Biomass Transfer Research Articles

Convective heat transfer coefficients models for biomass cylindrical particles from low to high aspect ratio

This study investigates the heat transfer of co-firing biomass in coal-fired power station boilers, with a focus on practical application for realistic particle shapes. At present, there are no heat transfer or Nusselt number (Nu) correlations available for biomass particles of cylindrical shape such as straw particles. In this study, a direct numerical simulation (DNS) of the heat transfer between cylindrical particles in a heated flow are performed with OpenFOAM-using a body-fitted mesh. The impact of the Reynolds number Re, aspect ratio AR, and angle of incidence θ in the range of (10 ≤ Re ≤ 2000, 1 ≤ AR ≤ 18, 0° ≤ θ ≤ 90°) on the Nusselt number are determined using a systematical analysis of the thermal flow characteristics for different particle temperature fields. The results show that the aerodynamics and geometrical factors of the cylindrical shape play a dominant role in the heat transfer. A model for the Nusselt number is proposed based on a curve fit of the simulation results, which has a root mean square error (RMSE) of 2.2 × 10-2 and an average relative error of 1.15 %. The independence test of the model has an average error of 5.1 %, indicating a high prediction accuracy. Compared to experimental and simulated data from the literature, the model demonstrates reasonable accuracy within its range of applicability, with a relative error of only 5.05 %. This study provides insights into the heat transfer of biomass particles with cylindrical shape and presents a new mathematical model for the Nusselt number, which can be used to improve the accuracy of the heat transfer prediction using point particle models.

Response of Triticum Vulgare Growth and Nitrogen Allocation to Irrigation Methods and Regimes under Subsoiling Tillage

Subsoiling tillage breaks up the shallow plow layer and thickened plow pan resulting from prolonged crop rotation, thus enhancing the soil tillage layer environment and fostering crop growth. However, these changes in tillage practices are not accompanied by corresponding advancements in irrigation technology. Therefore, this study compared drip irrigation (DI) and micro-sprinkler irrigation (MS) with three watering levels (H, M, L) based on soil water content (70%, 60%, 50% of field capacity) against traditional surface irrigation (CK, 70%FC) to find the most suitable irrigation approach for subsoiling wheat fields. This study found that adjusting irrigation methods and regimes significantly impacted wheat growth and yield. Drip irrigation boosts winter wheat grain yield, harvest index, biomass transfer amount, biomass transfer rate, nitrogen accumulation, nitrogen use efficiency, and nitrogen harvest index significantly compared to surface and micro-sprinkler methods. Drip irrigation, notably the DI-M treatment, significantly enhances winter wheat grain yield by 28.7% compared to CK. Drip irrigation produced optimal results when soil water levels decreased to 60% of the field capacity. This suggests adopting a combination of DI, with irrigation initiated at 60% of field capacity, for enhanced wheat production and resource efficiency.

Photosynthetic capacity and assimilate transport of the lower canopy influence maize yield under high planting density.

Photosynthesis is a major trait of interest for the development of high-yield crop plants. However, little is known about the effects of high-density planting on photosynthetic responses at the whole-canopy level. Using the high-yielding maize (Zea mays L.) cultivars "LY66," "MC670," and "JK968," we conducted a 2-yr field experiment to assess ear development in addition to leaf characteristics and photosynthetic parameters in each canopy layer at 4 planting densities. Increased planting density promoted high grain yield and population-scale biomass accumulation despite reduced per-plant productivity. MC670 had the strongest adaptability to high-density planting conditions. A physiological analysis showed that increased planting density primarily led to decreases in the single-leaf area above the ear for LY66 and MC670 and below the ear for JK968. Furthermore, high planting density decreased chlorophyll content and the photosynthetic rate due to decreased canopy transmission, leading to severe decreases in single-plant biomass accumulation in the lower canopy. Moreover, increased planting density improved presilking biomass transfer, especially in the lower canopy. The yield showed significant positive relationships with photosynthesis and biomass in the lower canopy, demonstrating the important contributions of these leaves to grain yield under dense planting conditions. Increased planting density led to retarded ear development as a consequence of reduced glucose and fructose contents in the ears, indicating reductions in sugar transport that were associated with limited sink organ development, reduced kernel number, and yield loss. Overall, these findings highlighted the photosynthetic capacities of the lower canopy as promising targets for improving maize yield under dense planting conditions.

Fertilisation strategies and their influence on nutrient flows in organic apple orchards

AbstractIn organic fruit production, permitted fertilisers contain multiple nutrients with stoichiometries differing from the nutrient offtakes of the fruit trees. Furthermore, some pesticides contain nutrients resulting in additional inputs. These conditions may cause unbalanced nutrient supplies and thereby influence the long-term sustainability of the system. An analysis of nutrient management practices in organic apple farms was conducted in three Southern and one Northern German apple-growing region. Data on nutrient inputs (via fertilisers and pesticides) and outputs (via fruit) per orchard were collected along with soil samples from up to five orchards per farm on 19 farms. On average, farmers fertilised 37 kg N and harvested 23 Mg apples per ha and year. Nutrient budgets showed imbalances for N (+ 25 kg ha−1 year−1), P (+ 3 kg), K (− 4 kg), Ca (+ 37 kg), Mg (+ 4 kg), S (+ 53 kg), Na (+ 4 kg) and Cl (+ 3 kg). Base fertilisers like compost or manure contributed to higher nutrient inputs due to a larger P and K-to-N-ratio. Commercial organic fertilisers such as keratins or vinasse contained much lower ratios. The main S input sources were pesticides (46 kg). N inputs by base (p = 0.06) and commercial (p = 0.37) fertilisers had no significant effect on the yield. Balanced nutrition can best be achieved by applying a combination of 20% of the total N demand via base fertilisers, complemented with commercial fertilisers with low element-to-N-ratios (e. g. keratin fertilisers, vinasse or biological N2 fixation). No correlation was found between soil nutrient status and nutrient budgets. Site conditions and internal field nutrient flows (transfer of the inter-row biomass via mulching into the tree row) had a stronger influence on the soil nutrient content than fertilisation strategy. In addition, fruit orchards showed a spatial differentiation of soil nutrient contents. Elevated P and K contents above the recommended range in the tree row were found in 67% of the orchards, while tendencies of depletion were found in the inter-row area. Mulching schemes which transfer biomass from the inter-row area to the tree row need to be adapted to this condition.

Incident Light Level Influences Elemental Budgets of Serianthes nelsonii Merr. Leaf Development

Recovery efforts for the endangered Serianthes nelsonii have been deficient. To learn more about leaf development costs, the content of biomass and essential elements were determined in the supportive and laminae tissue of leaves that were constructed under different levels of incident light. The biomass required to construct a leaf in 22% light transmission was 65% of that in full sun, and light treatment did not influence the balance between supportive and laminae tissues. Concentrations of carbon, phosphorus, iron, manganese, and boron were greatest for in full-sun laminae, but those of nitrogen, potassium, calcium, magnesium, and zinc were greatest in shaded laminae. The same patterns with regard to light were exhibited in supportive tissues for carbon, nitrogen, potassium, calcium, magnesium, and zinc. In contrast, the supportive tissue phosphorus content was greatest in shaded leaves, and the light level did not influence the supportive tissue concentrations of the remaining elements. The leaf laminae consistently exhibited greater concentrations of elements with the exception of potassium and nickel, which were greater in the supportive tissues. These results indicate that the construction of full-sun S. nelsonii leaves is more costly than that of shaded leaves, and the transfer of biomass and essential elements between the supportive and laminae tissues is not substantially influenced by the developmental light level. Identifying the drivers of S. nelsonii leaf element concentrations is crucial for understanding the role of this charismatic tree in community-level processes.

Effect of immersed tubes configurations on mixing and heat transfer of mixed biomass and silica sand in a bubbling fluidized bed using CFD-DEM and statistical experimental design analysis

The presence of immersed tubes within fluidized beds enhances mixing efficiency and heat transfer. However, the influence of design parameters remains unexplored systematically. This study investigates the impact of design parameters on mixed biomass fluidized beds with immersed tubes employing a combined approach of CFD-DEM simulations and 2k factorial design analysis. Findings reveal that the angle between tubes and tube diameter are primary influential parameters, significantly influences particle mixing and heat transfer efficiency. Optimal conditions, identified through analyses of averaged mixing index and heat transfer coefficient, point to a staggered configuration with specific dimensionless of tube diameter per column width of 0.0515 and a tube spacing per tube zone height of 0.14. These insights offer valuable guidance for optimizing and emphasize the significance of design parameters incorporating immersed tubes, providing practical guidelines for enhancing mixing efficiency and heat transfer in various applications, especially those employing mixed biomass and silica sand.

Numerical investigation of mixing and heat transfer of mixed biomass and silica sand particles in a bubbling fluidized bed combustor

Using fluidized bed combustion technology, biomass is being promoted for electricity production. However, a lack of biomass in a particular location or season poses a problem, leading to low thermal efficiency when using a single biomass. Thus, mixed biomass is considered a potential solution. This study uses CFD-DEM simulation to investigate the effects of various biomass types, loadings, and blending ratios on hydrodynamics and heat transfer in a bubbling fluidized bed. Coarse bagasse size provides the most efficient mixing behavior for a single biomass mixture. A blending ratio of 1:3 wood chip to coarse bagasse with 5% biomass loading, using 1 mm silica sand, is the appropriate condition. The primary factor for mixing is the difference in biomass sizes, while different biomass loadings have no significant influence. Smaller sand particles enhance the mixing and heat transfer. These findings provide useful guidelines for efficient biomass conditions in fluidized bed combustors.

Long-term oscillations in the normalized biomass-size spectrum reveal the impact of oligotrophication on zooplankton trophic structure in the North Atlantic Subtropical Gyre

Ocean warming of the North Atlantic Subtropical Gyre (NASG) induced oligotrophication and a decrease in integrated net primary production during the 2010s, potentially affecting higher trophic levels. We analyzed long-term records (1994–2019) of daytime and nighttime zooplankton biomass in five size classes from the NASG. Daytime biomass decreased in the three largest size classes during the 2010s, while decrease in nighttime biomass was less evident due to the relative stability in diel vertical migrator biomass. We used the normalized biomass size spectrum (NBSS) to estimate the relative transfer efficiency between trophic levels. The steepness of the NBSS slope at the end of the time series increased by 14% (daytime) and 24% (nighttime) from the maximum observed annual average values (2011 and 2009, respectively). This suggests oligotrophication during the 2010s led to a significant reduction in the transfer of biomass across trophic levels, with negative impacts on the NASG planktonic food web.

Optimizing Physics-Informed Neural Network in Dynamic System Simulation and Learning of Parameters

Artificial neural networks have changed many fields by giving scientists a strong way to model complex phenomena. They are also becoming increasingly useful for solving various difficult scientific problems. Still, people keep trying to find faster and more accurate ways to simulate dynamic systems. This research explores the transformative capabilities of physics-informed neural networks, a specialized subset of artificial neural networks, in modeling complex dynamical systems with enhanced speed and accuracy. These networks incorporate known physical laws into the learning process, ensuring predictions remain consistent with fundamental principles, which is crucial when dealing with scientific phenomena. This study focuses on optimizing the application of this specialized network for simultaneous system dynamics simulations and learning time-varying parameters, particularly when the number of unknowns in the system matches the number of undetermined parameters. Additionally, we explore scenarios with a mismatch between parameters and equations, optimizing network architecture to enhance convergence speed, computational efficiency, and accuracy in learning the time-varying parameter. Our approach enhances the algorithm’s performance and accuracy, ensuring optimal use of computational resources and yielding more precise results. Extensive experiments are conducted on four different dynamical systems: first-order irreversible chain reactions, biomass transfer, the Brusselsator model, and the Lotka-Volterra model, using synthetically generated data to validate our approach. Additionally, we apply our method to the susceptible-infected-recovered model, utilizing real-world COVID-19 data to learn the time-varying parameters of the pandemic’s spread. A comprehensive comparison between the performance of our approach and fully connected deep neural networks is presented, evaluating both accuracy and computational efficiency in parameter identification and system dynamics capture. The results demonstrate that the physics-informed neural networks outperform fully connected deep neural networks in performance, especially with increased network depth, making them ideal for real-time complex system modeling. This underscores the physics-informed neural network’s effectiveness in scientific modeling in scenarios with balanced unknowns and parameters. Furthermore, it provides a fast, accurate, and efficient alternative for analyzing dynamic systems.

Interactive effects of viral lysis and warming in a coastal ocean identified from an idealized ecosystem model

Marine viruses have been identified as key players in biogeochemical cycles and in the termination of phytoplankton blooms; however, most biogeochemical models have yet to resolve viral dynamics. Here, we incorporate a viral component into a 1D ecosystem model to explore the influence of viruses on ecosystem dynamics under current and future climatic conditions in a coastal ocean. Virus-phytoplankton interactions and zooplankton grazing were mechanistically described through size-based contact rates. The model demonstrated that the presence of viruses increased nutrient retention in the upper water column. This corresponded to a reduction in phytoplankton biomass, production of dead organic matter and transfer of biomass to higher trophic levels. Viral presence played a key role in deeper water layers, near the thermocline. While warming alone reversed these trends, the combination of warming and viral presence enhanced the effect of viruses, indicative of synergistic interaction. Our results highlight the need of incorporating viral dynamics in the existing marine ecosystem models to better predict ecosystem responses to climate change.

Warming alters the top–down effect of a common mesopredator in an aquatic food web

Global warming is altering the composition and functioning of both terrestrial and aquatic ecosystems. Most research has focussed on direct effects of warming on species and their population dynamics, while less is known about indirect effects through species interactions. Trophic cascades are especially likely to influence the effects of warming given that trophic levels differ in their response to warming because of differences in metabolism and vital rates such as growth and reproduction. We investigated if the top–down effect of a common mesopredator, the threespine stickleback, alters the impact of warming on a Baltic Sea food web. We manipulated both temperature and the presence of stickleback in mesocosms, and found the stickleback to alter the impact of warming on lower trophic levels. This was through increased consumption of herbivores that exceeded the rate at which the herbivore population could grow under higher temperature, which in turn increased algae biomass compared to a scenario without stickleback, but not compared to conditions under normal temperature. Thus, the mesopredator increased the transfer of biomass to higher trophic levels of the food web when temperature was increased. This stresses the importance of considering the impact of warming on multiple trophic levels and their interactions. Failing to consider differences in responses among trophic levels and the impact this has on their interactions can result in faulty conclusions about the impact of warming on ecosystems.

CFD-DEM investigation of the flow characteristic of biomass particles and heat carrier in a novel V-shaped down-tube pyrolysis reactor

During biomass thermochemical conversion, addition of inert heat carriers such as sand, metal and ceramic balls into the reactor can effectively promote the flow mixing and conduction heat transfer of biomass. Therefore, it is important to understand the flow behavior of the binary mixture containing biomass and heat carrier for efficient utilization of biomass energy. In this study, computational fluid dynamics and discrete element method (CFD-DEM) were used to evaluate the flow behavior and law of the binary mixture of heat carrier and biomass in a novel down-tube pyrolysis reactor. The results show important effects of different ceramic ball sizes and different mass ratios on the flow behavior of binary mixtures. Under the same mass ratio, the smaller the particle size of ceramic balls were, the greater the effect to promote the motion of biomass particles. The fluid-like motion changed more obvious with the increase of mass ratio and biomass particles.

Valorization of Corn Cobs for Xylitol and Bioethanol Production through Column Reactor Process

Corncobs are a plentiful lignocellulosic material that can be utilized for energy production as well as the generation of other high-value products. Within the modern concept of biorefineries, we present processes conducted in a column reactor for the valorization of corncobs as a substrate for ethanol and xylitol production. In the first step, corncobs were subjected to acid hydrolysis, resulting in a hemicellulosic hydrolysate rich in xylose sugars intended for xylitol production by Candida tropicalis UFMGBX12-a. The YP/S (yield coefficient of product to substrate) and QP (productivity) values were approximately 0.2 g/g and 0.15 g/L·h, respectively, for the assays conducted in the column reactor. Next, the remaining solid portion of cellulignin was used for ethanol production through semi-simultaneous saccharification and fermentation process by Scheffersomyces parashehatae UFMG-HM 52.2. This approach involved an intensified successive process consisting of alkaline pretreatment of cellulignin, followed by enzymatic hydrolysis and fermentative processes conducted in the same reactor without biomass transfer. After obtaining the enzymatic hydrolysate, a QP value of 0.4 g/L·h for ethanol production was observed in the fermentation process conducted in the column reactor. The results demonstrate the potential of corncobs as a carbon source for biomolecules production, utilizing a process conducive to scale-up.

Pre-asymptotic dispersion of active particles through a vertical pipe: the origin of hydrodynamic focusing

When motile algal cells are exposed to gyrotactic torques, their swimming directions are guided to form radial accumulation, well known as hydrodynamic focusing. The origin of hydrodynamic focusing from the effects of active swimming, ambient flow and particle anisotropy is elucidated in the present study on the pre-asymptotic dispersion of active particles through a vertical pipe. With an extension of the Galerkin method to pipe flows, time-dependent solutions directly from the Smoluchowski equation in the position and orientation space are derived by series expansions of spherical harmonics and Bessel functions. Ballistic and diffusive scaling laws are examined with the predominance of self-propelled swimming, and computation is validated against an explicit benchmark solution and Lagrangian particle simulation. In the limit of extreme shear, the competitive roles of shear dispersion and Brownian rotation are reflected concretely in the pre-asymptotic phase of hydrodynamic focusing. For flows with various shear strengths, a concentration peak in near-wall regions with a smooth transition to hydrodynamic focusing is illustrated with richer phenomena in upwelling and downwelling flows. A newly observed regime through a vertical pipe, named transient effective trapping, is revealed as a transitional mode towards hydrodynamic focusing. The pre-asymptotic approach to hydrodynamic focusing is elaborated intensively through extensive solutions of concentration moments and macroscopic transport coefficients characterised by swimming and flow Péclet numbers. The unique findings for the origin of hydrodynamic focusing could provide insight into related micro-algae reactor technology and contribute to flow control and biomass transfer in confined environments.

Spadefoot Pelobates vespertinus (Amphibia, Pelobatidae) as a transmitter of fatty acids from water to land in a forest-steppe floodplain

The transfer of biomass and polyunsaturated fatty acids by the spadefoot P. vespertinus (previously subspecies of P. fuscus) from aquatic to terrestrial ecosystems was studied for five years in small floodplain water bodies of a forest-steppe zone. Average emergence of metamorphs from unit of water area, wet mass was 6.7 g m−2 year−1. A ratio of the emergence to biomass was calculated and represented as E/B coefficient (an analog of P/B production/biomass coefficient). The average E/B was found to be 0.038 year−1. The introduced coefficient can be used for a coarse estimation of the emergence on the basis of tadpole biomass measurements. A considerable partitioning of tadpoles and metamorphs in the composition of fatty acids in their biomass was revealed. Tadpoles had significantly higher mean levels (percent of total fatty acids) of 16:0, 16:1n-9, 18:0, 20:5n-3 and 22:5n-3, while metamorphs had significantly higher levels of 14:0, 15:0, 17:0, 17:1n-8, 18:2n-6, 20:2n-6, 20:4n-6 and 22:5n-6, likely due to the shifting to terrestrial food. Metamorphs had significantly higher content of total fatty acids, mg g−1 of wet weight, and, in spite of lower level, they had significantly higher content of eicosapentaenoic acid (20:5n-3, EPA) than tadpoles. Metamorphs also had significantly higher content of docosahexaenoic acid (22:6n-3, DHA) and sum of EPA + DHA than tadpoles. Average flux of EPA + DHA from unit of water area with metamorphs was 3.27 mg m−2 year−1. The metamorphs appeared to be qualitatively and quantitatively prominent prey for a number of terrestrial consumers.

An Optimal Family of Block Techniques to Solve Models of Infectious Diseases: Fixed and Adaptive Stepsize Strategies

The contemporary scientific community is very familiar with implicit block techniques for solving initial value problems in ordinary differential equations. This is due to the fact that these techniques are cost effective, consistent and stable, and they typically converge quickly when applied to solve particularly stiff models. These aspects of block techniques are the key motivations for the one-step optimized block technique with two off-grid points that was developed in the current research project. Based on collocation points, a family of block techniques can be devised, and it is shown that an optimal member of the family can be picked up from the leading term of the local truncation error. The theoretical analysis is taken into consideration, and some of the concepts that are looked at are the order of convergence, consistency, zero-stability, linear stability, order stars, and the local truncation error. Through the use of numerical simulations of models from epidemiology, it was demonstrated that the technique is superior to the numerous existing methodologies that share comparable characteristics. For numerical simulation, a number of models from different areas of medical science were taken into account. These include the SIR model from epidemiology, the ventricular arrhythmia model from the pharmacy, the biomass transfer model from plants, and a few more.

Managing aquatic habitat structure for resilient trophic interactions.

Structural habitat (the three-dimensional arrangement of physical matter, abiotic and biotic, at a location) is a foundational element for the resilience and maintenance of biodiversity, yet anthropogenic development is driving the global simplification of aquatic environments. Resource managers regularly seek to conserve aquatic food webs by increasing structural habitat complexity with expected benefits to fisheries; however, the global effectiveness of such actions is unclear. Our synthesis and theoretical analyses found that the response of a consumer-resource interaction (predatory sportfish and forage fish prey) to the addition of prey refuge habitat differed among systems with low and high rates of biomass transfer from resource to consumer (i.e., biomass potential); stabilization was not the rule. Greater prey refuge habitat availability tended to stabilize systems characterized by high biomass potential while simultaneously increasing consumer densities. In contrast, increasing prey refuge habitat availability in systems characterized by low biomass potential tended to mute energy transfer and moved consumer densities toward local extinction. Importantly, biomass potential and prey refuge can have antagonistic effects on stability and relative consumer densities, and it is therefore important to consider the local conditions of a system when using habitat manipulation as a management measure. Further development of our context-dependent perspective to whole food webs, and across different environments, may help to guide structural habitat management to better restore and protect aquatic ecosystems.

Channel abandonment alters trophic characteristics of highland rivers

The Qinghai-Tibet Plateau (QTP) serves as a collection of unique ecosystems featured as oligotrophic and hypometabolic conditions, and is particularly vulnerable to threats posed by anthropogenic and natural disturbances. Active fluvial processes on the QTP, especially the lateral migration of rivers and channel abandonment accompanied by variations in the hydrological connectivity, and changes in river geomorphology, intensively modify this highland river-floodplain system. However, little is known about how these processes alter the trophic characteristics of highland river system on earth. In this study, we conducted field investigations on a typical meandering river, the Quanji River (QR), located in the northeastern QTP by sampling macroinvertebrates, surveying trophic sources, and measuring a range of environmental conditions. Based on the collected data, we identified four biotopes for the QR through hierarchical clustering, established the representative food web for each biotope through the allometric diet breadth model, and estimated the biomass storage and flux within food web for each biotope through the biomass balance model. Our results show that the identified biotopes differed markedly in hydrological connectivity. Biotopes 1 and 2, which were in the main river channel represented the condition of high connectivity, Biotope 3 in the open channel represented the median connectivity, while Biotope 4 in the semi-open/closed channel represented the low connectivity. In contrast to the unimodal pattern commonly observed in lowland rivers, indices for the highland QR, including the taxa richness, trophic group richness, biomass flux, biomass transfer efficiency, and trophic stability demonstrated a single-valley response pattern to the hydrological connectivity. We argue that the intermediate disturbance hypothesis still works on highland river ecosystems, whereas the optimal disturbance occurs in the low connectivity rather than median connectivity. We attribute this skewness to the low resistance and resilience of highland macroinvertebrate community in the face of hydrodynamic disturbances brought by flood events, and the biological disturbances from the predation by endemic migratory fish (Gymnocypris przewalskii) in QR. This study reveals that lateral migration and channel abandonment play important roles in highland river systems in the QTP in the context of biological and energetic perspectives and suggests that management strategies for highland rivers should be made different from those of lowland rivers.

Fractional Order Techniques for Stiff Differential Equations Arising from Chemistry Kinetics

In this paper, we consider the stiff systems of ordinary differential equations arising from chemistry kinetics. We develop the fractional order model for chemistry kinetics problems by using the Caputo Fabrizio and Atangana-Baleanu derivatives in Caputo sense. We apply the Sumudu transform to obtain the solutions of the models. Uniqueness and stability analysis ofthe problem are also established by using the fixed point theory results. Numerical results are obtained by using the proposed schemes which supports theoretical results. These concepts are very important for using the real-life problems like Brine tank cascade, Recycled Brine tank cascade, pond pollution, home heating and biomass transfer problem. These results are crucial for solving the nonlinear model in chemistry kinetics.

Warming Disadvantages Phytoplankton and Benefits Bacteria During a Spring Bloom in the Mediterranean Thau Lagoon

To assess the response of a natural plankton community to the future scenario of a warming of +3°C predicted for coastal Mediterranean regions, an in situ mesocosm experiment was carried out over 19 days in a Mediterranean coastal lagoon in 2018. During this experiment, a phytoplankton bloom occurred and the abundances of several cytometric groups of phytoplankton (cyanobacteria, picophytoplankton and nanophytoplankton) and bacteria (low- and high-nucleic acid bacteria), as well as their growth and grazing mortality rates and their carbon biomass, were studied over the course of the experiment. Experimental warming led to a significant reduction of 47% of the phytoplankton biomass in average, based on Chl-a concentrations. This reduction was also observed for nanophytoplankton abundances during the whole experiment and for eukaryotic picophytoplankton only during the bloom period. This result coincided with a significant decrease in orthophosphate concentrations under warming during the prebloom and bloom periods simultaneous to an increase in bacterial abundances. At the same time, the higher growth rates of bacteria and the lower ones of phytoplankton observed at the beginning of the bloom could suggest that competition between phytoplankton and bacteria for orthophosphate might have contributed to the phytoplankton biomass decrease under warming. In addition, higher grazing mortality rates of phytoplankton groups under warming, notably nanophytoplankton at the end of the bloom and in postbloom (by 59 to 626%), as well as eukaryotic picophytoplankton over the course of the experiment (by 58 to 255%) could also have contributed to the lower phytoplankton biomass under warming. Based on these results, estimations of average phytoplankton carbon biomass production and transfer showed reductions of 42 and 45%, respectively, under warming, whereas those of bacteria were enhanced by 13 and 8%, respectively. These results indicated that warming induced a shift at the base of the microbial food web, going toward a more bacteria-based system. This suggested that under future warming scenarios, the microbial food web could become less productive and could negatively affect the functioning of the whole food web in coastal waters.