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2021

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Articles 3061 - 3090 of 27886

Full-Text Articles in Physical Sciences and Mathematics

Pasture Seed Production Technology In Brazil, Ronaldo Pereira De Andrade Sep 2021

Pasture Seed Production Technology In Brazil, Ronaldo Pereira De Andrade

IGC Proceedings (1993-2023)

Efficient and low cost production systems, which rely on the use of cultivated pastures, are the basis of beef and milk production in Brazil. The success of these pasture-based systems would not be possible without the support of an aggressive and dynamic pasture seed production sector to supply the internal demand, which is estimated to be around 90000 tons per year. The market is dominated by grass species and among them, Brachiaria. brizantha cv. Marandu accounts for more than 80% of the total seed volume in the market. Seed production systems in Brazil vary from highly specialized to opportunistic accordingly …


Mgrre_Pureoilscouttickets_Hannum_1_21127013740000, Mgrre Sep 2021

Mgrre_Pureoilscouttickets_Hannum_1_21127013740000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.


Shallow Rupture Propagation Of Pleistocene Earthquakes Along The Hurricane Fault, Ut, Revealed By Hematite (U-Th)/He Thermochronometry And Textures, Madison P. Taylor, Alexis K. Ault, Margaret L. Odlum, Dennis L. Newell Sep 2021

Shallow Rupture Propagation Of Pleistocene Earthquakes Along The Hurricane Fault, Ut, Revealed By Hematite (U-Th)/He Thermochronometry And Textures, Madison P. Taylor, Alexis K. Ault, Margaret L. Odlum, Dennis L. Newell

Geoscience Faculty Research

The material properties and distribution of faults above the seismogenic zone promote or inhibit earthquake rupture propagation. We document the depths and mechanics of fault slip along the seismically active Hurricane fault, UT, with scanning and transmission electron microscopy and hematite (U-Th)/He thermochronometry. Hematite occurs as mm-scale, striated patches on a >10 m2 thin, mirror-like silica fault surface. Hematite textures include bulbous aggregates and cataclasite, overlain by crystalline Fe-oxide nanorods and an amorphous silica layer at the slip interface. Textures reflect mechanical, fluid, and heat-assisted amorphization of hematite and silica-rich host rock that weaken the fault and promote rupture propagation. …


Meeting The Changing Need For Herbage Seed Quality Assurance In The 21st Century, D. S. Loch, K. G. Boyce Sep 2021

Meeting The Changing Need For Herbage Seed Quality Assurance In The 21st Century, D. S. Loch, K. G. Boyce

IGC Proceedings (1993-2023)

Quality assurance is a key element in the herbage seed supply chain. The measurement and management of seed quality is discussed in terms of its four main parameters - genetic, physical, vital, and phytosanitary quality - which provide information on the expected performance of herbage seed when sown in the field. During the past century, seed quality management systems have evolved in response to national and regional differences in economic development, crop characteristics, merit testing, and the demands of international trade. The pace of change in the management of seed quality assurance has intensified in developed countries over the past …


Novel Grasses And Legumes Germplam: Advances And Perspectives For Tropical Zones, E. A. Pizarro Sep 2021

Novel Grasses And Legumes Germplam: Advances And Perspectives For Tropical Zones, E. A. Pizarro

IGC Proceedings (1993-2023)

It has been the aim, in the present article, to bring together as much as possible scientific evidence and experience in new available germplasm for tropical zones.

The economic importance of the Brachiaria, Paspalum and Pennisetum grasses is well established. New germplasm has become available since 1980. This paper reviews evaluations of Brachiaria accessions in humid lowlands and savannas of tropical America. The selection criteria need to be revised. Also, it is necessary to expose the new material as early as possible to farmers in order to select new germplasm with high chances of adoption.

Within the genus Paspalum …


Temperate Forage Grass-Legume Mixtures: Advances And Perspectives, A. S. Laidlaw, N. Teuber Sep 2021

Temperate Forage Grass-Legume Mixtures: Advances And Perspectives, A. S. Laidlaw, N. Teuber

IGC Proceedings (1993-2023)

The paper summarises some of the advances which have been made a) in increasing understanding of the grass-legume association, especially grass-white clover, so that the association can be more predictably exploited and b) in overcoming limitations in the use of such mixtures. The contribution which forage legumes make to the N economy of mixtures is reviewed with estimates approaching 400 kg N ha-1 for some. Uptake by grass of legume- derived N (N transfer) reduces soil mineral N levels and increases the proportion of fixed N in the total legume N relative to legume monoculture. Although N transfer also …


An Accelerated Variance-Reduced Conditional Gradient Sliding Algorithm For First-Order And Zeroth-Order Optimization, Xiyuan Wei, Bin Gu, Heng Huang Sep 2021

An Accelerated Variance-Reduced Conditional Gradient Sliding Algorithm For First-Order And Zeroth-Order Optimization, Xiyuan Wei, Bin Gu, Heng Huang

Machine Learning Faculty Publications

The conditional gradient algorithm (also known as the Frank-Wolfe algorithm) has recently regained popularity in the machine learning community due to its projection-free property to solve constrained problems. Although many variants of the conditional gradient algorithm have been proposed to improve performance, they depend on first-order information (gradient) to optimize. Naturally, these algorithms are unable to function properly in the field of increasingly popular zeroth-order optimization, where only zeroth-order information (function value) is available. To fill in this gap, we propose a novel Accelerated variance-Reduced Conditional gradient Sliding (ARCS) algorithm for finite-sum problems, which can use either first-order or zeroth-order …


Mgrre_Pureoilscouttickets_Wallace_1_21127013560000, Mgrre Sep 2021

Mgrre_Pureoilscouttickets_Wallace_1_21127013560000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.


Ensemble Learning Using Error Correcting Output Codes: New Classification Error Bounds, Hieu Nguyen, Mohammed Sarosh Khan, Nicholas Kaegi, Shen-Shyang Ho, Jonathan Moore, Logan Borys, Lucas Lavalva Sep 2021

Ensemble Learning Using Error Correcting Output Codes: New Classification Error Bounds, Hieu Nguyen, Mohammed Sarosh Khan, Nicholas Kaegi, Shen-Shyang Ho, Jonathan Moore, Logan Borys, Lucas Lavalva

College of Science & Mathematics Departmental Research

New bounds on classification error rates for the error-correcting output code (ECOC) approach in machine learning are presented. These bounds have exponential decay complexity with respect to codeword length and theoretically validate the effectiveness of the ECOC approach. Bounds are derived for two different models: the first under the assumption that all base classifiers are independent and the second under the assumption that all base classifiers are mutually correlated up to first-order. Moreover, we perform ECOC classification on six datasets and compare their error rates with our bounds to experimentally validate our work and show the effect of correlation on …


Novel Theorems And Algorithms Relating To The Collatz Conjecture, Michael R. Schwob, Peter Shiue, Rama Venkat Sep 2021

Novel Theorems And Algorithms Relating To The Collatz Conjecture, Michael R. Schwob, Peter Shiue, Rama Venkat

Mathematical Sciences Faculty Research

Proposed in 1937, the Collatz conjecture has remained in the spotlight for mathematicians and computer scientists alike due to its simple proposal, yet intractable proof. In this paper, we propose several novel theorems, corollaries, and algorithms that explore relationships and properties between the natural numbers, their peak values, and the conjecture. These contributions primarily analyze the number of Collatz iterations it takes for a given integer to reach 1 or a number less than itself, or the relationship between a starting number and its peak value.


The Relative Importance Of Wind-Driven And Chimney Effect Cave Ventilation: Observations In Postojna Cave (Slovenia), Lovel Kukuljan, Franci Gabrovsek, Matthew Covington Sep 2021

The Relative Importance Of Wind-Driven And Chimney Effect Cave Ventilation: Observations In Postojna Cave (Slovenia), Lovel Kukuljan, Franci Gabrovsek, Matthew Covington

International Journal of Speleology

Density-driven chimney effect airflow is the most common form of cave ventilation, allowing gas exchange between the outside and the karst subsurface. However, cave ventilation can also be driven by other mechanisms, such as barometric changes or pressure differences induced by the outside winds. We discuss the mechanism and dynamics of wind-driven ventilation using observations in Postojna Cave, Slovenia. We show how seasonal airflow patterns driven by the chimney effect are substantially modified by outside winds. Wind flow over irregular topography forms near-surface air pressure variations and thus pressure differences between cave entrances at different locations. These pressure differences depend …


Effect Of Sources And Rates Of Nitrogen On Nutrients Extraction In Coastcross Pastures, A. C. Primavesi, O. Primavesi, L. De A. Corrêa, H. Cantarella, A. G. Da Silva, A. R. Freitas Sep 2021

Effect Of Sources And Rates Of Nitrogen On Nutrients Extraction In Coastcross Pastures, A. C. Primavesi, O. Primavesi, L. De A. Corrêa, H. Cantarella, A. G. Da Silva, A. R. Freitas

IGC Proceedings (1993-2023)

The contents and the extraction of mineral nutrients were determined in a coastcross pasture established on a dark red latosol (Hapludox), in São Carlos, SP, Brazil, under tropical altitude climate, receiving five rates of urea and ammonium nitrate, applied on surface. There were differences (P< 0.05) among sources and rates of N. Nutrients extraction increased with the nitrogen levels. Especially high were total N (319 and 446 kg ha-1) and K (341 and 467 kg ha-1) extractions. When forage yield was high (treatment with 500 kg of N ha-1) and for both fertilizers, macronutrients extraction was greater for K and N, followed by Ca, S, P and Mg. Micronutrients extraction occurred in the following decreasing order: Fe, Mn, …


Dry Matter Production Response Of Coastcross (Cynodon Dactylon (L.) Pears) To Sources And Rates Of Nitrogen, L. De A. Corrêa, H. Cantarella, A. C. Primavesi, O. Primavesi, A. R. Freitas, A. G. Da Silva, E. B. Pott Sep 2021

Dry Matter Production Response Of Coastcross (Cynodon Dactylon (L.) Pears) To Sources And Rates Of Nitrogen, L. De A. Corrêa, H. Cantarella, A. C. Primavesi, O. Primavesi, A. R. Freitas, A. G. Da Silva, E. B. Pott

IGC Proceedings (1993-2023)

Dry matter production of a coastcross pasture grown on a dark red latosol (Hapludox), in São Carlos, São Paulo State, Brazil, under tropical altitude climate, was evaluated. The goal was to verify the efficiency of N rates as urea and ammonium nitrate: 0, 25, 50, 100 and 200 kg ha-1 per cutting, in five periods. Both sources were equally efficient. The mean N rates, which produced 80% of maximum forage yield, were 78 and 58 kg N ha-1, respectively, for urea and ammonium nitrate, and were related to dry matter yields of 2,769 and 3,347 kg ha …


Mechanism Design For Entities' Passive Dimensional Sensing Interaction In Discrete Event Simulations, Yan Fei, Bin Gan, Zhaodi Chen, Wenjuan Ma, Luyao Li, Zhang Ke Sep 2021

Mechanism Design For Entities' Passive Dimensional Sensing Interaction In Discrete Event Simulations, Yan Fei, Bin Gan, Zhaodi Chen, Wenjuan Ma, Luyao Li, Zhang Ke

Journal of System Simulation

Abstract: Dimensional sensing interaction mechanism is a method of computing the entities' visibility on the basis of the position and visible range, and informing when and where the entities can perceive each other. Entities' active computing on the relative position needs a lot of computation and is low efficiency, and slow down the simulation execution at last. The mechanism and framework of the passive dimensional sensing interaction, including the spatial grid models, discrete movement models, and passive sense models are researched. Dimensional sensing interaction manager is designed to realize the computation of entities' dimensional sensing interaction in discrete event-based battle …


The Fierce Green Fire: Vol. 12 Issue 1, Wofford College. Department Of Environmental Studies Sep 2021

The Fierce Green Fire: Vol. 12 Issue 1, Wofford College. Department Of Environmental Studies

The Fierce Green Fire

No abstract provided.


Combination Of High Specific Activity Carbon-14 Labeling And High Resolution Mass Spectrometry To Study Pesticide Metabolism In Crops: Metabolism Of Cycloxaprid In Rice, Dahang Shen, Zhijiang Lu, Jiayin Zhong, Sufen Zhang, Qingfu Ye, Wei Wang, Jay Gan Sep 2021

Combination Of High Specific Activity Carbon-14 Labeling And High Resolution Mass Spectrometry To Study Pesticide Metabolism In Crops: Metabolism Of Cycloxaprid In Rice, Dahang Shen, Zhijiang Lu, Jiayin Zhong, Sufen Zhang, Qingfu Ye, Wei Wang, Jay Gan

Environmental Science and Geology Faculty Research Publications

The study of pesticide metabolism in crops is critical for assessing the mode of action and environmental risks of pesticides. However, the study of pesticide metabolism in crops is usually complicated and it is often a daunting challenge to accurately screen the metabolites of novel pesticides in complex matrices. This study demonstrated a combined use of high-specific activity carbon-14 labeling and high-resolution mass spectrometry (HSA-14C-HRMS) for metabolism profiling of a novel neonicotinoid cycloxaprid in rice. By generating the characteristic radioactive peaks on the liquid chromatogram, the use of 14C can eliminate the severe interference of complex matrices …


Carbon Neutrality Should Not Be The End Goal: Lessons For Institutional Climate Action From U.S. Higher Education, Alexander R. Barron, Maya Domeshek, Lucy Metz, Laura Draucker, Aaron L. Strong Sep 2021

Carbon Neutrality Should Not Be The End Goal: Lessons For Institutional Climate Action From U.S. Higher Education, Alexander R. Barron, Maya Domeshek, Lucy Metz, Laura Draucker, Aaron L. Strong

Environmental Science and Policy: Faculty Publications

Aggressive climate action pledges from governments, businesses and institutions have increasingly taken the form of commitments to net carbon neutrality. Higher education institutions (HEIs) are uniquely positioned to innovate in this area, and over 800 U.S. colleges and universities have pledged to achieve net carbon neutrality. Eleven leading U.S. HEIs have already attained this status. Here, we examine their approaches to achieving net carbon neutrality, highlighting risks associated with treating emissions reduction approaches such as carbon offsets, renewable energy certificates, and bioenergy as best practice in isolation from broader policy frameworks. While pursuing net carbon neutrality has led to important …


Hurricane Trajectory Outlier Detection Method Based On Variational Auto-Encode, Wanting Qin, Songyang Lao, Tang Jun, Lu Cong Sep 2021

Hurricane Trajectory Outlier Detection Method Based On Variational Auto-Encode, Wanting Qin, Songyang Lao, Tang Jun, Lu Cong

Journal of System Simulation

Abstract: Hurricanes often cause incalculable human and economic losses, and the trajectory outlier detection can provide the auxiliary information or abnormal warning of the disaster. On deep learning, a method of hurricane trajectory outlier detection based on variable auto encoder (VAEOD) is proposed in this paper. The trajectory is divided into equal sequence sub trajectories based on the sliding window as the input of VAE. The trajectory reconstruction model is trained by the VAE. The parallel, vertical and angle distance of reconstructed trajectory and the input trajectory are compared to find out the outlier trajectory segments. The simulation experiment on …


Trace Fossils, Algae, Invertebrate Remains And New U-Pb Detrital Zircon Geochronology From The Lower Cambrian Torneträsk Formation, Northern Sweden, Stephen Mcloughlin, Vivi Vajda, Timothy P. Topper, James L. Crowley, Fan Liu, Ove Johansson, Christian B. Skovsted Sep 2021

Trace Fossils, Algae, Invertebrate Remains And New U-Pb Detrital Zircon Geochronology From The Lower Cambrian Torneträsk Formation, Northern Sweden, Stephen Mcloughlin, Vivi Vajda, Timothy P. Topper, James L. Crowley, Fan Liu, Ove Johansson, Christian B. Skovsted

Geosciences Faculty Publications and Presentations

Nineteen ichnotaxa, together with algal and invertebrate remains, and various pseudo-traces and sedimentary structures are described from the Torneträsk Formation exposed near Lake Torneträsk, Lapland, Sweden, representing a marked increase in the diversity of biotic traces recorded from this unit. The “lower siltstone” interval of the Torneträsk Formation contains mostly simple pascichnia, fodinichnia and domichnia burrows and trails of low-energy shoreface to intertidal settings. The assemblage has very few forms characteristic of high-energy, soft-sediment, foreshore or upper shoreface environments (representative of the Skolithos ichnofacies).

Uranium-lead (U-Pb) LA-ICPMS analysis of zircon from a thin claystone layer within the “lower siltstone” interval …


Mgrre_Pureoilscouttickets_Flood_1_21127013450000, Mgrre Sep 2021

Mgrre_Pureoilscouttickets_Flood_1_21127013450000, Mgrre

Legacy Scout Tickets from Pure Oil Company

No abstract provided.


Classification Of Flight Delay Based On Nonlinear Weighted Xgboost, Tang Hong, Wang Dong, Song Bo, Wenkui Chu, Linyuan He Sep 2021

Classification Of Flight Delay Based On Nonlinear Weighted Xgboost, Tang Hong, Wang Dong, Song Bo, Wenkui Chu, Linyuan He

Journal of System Simulation

Abstract: Aiming at the classification of flight delay under imbalance data, a novel method based on nonlinear weighted XGBoost (extreme gradient boosting) is proposed. The imbalance of flight delay data and the influence for classification performance caused by the data imbalance are analyzed. A heuristic nonlinear weighting method based on sample proportion is proposed, and the negative log likelihood loss function is optimized. The real flight delay dataset is used to validate the performance of the classification algorithm. The experiment results show that the proposed nonlinear weighted XGBoost algorithm can improve the classification accuracy of flight delay, while ensuing a …


Modeling Research Of Cognition Behavior For Intelligent Wargaming, Xiaoyuan He, Shengming Guo, Wu Lin, Li Dong, Xu Xiao, Li Li Sep 2021

Modeling Research Of Cognition Behavior For Intelligent Wargaming, Xiaoyuan He, Shengming Guo, Wu Lin, Li Dong, Xu Xiao, Li Li

Journal of System Simulation

Abstract: Aiming at the problem of cognitive behavior modeling in the construction and application of intelligent wargaming system, one modeling framework based on Actor-Operations-Scene (AOS) was proposed for C2 agent in wargaming. Then the realization of cognitive behavior modeling method for C2 agent was explored, including the modeling for the scenario oriented knowledge graph, intelligent situation awareness, operational planning, integrated operational control. It provides a feasible scheme for the construction and application of intelligent wargaming system.


Fault Diagnosis Of Industrial Process Based On Lle And K-Means Clustering Algorithm, Li Yuan, Zewei Geng Sep 2021

Fault Diagnosis Of Industrial Process Based On Lle And K-Means Clustering Algorithm, Li Yuan, Zewei Geng

Journal of System Simulation

Abstract: Because of the similarity of various types of data in the industrial process. The fault diagnosis using the K-means algorithm has a large error rate. A K-means clustering algorithm based on Locally Linear Embedding (LLE) is proposed. the normal data is reduced by the LLE algorithm and the projection matrix is obtained. The projection matrix is used to map the original fault data to the low-dimensional space and the K-means algorithm clusters is used to carry out the data to establish a detection and diagnosis model. The method is applied to the fault detection and diagnosis in the TE …


Learning Ant Colony Algorithm For Green Multi-Depot Vehicle Routing Problem, Hu Rong, Wenbo Chen, Bin Qian, Guo Ning, Fenghong Xiang Sep 2021

Learning Ant Colony Algorithm For Green Multi-Depot Vehicle Routing Problem, Hu Rong, Wenbo Chen, Bin Qian, Guo Ning, Fenghong Xiang

Journal of System Simulation

Abstract: Considering the congested roads situation of urban central areas in China, a speed calculation method based on vehicle driving sections is designed, and a model for the Green Multi-Depot Vehicle Routing Problem with Total Fuel-Consumption cost Criterion (TFC-GMDVRP) is established, considering simultaneously the vehicle travel distance, load, and speed factors. A learning ant colony optimization algorithm (LACO), combining a knowledge model and an ant colony optimization algorithm (ACO), is proposed for solving the TFC-GMDVRP. In order to improve the performance and robustness of the algorithm's global search, the parameter knowledge that contains the different …


A Novel Approach For Smart Contracts Using Blockchain, Dr Khaled Nagaty, Manar Abdelhamid Sep 2021

A Novel Approach For Smart Contracts Using Blockchain, Dr Khaled Nagaty, Manar Abdelhamid

Computer Science

No abstract provided.


Application Of Two-Population Fish Swarm Algorithm In Distributed Portfolio, Fuyu Wang, Tang Tao Sep 2021

Application Of Two-Population Fish Swarm Algorithm In Distributed Portfolio, Fuyu Wang, Tang Tao

Journal of System Simulation

Abstract: Aiming at the disadvantages of artificial fish swarm algorithm, such as low precision and easily falling into local optimum, combining the idea of gravity algorithm and teaching optimization, a two-population fish swarm search algorithm is proposed. Cross-thinking is adopted to optimize the results obtained by the two populations and avoid the local optimization. Metropoils criterion of simulated annealing is added to the standard function verifies the algorithm, and the results show that the two-population fish swarm algorithm is better than the traditional artificial fish swarm algorithm and the known literature algorithm. Based on the known literature, a distributed …


Whole Ship Simulation Training Platform Based On Virtual Reality, Jiawen Sun, Hongxiang Ren, Fangbing Xiao, Xiaobin Jiang Sep 2021

Whole Ship Simulation Training Platform Based On Virtual Reality, Jiawen Sun, Hongxiang Ren, Fangbing Xiao, Xiaobin Jiang

Journal of System Simulation

Abstract: Under the current navigation education mode, it is common that trainees lack the overall navigation knowledge and the operation practice on onboard equipment and instruments. It is necessary to develop a whole ship simulation training platform that is not limited by time and sites. The six-degree freedom mathematical model of ship motion is established by using the separation modeling theory of ship maneuverability. The flexible object simulation technology, the modeling and rendering of ocean wave technology, and the reverse dynamics technology are adopted to realize the ship scene roaming and equipment interaction. The simulation results show that …


Evolutionary Simulation Of Medical Products Export Safety Supervision Considering Regulation Of Importing Country, Xiaoli Li, Cejun Cao, Fanshun Zhang Sep 2021

Evolutionary Simulation Of Medical Products Export Safety Supervision Considering Regulation Of Importing Country, Xiaoli Li, Cejun Cao, Fanshun Zhang

Journal of System Simulation

Abstract: In order to investigate the impacts of the regulation of importing country on export safety supervision regarding medical products in the COVID-19 epidemic situation, an evolutionary game model considering the relation between export enterprise and supervision of government is constructed. Based on MATLAB simulation, the influences of different factors including regulation level of importing country, punishment mechanism on export safety supervision of medical products are analyzed. Results show that the illegal behaviors of the export enterprises of medical products can be restrained when the regulation level of importing country reaches a certain threshold. But that would fuel the passively …


Gw Ori: Circumtriple Rings And Planets, Jeremy L. Smallwood, Rebecca Nealon, Cheng Chen, Rebecca G. Martin, Jiaqing Bi, Ruobing Dong, Christophe Pinte Sep 2021

Gw Ori: Circumtriple Rings And Planets, Jeremy L. Smallwood, Rebecca Nealon, Cheng Chen, Rebecca G. Martin, Jiaqing Bi, Ruobing Dong, Christophe Pinte

Physics & Astronomy Faculty Research

GW Ori is a hierarchical triple star system with a misaligned circumtriple protoplanetary disc. Recent Atacama Large Millimeter/submillimeter Array observations have identified three dust rings with a prominent gap at 100 au and misalignments between each of the rings. A break in the gas disc may be driven by the torque from either the triple star system or a planet that is massive enough to carve a gap in the disc. Once the disc is broken, the rings nodally precess on different time-scales and become misaligned. We investigate the origins of the dust rings by means of N-body integrations and …


Lethal Microbial Blooms Delayed Freshwater Ecosystem Recovery Following The End-Permian Extinction, Chris Mays, Stephen Mcloughlin, Tracy D. Frank, Christopher R. Fielding, Sam M. Slater, Vivi Vajda Sep 2021

Lethal Microbial Blooms Delayed Freshwater Ecosystem Recovery Following The End-Permian Extinction, Chris Mays, Stephen Mcloughlin, Tracy D. Frank, Christopher R. Fielding, Sam M. Slater, Vivi Vajda

Department of Earth and Atmospheric Sciences: Faculty Publications

Harmful algal and bacterial blooms linked to deforestation, soil loss and global warming are increasingly frequent in lakes and rivers. We demonstrate that climate changes and deforestation can drive recurrent microbial blooms, inhibiting the recovery of freshwater ecosystems for hundreds of millennia. From the stratigraphic successions of the Sydney Basin, Australia, our fossil, sedimentary and geochemical data reveal bloom events following forest ecosystem collapse during the most severe mass extinction in Earth’s history, the end- Permian event (EPE; c. 252.2 Ma). Microbial communities proliferated in lowland fresh and brackish waterbodies, with algal concentrations typical of modern blooms. These initiated before …