenario C-2) significantly mitigates land and fertilizer demand. Achieving these targets requires a holistic approach that integrates technological infrastructure with socio-political shifts in land use planning and consumer behavior.

Posted: 30 April 2026

https://doi.org/10.20944/preprints202604.2148.v1

Brief Report
Environmental and Earth Sciences
Paleontology
Tradition of Wrapping Grains in Funerary Rituals 2200 Years Ago

Fan Yang

,

Yong Ge

,

Ling Fang

,

Haiyan Wang

,

Shuzhi Wang

,

Jiajun Wang

,

Zhiguo Zhang

Abstract: The origin of zongzi — rice and millet wrapped in leaves — has long been debated owing to a millennium-long gap between its legendary association with Qu Yuan (c. 340–278 BC) and the earliest unequivocal evidence, which dates only to the Song Dynasty. Here we present well-dated archaeological evidence of plant bundles (c. 2200 cal. BP) from the Wuwangdun Site, the first well-excavated tomb of King Kaolie of Chu. These plant bundles share the essential characteristics of modern zongzi and overlap both temporally and geographically with the Qu Yuan legend. They consist of Quercus dentata leaves containing rice (Oryza sativa, 43.6%), broomcorn millet (Panicum miliaceum, 26.1%) and foxtail millet (Setaria italica, 28.5%), secured with cords made from Panicoideae and Chloridoideae plants — a wrapping practice structurally identical to that of modern zongzi. Most seeds were preserved as whole husks, indicating that the bundles were used as funerary offerings rather than for consumption, which aligns with the legend that zongzi were thrown into the river to commemorate Qu Yuan. Notably, Q. dentata leaves are still used to wrap zongzi in regions that once formed the northern border of the Chu Kingdom. Our findings demonstrate that the plant bundles from the Wuwangdun Site most likely represent the prototype of zongzi, bridging the gap between legend and material culture and showing that the tradition of wrapping grains for ritual purposes began in the Chu Kingdom no later than 2200 years ago.

Posted: 30 April 2026

https://doi.org/10.20944/preprints202604.2070.v1

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